Acquired valve disease Flashcards
1
Q
Color-flow Doppler is notoriously variable if technical factors are not set properly. The color jet area of any regurgitation is inversely proportional to…..
A
pulse repetition frequency (PRF and Nyquist limits), frame rates, and color gain.
The size of color jet area changes dramatically with different PRF settings.
2
Q
Increasing PRF will decrease the …………………..and vice versa. Fig 5.1
A
Increasing PRF will decrease the apparent size of a regurgitant jet and vice versa. Fig 5.1
3
Q
The American society of echocardiography recommends setting the Nyquist limit between …….. cm/sec.
Gain should be turned ip to see color speckling and then turned back until speckling disappears..
A
Nyquist limit between 50 and 60 cm/sec.
Using consistent and similar settings on the echo equipment will help minimize errors in assessment and provide more accurate evaluation of changes over serial studies.
4
Q
Color-flow settings for regurgitation:
Set gain just below level where speckle occurs.
Optimize frame rate: how?
A
Decrease 2D sector size
Decrease color sector size
Adjust packet size
Adjust smoothing and frame averaging
Jet area increases with decreasing PRF
Ideally set PRF to 50-60 cm/sec
5
Q
Eccentric jets can limi the ability to assess severity. Jets that slide along a lateral wall of the receiving chamber flatten out because of the ……effect
A
The Coanda effect.
This reduces spread into the chamber.
These eccentric jets will appear much smaller than jets of comparable severity that are centrally directed.
6
Q
Color-flow Doppler regurgitant jet areas are also affected by driving pressure. Jet area increases and decreases with changes in driving pressure. Therefore, it is important to measure ……and take medications into consideration when assessing regurgitant severity.
A
blood pressure
7
Q
The evaluation of valvular regurgitation by echo must consider the patient’s clinical status. Why?
A
Physiological changes can alter the results between echocardiographic examinations of the same patient.
8
Q
Physiologic MR in animals is less common than insufficiencies at the other cardiac valves.
A
Physiologic MR in animals is less common than insufficiencies at the other cardiac valves.
9
Q
Both the size and duration of valvular leaks help differentiate between physiologic and pathologic regurgitation. Physiologic regurgitation has low velocity, occupies a small area behind the valve, and rarely encompasses the entire portion of systole or diastole. These small leaks are often associated with valve closure and are called?
A
Trace regurgitation or mitral closing volume.
10
Q
Physiologic regurgitation has:
Low velocity Weak flow profile Is trivial in size just behind the valve Is generally nonturbulent Is not holosystolic or holodiastolic
A
Low velocity Weak flow profile Is trivial in size just behind the valve Is generally nonturbulent Is not holosystolic or holodiastolic
11
Q
Trace or mild MR seen in ….10% of normal healthy dogs
A
approximately 10 %
12
Q
Slight rounding and curling at the tips of the mitral valve leaflets are consistent with early degenerative changes.
A
Fig 5.2
13
Q
Mitral valvular lesions may become very large and irregular. Can echo differentiate between degenerative and vegetative lesions?
A
No.
Fig 5.3
14
Q
Bowing of the inter ventricular and atrial septum’s toward the right indicates?
A
Dilation of both the LV and LA.
Fig 5.3
15
Q
A small nonturbulent flow area located proximal to the mitral valve leaflets during early systole usually represents….?
A
…. back flow secondary to valve closure.
This usually last for a very short time. (
16
Q
The typical characteristics of myxomatous degeneration include?
A
- LV and LA dilation
- Wall and septal hypertrophy
- Increased thickness, nodularity, and prolapse of one or both mitral valve leaflets
- Elevated parameters of systolic function
- Hyperdynamic wall and septal motion
Less common features include pericardial effusion, lack of hypertrophy, decreases in systolic function, and ruptured chordae tendineae
17
Q
The degenerative mitral valve changes eventually prevent proper leaflet alignment and closure. The lesions are generally smooth and small creating a club-shaped appearance to the leaflet tips during early stages of the disease but may become large and irregular as the disease progresses. Generally, but not always, larger lesions are associated with more severe insufficiency.
A
Figures 5.2, 5.3, 5.4
18
Q
Large breed dogs with acquired mittal valve insufficiency seem to have fewer observable changes of the valve leaflets despite significant regurgitation. Prolapse may be observed without any abnormal thickness or irregularity of the leaflets.
A
Large breed dogs with acquired mittal valve insufficiency seem to have fewer observable changes of the valve leaflets despite significant regurgitation. Prolapse may be observed without any abnormal thickness or irregularity of the leaflets.
19
Q
The identification of lesions is………..dependent (3)
A
Gain
Depth
Transducer dependent
It is good to compare the leaflets to other structures at that approximate depth. The thickness of endocardial echoes is used to assess leaflet thickness in man. They should be similar.
20
Q
When mitral lesions are small, be careful to interrogate several planes since chordal attachments to the leaflets are difficult to distinguish from lesions.
A
Fig 4.9
21
Q
Right parasternal 4 ch views of the heart are excellent for imaging the mitral valve (fig 5.3). The LV inflow outflow vies is also good, but the valves may appear to be thicker than they truly are if the imaging plane is not perfect.
A
Right parasternal 4 ch views of the heart are excellent for imaging the mitral valve (fig 5.3). The LV inflow outflow vies is also good, but the valves may appear to be thicker than they truly are if the imaging plane is not perfect.
22
Q
The sound beam needs to be directed throughout the center of the annulus, and to do so the probe needs to be lifted up toward the animal’s thorax creating a clean LA with leaflets that move and open well into the LV. Are transverse images valuable?
A
Transverse images of the valve are useful of identifying large lesions, but they can be misleading when looking for small ones. Fig 5.5
23
Q
The nodular leaflets appear …………and………. on M-mode images.
A
The nodular leaflets appear shaggy and irregular on M-mode images. Fig 5.6.
24
Q
Although it is not common, there may be ……….. fluttering of the mitral valve on M-mode images as the regurgitant jet flows through it.
When lesions are large the thickness of the mitral valve on the image masks the fluttering.
A
Although it is not common, there may be systolic fluttering of the mitral valve on M-mode images as the regurgitant jet flows through it.
When lesions are large the thickness of the mitral valve on the image masks the fluttering.
25
Degenerative mitral valve disease is the most common cause of ruptured chordae tendineae in the dog. Can vegetative growth of the mitral valve also result in ruptured chordae tendineae?
Rarely
26
The mitral valve has ................. chordae tendineae, which attach the tips of the leaflets to the papillary muscles and are responsible for most of the structural integrity of the valve.
The mitral valve has primary or first order chordae tendineae, which attach the tips of the leaflets to the papillary muscles and are responsible for most of the structural integrity of the valve.
27
Secondary and tertiary chordae tendineae attach the ................ of the valve leaflets and the ............... area of the leaflets to the papillary muscles and ventricular walls.
Secondary and tertiary chordae tendineae attach the midventricular portions of the valve leaflets and the commissural area of the leaflets to the papillary muscles and ventricular walls.
28
The majority of dogs with echo evidence of ruptured chordae tendinea have ............ mitral insufficiency based upon color-flow Doppler evaluation of regurgitant jet size and heart failure class.
The majority of dogs with echo evidence of ruptured chordae tendinea have severe mitral insufficiency based upon color-flow Doppler evaluation of regurgitant jet size and heart failure class.
29
Most instances of ruptured chordae affect the ....... leaflet of the mitral valve, and ruptured of chordae to the ......... (posterior) leaflet is much less common.
Most instances of ruptured chordae affect the septal leaflet of the mitral valve, and ruptured of chordae to the parietal (posterior) leaflet is much less common.
30
Rupture of a chordae tenineae resulting in a flail leaflet is diagnosed when ...............?
Rupture of a chordae tenineae resulting in a flail leaflet is diagnosed when the leaflet points back into the LA chamber during systole.
Fig 5.7, 5.8, 5.9
31
During diastole, the leaflet may sometimes bend back on itself within the LV outflow tract.
Fig 5.10, 5.11
32
The mitral valve shows chaotic motion during diastole and systole on both M-mode and RT images after a chordae has ruptured.
Fig 5.12
These findings are seen on both parasternal and apical images.
33
Minor chordal rupture may be seen in only one echocardiographic plane while major chordal rupture tends to be seen in several imaging planes.
Minor chordal rupture may be seen in only one echocardiographic plane while major chordal rupture tends to be seen in several imaging planes.
34
The CF jet of MR caused by chordal rupture is usually...
Eccentric
35
When Doppler confirms the presence of severe MR without the concurrent LV and LA dilation seen i a chronic process, look for .......................
When Doppler confirms the presence of severe MR without the concurrent LV and LA dilation seen i a chronic process, look for a ruptured chordae.
Fig 5.13
36
An eccentric regurgitant jet implies the presence of ?
Prolapse or flail leaflets.
37
Papillary muscle rupture occurs. This is usually a consequence of ....?
trauma
38
M-mode echo shows an abnormal mass moving within the LV chamber, but 2D images provide clear visualization of the torn muscle and its movement within the chamber. The 2D echo features of papillary muscle rupture include ...?
....visualization of a portion of the papillary muscle attached to the chordae tendineae, severe mitral valve prolapse, or flail leaflets, and abnormal appearance of the papillary muscle where the tip of it has torn off.
39
Mitral valve prolapse (MVP) may be primary or secondary.
| Primary MVP results from?
Intrinsic abnormalities of the mitral valve leaflets, usually myxomatous degeneration.
40
Secondary MVP is present without inherent pathologic valvular abnormalities. This is typically secondary to?
Hemodyanmic causes such as volume contraction and reduced LV size or myocardial disease resulting in akinetic muscle and abnormal papillary muscle function.
41
When secondary or tertiary chordal rupture is present, the body of the leaflet billows back into the atrial chamber and only prolapse is appreciated.
When secondary or tertiary chordal rupture is present, the body of the leaflet billows back into the atrial chamber and only prolapse is appreciated.
42
When both mitral valve leaflets are involved in the degenerative process with either valvular prolapse or irregularity, the prognosis for survival becomes poorer.
When both mitral valve leaflets are involved in the degenerative process with either valvular prolapse or irregularity, the prognosis for survival becomes poorer.
43
In dogs, prolapse of the mitral valve is usually secondary to .....?
In dogs, prolapse of the mitral valve is usually secondary to myxomatous degeneration of the leaflets, chronic stretch of the chordae tendineae and redundancy into the atrium during systole.
44
MVP may be seen without any evidence of insufficiency and seems to be genetically influenced in CKCS and Dachshunds.
MVP may be seen without any evidence of insufficiency and seems to be genetically influenced in CKCS and Dachshunds. These dogs tend to show prolapse as early as 3 years of age without any clinical signs or murmurs and have a high incidence of mitral valvular
insufficiency later in life.
Of 19 CKCS dogs with mitral valvular insufficiency in one study, 84% had MVP
3 year-old Dachshunds without heart murmur had a 47% incidence of MVP.
45
MVP prolapse can be secondary to?
-Degenerative valve disease
Or hemodynamic causes
- Akinetic or dyskinetic myocardium
- Abnormal papillary muscle function
46
The course of MVP in man is usually benign. What about in dogs?
The course of MVP in man is usually benign but this is not so in dogs where there is greater incidence of degenerative valvular disease. Dogs have more significant insufficiency and higher classes of heart failure with mitral valve prolapse.
47
When is the diagnosis of MPV made?
When one or both leaflets buckle back toward the LA during systole.
48
The mitral valve annulus is identified by?
A line drawn from the base of the aortic valve to the point of attachment of the parietal mitral valve leaflet on right parasternal long-axis LV outflow views or by a line joining the attachment point of both mitral leaflets on right parasternal 4 ch views. Fig 5.14, Fig 5.15
49
Normally, the body of the mitral valve leaflets does not extend beyond the line into the LA. Buckling of either leaflet into the atrium beyond this line indicates mild mitral valve prolapse.
Normally, the body of the mitral valve leaflets does not extend beyond the line into the LA. Buckling of either leaflet into the atrium beyond this line indicates mild mitral valve prolapse.
50
A line drawn further back into the atrium from the dense echogenic area at the ............ part of the atrial septum to the ..................... behind the posterior mitral valve leaflet represents the border between mild and severe prolapse/MVP.
A line drawn further back into the atrium from the dense echogenic area at the lower part of the atrial septum to the atrioventricular junction behind the posterior mitral valve leaflet represents the border between mild and severe prolapse/MVP. Fig 5.16 and 5.17.
51
One study showed that the diagnostic accuracy of detecting MVP increases with experience.
One study showed that the diagnostic accuracy of detecting MVP increases with experience.
52
Apical 4 ch views are not recommended for the diagnosis of MVP in man, since this plane through the mitral annulus shows normal curving of the anterior leaflet into the left atrium. Only when the septal leaflet bends greater than 1 cm into the LA on apical 4 ch views is it considered abnormal in man. What about Posterior leaflet buckling in the apical 4 ch view: Is this also a normal finding?
Posterior leaflet buckling in the apical 4 ch view is always abnormal.
Parasternal LV long-axis views are recommended in man.
The accuracy of diagnosis MVP on apical 4 ch views has not been studied in animals.
53
Volume overload of the LA and LV is seen with hemodynamically significant chronic mitral valvular insufficiency. The degree of LA enlargement is often used as an indicator of stage of heart failure based upon New York Heart Association criteria
Volume overload of the LA and LV is seen with hemodynamically significant chronic mitral valvular insufficiency. The degree of LA enlargement is often used as an indicator of stage of heart failure based upon New York Heart Association criteria
54
The atrial sizes of dogs in stage 3 and 4 of the NYHA criteria are significantly larger than the atria of stage 2. LA sizes of dogs in stage 2 failure were significantly larger than the atria of dogs with no heart failure or stage 1 heart failure.
The atrial sizes of dogs in stage 3 and 4 of the NYHA criteria are significantly larger than the atria of stage 2. LA sizes of dogs in stage 2 failure were significantly larger than the atria of dogs with no heart failure or stage 1 heart failure.
55
There is no difference between the atrial sizes of dogs with stage 1 heart failure and no heart failure.
There is no difference between the atrial sizes of dogs with stage 1 heart failure and no heart failure.
56
Significant insufficiencies without the concurrent chamber enlargement are suggestive of?
An acute process and ruptured chordae. Fig 5.13
57
LA to aortic root ratios of greater than 1.7 have been found to be spoor prognostic indicator for survival.
LA to aortic root ratios of greater than 1.7 have been found to be spoor prognostic indicator for survival.
58
In dogs with normal systolic function or mildly depressed systolic function, the degree of LA dilation correlates well with severity of the regurgitant volume.
In dogs with normal systolic function or mildly depressed systolic function, the degree of LA dilation correlates well with severity of the regurgitant volume.
59
Mild LA enlargement may be seen in dogs with early MR before there is any measurable ventricular dilation. 2D images should be used in various planes in order to determine if enlargement is present (may not be apparent on the M-mode).
Echo evidence of mild LA dilation may be more accurate than radiographic assessment because of the objective versus subjective measuring involved.
In dogs with normal systolic function or mildly depressed systolic function, the degree of LA dilation correlates well with severity of the regurgitant volume.
60
The LA/Ao ratio is used to evaluate atrial size. As the severity of MR increases, however, this ratio may not accurately reflect increases in atrial size. Aortic root size may decrease with ....................... flow. This decrease in aortic root size is also seen in ......... circulating blood volume.
The LA/Ao ratio is used to evaluate atrial size. As the severity of MR increases, however, this ratio may not accurately reflect increases in atrial size. Aortic root size may decrease with reduced forward flow. This decrease in aortic root size is also seen in low circulating blood volume.
61
Severe LA enlargement and concurrent high LA pressures in dogs with mitral valvular disease can on rare occasions result in rupture of the atrial septum creating an......... defect or it may tear in the......... wall of the atrium or auricular appendage resulting in fluid accumulation within the pericardial sac.
Severe LA enlargement and concurrent high LA pressures in dogs with mitral valvular disease can on rare occasions result in rupture of the atrial septum creating an atrial septal defect or it may tear in the lateral wall of the atrium or auricular appendage resulting in fluid accumulation within the pericardial sac.
Echo evidence of fluid accumulation within the sac will be seen.
62
Pericardial effusion occurs seondary to CHF, but the presence of a thrombus within the pericardial space confirms the diagnosis of atrial splitting since pericardial effusions secondary to neoplasm, pericarditis, or heart failure do .............................
Pericardial effusion occurs seondary to CHF, but the presence of a thrombus within the pericardial space confirms the diagnosis of atrial splitting since pericardial effusions secondary to neoplasm, pericarditis, or heart failure do not tend to form clots. Fig. 5.21
63
Thrombus within the pericardial space develops linear layers of ....... material that conforms to the shape of the heart.
hyperechoic material
Fig 5.22, 5.23
64
Tumors within the pericardial sac are generally more .......
rounded and not laminar in appearance.
65
Thrombus in the pericardial sac manifests itself in .............. that conform to the shape of the sac. Round or oval soft tissue shapes are usually tumors.
Thrombus in the pericardial sac manifests itself in linear echoic layers that conform to the shape of the sac. Round or oval soft tissue shapes are usually tumors.
66
Mitral valve motion may refelct elevated LV diastolic pressures. Closure of the mitral valve is ........... after atrial contraction, and a ....bump or shoulder is described in animals and man.
This motion is reported to occur in animals where LV diastolic pressures exceed ..... mmHg
Closure of the mitral valve is delayed after atrial contraction, and a B bump or shoulder is described in animals and man.
Fig 4.99, 5.24
> 30 mmHg
67
Motion of the interventricular septum and free wall are exaggerated in animals with MR, volume overload, and preserved myocardial function. This is secondary to?
Secondary to the increased volume flowing into and out of the LV chamber relative to the volume filling the RV chamber.
68
Septal motion may be greater than free wall motion since it is affected to a greater degree by volume changes in the right and left ventricles.
Septal motion may be greater than free wall motion since it is affected to a greater degree by volume changes in the right and left ventricles. Fig 5.25
69
Aortic valve motion may be abnormal in animals with significant MR. Blood will flow into the lower pressure LA instead of the higher pressure systemic circulation as systole progresses and ............ closure of the aortic valve is seen. A .......... shaped aortic valve is seen on M-mode images as opposed to a ............. shape during systole.
Aortic valve motion may be abnormal in animals with significant MR. Blood will flow into the lower pressure LA instead of the higher pressure systemic circulation as systole progresses and gradual closure of the aortic valve is seen. A triangular shaped aortic valve is seen on M-mode images as opposed to a rectangular shape during systole. Fig 4.96
70
2 D and M-mode features of MR:
```
Degenerative valvular lesions
LA and LV dilation
Exaggerated IVS and LVW motion
Possible delayed MV closure
Possible gradual Av closure.
```
71
```
left ventricular function:
Fractional shortening (FS) as a measure of myocardial function in dogs with chronic degenerative mitral valve insufficiency should be elevated because of the presence of.....?
```
Increased preload, decreased afterload, and generally increased contractile properties.
Fig 5.26
72
Is there a correlation between the stage of heart failure based upon American Heart Association criteria and the fractional shortening?
No
73
Congestive heart failure in dogs with chronic mitral insufficiency is secondary to severe regurgitation and volume overload of the left atrium and ventricle, not myocardial failure in most cases.
Fig 5.26
74
Normal myocardial contractility results in a ......... LV systolic chamber size no matter how dilated the LV becomes.
Normal myocardial contractility results in a normal LV systolic chamber size no matter how dilated the LV becomes.
75
Studies show that using fractional shortening and systolic dimensions or systolic index in dogs can separate dogs with abnormal myocardial function from those with normal myocardial function.
Therefore, while fractional shortening is dependent upon preload, afterload, and contractility, .............. and ................. are not affected by preload.
Studies show that using fractional shortening and systolic dimensions or systolic index in dogs can separate dogs with abnormal myocardial function from those with normal myocardial function.
Therefore, while fractional shortening is dependent upon preload, afterload, and contractility, systolic dimensions and systolic index are not affected by preload.
76
Hearts with normal myocardial contractility will shorten to ............. systolic dimensions regardless of how dilated the heart becomes.
Hearts with normal myocardial contractility will shorten to normal systolic dimensions regardless of how dilated the heart becomes.
77
Only when the intrinsic contractility of the myocardium starts to fail will ............. dimensions become larger than normal.
Only when the intrinsic contractility of the myocardium starts to fail will systolic dimensions become larger than normal.
Fig 4.56,4.57, 5.27
78
Only when the intrinsic contractility of the myocardium starts to fail will systolic dimensions become larger than normal.
Using this as an indicator, Kittleson found that dogs have a normal systolic index of less than ..... ml/m2.
30
79
Dogs with an index of greater than .......... ml/m2 had severe myocardial failure, dogs with a systolic index ranging from 52 +/- 6 ml/m2 have mild myocardial impairment, and dogs between these two ranges with a mean of ......... ml/m2 have moderately reduced myocardial contractility.
Dogs with an index of greater than 100 ml/m2 had severe myocardial failure, dogs with a systolic index ranging from 52 +/- 6 ml/m2 have mild myocardial impairment, and dogs between these two ranges with a mean of 73 ml/m2 have moderately reduced myocardial contractility.
The volume equation used in this study was Teichholz.
80
Systolic index is calculated by?
Systolic index is calculated by dividing the end-systolic volume by BSA.
81
One study suggested that a LV systolic index of greater than ..... ml/m2 is associated with a poor survival time.
One study suggested that a LV systolic index of greater than 30 ml/m2 is associated with a poor survival time.
82
Assessment of function with MR:
Normal myocardial function:
Systolic index ....... ml/m2
Normal myocardial function:
Systolic index
83
Assessment of function with MR:
Severe myocardial failure:
Systolic index ......... ml/m2
Severe myocardial failure:
Systolic index > 100 ml/m2
84
Assessment of function with MR:
Moderate myocardial failure:
Systolic index ca ........ ml/m2
Moderate myocardial failure:
Systolic index 70- 100 ml/m2
85
Mild myocardial failure:
Systolic index ca ........... ml/m2
Mild myocardial failure:
Systolic index 34-70 ml/m2
86
There are conflicting data regarding the presence of myocardial failure in dogs with chronic degenerative mitral valve disease. ....... breed dogs tend to develop myocardial failure secondary to chronic mitral valve disease more often than ....... breed dogs.
Large breed dogs tend to develop myocardial failure secondary to chronic mitral valve disease more often than small breed dogs.
87
Normal small and large breed dogs seem to have different systolic v'''''
olume indexes, therefore, it may be more accurate to assess myocardial function by calculating a ratio of ....?
A ratio of systolic dimension compared to expected systolic dimension for the body weight.
88
Dogs were diagnosed with myocardial failure if the end systolic dimension to end systolic dimension expected ratio was greater than normal. Normal in large breed dogs and small breed dogs?
Large breed dogs: 1.13 +/- 0.15
| Small breed dogs: 0.89 +/- 21
89
The expected end systolic dimension is based upon allometric ratios and calculated by using equation 5.1 where ESDe is end systolic expected dimension and BW is body weight:
ESDe =0.95 x BW upphöjt i 0.315
90
Allometric ratios show a difference in percent change in area of the LV chamber during contractility between normal dogs and dogs with degenerative mitral valve disease. A weighted change in area of ....... or greater differentiated the normal dogs from those with degenerative valve disease.
A weighted change in area of 2.1 or greater differentiated the normal dogs from those with degenerative valve disease.
This is nor necessarily that useful, but a further application of these ratios showed the ability to differentiate dogs with mitral regurgitation that were not in left-sided CHF from those that were.
This may have the potential to become a predictive variable for the development of CHF.
91
A weighted LA dimension was 76% sensitive and 81% specific at differentiating the two groups with a weighted LA size of ......... or greater.
A weighted LA dimension was 76% sensitive and 81% specific at differentiating the two groups with a weighted LA size of 1.55 or greater.
92
In order to weight these variable, they are compared to the M-mode derived aortic dimension.
The aorta is normalized to the animal's weight by using the following equation:
AOw = 0.795 x W upphöjt i 1/3
where W is the dog's weight in kg. The measured M-mode numbers are then divided by the weighted aortic value.
93
Weighted LA size:
predictive value for development of CHF?
>/= 1.55 = predictive for development of CHF
94
Lack of adequate hypertrophy is one factor that causes diminished myocardial function in dogs with LV volume overload secondary to chronic mitral valve disease.
Lack of adequate hypertrophy is one factor that causes diminished myocardial function in dogs with LV volume overload secondary to chronic mitral valve disease.
95
High ......... and increased wall ......... is the stimulus for hypertrophy, and volume overload may not provide an adequate stimulus for good compensatory hypertrophy as the heart dilates to make up for the valvular regurgitation.
High afterload and increased wall stress is the stimulus for hypertrophy, and volume overload may not provide an adequate stimulus for good compensatory hypertrophy as the heart dilates to make up for the valvular regurgitation.
96
The normal response to increased afterload is ................ This normalizes wall stress.
The normal response to increased afterload is hypertrophy. This normalizes wall stress.
97
Wall stress is determined by the ratio of radius to wall thickness as seen in the equation:
Wall stress = (P x r)/h
Where h = wall thickness, r = radii, P = systolic blood pressure
An increase in this ratio results in high wall stress and a decrease results in low wall stress.
98
The eccentric hypertrophy pattern seen with mitral insufficiency has a normal to high wall stress value since hypertrophy is usually ..............
The eccentric hypertrophy pattern seen with mitral insufficiency has a normal to high wall stress value since hypertrophy is usually limited.
99
MMVD:
During LV contraction, there is movement of blood into the low pressure LA chamber. This decreases the impetus for development of hypertrophy to compensate for the volume overload of MR.
The thin walls however are very ........... and allow for enhanced ventricular filling and increased stroke volume. Still, hearts with MR have the lowest mass-to-........... ratio, even less than hearts with aortic regurgitation.
The thin walls however are very compliant and allow for enhanced ventricular filling and increased stroke volume. Still, hearts with MR have the lowest mass-to-flume ratio, even less than hearts with aortic regurgitation.
100
When systolic function is reduced in hearts with LV volume overload secondary to MR, wall stress is very ........because of this low wall-to-chamber radius ratio. This is thought to contribute to progressive LV systolic failure.
When systolic function is reduced in hearts with LV volume overload secondary to MR, wall stress is very high because of this low wall-to-chamber radius ratio
101
Increased wall stress because of ........ wall thickness to chamber size ratio is thought to contribute to progressive LV systolic failure.
Increased wall stress because of low wall thickness to chamber size ratio is thought to contribute to progressive LV systolic failure.
102
Measurement of wall thickness to chamber size is a way to evaluate the degree of compensatory hypertrophy
The diastolic dimension of the LV chamber is divided in half to provide a radius measurement and the wall thickness (..) to chamber radius (...) is calculated.
Measurement of wall thickness to chamber size is a way to evaluate the degree of compensatory hypertrophy
The diastolic dimension of the LV chamber is divided in half to provide a radius measurement and the wall thickness (h) to chamber radius (r) is calculated.
103
Normal wall thickness to chamber radius in large breed dogs and small breed dogs?
Dogs 20 kg: 0.47 +/- 0.11
104
FS is also used to divide dogs with MMVD into various categories of impaired contractility:
Dogs with any degree of mitral insufficiency from mild to severe whether they are in CHF or not will have FS --------- if they have no myocardial dysfunction.
FS above the normal range if they have no myocardial dysfunction.
105
Dogs with mild to moderately impaired myocardial contractility will have FS within the normal range of ........%
33-45%
Severe myocardial failure is present when FS is below the normal range.
106
Mitral annular motion (MAM) taken from M-mode recordings of the mitral annulus on left apical 4 ch views becomes depressed if there is myocardial failure. Does this become depressed in most dogs with MMVD?
No, not in most dogs with MMVD but it is depressed in dogs with cardiomyopathy. Fig 5.28
107
Mitral annular motion (MAM) measures .......... shortening of the LV chamber and may be different from ......... fiber shortening, which is what is measured for fractional shortening.
Mitral annular motion (MAM) measures longitudinal shortening of the LV chamber and may be different from circumferential fiber shortening, which is what is measured for fractional shortening.
This may help differentiate normal from abnormal systolic function in some equivocal cases.
108
Color-flow Doppler evaluation:
Using this modality, and paying attention the the jet area with respect to the receiving chamber, the area of flow ......., and the jet ........ at its origin significantly improves the evaluation of severity of the regurgitation.
Color-flow Doppler evaluation:
Using this modality, and paying attention the the jet area with respect to the receiving chamber, the area of flow convergence, and the jet width at its origin significantly improves the evaluation of severity of the regurgitation.
109
Color-flow analysis of regurgitation uses:
Jet area
Flow convergence
Vena contracta
110
Jet size:
Pathological regurgitation can be semiquantitatively assessed by measuring the size of the color-flow jet within the atria in the case of AV valvular insufficiency or within the outflow tract or ventricle in the case of aortic or pulmonic insufficiency.
Pathological regurgitation can be semiquantitatively assessed by measuring the size of the color-flow jet within the atria in the case of AV valvular insufficiency or within the outflow tract or ventricle in the case of aortic or pulmonic insufficiency.
111
In man, mitral or tricuspid insufficiency jets that occupy less than .... % of the atrium are mild insufficiency. A jet that occupies ... to ....% of the atrial area represents moderate insufficiency and when greater than .... % of the atrium is filled by aliased flow of regurgitation, it si classified as severe insufficiency.
In man, mitral or tricuspid insufficiency jets that occupy less than 20% of the atrium are mild insufficiency.
A jet that occupies 20 to 40% of the atrial area represents moderate insufficiency and when greater than 50% of the atrium is filled by aliased flow of regurgitation, it si classified as severe insufficiency.
This method uses the largest regurgitation jet found in any plane.
Studies that average the jet size over several imaging planes do not show any significant improvement in predicting severity.
112
Assessment of MR based upon color jet area is the poorest of the color-flow assessment methods because of the technical factors mentioned previously, such as?
Gain
PRF
Fram rate
ec, as well as for the following situations:
When the systemic pressures driving the regurgitant jet are abnormal, these percentages are no longer accurate. The driving pressure affects the velocity of the color-flow jet and the area that it encompasses.
113
One in vitro study showed that an equal volume of regurgitation blood displayed varying sizes of color-flow jets based upon the pressure driving the regurgitant jet. Low systemic pressure and high LA pressure can show small jet areas despite having severe regurgitation, and high systemic pressure can cause a regurgitant jet to be quite large despite having mild insufficiency.
One in vitro study showed that an equal volume of regurgitation blood displayed varying sizes of color-flow jets based upon the pressure driving the regurgitant jet. Low systemic pressure ans high LA pressure can show small jet areas despite having severe regurgitation, and high systemic pressure can cause a regurgitant jet to be quite large despite having mild insufficiency.
114
Abnormal systemic pressure (low or high) makes jet area assessment of MR inaccurate
Abnormal systemic pressure (low or high) makes jet area assessment of MR inaccurate
115
Heart rate also affects regurgitant jet size. How?
Fast heart rates rend to result in underestimation of the degree of insufficiency when assessed with CF Doppler
116
Eccentric regurgitation jets limit the accuracy of using jet are for classification of severity. Why? This is called the ......... effect
An eccentric jet, which is commonly seen in the presence of mitral valve prolapse, causes the jet to hug the atrial walls. This prevents the jet from dispersing into the atrial chamber, turbulence is no longer as apparent, which results in underestimation of regurgitant severity. This is called a Coanda effect. Fig 5.36
117
When is the regurgitant/area assessment reliable?
When the regurgitant jet is centrally directed and there is a normal sinus rhythm, then the assessment of severity using CF-Doppler is usually reliable.
118
Other methods that attempt to overcome some of these limitations have been investigated. Muzzi et al calculated a MR jet area to left atrial ........... in ........ ch imaging planes in dogs. A ratio of 70% of left atrial area occupied by the regurgitant jet correlated with severe mitral regurgitation based upon comparison to other Doppler-derived calculations of regurgitant fractions and volumes as well as effective regurgitant orifice area.
Muzzi et al calculated a MR jet area to left atrial area in apical 4 ch imaging planes in dogs. A ratio of 70% of left atrial area occupied by the regurgitant jet correlated with severe mitral regurgitation based upon comparison to other Doppler-derived calculations of regurgitant fractions and volumes as well as effective regurgitant orifice area.
Fig 5.37
The correlation between regurgitant fraction and the area of the regurgitant jet measured from color Doppler was weak (r= 0.59), but correlation between regurgitant fraction and left atrial area was strong. (r= 0.88)
Evaluation of the ratio or regurgitant jet area to left atrial size is a reproducible measurement with little variation
119
When ruptured, chordae tendineae are a factor in the degree of regurgitation, however the severity of regurgitation assessed by color-flow jet area to left atrial area did not correlate with class of heart failure and clinical signs in a study.
When ruptured, chordae tendineae are a factor in the degree of regurgitation, however the severity of regurgitation assessed by color-flow jet area to left atrial area did not correlate with class of heart failure and clinical signs in a study.
120
There may be different clinical consequences when primary, secondary, or tertiary chordae rupture.
There may be different clinical consequences when primary, secondary, or tertiary chordae rupture.
121
Jet area can also be assessed by ........ Doppler if the time is taken to place a PW gate at various points in the atrium in order to assess the extent of the jet.
Jet area can also be assessed by spectral Doppler if the time is taken to place a PW gate at various points in the atrium in order to assess the extent of the jet.
122
Ratio of MR jet area to LA area:
70% = severe MR
123
Regurgitant jet area correlates well with regurgitant volume
Left atrial area correlates well with regurgitant fraction.
If MR was secondary to ruptured chordae tendinaea these above mentioned measurements were not accurate.
Regurgitant jet area correlates well with regurgitant volume
Left atrial area correlates well with regurgitant fraction.
If MR was secondary to ruptured chordae tendinaea these were not accurate.
124
Concern over the effects of gain, pulse repetition frequency, size of the dog, and heart rate on the assessment of CF evaluation of severity of regurgitation has led to studies that utilize other methods of assessing CF regurgitant jets.
Concern over the effects of gain, pulse repetition frequency, size of the dog, and heart rate on the assessment of CF evaluation of severity of regurgitation has led to studies that utilize other methods of assessing CF regurgitant jets.
125
One study in dogs uses ratios of regurgitant to forward flow. Frames displaying the largest color-flow areas are used. Regurgitant jets are traced and a MR jet mapping area was determined (MRMA) as well as the CF-area representing aortic forward flow (AFMA).
The ratios of these 2 areas (MRMA/AFMA) correlated well to the New York Heart Association classification of heart failure. This method may eliminate machine and user variation. Additionally it may help stage heart failure more appropriately by helping to differentiate the clinical signs of heart failure from other causes such as exercise intolerance due to aging and joint disease.
126
What is Proximal Isovelocity Surface Area (PISA)?
Is an area of flow acceleration and convergence proximal to the mitral valve as the regurgitant jet approaches the regurgitant orifice.
127
PISA: This method assumes that flow accelerates as it approaches the small orifice and that it does so in................... on the ventricular side of the valve..
This method assumes that flow accelerates as it approaches the small orifice and that it does so in concentric hemispheres on the ventricular side of the valve..
128
The more blood volume that moves backward throughout the valve the larger the proximal hemisphere is.
The more blood volume that moves backward throughout the valve the larger the proximal hemisphere is.
129
Studies have shown that this measurement can be used to determine not only the regurgitant orifice area but also ...........?
Studies have shown that this measurement can be used to determine not only the regurgitant orifice area but also regurgitant fraction and volume when used in conjunction with regurgitant flow velocity.
130
PISA:
Use apical 4 ch view
Use centrally directed MR jet
See flow convergence, vena contracta, and jet expansion
Nyquist limit should be ......... cm/sec
Use largest MR jet during mid systole
- Use zoom
- Adjust baseline in direction of regurgitation until perfect hemisphere is seen
- Nyquist limit should now be ca ........... cm/sec
Use apical 4 ch view
Use centrally directed MR jet
See flow convergence, vena contracta, and jet expansion
Nyquist limit should be 50-70 cm/sec
Use largest MR jet during mid systole
- Use zoom
- Adjust baseline in direction of regurgitation until perfect hemisphere is seen
- Nyquist limit should now be ca 18 to 40 cm/sec
131
In order to record and measure the proximal isovelocity hemisphere, the mitral regurgitant jet is identified on an apical 4 ch view. The proximal flow convergence, the vena contracta and the regurgitant jet should all be visualize and the Nyquist limit should be set somewhere between 50 and 70 cm/sec.
Fig 5.38
132
The lack of flow convergence area is consistent with ............. while the presence of a large flow convergence area is consistent with a significant regurgitant volume. Fig 5.39
The lack of flow convergence area is consistent with minimal to milc regurgitation while the presence of a large flow convergence area is consistent with a significant regurgitant volume. Fig 5.39
133
The largest regurgitant jet during peak to .......... should be isolated on fram-by frame images. Zooming in on the mitral valve at the location of flow convergence will optimize measurement accuracy.
The largest regurgitant jet during peak to mid-systole should be isolated on fram-by frame images. Zooming in on the mitral valve at the location of flow convergence will optimize measurement accuracy.
134
The baseline of the color map should be moved downward in the direction of regurgitation until the flow convergence area has a hemisphere of solid color outlined in the aliased signal. The Nyquist limit (Va in cm/sec) should be somewhere between .... and ..... cm/sec when this hemisphere is seen.
The Nyquist limit (Va in cm/sec) should be somewhere between 18 and 40 cm/sec when this hemisphere is seen.
135
The Nyquist limit at which the radius is measured is not the most important factor, the important features is that .....?
the flow convergence area is as close to a perfect hemisphere as possible.
136
The following factors should be recorded and measured:
Tadius of the hemisphere of the proximal flow convergence (r in cm)
The peak mitral regurgitant velocity (MRvmax in cm/sec) and its velocity time integral (MRvti in cm). Fig 5.40
137
Flow rate, effective regurgitant orifice area (EROA) and regurgitant vole (RV) are calculated as follows in equations 5.4 to 5.6
Equations 5.4-5.6
138
Notice that the EROA in the regurgitant volume equation is in ................., remember to convert the MRvmx to cm/sec if your machine calculate it in m/sec, and if your equipment reports EROA in mm upphöjt i 2, remember to change it to cm upphöjt i 2 if you are calculating regurgitant volume manually.
Notice that the EROA in the regurgitant volume equation is in cm upphöjt i 2, remember to convert the MRvmx to cm/sec if your machine calculate it in m/sec, and if your equipment reports EROA in mm upphöjt i 2, remeber to change it to cm upphöjt i 2 if you are calculating regurgitant volume manually.
139
Effective regurgitant orifice areas of /= ......cm upphöjt i 2 is consistent with a severe MR
Effective regurgitant orifice areas of /= 0.4 cm upphöjt i 2 is consistent with a severe MR
140
PISA-EROA (man)
mild MR
141
PISA-EROA (man)
0.2-0.39 cm upphöjt i2 = ....MR
Moderate MR
142
PISA-EROA (man)
0.4 cm upphöjt i2 = ....MR
Severe MR
143
The PISA method requires an ............. hemisphere and excellent alignment with a centrally directed regurgitant jet. Misalignment with an .......... jet will underestimate orifice areas.
The PISA method requires an elliptical hemisphere and excellent alignment with a centrally directed regurgitant jet. Misalignment with an eccentric jet will underestimate orifice areas.
144
Hemicircles measured too close to the mitral orifice are generally too ........, which will ............. flow rates
Hemicircles measured too close to the mitral orifice are generally too flat, which will underestimate flow rates
145
Convergence hemispheres too far away typically maintain too much of a ........ shape and will ........... flow rates.
Convergence hemispheres too far aways typically maintain too much of a parabolic shape and will overestimate flow rates. Fig 5.41, 5.42.
146
Try to optimize the flow convergent hemisphere to be as close to a ......... as possible.
Try to optimize the flow convergent hemisphere to be as close to a half circle as possible. Studies have shown good correlation with actual flow rates when flow convergence is recorded and measured accurately (r=0.96)
147
Three-dimensional imaging with color-flow Doppler has shown that the area of flow convergence varies based upon ............... and three-dimensional ..................... improves accuracy immensely,
Three-dimensional imaging with color-flow Doppler has shown that the area of flow convergence varies based upon imaging plane and three-dimensional reconstruction improves accuracy immensely,
148
Jet direction and flow convergence shape are affected by ............. and .........................
Jet direction and flow convergence shape are affected by orifice shape and valve structure.
149
There is much day-to-day variability in regurgitant fraction calculated via the PISA method in dogs. The .................however, has shown a much lesser degree of variability.
There is much day-to-day variability in regurgitant fraction calculated via the PISA method in dogs. The effective regurgitant orifice area (EROA) however, has shown a much lesser degree of variability.
150
Studies in man have shown that increased severity of MR based upon regurgitant fraction (>50%) or EROA (>40 mm upphöjt i 2) is correlated with?
Poorer outcomes regardless of the class of heart failure these individuals are in at the same time of the evaluation. It has been suggested that further study may determine if calculation of these parameters in asymptomatic dogs with large regurgitant fractions or EROA can be predictive of the course of clinical signs or in determining when to initiate medial therapy.
151
Kittleson et al showed that by using the PISA method to calculate regurgitant fraction, dogs with severe MR had more than ...... % of their LV volume move backward into the LA chamber during systole. Dogs with moderate MR had .......% regurgitant fractions, and dogs with mild MR had less than .....%.
Kittleson et al showed that by using the PISA method to calculate regurgitant fraction, dogs with severe MR had more than 75% of their LV volume move backward into the LA chamber during systole. Dogs with moderate MR had 45-75% regurgitant fractions, and dogs with mild MR had less than 45%.
152
Using just centrally directed jets, one study in dogs showed excellent repeatability with variation between 8 and 11% in MR fractions using the PISA method. This study also showed that with severe MR, using the regurgitant jet area often resulted in a jet area or LA area of ....... This makes differentiating between dogs with moderate or severe MR or trying to sub classify within the severe group, difficult if not impossible.
1:1.
153
PISA measures?
Instantaneous flow rate of the regurgitant jet, which means that it is a measure of the largest EROA during the regurgitant time period.
154
PISA also assumes holosystolic regurgitant flow. This method is not accurate when the insufficiency encompasses only a portion of the systolic time period. Using color M-mode can define the duration of regurgitation.
PISA also assumes holosystolic regurgitant flow. This method is not accurate when the insufficiency encompasses only a portion of the systolic time period. Using color M-mode can define the duration of regurgitation.
155
PISA is not accurate when the insufficiency encompasses only a portion of the systolic time period.
PISA is not accurate when the insufficiency encompasses only a portion of the systolic time period.
156
Using color M-mode can define the duration of regurgitation.
Using color M-mode can define the duration of regurgitation.
157
PISA measures the largest .......
EROA
158
Vena contracta
Measuring the ........... as it enters the LA through the mitral valve has also been studies in an effort to eliminate the other limitations of color flow evaluation.
Measuring the proximal regurgitant jet height as it enters the LA through the mitral valve has also been studies in an effort to eliminate the other limitations of color flow evaluation.
159
The smallest .............., the vena contracta, at the mitral regurgitant orifice is identified by carefully angling the sound beam in various directions.
The smallest regurgitant color-flow jet, the vena contracta, at the mitral regurgitant orifice is identified by carefully angling the sound beam in various directions.
160
......... images, or imaging planes that identify the vena contract ............to the sound plane, are recommended as it minimizes error arising from poor lateral resolution.
Long-axis parasternal images, or imaging planes that identify the vena contract perpendicular to the sound plane, are recommended as it minimizes error arising from poor lateral resolution. Fig 5.43
161
Views that orient the vena contract .......... to the sound beams should not be used.
Views that orient the vena contract parallel to the sound beams should not be used.
162
........ color sectors also provide the best lateral and temporal resolution.
Small color sectors also provide the best lateral and temporal resolution.
163
Identify the proximal .........., the vena contract, and the jet expansion into the LV chamber. The zoom in on the vena contract to minimize measurement error.
Identify the proximal flow convergence, the vena contract, and the jet expansion into the LV chamber. The zoom in on the vena contract to minimize measurement error. Fig 5.44
164
Vena contract:
- Use parasternal long-axis views
- See flow convergence, and vena contracta and jet expansion
- Zoom in
- Measure smallest regurgitant jet width through the valve
- Calculates the smallest EROA
- Use parasternal long-axis views
- See flow convergence, and vena contracta and jet expansion
- Zoom in
- Measure smallest regurgitant jet width through the valve
- Calculates the smallest EROA
165
Is the vena contract affected by driving pressurs or flow rate in fixed orifices?
The vena contract is not affected by driving pressurs or flow rate in fixed orifices.
166
In man, studies have shown that the vena contract correlates better with ......... severity than jet area when compared to invasive measurement methods.
that the vena contract correlates better with regurgitant severity than jet area when compared to invasive measurement methods.
167
The width of the vena contract has a 0.85 correlation coefficient to angiographic data. Mild regurgitation in man corresponds to a vea contract of less than 0.3 cm, while severe insufficiency has widths greater than 0.6 to 0.8 cm. There is considerable overlap in the midrange, and other methods of evaluation should also be used to confirm the assessment of severity. it remains to be seen if this is applicable in dogs.
The width of the vena contract has a 0.85 correlation coefficient to angiographic data. Mild regurgitation in man corresponds to a vea contract of less than 0.3 cm, while severe insufficiency has widths greater than 0.6 to 0.8 cm. There is considerable overlap in the midrange, and other methods of evaluation should also be used to confirm the assessment of severity. it remains to be seen if this is applicable in dogs.
168
Applying the area equation to the vena contracta width provides another measure of EROA. This measurement defines the orifice at its smallest of done correctly. Summating the vena contracta in patients with multiple regurgitant jets is not accurate, but summating their areas is.
Applying the area equation to the vena contracta width provides another measure of EROA. This measurement defines the orifice at its smallest of done correctly. Summating the vena contracta in patients with multiple regurgitant jets is not accurate, but summating their areas is.
169
Vena contracta (man)
...= severe
much overlap in between.
6 = severe
170
Spectral Doppler evaluation:
Jet area: Spectral Doppler can map the regurgitant jet area and severity of MR. Careful placement of the PW Doppler gate at various depths within the LA can provide information on how ..................
Jet area: Spectral Doppler can map the regurgitant jet area and severity of MR. Careful placement of the PW Doppler gate at various depths within the LA can provide information on how wide and deep the regurgitant jet extends into the LA.
171
An aliased signal is seen at any point where the gate detects a regurgitant jet.
An aliased signal is seen at any point where the gate detects a regurgitant jet. Figure 5.45
172
Spectral Doppler evaluation:
.............depth and width implies more severe regurgitation, and assessment is the same as with color-flow signals. This is a time-consuming method, and it may not be possible to interrogate the entire LA in some unhappy patients.
Increasing depth and width implies more severe regurgitation, and assessment is the same as with color-flow signals. This is a time-consuming method, and it may not be possible to interrogate the entire LA in some unhappy patients.
173
Regurgitant volume and fraction:
Regurgitant volume is calculated by subtracting ............. volume through the aortic valve from............ moving through the mitral valve into the LV chamber.
Regurgitant volume is calculated by subtracting forward stroke volume through the aortic valve from total LV volume moving through the mitral valve into the LV chamber. Equation 5.7
174
Regurgitant fraction is the percent of ?
The percent of total stroke volume that flows back into the LA chamber. Equation 5.8
175
Aortic area is calculated by determining the .............. of the aorta at the level of valve insertion from along-axis parasternal imaging plane or by tracing the ............... on transverse views. Equation 5.9.
This area is multiplied by the flow velocity integral of aortic flow taken from the apical five-chamber image with the PW gate placed at the level of the valve to obtain forward stroke volume. Equation 5.10
Aortic area is calculated by determining the cross-sectional area of the aorta at the level of valve insertion from along-axis parasternal imaging plane or by tracing the aortic area on transverse views. Equation 5.9
This area is multiplied by the flow velocity integral of aortic flow taken from the apical five-chamber image with the PW gate placed at the level of the valve to obtain forward stroke volume. Equation 5.10
176
Total stroke volume through the mitral valve is obtained by multiplying the ............ of transmitral flow taken at the level of the mitral annulus on an apical 4 ch imaging plane by the ............. on this same imagine plane
Total stroke volume through the mitral valve is obtained by multiplying the flow velocity integral of transmitral flow taken at the level of the mitral annulus on an apical 4 ch imaging plane by the diameter of the mitral annulus on this same imagine plane. Figures 4.62, 4.66, Equation 5.11, 5.12
177
Effective regurgitant orifice area is calculated by?
Multiplying the regurgitant fraction by the flow velocity integral of the MR jet (equation 5.13).
Regurgitant fractions calculated this way have a significant correlation with LA size (r=0.88).
178
There are som limitations that affect the accuracy and assessment of calculating regurgitant fraction this way: Such as?
Errors in annular diameter measurements are compounded when inserted into the area calculation. (r upphöjt i 2).
The valve used for normal stroke volume must not be insufficient.
Mitral annular area measurements also assume a circular-shaped annulus, which is not always the case.
Finally, information may be conflicting. For ex; severe regurgitation with minimal LV dilation may have a small calculated regurgitant volume may have a small calculated regurgitant volume but a high regurgitant fraction and EROA. This method of calculating the severity of mitral regurgitation is useful however when there are multiple or eccentric jets.
179
Calculating total ................ by using 2 D measurements of diastolic and systolic volumes overcomes this (using regurgitant fraction) problem.
Calculating total stroke volume by using 2 D measurements of diastolic and systolic volumes overcomes this (using regurgitant fraction) problem.
180
Using Simpson's rule (method of disks) to calculate end diastolic and end systolic volumes from apical 4 ch imaging planes allows calculation of ........ as well.
Using Simpson's rule (method of disks) to calculate end diastolic and end systolic volumes from apical 4 ch imaging planes allows calculation of total stroke volumes as well. Fig 4.59.
This can the be substituted into the RV and RF equations.
Foreshortened apical views limit the accuracy of this method.
181
transmitral E flow velocity > ....m/sec = Significant regurgitation
1.2 m/sec
182
transmitral valve flow:
| Transmitral flow velocity greater then 1,2 m/sec is predictive of?
poor survival time
183
Transmitral flow velocity is affected by?
Affected by both left atrial pressure and left ventricular filling pressure, and by volume flowing through the valve during diastole.
All of these are elevated in dogs and man with significant mitral valvular insufficiency.
184
Relationships between transmittal E velocity and IVRT and mean LA pressure (r=0.73) and between E:Ea and mean LA pressure (r=0.83) have been reported. The calculation of mean LA pressure (MLAP) from E:Ea is shown in equation 5.14
MLAP= 6.38 x E:Ea-28.3
where MLAP is mmHg, E is measured in m/sec, and Ea is measured in m/sec.
This study in dogs involved experimentally induced acute MR.
185
When fused E and A waves are found on spectral or tissue Doppler studies, the fused peak is treated as the peak E or E´. Fig 5.47.
When fused E and A waves are found on spectral or tissue Doppler studies, the fused peak is treated as the peak E or E´. Fig 5.47.
186
There is a wide confidence interval for each E:Ea and the predicted MLAP, but an E:Ea of less than 6 predicts a MLAP under 20 mmHg and E:Ea values greater than 9 predicts a MLAP greater than 20 mmHg
There is a wide confidence interval for each E:Ea and the predicted MLAP, but an E:Ea of less than 6 predicts a MLAP under 20 mmHg and E:Ea values greater than 9 predicts a MLAP greater than 20 mmHg
Valid application of E:Ea in the clinical setting with MMVD remains to be studied.
187
Using transmittal peak E velocity and isovolumic relaxation time in a regression equation also correlates (r=0.7) with LV end diastolic pressure (equation 5.15), where peak E is in cm/sec and IVRT is in msec (fig 5.48).
Using transmittal peak E velocity and isovolumic relaxation time in a regression equation also correlates (r=0.7) with LV end diastolic pressure (equation 5.15), where peak E is in cm/sec and IVRT is in msec (fig 5.48).
This study used experimentally induced changes in preload. Its application in chronic MR also needs to be validated.
188
Rapid mitral valve .......... time been correlated with poor prognosis in people and in dogs (
deceleration
A substantial correlation between deceleration time and ventricular stiffness has been found in man.
189
Impaired diastolic function is an important factor in many people with cardiac disease and may be so in animals as well.
Impaired diastolic function is an important factor in many people with cardiac disease and may be so in animals as well.
This restrictive filling pattern is the result of increased LV volume and concurrent impaired compliance, which causes rapid increases in LV pressure for a small change in volume, and as a result LV filling is abruptly decreased, shortening the deceleration time. Its application in dogs with MMVD needs further study.
190
Regurgitant Jet Appearance
Does the velocity of a MR jet provide any information regarding severity of the insufficiency?
The velocity of a MR jet does not provide any information regarding severity of the insufficiency, but the flow profiles and density of the signal do yield some useful information.
Regurgitant jet flow profiles provide some indication regarding the hemodynamic significant of the insufficient volume and LA pressures.
191
Mitral regurgitant jet appearance is usually symmetrical. Fig 5.49. A cutoff flow profile, a v wave, on the deceleration side of the flow profile suggests a ................... pressures secondary to the regurgitant volume.
A cutoff flow profile, a v wave, on the deceleration side of the flow profile suggests a rapid increase in LA pressures secondary to the regurgitant volume. Fig 5.49.
The result of this rapidly elevated atrial pressure is a decrease in regurgitant flow in mid to late systole. The flow profile is no longer symmetrical as would be seen in patients without high atrial pressures and compliant atrial chambers.
This type of flow profile is often seen in acute severe mitral insufficiency.
192
The strength or density of the regurgitant flow profile represents?
the number of red blood cells within the regurgitant jet.
193
A CW flow profile that is as dense as forward diastolic flow through the mitral valve represents a significant regurgitant volume. Fig 5.50
A CW flow profile that is as dense as forward diastolic flow through the mitral valve represents a significant regurgitant volume. Fig 5.50
194
Flow profiles that are barely discernible or do not show complete envelopes suggest that the regurgitant volume is small.
Flow profiles that are barely discernible or do not show complete envelopes suggest that the regurgitant volume is small.
195
The flow should be recorded through a regurgitant jet that includes ....?
The flow should be recorded through a regurgitant jet that includes the flow convergence, vena contract, and the jet expansion into the LA
196
MR jet appearance:
Presence of a v wave indicates:
High LA pressure
197
MR jet appearance:
Density:
Weak incomplete envelopes=
mild MR
198
MR jet as densa as trans MV flow=
severe MR
199
Pulmonary vein flow
Spectral Doppler assessment of pulmonary venous flow also provides information regarding the severity of mitral regurgitation.
Significant regurgitation results in reduced pulmonary ...... ... wave velocity and with severe regurgitation ....... of flow in the pulmonary veins during systole.
Significant regurgitation results in reduced pulmonary venous S wave velocity and with severe regurgitation reversal of flow in the pulmonary veins during systole.
200
........... jets and decreased atrial compliance or elevated LA pressure may affect the pulmonary vein flow profile too.
Eccentric jets and decreased atrial compliance or elevated LA pressure may affect this flow profile too. Fig 5.51
201
Pulmonary vein flow: Systolic reversal = severe.......
severe MR
202
Presence of pulmonary hypertension:
Pulmonary hypertension is a common consequence of left-sided heart disease that increases ..........
LA pressure
203
CF Doppler is used to align a TR jet with the spectral Doppler cursor. Pressure gradients obtained from TR jets are added to the RA pressure and provide an estimate of?
RV pressure.
204
Atrial pressure is estimated to be ...mmHg or less when there is no evidence of RA dilation and the vena cava collapse completely with respiration.
5 mmHg
Fig 5.52
205
The RA has an estimated pressure of approximately ..... mmHg if there is RA dilation, no evidence of right-sided CHF, and the vena cava collapse approximately ......% with respiration.
10 mmHg
Approximately 50%
206
When the vena cava does not collapse with respiration and there is evidence of right-sided CHF, right atrial pressure is estimated at >/= ....mmHg
>/= 15 mmHg
207
Calculated systolic RV pressure is equal to ...............pressure in the absence of pulmonary stenosis.
pulmonary artery systolic pressure
208
Pulmonary pressure of less than ..... mmHg reflects mild pulmonary hypertension, pressure between .... and ..... mmHg reflects moderate pulmonary hypertension, and estimated pressure above ..... mmHg is severe pulmonary hypertension.
Pulmonary pressure of less than 50 mmHg reflects mild pulmonary hypertension, pressure between 50 and 75 mmHg reflects moderate pulmonary hypertension, and estimated pressure above 75 mmHg is severe pulmonary hypertension.
209
Vena cava respiratory collapse and RA pressure:
Complete collapse with respiration= RA pressure
210
50% vena cava respiratory collapse with respiration = RA pressure of approximately ...mmHg
10 mmHg
211
No collapse with respiration =
RA pressure > 15 mmHg
212
Jets of pulmonary insufficiency may also be used to determine the presence of pulmonary hypertension.
Flow ....... and pressure ......... from the insufficient jet reflect diastolic pulmonary artery pressure.
Flow velocity and pressure gradient from the insufficient jet reflect diastolic pulmonary artery pressure.
213
The end diastolic peak velocity is used to calculate .................... pressure, and the initial peak velocity at the start of diastolic regurgitant flow reflects ........................ pressure and is a good representation of pulmonary wedge pressure.
The end diastolic peak velocity is used to calculate pulmonary artery diastolic pressure, and the initial peak velocity at the start of diastolic regurgitant flow reflects mean pulmonary artery diastolic pressure and is a good representation of pulmonary wedge pressure.
Fig 4.89. See more in chapter 4
214
Pulmonary hypertension is a negative predictive factor for ....... in the survival time of dogs with ruptured chordae tendinae.
```
Pulmonary hypertension is a negative predictive factor for survival in the survival time of dogs with ruptured chordae tendinae.
One study showed that 15% of dogs with MMVD have pulmonary hypertension. Most of these dogs were in ISACHC class III stage of heart failure, but almost a third were in class 1a or Ib stage of heart failure. No dog with mild MR based upon CF Doppler had documented pulmonary hypertension.
```
215
Another study in 53 dogs diagnosed with PH showed 30% of them had chronic mitral valve disease as the underlying cause.
When pulmonary hypertension was mild, most dogs were asyptomatic for right-sided heart disease, and most did not have echocardiographic detectable changes in the right side of the heart that would suggest the presence of pulmonary hypertension (i.e right ventricular hypertrophy, right atrial or pulmonary artery dilation).
216
The LA to Ao root ratio (LA/Ao) is significantly and positively correlated with both systolic and diastolic pulmonary artery pressure.
The LA to Ao root ratio (LA/Ao) is significantly and positively correlated with both systolic and diastolic pulmonary artery/vascular pressure.
217
Acute mitral regurgitation is difficult to assess with CF Doppler. The temporal resolution of color flow is not adequate with rapid heart rates. Maximize ........ in this situation.
frames rate
218
Small LA size, one that has not had the chance to chronically dilate, causes LA and LV pressure to ............... rapidly, and color regurgitant jets do not develop well.
Small LA size, one that has not had the chance to chronically dilate, causes LA and LV pressure to equilibrate rapidly, and color regurgitant jets do not develop well.
Use PISA and vena contracta in these situations since they seem to remain reliable under these conditions.
219
Systolic pulmonary ........ flow ......... and the presence of MR jet ...... wave provide insight into the severity of the regurgitation when color-flow analysis is not adequate.
Systolic pulmonary venous flow reversal and the presence of MR jet v wave provide insight into the severity of the regurgitation when color-flow analysis is not adequate.
220
.......... ............ insufficiency is seen in animals with atrioventricular AV conduction abnormalities.
Diastolic mitral insufficiency is seen in animals with atrioventricular AV conduction abnormalities.
it is seen with first, second, adnthird degree AV block as well as retrograde P waves.
221
The mitral regurgitation is typically seen during ........ when the atrial contraction is not followed by an appropriate ventricular contraction, which normally closes the valve. The insufficiency is hemodynamically insignificant and should be differentiated from pathologic systolic leaking of the valve.
The mitral regurgitation is typically seen during late diastole when the atrial contraction is not followed by an appropriate ventricular contraction, which normally closes the valve. The insufficiency is hemodynamically insignificant and should be differentiated from pathologic systolic leaking of the valve.
222
Overall Assessment of MR:
A mitral regurgitation index has been devised in man that assigns a number from 0 (absent) to 3 (significant) for 6 different parameters used in the evaluation of mitral regurgitation in man. These parameters include?
```
PISA radius
jet expansion into the LA
Vena contracta
Pulmonary venous flow
Pulmonary artery pressure
Left atrial size
```
The average of these scores is calculated.
A score of
223
Do not rely on a single method of assessment. Use multiple parameters to assess severity of MR.
Do not rely on a single method of assessment. Use multiple parameters to assess severity of MR.
224
The society of echocardiogrphic Tasc Force on the assessment of native valvular regurgitation in man recommends integrating several parameters to assess the severity of MR: This helps eliminate error in technique and measurement and helps define which parameters may be erroneous because of technical error, physiological reasons, and chronicity of the disease process.
The limitations och each method are listed in table 5.2
The committee has proposed several echo measurements that are more than 90% specific for the degree of regurgitation and several parameters that are supportive in evaluating the severity of MR.
These are listed in Table 5.3
225
Aortic regurgitation: AI may result from?
Degeneration
Vegetative lesions
Torn or flail cusps
Congenital malformation of the leaflets
Echocardiograpically it may not be possible to differentiate between these causes of insufficiency.
226
Aortic insufficiency shows the following on an echocardiogram:
-Left ventricular volume overload
Valvular lesions
-Diastolic flutter of the mitral and aortic valves
-Increased E point to septal separation (EPSS)
-Large increases in ventricular dimension may also result in dilation of the aortic root.
227
2D and M-mode evaluation:
Valve appearance and motion:
Valvular lesions are not always visible on the echocardiogram, and the absence of lesions does not mean the absence of disease. The resolving capabilities of low frequency transducers is often not sensitive enough to show nodules and irregularities smaller than 2 mm on aortic valves. Even in small animals with high resolution transducers, resolving small lesions is sometimes difficult.
Valvular lesions are not always visible on the echocardiogram, and the absence of lesions does not mean the absence of disease. The resolving capabilities of low frequency transducers is often not sensitive enough to show nodules and irregularities smaller than 2 mm on aortic valves. Even in small animals with high resolution transducers, resolving small lesions is sometimes difficult.
228
Degenerative lesions of the aortic valve are typically?
smooth, small, and rounded
Fig 5.53, 5.54
229
Large irregular hyperechoic masses associated with the leaflets are more suggestive of?
Fig 5.55, 5.56
| vegetative endocarditis
230
Degenerative lesions of the aortic valve:
| Large vegetations are often floppy and prolapse into the ....
outflow tract
231
Prolapsed aortic valve cusps with or without lesions bow into the ........... and are easily visible on real-time images.
Prolapsed aortic valve cusps with or without lesions bow into the outflow tract and are easily visible on real-time images.
Fig 5.57.
This is seen more frequently in horses as a cause of AI. Fig 5.58
232
M-mode images sometimes show multiple linear echoes representing the lesions during diastole or systole on aortic root images instead of the normal fine single line associated with the ............aortic valve.
closed and open aortic valve.
| Fig 5.59
233
2 D and M-mode features of AR?
Valvular lesions
LV volume overload if insufficiency significant
Diastolic MV flutter
Increased EPSS
234
AR secondary to rapid vegetative growth will not show ..................... overload.
AR secondary to rapid vegetative growth will not show LV volume overload.
235
.................... of the mitral valve is probably the most common M-mode finding in man and animals with AI. This is seen even if the volume of regurgitation is not severe.
Diastolic fluttering of the mitral valve is probably the most common M-mode finding in man and animals with AI. This is seen even if the volume of regurgitation is not severe.
236
The diastolic fluttering occurs secondary to .............associated with the regurgitant jet as it flows into the outflow tract.
The diastolic fluttering occurs secondary to turbulence associated with the regurgitant jet as it flows into the outflow tract.
237
M-mode images may show dramatic mitral valve fluttering, a ..................... appearance, during ...................when the mitral leaflet is wide open, and this is especially easy to appreciate with slow heart rates.
M-mode images may show dramatic mitral valve fluttering, a sawtooth appearance, during diastole when the mitral leaflet is wide open, and this is especially easy to appreciate with slow heart rates.
Fig 4.100, 5.60, 5.61
This fine vibration may encompass the entire diastolic time period or any portion ot it. The regurgitant jet does not have to directly strike the leaflet to create this fluttering; jets that are directed away from the mitral valve create the vibration simply because of turbulence within the LV outflow tract.
238
Regurgitant jets directed toward the ventricular septum may cause early ............ vibration of the septum.
Regurgitant jets directed toward the ventricular septum may cause early diastolic vibration of the septum.
239
Can diastolic MV flutter be seen even with mild AR?
Yes!
240
The mitral valve may also show reverse doming of the septal leaflet back toward the LA chamber during .......... as the force of the AR jet flows into the LV outflow tract.
The mitral valve may also show reverse doming of the septal leaflet back toward the LA chamber during diastole as the force of the AR jet flows into the LV outflow tract.
On transverse views this appears as indentation of the septal leaflet toward the free wall of the LV chamber.
241
The mitral valve E ...............in animals with significant AR is increased as the regurgitant jet ................ motion of the mitral valve.
The mitral valve E point to septal separation (EPSS) in animals with significant AR is increased as the regurgitant jet restricts motion of the mitral valve. Fig 4.99
242
The mitral valve E point to septal separation (EPSS) in animals with significant AR is increased as the regurgitant jet restricts motion of the mitral valve. Does a large EPSS in this case correlate with decreased EF and severity of insufficiency?
A large EPSS in this case does not correlate with decreased EF but neither does it necessary correlate with severity of the valvular insufficiency.
243
Mitral valve motion may be dramatically altered and reduced with significant AR.
The mitral valve may also close ........ than usual, before the beginning of the QRS complex. This occurs secondary to?
The mitral valve may also close earlier than usual, before the beginning of the QRS complex.
This occurs secondary to elevated LV diastolic filling pressures, and with acute severe AR, LV diastolic pressure increases rapidly and can become higher than LA pressure toward the end of diastole resulting in premature mitral valve closure.
This is usually seen in animas already in CHF.
244
MV closure before the start of the QRS complex=
High LV presure.
245
Diastolic flutter of the aortic valve is also reported with AR. This is most commonly seen in?
Horses with aortic valve insufficiency.
The vibration occurs secondary to flow through the cusps when they should be closed during diastole. Aortic valve diastolic flutter has been reported with fenestration of the aortic cusps, torn cusps, and endocarditis involving the aorta in horses.
246
LV size and function:
Volume overload occurs with chronic moderate to severe aortic insufficiency. Does AI have a greater negative impact upon myocardial function than MR?
Yes, most often
247
Afterload and wall stress are higher in animals with AI versus MR since there is no?
There is no flow into a low pressure LA early during systole.
248
All of the volume within the left ventricle must be dealt with when only the aortic valve is insufficient. Volume overload should lead to compensatory ........... hypertrophy, and function should elevate secondary to stretch of the myocardial fibers.
eccentric
249
Failure to see an elevation in fractional shortening and a normal systolic dimension suggests the presence of ..................
Failure to see an elevation in fractional shortening and a normal systolic dimension suggests the presence of myocardial failure.
250
Acute aortic regurgitation often results in significant symtoms since there is no time for ............................mechanisms to manifest themselves.
Acute aortic regurgitation often results in significant symtoms since there is no time for compensatory mechanisms to manifest themselves.
251
Studies that create aortic regurgitation show an acute increase in volume and wall stress with a return to normal wall stress after ................... has occurred. This takes approximately 1 month.
Studies that create aortic regurgitation show an acute increase in volume and wall stress with a return to normal wall stress after compensatory hypertrophy has occurred. This takes approximately 1 month.
252
The severity of aortic insufficiency is best evaluated with .............. ultrasound, but its effect on the LV must be assessed as well.
The severity of aortic insufficiency is best evaluated with Doppler ultrasound, but its effect on the LV must be assessed as well.
253
Hemodynamically insignificant insufficiencies will not cause the ventricle to dilate. Chronically, mild to moderate leaks cause an increase in LV diastolic dimension, compensatory hypertrophy, and ............fractional shortening.
Hemodynamically insignificant insufficiencies will not cause the ventricle to dilate. Chronically, mild to moderate leaks cause an increase in LV diastolic dimension, compensatory hypertrophy, and elevated fractional shortening.
The heart affected by acute severe insufficiency will not have developed these compensatory changes.
254
LV function in AR (man):
| Ejection fraction
Ejection fraction
255
Assessment of LV function is an important parameter in patients with aortic insufficiency. Ejection fractions calculated from apical images provide some assessment of prognosis in man. An ejection fraction of less than 50 to 55% endures a poor prognosis in people with aortic regurgitation regardless of if they are symptomatic. This has not been evaluated in animals.
Assessment of LV function is an important parameter in patients with aortic insufficiency. Ejection fractions calculated from apical images provide some assessment of prognosis in man. An ejection fraction of less than 50 to 55% endures a poor prognosis in people with aortic regurgitation regardless of if they are symptomatic. This has not been evaluated in animals.
256
Color-flow Doppler utilizes 3 methods to assess the severity of aortic insufficiency. These are?
- The proximal flow convergence in the aorta
- Vena contracta
- Jet direction and size into the LV outflow tract and chamber
257
Historically, the Doppler assessment of the severity of AR in man is based upon the extent of the regurgitant jet into the LV outflow tract and chamber. A regurgitant jet that extends just beyond the aortic valve and dissipates into a non...........
signal quickly is considered to be mild, a jet that extends to the tips of the .............. is moderate in severity, and a jet that extends beyond the ............. into the LV chamber is severe.
A regurgitant jet that extends just beyond the aortic valve and dissipates into a nonaliased signal quickly is considered to be mild, a jet that extends to the tips of the mitral valves is moderate in severity, and a jet that extends beyond the mitral leaflets into the LV chamber is severe.
The correlation here with actual severity is less than for mitral insufficiency because this flow is influenced by the volume and compliance of the LV chamber, the size of the orifice, the pressure gradient, and the duration of the gradient between the aorta and LV:
Fig 5.62-5.66
258
Aortic regurgitation is significant when the color flow signal fills the ........ of the outflow tract and extends beyond..................
Aortic regurgitation is significant when the color flow signal fills the width of the outflow tract and extends beyond the tips of the mitral leaflets.
259
Analyzing jet .......... is preferred over jet .......... when assessing the significance of aortic regurgitation with CF Doppler.
Analyzing jet height is preferred over jet length when assessing the significance of aortic regurgitation with CF Doppler.
This method appears to have a much better correlation with actual significance of the regurgitation than jet length. .
260
Jet height measured just .............. to the aortic valve (within 1 cm) compared to the diameter of the left ventricular outflow tract has a correlation of (r=0.91) with quantitative methods of assessment. This measurement is obtained from ................... parasternal images whenever possible to maximize axial resolution of the color jet.
Jet height measured just proximal to the aortic valve (within 1 cm) compared to the diameter of the left ventricular outflow tract has a correlation of (r=0.91) with quantitative methods of assessment. This measurement is obtained from long-axis parasternal images whenever possible to maximize axial resolution of the color jet.
Fig 5.67.
261
Jet height to outflow tract width ratio of >/= 65% correlates highly with severe insufficiency, a jet height to outflow tract ratio of 24% represents mild insufficiency, moderate insufficiency has a jet height to outflow tract ration of between 25 and 46%, and those between 47% and 64% are moderate to severe.
Jet height to outflow tract width ratio of >/= 65% correlates highly with severe insufficiency, a jet height to outflow tract ratio of 24% represents mild insufficiency, moderate insufficiency has a jet height to outflow tract ration of between 25 and 46%, and those between 47% and 64% are moderate to severe.
262
Of all the method for assessing AR, the jet height shows the best correlation with angiographically measured severity.
Of all the method for assessing AR, the jet height shows the best correlation with angiographically measured severity.
263
When jet height is recorded from transverse imaging planes, the radius can be used to calculate jet ......... A proximal jet ....... to LV outflow tract area ratio is obtained.
When jet height is recorded from transverse imaging planes, the radius can be used to calculate jet area. A proximal jet area to LV outflow tract area ratio is obtained. (fig 5.68)
A ratio of +/-60% is consistent with the diagnosis of severe AR.
264
The jet height and jet area based on jet height methods become inaccurate when...?
When jets are eccentric.
Aortic insufficiency that diffusely leaks along an entire cusp line is also difficult to assess with these methods. Fig 5.69
Jet area is usually subjectively assessed as opposed to direct measurement of jet height and area.
265
Regurgitant jet height to outflow tract width:
- Measure just ......... to valve (approximately 1 cm.
- Use parasternal.............images
- It is inaccurate if .......... jet
- Use zoom
- Measure just proximal to valve (approximately 1 cm.
- Use parasternal long-axis images
- It is inaccurate if eccentric jet
- Use zoom
266
```
Regurgitant jet height to outflow tract width: Severity:
Ratio > 65% = Severe AR
Ratio 25-46% = moderate AR
Ratio 47-64% = moderate to severe AR
Ratio
```
Ratio > .......% = Severe AR
Ratio .......% = moderate AR
Ratio ......% = moderate to severe AR
Ratio
267
Vena contracta is also applied to AR jets. The vena contract is the?
The smallest width of the regurgitant jet as if flows through the aortic valve.
268
Vena contracta:
As with jet height, this measurement should be obtained from ................ parasternal outflow views in order to maximize axial resolution, and all components of the insufficiency should be seen, proximal flow convergence, vena contracta, and jet expansion into the outflow tract.
As with jet height, this measurement should be obtained from long-axis parasternal outflow views in order to maximize axial resolution, and all components of the insufficiency should be seen, proximal flow convergence, vena contracta, and jet expansion into the outflow tract.
Fig 5.70
269
Vena contracta will always be smaller that jet height since the regurgitant jet will expand after it enters the outflow tract.
Vena contracta will always be smaller that jet height since the regurgitant jet will expand after it enters the outflow tract.
270
A vena contract size of > ....... cm is highly sensitive for severe aortic regurgitation, a vena contract width of >/= .....mm is highly specific for severe regurgitation, while a vena contract of
A vena contract size of > 0.5 cm is highly sensitive for severe aortic regurgitation, a vena contract width of >/= 7 mm is highly specific for severe regurgitation, while a vena contract of
271
A ..... -mm size has the best combination of specificity and sensitivity for significant AR.
A 6 -mm size has the best combination of specificity and sensitivity for significant AR.
272
Vena contracta:
Measure smallest .........through valve
Use .............. long-axis images
See flow convergence, and vena contracta and jet expansion
Use zoom
Severity:
...... mm= severe AR
Measure smallest width through valve
Use parasternal long-axis images
See flow convergence, and vena contracta and jet expansion
Use zoom
Severity:
6 mm= severe AR
273
Regurgitant orifice size can be calculated. Orifice size corresponds to the?
To the area of the vena contract.
An experimental study in dogs found a good correlation between area of the vena contract and EROA (r = 0.91).
274
An orifice size > 0.3 cm upphöjt i 2 and a regurgitant volume of > 60 ml/beat in man imply severe aortic regurgitation.
An orifice size > 0.3 cm upphöjt i 2 and a regurgitant volume of > 60 ml/beat in man imply severe aortic regurgitation.
275
Effective regurgitant orifice area can be calculated from vena contracta using equation 5.16
Effective regurgitant orifice area can be calculated from vena contracta using equation 5.16
276
Effective regurgitant orifice area is influenced by?
systemic pressure as well as size of the aorta.
277
..............ascending aorta and systemic hypertension prevent proper coaptation of the aortic valve cusps leading to ..................
Distended ascending aorta and systemic hypertension prevent proper coaptation of the aortic valve cusps leading to insufficiency.
Decreasing pressure will reduce orifice size and decrease the amount of regurgitation.
278
Vena contracta and EROA (dogs) > 0.3 cm upphöjt i 2 =
Severe
279
Limitations of using vena contracta assessment in dogs with AR?
The vena contract is not always symmetrical, and its width in one imaging plane may not be the same in another imaging plane. This is also a very small diameter, and a miscalculation because of poor image quality, not zooming in, and so on, can compound the error and assign a severity that does not reflect an accurate assessment of regurgitation.
280
Proximal isovelocity surface area:
Proximal flow convergence is used to assess aortic regurgitation in man. Adjust the Nyquist limit until a ............of flow convergence with an aliasing border is see.
This should be obtained .............. when velocity of regurgitant flow is maximal.
Proximal flow convergence is used to assess aortic regurgitation in man. Adjust the Nyquist limit until a hemisphere of flow convergence with an aliasing border is see.
Fig 5.71, 5.72.
This should be obtained early in diastole when velocity of regurgitant flow is maximal.
281
Proximal isovelocity surface area:
Calculating the flow velocity integral of the regurgitant jet allows the calculation of ........... and regurgitant jet allows the calculation of EROA and regurgitant volume just as it does in mitral regurgitation.
Calculating the flow velocity integral of the regurgitant jet allows the calculation of EROA and regurgitant jet allows the calculation of EROA and regurgitant volume just as it does in mitral regurgitation.
(Equations 5.17-5.19, 5.22)
282
Calculation of EROA and RV using PISA in aortic regurgitation has the same intrinsic errors that PISA calculations have for mild regurgitation.
The lack of or a minimal flow convergence area is consistent with .............. while a large flow convergence area reflects .................
The lack of or a minimal flow convergence area is consistent with mild regurgitation while a large flow convergence area reflects severe AR.
283
Severe AR is present with an EROA of >/= 3 cm upphöjt i 2 and a regurgitant volume of >/= 60 ml in man
Severe AR is present with an EROA of >/= 3 cm upphöjt i 2 and a regurgitant volume of >/= 60 ml in man
284
PISA and EROA:
See all components of AR jet
- Flow ...........
- Vena ........
- Jet ............
Measure early in ......... when flow maximal
- This is not accurate whit eccentric jets
- Use apical view
- use zoom
- Adjust Nyquist limit for best hemisphere
See all components of AR jet
- Flow convergence
- Vena contracta
- Jet expansion
Measure early in diastole when flow maximal
- This is not accurate whit eccentric jets
- Use apical view
- use zoom
- Adjust Nyquist limit for best hemisphere
285
Spectral Doppler:
Using slopes and pressure half-times, spectral Doppler provides additional hemodynamic information concerning the severity and hemodynamic significance of aortic regurgitation.
Using slopes and pressure half-times, spectral Doppler provides additional hemodynamic information concerning the severity and hemodynamic significance of aortic regurgitation.
286
The slope and half-time (see chapter 4) of an aortic insufficiency jet is dependent upon .......?
The slope and half-time (see chapter 4) of an aortic insufficiency jet is dependent upon how fast the aortic and ventricular pressures equilibrate during diastole.
287
A large regurgitant orifice allows the pressure to equilibrate rapidly (aortic pressure drops quickly and LV pressure rises rapidly during diastole as volume leaves the aorta and enters the LV) resulting in a ...... slope and .........pressure half-time. Fig 4.91 and 5.73.
A large regurgitant orifice allows the pressure to equilibrate rapidly (aortic pressure drops quickly and LV pressure rises rapidly during diastole as volume leaves the aorta and enters the LV) resulting in a steep slope and short pressure half-time.
288
A small regurgitant orifice delays the equilibration, and a ............... profile is seen with a ............ pressure half-time.
A small regurgitant orifice delays the equilibration, and a plateau-shaped profile is seen with a long pressure half-time. Fig 4.92, 5.74
In other words, the pressure gradient at the end of diastole is relatively unchanged from the pressure gradient at the beginning of diastole.
289
In man, a pressure gradient half-time of greater than 500 msec is indicative of hemodynamically insignifiicant aortic regurgitation whereas a pressure half-time of less than 300 msec (some use 200 msec) implies mild aortic insufficiency.
In man, a pressure gradient half-time of greater than 500 msec is indicative of hemodynamically insignifiicant aortic regurgitation whereas a pressure half-time of less than 300 msec (some use 200 msec) implies mild aortic insufficiency.
This method shows much overlap between levels of severity, but it is good at differentiating between mild regurgitation and sever regurgitation by using a pressure half-time of 400 msec. (specificity of 0.92)
290
Significant AR allows LV and Ao diastolic pressures to equalize rapidly resulting in .......... pressure half-times
Significant AR allows LV and Ao diastolic pressures to equalize rapidly resulting in short pressure half-times
291
AR pressure half-time (=man)
....... msec = mild AR
Much overlap in midrange
500 msec = mild AR
| Much overlap in midrange
292
AR Slope (man)
mild
293
```
AR Slope (man)
> 3 m/sec upphöjt i 2 =
```
Severe AR
294
Is calculating slope instead of pressure half-time better?
Calculating slope instead of pressure half-time of course has the same degree of ambiguity and there is considerable overlap. However, a deceleration slope of > 2 m/sec upphöjt i 2 differentiates mild regurgitation from moderate to severe regurgitation, and a slope of > 3 m/sec upphöjt i 2 differentiates between mild to moderate and severe aortic insufficiency in man. Fig 5.75
295
These two parameters, slope and half-time, are dependent upon several different factors however, including?
The size of the regurgitant aperture
Left ventricular compliance
Aortic diastolic pressure.
296
Decreasing systemic vascular resistance with afterload reducing agents decreases the regurgitant fraction but also increases aortic compliance, which allows the pressures between the LV and aorta to equilibrate faster.
This .............. the slope (making the profile less plateau shaped) and ................ the pressure half-time of the regurgitant jet flow profile giving the false impression that the regurgitant fraction has worsened.
Decreasing systemic vascular resistance with afterload reducing agents decreases the regurgitant fraction but also increases aortic compliance, which allows the pressures between the LV and aorta to equilibrate faster.
This increases the slope (making the profile less plateau shaped) and decreases the pressure half-time of the regurgitant jet flow profile giving the false impression that the regurgitant fraction has worsened.
297
Increased afterload generally ................... the regurgitant fraction, but slope and pressure half-times are not affected to any great degree because both ventricular and aortic compliance ............. to relatively the same degree.
Increased afterload generally increases the regurgitant fraction, but slope and pressure half-times are not affected to any great degree because both ventricular and aortic compliance decrease to relatively the same degree.
298
Comparing PHT before and after afterload reduction is ................. comparison.
Comparing PHT before and after afterload reduction is not a valid comparison.
299
The amounts of regurgitation and regurgitant fraction are directly related to changes in?
Directly related to changes in the orifice size and this influence ventricular size, slope, and pressure half-time.
However, when there are changes in afterload secondary to drug therapy or other disease process, slope and pressure half-time are no longer directly related to regurgitant volume.
300
Clinical relief of symptoms is a better indicator of reduction in regurgitant volume than slopes and pressure half-times after afterload reduction has been initiated.
Clinical relief of symptoms is a better indicator of reduction in regurgitant volume than slopes and pressure half-times after afterload reduction has been initiated.
301
Regurgitant volume and fraction.
Quantitative methods can determine regurgitant fractions and volumes. Regurgitant volume (RV) is calculated by subtracting ............. from ...........................
Regurgitant volume and fraction.
Quantitative methods can determine regurgitant fractions and volumes. Regurgitant volume (RV) is calculated by subtracting pulmonary stroke volume from aortic stroke volume. Equation 5.20
302
Aortic stroke volume should be the same as pulmonary stroke volume in the normal heart.
Aortic stroke volume should be the same as pulmonary stroke volume in the normal heart.
303
Areas of the pulmonary artery and aorta area are calculated by Equations 5.17 and 5.18.
Their diameters are measured at the level of the ...............
Area is then multiplied by the ................ integrals of each vessel. Equations 5.19 and 5.21.
Areas of the pulmonary artery and aorta area are calculated by Equations 5.17 and 5.18.
Their diameters are measured at the level of the valves.
Area is then multiplied by the flow velocity integrals of each vessel. Equations 5.19 and 5.21.
304
Flow velocity integrals are obtained with PW Doppler at the level of the valve.
Flow velocity integrals are obtained with PW Doppler at the level of the valve.
305
Regurgitant fraction (RF) reflects the .............
Regurgitant fraction (RF) reflects the percent of volume regurgitating. Equation 5.22
306
Equation 5.22
Equation 5.22
307
Total stroke volume (aortic volume) can also be calculated from 2D measurement of LV volume using Simpsons's rule.
Total stroke volume (aortic volume) can also be calculated from 2D measurement of LV volume using Simpsons's rule.
308
Effective regurgitant orifice area (EROA) is calculated by?
Multiplying the regurgitant volume by the CW flow velocity integral of the aortic regurgitant jet. Fig 5.76. Equation 5.23
309
EROA AR=
RV AR x FVI AR Equation 5.23
310
An effective regurgitant orifice size of >/= ... cm upphöjt i 2 and a regurgitant volume of > .....ml are both consistent with severe regurgitation in man.
An effective regurgitant orifice size of >/= 3 cm upphöjt i 2 and a regurgitant volume of > 60 mlnare both consistent with severe regurgitation in man.
311
This quantitative method is not accurate when the aortic valve are ............. The presence of a ventricular septal effect or atrial septal defect increases volume through the pulmonary artery, and valvular regurgitation affects stroke volume through the leaky valve, all of which make these calculations inaccurate.
This quantitative method is not accurate when the aortic valve are stenotic. The presence of a ventricular septal effect or atrial septal defect increases volume through the pulmonary artery, and valvular regurgitation affects stroke volume through the leaky valve, all of which make these calculations inaccurate.
312
Studies in man have shown that the errors inherent in deriving regurgitant fraction by measuring cross-sectional areas may be avoided by simply using flow velocity integrals. Normal human individuals have a ratio of 0.77 of mitral valve flow integral to LV outflow tract flow integral. Regurgitant fraction is estimated by applying equation 5.24. This has not been studied in animals at this time.
Studies in man have shown that the errors inherent in deriving regurgitant fraction by measuring cross-sectional areas may be avoided by simply using flow velocity integrals. Normal human individuals have a ratio of 0.77 of mitral valve flow integral to LV outflow tract flow integral. Regurgitant fraction is estimated by applying equation 5.24. This has not been studied in animals at this time.
313
Flow velocity integral:
Trans MV flow/LVOT integral ratio:
= 0.77 normally
Becomes ........... with more significant AR
= 0.77 normally
| Becomes smaller with more significant AR
314
Diastolic flow reversal:
The use of transesophageal echo adds another parameter that can be used to evaluate the severity of AR. Spectral analysis of flow in the descending aorta determines if there is significant reversal of flow in the aorta during ...........
Spectral analysis of flow in the descending aorta determines if there is significant reversal of flow in the aorta during diastole.
315
There is normally a trivial amount of flow reversal during early diastole in the descending aorta.
A ......... reversal of flow is a sign of at least moderate regurgitation.
There is normally a trivial amount of flow reversal during early diastole in the descending aorta.
A holodiastolic reversal of flow is a sign of at least moderate regurgitation.
316
When the retrograde flow velocity integral is higher than .............. ....... flow velocity integral in the descending aorta, the hemodynamic significant of the regurgitation is considerable.
When the retrograde flow velocity integral is higher than systolic forward flow velocity integral in the descending aorta, the hemodynamic significant of the regurgitation is considerable.
317
Regurgitant jet appearance:
| Difficulty obtaining a complete envelope and the presence of a light regurgitant flow profile imply a ....degree of AR
mild
318
Regurgitant Jet appearance:
There is too much overlap in flow profile density when regurgitation becomes moderate and severe to use this parameter in the assessment of AR
There is too much overlap in flow profile density when regurgitation becomes moderate and severe to use this parameter in the assessment of AR
319
Aortic valve lesions may also create an obstruction to outflow. When they do so the effects on the heart will include ......?
hypertrophy of the wall and septum.
320
A pressure gradient can be derived by applying the ............. equation to the flow velocity through the stenotic area. Realize that the regurgitant volume, if the present, affect volume and resulting pressure gradient.
A pressure gradient can be derived by applying the Bernoulli equation to the flow velocity through the stenotic area. Realize that the regurgitant volume, if the present, affect volume and resulting pressure gradient.
321
Overall assessment of AR:
There is no single method of assessing the severity of AR that is considered to be precise. A combination of the above methods that include 2D, M-mode, and CF and spectral Doppler should be evaluated, and an overall assessment of hemodynamic significance should be determined.
There is no single method of assessing the severity of AR that is considered to be precise. A combination of the above methods that include 2D, M-mode, and CF and spectral Doppler should be evaluated, and an overall assessment of hemodynamic significance should be determined.
322
An index of significance for AR has been proposed by Chin et al. Using vena contracta, jet color jet height ratio to LV outflow tract height, spectral signal strength, diastolic flow reversal in the descending aorta and pressure half-time, points are assigned to each parameter. The average of these points are used to classify the regurgitation into classes of severity. The correlation to more time-consuming quantitative methods of assessment was high.
Table 5.4 lists the parameters and grading systems.
An index of significance for AR has been proposed by Chin et al. Using vena contracta, jet color jet height ratio to LV outflow tract height, spectral signal strength, diastolic flow reversal in the descending aorta and pressure half-time, points are assigned to each parameter. The average of these points are used to classify the regurgitation into classes of severity. The correlation to more time-consuming quantitative methods of assessment was high.
Table 5.4 lists the parameters and grading systems.
323
When AR appears to be hemodynamically significant, all of the following parameters should be evaluated and integrated into the assessment of severity:.............?
When AR appears to be hemodynamically significant, all of the following parameters should be evaluated and integrated into the assessment of severity: LV size, LV function, Proximal jet width, pressure half-time, vena contracta, and aortic flow velocity.
324
The society of echocardiography Task Force on the Assessment of native Vlavular regurgitation in man has compiled recommendations for the assessment of AR, as shown in Table 5.5.
Several parameters are very specific for severity (jet height to outflow tract area, vena contracta, and diastolic flow reversal in the descending aorta), while others are supportive in the assessment of severity (pressure half-time, LV size).
They also recommend quantitative measurement of AR volume and fraction if there in no consensus when using the less quantitative methods.
325
Parameters very specific for assessment of AR:
| 3
- Jet height to LVOT width ratio
- Vena contracta
- Diastolic flow reversal in the descending aorta.
326
Tricuspid regurgitation: Degenerative valvular disease involving the tricuspid valve occur less commonly than myxomatous degeneration of the mitral valve and when it does, it is generally in addition the the left-sided valvular disease. A high percentage of normal animals have trivial to mild tricuspid insufficiency and this should not be mistaken for tricuspid valve disease.
Degenerative valvular disease involving the tricuspid valve occur less commonly than myxomatous degeneration of the mitral valve and when it does, it is generally in addition the the left-sided valvular disease. A high percentage of normal animals have trivial to mild tricuspid insufficiency and this should not be mistaken for tricuspid valve disease.
TR may be present as a consequence of MMVD that has led to pulmonary hypertension
327
2D and M-mode evaluation:
| Assessment of the tricuspid valve is best from ?
4 ch parasternal or apical views.
Long-axis left ventricular outflow views of the heart typically and not good enough to assess the tricuspid valve.
It often looks thick when it is not. This is true in the small and large animal.
328
The tricuspid valve may prolapse just as the mistral valve does secondary to stretch of the chordae or minor chordal rupture.
The tricuspid valve may prolapse just as the mistral valve does secondary to stretch of the chordae or minor chordal rupture. Fig 5.77
329
The changes that tricuspid insufficiency creates in the right ventricle and atrium are of great importance when assessing the hemodynamic significance of the leaks.
The changes that tricuspid insufficiency creates in the right ventricle and atrium are of great importance when assessing the hemodynamic significance of the leaks. Fig 5.78, 5.79
330
The normal right ventricle is about 1/3 the size of the LV chamber on the long-axis LV inflow outflow view. Once this relationship changes, ...................should be suspected.
The normal right ventricle is about 1/3 the size of the LV chamber on the long-axis LV inflow outflow view. Once this relationship changes, TR, PI, PH, or all of the above should be suspected.
331
Once diastolic pressures within the RV increase and exceed LV diastolic pressures, ................... motion will be seen.
Once diastolic pressures within the RV increase and exceed LV diastolic pressures, paradoxical septal motion will be seen. The motion may be subtle when pressures are fairly equal or it may be dramatic when RV pressure elevation is severe. Fig 4.103, 5.80, 5.81.
332
If there is concurrent left-sided disease that would elevated LV diastolic pressure, as in mitral or aortic insufficiencies, then paradoxical motion will not be seen until ......................despite a very large RV.
If there is concurrent left-sided disease that would elevated LV diastolic pressure, as in mitral or aortic insufficiencies, then paradoxical motion will not be seen until right-sided pressure exceeds left despite a very large RV.
333
Paradoxial spetal motion is seen with?
Elevated RV diastolic pressure.
334
Right heart dilation because of TR should be differentiated from right ventricular enlargement secondary to ................
Right heart dilation because of TR should be differentiated from right ventricular enlargement secondary to pulmonary hypertension.
335
TR will create volume overload of the RA and RV but will not enlarge the .........
pulmonary artery.
| Fig 5.82
336
Pulmonary hypertension causes the pulmonary artery and RV to dilate and eventual hypertrophy. ............... dilation is seen with pulmonary hypertension when the tricuspids valve becomes incompetent or filling pressure in the RV is high.
Pulmonary hypertension causes the pulmonary artery and RV to dilate and eventual hypertrophy. Right atrial dilation is seen with pulmonary hypertension when the tricuspids valve becomes incompetent or filling pressure in the RV is high.
337
Paradoxial septal motion may be seen with either problem since ............. pressure elevates with both pulmonary hypertension and TR.
Paradoxial septal motion may be seen with either problem since diastolic pressure elevates with both pulmonary hypertension and TR.
338
RV dilation because of TR:
- Little observable RVH
- Normal or small PA size
RV dilation because of TR:
- Little observable RVH
- Normal or small PA size
339
RV dilation because of chronic pulmonary hypertension
- Observable RVH if chronic
- Dilated PA
RV dilation because of chronic pulmonary hypertension
- Observable RVH if chronic
- Dilated PA
340
Evaluating the vena cava as it crosses the diaphragm is a way to subjectively assess .........pressure.
Evaluating the vena cava as it crosses the diaphragm is a way to subjectively assess right atrial pressure.
341
Atrial pressure is estimated to be ...mmHg or less when there is no evidence of right atrial dilation and the vena cava collapses completely with respiration.
Atrial pressure is estimated to be 5 mmHg or less when there is no evidence of right atrial dilation and the vena cava collapses completely with respiration. Fig 5.52
342
The right atrium has an estimated pressure of approximately ..... mmHg if there is right atrial dilation, no evidence of right-sided CHF and the vena cava collapses approximately ..... % with respiration.
The right atrium has an estimated pressure of approximately 10 mmHg if there is right atrial dilation, no evidence of right-sided CHF and the vena cava collapses approximately 50% with respiration.
343
When the vena cava does not collapse with respiration and there is evidence of right-sided CHF, right atrial pressure is estimated at >/= .... mmHg
>/= 15 mmHg
344
Color-flow Doppler imaging:
CF Doppler assessment using TR jet area is less reliable than for MR. However, jets that extend deep into the RA chamber are associated with significant regurgitation.
Fig 5.83
345
Eccentric jets are common and multiple imaging planes should be used, including left apical and cranial views of the tricuspid valve.
Eccentric jets are common and multiple imaging planes should be used, including left apical and cranial views of the tricuspid valve.
346
PISA is challenging at the tricuspid annulus, but the vena contracta has a high correlation with severity in man. A vena contract width of ..... mm in man has a 93% specificity for severe TR and a 89% sensitivity.
PISA is challenging at the tricuspid annulus, but the vena contracta has a high correlation with severity in man. A vena contract width of 7 mm in man has a 93% specificity for severe TR and a 89% sensitivity.
347
Spectral Doppler Imaging can be used to determine the......of the regurgitant jet and estimate pressure of the RV and pulmonary vascular system.
the velocity
348
............... (3) are imaging planes that usually optimize the alignment of the tricuspid regurgitant jet and the Doppler cursor.
Apical 4 ch views, modified apical 4 ch views, and left cranial transverse views are imaging planes that usually optimize the alignment of the tricuspid regurgitant jet and the Doppler cursor. Fig 5.84
349
Remember that the velocity of regurgitant flow is not representative of severity for this or any valvular insufficiency. (fig 5.84).
Remember that the velocity of regurgitant flow is not representative of severity for this or any valvular insufficiency. (fig 5.84).
350
A huge regurgitant volume may often have very low velocity (
A huge regurgitant volume may often have very low velocity (
351
The use of spectral Doppler to evaluate regurgitant fraction and volume is difficult because of significant error in measuring the tricuspid annulus. Sources of this error?
Both the inability to align trans tricuspid flow with the Doppler cursor and the asymmetric shape of the tricuspid annulus are sources of this error.
352
Spectral Doppler is used in the hepatic vessels however and are a reflection of ............... just as ............. venous flow is analyzed on the left side of the heart.
Spectral Doppler is used in the hepatic vessels however and are a reflection of right atrial pressure just as pulmonary venous flow is analyzed on the left side of the heart.
353
Systolic reversal of flow in the hepatic vein is.... % sensitive for severe regurgitation.
80
354
............... may also affect hepatic flow.
Respiratory variation, preload, and impaire right ventricular compliance and relaxation may also affect hepatic flow.
355
Spectral Doppler and TR:
RF and RV have much error
Use for RV pressure calculation
RF and RV have much error
| Use for RV pressure calculation
356
Systolic flow reversal in hepatic veins is very specific for .........
Systolic flow reversal in hepatic veins is very specific for severe TR
357
Overall Assessment of TR:
The evaluation of TR is more error prone than the assessment of MR.
Table 5.6 lists the parameters that help define the severity of TR in man. These parameters, set by the Society of Echo task Force on the Assessment of Native valvular regurgitation in man, include analysis of ventricular and atrial size, jet area, vena contracta, PISA, jet density, regurgitant profile shape, and hepatic vein flow.
The more parameters that are in agreement with regard to severity, the more reliable the assessment will be.
358
Pulmonary regurgitation:
Small amounts of pulmonary insufficiency are also a normal finding in most species. Generally non physiologic pulmonary insufficiency occurs secondary to ...........?
Small amounts of pulmonary insufficiency are also a normal finding in most species. Generally non physiologic pulmonary insufficiency occurs secondary to infective lesions or in association with other disease such as PDA, pulmonic stenosis, PH, or significant volume overload f the right side of the heart where the pulmonary annulus may be dilated.
359
Pulmonary insufficiency does not have the history of evaluation that insufficiens at the other valves do. Rarely is pulmonary insufficiency significant enough to be of concern. Severe pulmonary insufficiency may be seen with ........ and after...............
Severe pulmonary insufficiency may be seen with valvular dysplasia and after interventional procedure.
360
Although trivial to mild pulmonary regurgitation is a common finding in normal animals, it may become severe when pulmonary hypertension is present and even then is rarely life threatening.
Although trivial to mild pulmonary regurgitation is a common finding in normal animals, it may become severe when pulmonary hypertension is present and even then is rarely life threatening.
361
2D evaluation:
2D echo can be used to define the underlying cause of insufficiency. Dilation of the pulmonary artery is consistent with the diagnosis of ..............., in the absence of .................
Dilation of the pulmonary artery is consistent with the diagnosis of pulmonary hypertension, in the absence of shunts.
362
In the absence of pulmonary hypertension and significant TR, dilation of the ....... is a sign that the pulmonary regurgitation is significant.
In the absence of pulmonary hypertension and significant TR, dilation of the RV is a sign that the pulmonary regurgitation is significant.
363
Jet length of pulmonary regurgitation is not very specific for severity because small changes in driving .......... it.
Jet length of pulmonary regurgitation is not very specific for severity because small changes in driving pressure affect it.
364
jet area correlates better with severity of regurgitation but is still extremely variable with much overlap between the grades of severity.
jet area correlates better with severity of regurgitation but is still extremely variable with much overlap between the grades of severity.
365
Vena contracta has not been studied and validated for pulmonary regurgitation.
Vena contracta has not been studied and validated for pulmonary regurgitation.
366
Thera are no reliable methods to quantify pulmonary regurgitation with CW Doppler. Short pressure half-times are seen severe regurgitation as they are with aortic regurgitation, but in the presence of low pulmonary artery diastolic pressure, rapid deceleration may be seen without significant regurgitation.
Short pressure half-times are seen severe regurgitation as they are with aortic regurgitation, but in the presence of low pulmonary artery diastolic pressure, rapid deceleration may be seen without significant regurgitation.
367
Use spectral Doppler to calculate diastolic PA pressure
No accurate method to assess severity of PR.
Use spectral Doppler to calculate diastolic PA pressure
No accurate method to assess severity of PR.
368
Using spectral Doppler to determine end diastolic pulmonary artery pressure is frequently done.
Using spectral Doppler to determine end diastolic pulmonary artery pressure is frequently done.
This is discussed more in Chapter 4, but peak early diastolic velocity represents mean pulmonary artery pressure, while end diastolic pressure gradient represents pulmonary end diastolic pressure. Fig 4.90
369
Spectral Doppler imaging:
Quantification of regurgitant fraction and volume is inaccurate since the pulmonary artery ............ changes throughout the cardiac cycle, and it has not been validated.
Quantification of regurgitant fraction and volume is inaccurate since the pulmonary artery diameter changes throughout the cardiac cycle, and it has not been validated.
370
Spectral Doppler imaging:
Use the pulmonary artery diameter early in systole, 2 of 3 frames after the beginning of the QRS complex, if regurgitant fractions are measured using a combination of spectral and 2D dimensional echo.
Use the pulmonary artery diameter early in systole, 2 of 3 frames after the beginning of the QRS complex, if regurgitant fractions are measured using a combination of spectral and 2D dimensional echo.
371
Overall Assessment of pulmonary regurgitation:
There are no well-established parameter to evaluate the severity of pulmonary regurgitation. Using multiple parameters is helpful and is clinically useful if they agree.
There are no well-established parameter to evaluate the severity of pulmonary regurgitation. Using multiple parameters is helpful and is clinically useful if they agree. The
372
The society of echocardiography task force on the assessment of native valvular regurgitation in man had defined several parameters and their relationship to severity of pulmonary insufficiency.
These are listed i Table 5.7
373
Endocarditis:
The aortic valve is the most common site of vegetative endocarditis in the horse with the mitral and tricuspid valves following in frequency of occurrence. What about in dogs?
In the dog, the mitral valve is the most susceptible valve for vegetative growth followed by the aortic valve. The pulmonary and tricuspid valves are rarely affected in the dog. Fig 5.55-5.57 and 5.85.
374
In man, the predisposition for development of vegetative growth seems to be related to pressure on the valves while they are closed. There is a theory that bacterial endocarditits develops secondary to high pressure flow on the respective valves when they are open. Lesions are seen more often on the ........... side of aortic valves and on the .......... side of mitral valves.
Lesions are seen more often on the ventricular side of aortic valves and on the atrial side of mitral valves.
375
Most dogs are older and are ............. breeds. There are no documented predisposing factors for the development of bacterial endocarditis except for the presence of.................?
Most dogs are older and are medium to large breeds. There are no documented predisposing factors for the development of bacterial endocarditis except for the presence of subaortic stenosis.
376
The lesions of bacterial endocarditis are usually smooth and nodular when small but become irregular as their grow. Large lesions are .............?
The lesions of bacterial endocarditis are usually smooth and nodular when small but become irregular as their grow. large lesions are echogenic, heterogenous, irregular, pedunculated, and often mobile. .
377
Lage vegetative lesions often contain a heterogenous appearance with ........echic areas within the lesion. Fig 5.87
Lage vegetative lesions often contain a heterogenous appearance with hypoechic areas within the lesion. Fig 5.87
378
When the growth involves the AV valves, they may extend onto the chordae tendineae. The lesions may cause valvular insufficiency when the growth prevents proper closure of the cusps. Even larger lesions however may only create small insufficiencies.
When the growth involves the AV valves, they may extend onto the chordae tendineae. The lesions may cause valvular insufficiency when the growth prevents proper closure of the cusps. Even larger lesions however may only create small insufficiencies.
379
It is almost impossible to differentiate between degenerative and vegetative lesion on mitral valves, and this is the most common cause of false positives.
It is almost impossible to differentiate between degenerative and vegetative lesion on mitral valves, and this is the most common cause of false positives.
380
The clinical picture and history must be used in conjunction with echo findings. The lesions typically will get somewhat smaller as the infective process resolves and only scar tissue remains. Can they completely disappear?
They will never completely disappear however, and insufficiencies when present, often remain and may even become worse.
381
Although valve lesions most commonly cause insufficiencies, ............. to flow may also occur.
Although valve lesions most commonly cause insufficiencies, obstruction to flow may also occur.
This can be determined with Doppler echo and applying the Bernoulli equation to the velocity of inflow or outflow through the affected valve.
382
Endocarditis: Remember that when insufficiency and obstruction are both present, flow velocity will be elevated secondary to .......
both problems.
383
Endocarditis lesions never disappear
May become smaller as they scar
Insufficiency or stenosis persists
Endocarditis lesions never disappear
May become smaller as they scar
Insufficiency or stenosis persists
384
Cardiac chamber sizes will be normal unless .....?
Unless hemodynamically significant insufficiencies develop
385
Acute endocarditis results in rapid development of heart failure whereas chronic endocarditis may take months to progress before signs of failure occur.
Acute endocarditis results in rapid development of heart failure whereas chronic endocarditis may take months to progress before signs of failure occur.
386
Chamber enlargement will be accompanied by compensatory hypertrophy, increased cardiac function, and excessive wall motion secondary to the volume overload unless myocardial failure is present.
Chamber enlargement will be accompanied by compensatory hypertrophy, increased cardiac function, and excessive wall motion secondary to the volume overload unless myocardial failure is present.
387
Tricuspid and pulmonary insufficiencies create right-sided volume overload while mitral and aortic insufficiencies will cause left-sided changes.
Tricuspid and pulmonary insufficiencies create right-sided volume overload while mitral and aortic insufficiencies will cause left-sided changes.
388
The hemodynamic effects on the heart with chronic endocarditis are the same as those seen with chronic degenerative lesions resulting in insufficiency.
The hemodynamic effects on the heart with chronic endocarditis are the same as those seen with chronic degenerative lesions resulting in insufficiency.
389
Endocarditis may cause abscesses and secondary rupture of the ventricular, atrial, or great vessel walls adjacent to the infective lesion. Other complications of infective endocarditis include?
Myocardial infarction secondary to embolism into the coronary arteries, pulmonary thromboeembolism secondary to right-sided lesions, or congestive heart failure secondary to significant valvular insufficiency.
390
Studies in man have shown that aortic valve endocarditis .......... less often than mitral valve endocarditis, but the aortic valve lesions are more often associated with .........formation.
Studies in man have shown that aortic valve endocarditis embolizes less often than mitral valve endocarditis embolizes less often than mitral valve endocarditis but the aortic valve lesions are more often associated with abscess formation.
391
Myocardial infarction will create localized or widespread myocardial dysfunction visible on real-time images. M-mode images obtained over the infarcted area show hypokinetic or akinetic myocardium.
Myocardial infarction will create localized or widespread myocardial dysfunction visible on real-time images. M-mode images obtained over the infarcted area show hypokinetic or akinetic myocardium.
392
Lesions approaching the .......cm size are associated with embolization and high complication and mortality rates.
Lesions approaching the 1 cm size are associated with embolization and high complication and mortality rates.
393
Many cases of vegetative endocarditis are undected until necropsy examination or until an echocardiogram is obtained for other unrelated reasons. These lesions are small and create no significant hemodynamic alterations.
Many cases of vegetative endocarditis are undected until necropsy examination or until an echocardiogram is obtained for other unrelated reasons. These lesions are small and create no significant hemodynamic alterations.
