Stenotic lesions

Question 1

Outflow obstructions created by aortic or pulmonary stenosis create excessive work for the ventricles and lead to concentric hypertrophy of the respective chamber. The hypertrophy develops in order to normalize ………………..

Answer 1

The hypertrophy develops in order to normalize systolic wall stress

Question 2

Pulmonary stenosis leads to hypertrophy of both the right ventricular wall and the septum, while aortic stenosis leads to increased free wall and septal thicknesses.

Answer 2

Pulmonary stenosis leads to hypertrophy of both the right ventricular wall and the septum, while aortic stenosis leads to increased free wall and septal thicknesses.

The chamber size may be smaller than normal secondary to the hypertrophy.

Question 3

Mild obstructions to outflow may not result in any visible changes within the heart, and Doppler studies are necessary to confirm the presence of mild stenosis on either side of the heart.

Answer 3

Mild obstructions to outflow may not result in any visible changes within the heart, and Doppler studies are necessary to confirm the presence of mild stenosis on either side of the heart.

Question 4

Inflow obstruction secondary to mitral and tricuspid stenosis is much less common. The resistance to filling of the ventricular chambers results in…?

Answer 4

Dilated atria.

The AV valves are often incompetent as well.

Question 5

Obstructions can also exist within the atrial chambers and will create the same hemodynamic problems as valvular stenosis.

Answer 5

Obstructions can also exist within the atrial chambers and will create the same hemodynamic problems as valvular stenosis.

Question 6

The many varying morphological manifestations of these stenotic lesions are presented here. An algorithm has been created that provides the echocardiography with specific parameters that logically lead to a diagnosis and assessment of severity in animals with isolated congenital heart defects.

Answer 6

The many varying morphological manifestations of these stenotic lesions are presented here. An algorithm has been created that provides the echocardiography with specific parameters that logically lead to a diagnosis and assessment of severity in animals with isolated congenital heart defects. Fig 10.1

This algorithm works well when the congenital heart disease is not complicated with other concurrent cardiac problems such as valvular insufficiency, pulmonary hypertension, or combinations or stenotic or shunt lesions.

Question 7

Outflow obstructions:
Subaortic stenosis is a common defect in large breed dogs. Tidholm found that the incidence of aortic stenosis in these dogs was 35%, and the occurrence of pulmonic stenosis was 20% in a retrospective study of 151 dogs.

Answer 7

Subaortic stenosis is a common defect in large breed dogs. Tidholm found that the incidence of aortic stenosis in these dogs was 35%, and the occurrence of pulmonic stenosis was 20% in a retrospective study of 151 dogs.

Question 8

Which breeds are among the breeds most susceptible to aortic stenosis?

Answer 8

The Golden retriver
Rottweiler
Boxer
German Shepherd
Newfoundland

Question 9

Aortic stenosis is rare in the cat , but features of the disease are similar to those found in dogs and man.

Answer 9

Aortic stenosis is rare in the cat , but features of the disease are similar to those found in dogs and man.

Question 10

How can aortic stenosis manifest itself?

Answer 10

As suprvalvular, valvular, or subvalvular

Although supravalvular stenosis is extremely rare, it is reported in the cat and was accompanied by a valvular aortic stenosis.

Question 11

Valvular aortic stenosis is also rarely seen as a single entity but does occur in conjunction with the most common form of stenosis, the subvalvular obstruction, which is seen in > …… % of dogs with aortic stenosis.

Answer 11

Valvular aortic stenosis is also rarely seen as a single entity but does occur in conjunction with the most common form of stenosis, the subvalvular obstruction, which is seen in > 90% of dogs with aortic stenosis.

Question 12

Which are the main manifestations of subaortic stenosis?

Answer 12

A narrowed LV outflow tract secondary to nodules or a ridge of fibrous tissue, or an aortic valve area secondary to commissural fusion of the cusps, concentric LV hypertrophy, and increased blood flow velocity through the stenotic area.

Question 13

Subvalvular aortic stenosis— features of the obstruction:

Answer 13

Fibrous ring or nodules are proximal to the aortic valve

• –Ring may pul mitral valve up to outflow tract
• –Small fibrous tissue may not be seen
• –If a dynamic component is present, the band usually extends from it

Rarely the anterior mitral valve is stiff and creates a tunnel

Less commonly there may be hypoplasia of the annulus

Question 14

A complete echo exam in animals with suspected AS includes?

Answer 14

All standard right- and left-iaging planes in order to optimize images of the outflow tract and aorta. The echo should provide info about mitral valve cusp anatomy and motion, visualization of a normal left coronary artery, poststenotic dilation of the ascending aorta, narrowing of the outflow tract, and accurate flow velocity within the outflow tract and aorta.

Right parasternal imaging planes of the outflow tract should identify the type of lesion, provide insight to mitral and aortic valve motion, and is used for color-flow analysis.

Transverse views from the right and left help assess the size of the outflow tract at the level of the obstruction relative to the aortic root and are often best at defining aortic valve motion.

Apical and subcostal views not only provide structural information but are also used to obtain flow velocity and pressure gradients.

Question 15

See echo algorithm for the evaluation of canine congenital heart disease. Fig 10-1

Answer 15

See echo algorithm for the evaluation of canine congenital heart disease. Fig 10-1

Question 16

Make sure to screen for other concurrent congenital defects. Pulmonic stenosis, PDA, VSD, and MD have all been reported to occur with AS.

Answer 16

Make sure to screen for other concurrent congenital defects. Pulmonic stenosis, PDA, VSD, and MD have all been reported to occur with AS.

Question 17

Echo evaluation of aortic stenosis should include:

Answer 17

• Mitral valve morphology
• Mitral valve motion
• Aortic valve anatomy
• Determine the presence of a normal left coronary artery
• Identify a poststenotic dilation
• LV outflow tract morphology
• Flow velocity of the outflow tract and aorta.

Question 18

2D evaluation of aortic stenosis:
Class 1 and 2 LV outflow obstruction is discrete and fixed. A fibrous ridge of tissue (class …) or nodules (class …) are present within the LV outflow tract. The fibrous band of tissue may be small and encircle the outflow tract with very little protrusion into the lumen of the tract or it may be extensive, creating a small …………… for blood flow.

Answer 18

Class 1 and 2 LV outflow obstruction is discrete and fixed. A fibrous ridge of tissue (class 2) or nodules (class 1) are present within the LV outflow tract. The fibrous band of tissue may be small and encircle the outflow tract with very little protrusion into the lumen of the tract or it may be extensive, creating a small orifice for blood flow.

Question 19

AS: Where will the fibrous rings be seen?

Answer 19

May be seen just proximal to the aortic valve on right parasternal LV outflow and transverse views.
Small fibrous bands may not be visualized.
Fig 10.2, 10.3

Question 20

AS: Nodules on the ventricular side of the aortic valve are also described and fall into this category of obstruction.

Answer 20

Nodules on the ventricular side of the aortic valve are also described and fall into this category of obstruction.

Question 21

The development of the subvalvular obstruction is progressive as the animal grows, and although eco exams may bot show any abnormality of the outflow tract in young dogs, this may not be the case when the dog is older.

Answer 21

The development of the subvalvular obstruction is progressive as the animal grows, and although eco exams may bot show any abnormality of the outflow tract in young dogs, this may not be the case when the dog is older.

Question 22

AS: Fan the transducer in and out of the long-axis and transverse planes in order to bring the obstructive band into view. The ring is usually close to the aortic valve annulus, but it may be seen further down into the outflow tract, several mm away from the annulus. Fig 10.4

Answer 22

Fan the transducer in and out of the long-axis and transverse planes in order to bring the obstructive band into view. The ring is usually close to the aortic valve annulus, but it may be seen further down into the outflow tract, several mm away from the annulus. Fig 10.4

Question 23

AS: The band of tissue may be reflected onto the mitral annulus, and this can be appreciated on 2D images. Features of the mitral valve?

Answer 23

The mitral valve leaflet is pulled up toward the outflow tract before extending into the ventricular chamber instead of extending straight out from the posterior aortic wall as it normally would = a sign that a ring is present even when a fibrous band is not apparent. Fig 10.5

Question 24

A feature that is thought to differentiate congenital fixed subaortic stenosis from dynamic obstructive hypertophic cardiomyopathy in the cat is?

Answer 24

The absence of systolic anterior mitral valve motion in cats with AS.

Question 25

Subaortic stenosis may also manifest itself as a dynamic obstruction involving hypertrophy or a muscular ridge at the base of the interventricular septum. Where is this best seen?

Answer 25

On right or left parasternal long-axis LV outflow views.

The muscle thickens into the outflow tract, and during contraction the obstruction becomes even greater. Fig 10.6

The degree of obstruction and variations in flow velocity can occur from beat to beat depending upon loading conditions, heart rate, and sympathetic stimulation. Dynamic and fixed obstructions may occur together, and typically, the fibrous ring extends from the base of the septum at its maximum extension into the outflow tract. Fig 10.7

Question 26

Class III subaortic stenosis involves a ……………… of stenosis.

Answer 26

a tunnel type

Question 27

AS: Class III: The mitral valve is stiff and forms the posterior wall of an obstructive subvalvular tunnel while the septum forms the anterior wall of the tunnel. Fig 10.8

Answer 27

The mitral valve is stiff and forms the posterior wall of an obstructive subvalvular tunnel while the septum forms the anterior wall of the tunnel. The metal valve may be dysplastic. A fibrous band may be present but is often difficult to see in these hearts. The width of the tunnel is much less than the width of the aorta. Fig 10.8

Question 28

AS: The annulus of the aorta may also be affected. A small diameter at the level of the leaflets is seen when hypoplasia of the aorta exists.

Answer 28

The annulus of the aorta may also be affected. A small diameter at the level of the leaflets is seen when hypoplasia of the aorta exists. This form of stenosis seems to occur frequently in Boxers. There may or may not be dynamic obstruction or a subvalvular membrane with this type of stenosis. Fig 10.8b, Fig 10.9.

Question 29

Partial fusion of the cusps can exist and may be seen on long-or short-axis views of the aortic valves. Fig 10-10. Asymmetric opening of the cusps is especially easy to see on transverse views of the heart base. This is difficult to identify on M-mode images since reduced flow through the valves will cause incomplete opening of the valve on M-mode images. Stiff immobile leaflets without fusion may be seen with any of the manifestations of aortic stenosis especially in Boxers and cats. Fig 10.11

Answer 29

Partial fusion of the cusps can exist and may be seen on long-or short-axis views of the aortic valves. Fig 10-10. Asymmetric opening of the cusps is especially easy to see on transverse views of the heart base. This is difficult to identify on M-mode images since reduced flow through the valves will cause incomplete opening of the valve on M-mode images. Stiff immobile leaflets without fusion may be seen with any of the manifestations of aortic stenosis especially in Boxers and cats. Fig 10.11

Question 30

The poststenotic dilation observed with aortic stenosis may be seen on right parasternal long-axis LV outflow views of the heart, but it is best seen on …………………… and aorta.

Answer 30

The poststenotic dilation observed with aortic stenosis may be seen on right parasternal long-axis LV outflow views of the heart, but it is best seen on left parasternal long-axis images of the LV outflow tract and aorta. Fig 10.12

Question 31

The walls of the aorta diverge away from each other distal to the aortic valves. The sinus of Valsalva is often dilated, and sometimes one or both coronary artery ostia may be dilated as well.

Answer 31

The walls of the aorta diverge away from each other distal to the aortic valves. The sinus of Valsalva is often dilated, and sometimes one or both coronary artery ostia may be dilated as well.

Question 32

Comparison of the LV outflow tract cross-sectional area to the aortic root cross-sectional
area can provide additional information regarding the severity of the subaortic stenosis especially when flow velocity is affected by factors other than the stenosis.

Answer 32

Comparison of the LV outflow tract cross-sectional area to the aortic root cross-sectional
area can provide additional information regarding the severity of the subaortic stenosis especially when flow velocity is affected by factors other than the stenosis.

Question 33

LV outflow tract cross-sectional area to the aortic root cross-sectional
area: Using a right parasternal transverse view of the left ventricular outflow tract at the level of the obstruction and of the aorta at the level of the sinus of Valsalva during diastole, trace the cross-sectional area along the inner edge of the myocardium for each. Fig 10.13. This ratio predicted severity of the subaortic stenosis more than the degree of hypertrophy. Normal canine hearts have an LVOT:AO ratio of ……….. Moderate and severe subaortic stenosis could be predicted by statistically significant differences in this ratio from normal and between each other. Ratios of > 0.5, 0.3-0.5 and

Answer 33

Using a right parasternal transverse view of the left ventricular outflow tract at the level of the obstruction and of the aorta at the level of the sinus of Valsalva during diastole, trace the cross-sectional area along the inner edge of the myocardium for each. Fig 10.13. This ratio predicted severity of the subaortic stenosis more than the degree of hypertrophy. Normal canine hearts have an LVOT:AO ratio of 0.509-0.737. Moderate and severe subaortic stenosis could be predicted by statistically significant differences in this ratio from normal and between each other. Ratios of > 0.5, 0.3-0.5 and

Question 34

Cross-sectional area of stenosis:
Area at transverse obstrcution
Area at sinus of Valsalva

Normal LVOT:AO = 0.509-0.737

0. 3-5 = ………. severity
1. 5 = ……….. stenosis

Answer 34

Cross-sectional area of stenosis:
Area at transverse obstrcution
Area at sinus of Valsalva

Normal LVOT:AO = 0.509-0.737

0. 3-5 = moderate severity
1. 5 = mild stenosis

Useful in low or high stroke volume settings
Overlap between normal and mild

Question 35

Effective orifice area is calculated in man to assess the severity of valvular aortic stenosis. Bélanger et al found a correlation between calculated effective outflow tract area and pressure gradient across the outflow tract in dogs. The continuity principles states that …………..

Answer 35

Bélanger et al found a correlation between calculated effective outflow tract area and pressure gradient across the outflow tract in dogs. The continuity principles states that barring any shunts or insufficiencies, volumes moving through the 2 different places in the heart, in this case, the left ventricular outflow tract and the aortic root, must be equal as shown in Equation 10.1

Question 36

Using the principles in equation, we can rearrange the equation to calculate stenotic area size and effective orifice area (EOA). Equation 10.2. This works well in man, where the stenosis is typically subvalvular,In dogs, the obstruction is usually subvalvular and it is not possible to record tract and aortic velocity separately. Since flow velocity integrals (FVI) are proportionate to volume flowing through the vessel, Bélanger used the RVOT FVI multiplied by CSA of the pulmonary valve to represent normal stroke volume and compared it to FVI multipled by CSA of the LVOT in order to determine the effective area of the stenosis. Equation 10.3 and 10.4

Answer 36

Using the principles in equation, we can rearrange the equation to calculate stenotic area size and effective orifice area (EOA). Equation 10.2. This works well in man, where the stenosis is typically subvalvular,In dogs, the obstruction is usually subvalvular and it is not possible to record tract and aortic velocity separately. Since flow velocity integrals (FVI) are proportionate to volume flowing through the vessel, Bélanger used the RVOT FVI multiplied by CSA of the pulmonary valve to represent normal stroke volume and compared it to FVI multipled by CSA of the LVOT in order to determine the effective area of the stenosis. Equation 10.3 and 10.4
se mera se 486.

As in the ratio of LVOT to AO, EOA cannot differentiate between mild stenosis and normal LVOT. This may be of use in the evaluation of SAS in dogs with poor systolic function or in dogs that have been put on negative inotropic drugs where pressure gradients will underestimate the significance of the stenosis or in patients that have undergone interventional techniques that result in valvular regurgitation at the aortic valve where pressure gradients will overestimate the severity of the stenosis.

Question 37

AS: Focal areas of increased echogenicity are indicative of….?

Answer 37

Myocardial fibrosis
This is typically seen in more severely affected animals, and myocardial function may be compromised if the fibrosis is extensive.

Question 38

AS: The …………..and the ………… are common sites for fibrosis.

Answer 38

The papillary muscles and the base of the ventricular septum are common sites for fibrosis. Fig 10. 14
The increased echogenicity is easily seen on transverse and long-axis views.

Question 39

AS: The degree of hypertrophy in human patients with hypertension is variable and is greatly dependent upon the …

Answer 39

The duration, frequency, and severity of hypertension during daily activities.
Some animals have very little if any obstruction at rest but have dramatic gradients when excites as might be expected during some echo exams.

Question 40

AS: M-mode
Measurement of LV free wall and septum will reveal the presence of hypertrophy. The hypertrophic response to increased pressure occurs in order to maintain normal wall stress and systolic function.

Answer 40

Measurement of LV free wall and septum will reveal the presence of hypertrophy. The hypertrophic response to increased pressure occurs in order to maintain normal wall stress and systolic function.

Question 41

AS: M-mode: The ratios of ventricular septum to LV diastolic chamber size in diastole and LV wall to LV diastolic chamber size are increased, and a direct correlation between the degree of hypertrophy and the severity of the stenosis has been documented in Boxers. The ratio of septum to LV chamber size in a normal canine heart is?

Answer 41

0.22-0.34

AS: The degree of concentric hypertrophy does not always correlate well with the severity of outflow obstruction and pressure gradient in aortic stenosis in other breeds.

Question 42

AS: Mild hypertrophy is sometimes seen with Doppler documented moderate to severe obstructions; therefore hypertrophy cannot be used as an indicator of severity.

Answer 42

Mild hypertrophy is sometimes seen with Doppler documented moderate to severe obstructions; therefore hypertrophy cannot be used as an indicator of severity.

Question 43

AS: An inadequate degree of of hypertrophy in response to the obstruction can result in early development of systolic myocardial failure and CHF.

Answer 43

An inadequate degree of of hypertrophy in response to the obstruction can result in early development of systolic myocardial failure and CHF.

In man, patients with significant hypertrophy secondary to their stenosis have excellent systolic function but are probe to decreases myocardial perfusion leading to ischemia, fibrosis, and arrhythmia.

Question 44

Degree of LVH in SAS does not necessarily correlate well with severity

Answer 44

Degree of LVH in SAS does not necessarily correlate well with severity

Question 45

LA enlargement is sometimes seen in dogs and cats with AS. There are several potential causes for atrial dilation with subaortic stenosis. Such as?

Answer 45

Systolic anterior motion of the mitral valve invariably causes the valve to leak.
Mitral valve involvement with the subvalvular fibrous band of tissue may lead to insufficiency secondary to structural or functional abnormalities. Some degree of mitral insufficiency is seen in many dogs with aortic stenosis.
There may also be diastolic dysfunction leading to a dilated LA as the failure progresses.

Question 46

Assessment of function:
Young animals with AS have high fractional shortening, and velocity of circumferential shortening is increased. Ejection time is also typically normal. Mitral annular motion (MAM), a parameter of systolic function (ch 4) is ………………. in Boxer dogs with severe subaortic stenosis, although in another study consisting of a variety of breeds and sizes, it appeared that MAM in SAS heart was not different from normal hearts.

Answer 46

Young animals with AS have high fractional shortening, and velocity of circumferential shortening is increased. Ejection time is also typically normal. Mitral annular motion (MAM), a parameter of systolic function (ch 4) is decreased in Boxer dogs with severe subaortic stenosis, although in another study consisting of a variety of breeds and sizes, it appeared that MAM in SAS heart was not different from normal hearts.

Question 47

Indexed MAM is significantly different between normal hearts and between hearts in Boxers with mild, moderate, and severe AS. Boxer dogs with severe subaortic stenosis, pressure gradient > 80 mmHg, had indexed MAM of 0.79-0.99 (normal = 0.88-2.0 cm)

Answer 47

Indexed MAM is significantly different between normal hearts and between hearts in Boxers with mild, moderate, and severe AS. Boxer dogs with severe subaortic stenosis, pressure gradient > 80 mmHg, had indexed MAM of 0.79-0.99 (normal = 0.88-2.0 cm)

Question 48

MAM depressed in severe SAS in Boxers:
Normal indexed MAM: ………. cm

Severe SAS (PG>80) -indexed MAM 0.79-0.99

Answer 48

Normal indexed MAM: 0.88-2.0 cm

Severe SAS (PG>80) -indexed MAM …………

Question 49

AS: …………….. failure has been documented in Boxers (34%).

Answer 49

Diastolic failure has been documented in Boxers (34%).

Question 50

A major contributor to clinical signs of exercise intolerance, lethargy, and dyspnea in people in the presence of diastolic dysfunction. The ……………… in aortic stenosis possibly leads to impaired diastolic function.

Answer 50

The compensatory LV hypertrophy in aortic stenosis possibly leads to impaired diastolic function.

Question 51

Grades of diastolic function: see ch 4 table 4.3

Answer 51

Grades of diastolic function: see ch 4 table 4.3

Question 52

………………….. flow is the most common manifestation of diastolic impairment och echo studies in dogs, and was seen in 11 out 23 Boxers with mild to severe outflow obstruction, and of these dogs, 58% had exercise intolerance and syncopal episodes.

Answer 52

Pseudonormal transmitral flow is the most common manifestation of diastolic impairment och echo studies in dogs, and was seen in 11 out 23 Boxers with mild to severe outflow obstruction, and of these dogs, 58% had exercise intolerance and syncopal episodes.
This pattern of diastolic dysfunction was seen in 4 dogs with mild obstruction, but 2 also had pulmonic stenosis that will cause septal hypertrophy and possibly poor LV filling (preload). 2 had moderate AI that can affect LV diastolic pressure.
Delayed relaxation was seen nearly as frequently with 10 of the 23 dogs having IVRT periods greater than 69 msec. Only 2 of 23 Boxers with AS had a restrictive pattern of LV filling.

Question 53

AS: Dynamic outflow obstruction displays the same type of M-mode echo findings as those seen with obstruction secondary to……………..

Answer 53

Dynamic outflow obstruction displays the same type of M-mode echo findings as those seen with obstruction secondary to HCM. Systolic anterior motion of the mitral valve confirms the presence of high velocity flow within the outflow tract.

Question 54

AS: As in hypertrophic obstructive cardiomyopathy, the degree and duration of SAM is indicative of how severe the gradient is. Longer apposition to the septum is associated with more severe obstruction.

Answer 54

As in hypertrophic obstructive cardiomyopathy, the degree and duration of SAM is indicative of how severe the gradient is. Longer apposition to the septum is associated with more severe obstruction.

Question 55

…………… closure of the aortic valve is seen in almost half of dogs with AS because flow is interrupted secondary to the obstruction. Systolic closure is seen with both discrete and dynamic aortic stenosis. Fig 10.15.

Answer 55

Early systolic closure of the aortic valve is seen in almost half of dogs with AS because flow is interrupted secondary to the obstruction. Systolic closure is seen with both discrete and dynamic aortic stenosis. Fig 10.15.

Question 56

AS: Color-flow Doppler evaluation:
Valvular insufficiencies will add volume to the concentrically hypertrophied heart. When quantitative assessment of the LV in a young animal reveals increased LV diastolic chamber size despite hypertrophy of the wall and septum and a discrete aortic stenosis is clearly apparent, then significant valvular insufficiency or a shunt of some type is typically present (fig 10.8, 10.9)

Answer 56

Valvular insufficiencies will add volume to the concentrically hypertrophied heart. When quantitative assessment of the LV in a young animal reveals increased LV diastolic chamber size despite hypertrophy of the wall and septum and a discrete aortic stenosis is clearly apparent, then significant valvular insufficiency or a shunt of some type is typically present (fig 10.8, 10.9)

Question 57

AS: more eccentric pattern of enlargement may be seen in older dogs. Why?

Answer 57

Myocardial failure in older dogs may affect the ability of the heart to hypertrophy adequately, and a more eccentric pattern of enlargement may be seen in these dogs.

Question 58

Both mitral and aortic insufficiencies are seen with subaortic stenosis. Mitral insufficiency may be secondary to?

Answer 58

Mitral valve dysplasia that primarily affects the chordae tendinaes, some of which may attach to the subvalvular ring or secondary to systolic anterior mitral valve motion.

Question 59

Aortic insufficiency has been reported in anywhere from half to more than 3/4 of dogs with aortic stenosis.

Answer 59

Aortic insufficiency has been reported in anywhere from half to more than 3/4 of dogs with aortic stenosis. Fig 10.16

Question 60

Aortic insufficiency may cause diastolic ……… of the septal mitral valve leaflet.

Answer 60

Aortic insufficiency may cause diastolic flutter of the septal mitral valve leaflet.

Question 61

Infective endocarditis is a complication that may develop as the animal becomes older and was seen in approximately 5 % of dogs with subaortic stenoisis in one study.

Answer 61

Infective endocarditis is a complication that may develop as the animal becomes older and was seen in approximately 5 % of dogs with subaortic stenoisis in one study.

Question 62

CHF may develop because of significant aortic or mitral insufficiency that develops secondary to infective endocarditis. CHF is otherwise uncommon in dogs with subaortic stenosis.

Answer 62

CHF may develop because of significant aortic or mitral insufficiency that develops secondary to infective endocarditis. CHF is otherwise uncommon in dogs with subaortic stenosis.

Question 63

Aortic regurgitation seen in …?

Answer 63

50-75% of dogs with SAS

Question 64

AS: Color-flow Doppler identifies the turbulent and high velocity blood flow through the outflow tract and aorta. The aliased color signal helps identify the length and location of a subvalvular obstruction.

Answer 64

Color-flow Doppler identifies the turbulent and high velocity blood flow through the outflow tract and aorta. The aliased color signal helps identify the length and location of a subvalvular obstruction. Fig 10.17, 10.18, 10.19

Question 65

AS: Color-flow Doppler if available should also be used to help align the spectral Doppler cursor. Although color-flow Doppler is not necessary in order to evaluate the severity of the stenosis, it helot rapidly identify other complicating factors such as insufficiencies and concurrent shunts.

Answer 65

Color-flow Doppler if available should also be used to help align the spectral Doppler cursor. Although color-flow Doppler is not necessary in order to evaluate the severity of the stenosis, it helot rapidly identify other complicating factors such as insufficiencies and concurrent shunts.

Question 66

AS: Spectral Doppler evaluation: High velocity flow obtained through the LV outflow tract or aorta is the defining feature of obstruction to outflow. The correlation between pressure gradients obtained from Doppler examination of outflow tract flow and catheter-derived pressure gradients is high.

Answer 66

High velocity flow obtained through the LV outflow tract or aorta is the defining feature of obstruction to outflow. The correlation between pressure gradients obtained from Doppler examination of outflow tract flow and catheter-derived pressure gradients is high.

Question 67

AS: The principle of conservation of mass states that in a closed system, velocity must ……….. as flow moves through a discrete narrower area.

Answer 67

The principle of conservation of mass states that in a closed system, velocity must increase as flow moves through a discrete narrower area.

Question 68

AS: The modified Bernoulli equation can be applied (se ch 4) to the peak velocity, and a pressure gradient is calculated.

Answer 68

The modified Bernoulli equation can be applied (se ch 4) to the peak velocity, and a pressure gradient is calculated.

Question 69

Which views should be used to record spectral Doppler flow through the stenotic region and aorta?

Answer 69

Left and right parasternal apical 5-ch views and the subcostal 5-ch view of the heart.

Question 70

Studies have shown that the optimal window for recording the flow velocities in aortic stenosis whether using a dedicated Doppler probe or an imaging transducer is…?

Answer 70

The subcostal window.

Recommended when examining dogs with suspected subaortic stenosis as parasternal apical view may not provide appropriate alignment with the stenosis and its maximal velocity. Maximal velocities were underestimated by 26% when flow was interrogated on left apical windows as compared to subcostal windows.

Question 71

AS: While the subcostal 5-ch view yields the highest flow velocities in hearts with SAS, flow velocities and pressure gradients obtained from the left parasternal apical view and those obtained from an apex up right parasternal image are not significantly different in normal dogs and cats.

Answer 71

While the subcostal 5-ch view yields the highest flow velocities in hearts with SAS, flow velocities and pressure gradients obtained from the left parasternal apical view and those obtained from an apex up right parasternal image are not significantly different in normal dogs and cats.

Question 72

AS: Are there any documented difference between maximum velocity using high puls repetion frequency and CW Doppler at any transducer location?

Answer 72

There is no documented difference between maximum velocity using high puls repetion frequency and CW Doppler at any transducer location.

Question 73

AS: Do HR and BW affect maximal velocity assessed?

Answer 73

HR and BW do not affect maximal velocity except for a slight relationship between BW and peak velocity when using HPRF at the apical location.

Question 74

AS: Forward stroke volume does affect flow velocity and the calculated pressure gradient. Decreases in forward flow caused by ……………………….. (3) will result in underestimation of disease severity.

Answer 74

Decreases in forward flow caused by myocardial failure, MR, and any sedative or anesthesia will result in underestimation of disease severity.

Question 75

AS: CW Doppler and low transducer frequency should be used for evaluation of LV outflow tract and aortic root flow velocities because of better signal strength at that depth from …………. frequency transducers. PW Doppler is rarely capable of recording a ………….. flow signal from apical and subcostal transducer locations when flow velocity is elevated.

Answer 75

CW Doppler and low transducer frequency should be used for evaluation of LV outflow tract and aortic root flow velocities because of better signal strength at that depth from lower frequency transducers. PW Doppler is rarely capable of recording a nonaliased flow signal from apical and subcostal transducer locations when flow velocity is elevated.

Question 76

AS: 2D images do not show evidence of abnormalities when obstruction is mild. PW Doppler can be used to identify the exact location of te obstruction but it is of little value otherwise in assessing the high velocity flow of aortic stenosis.

Answer 76

2D images do not show evidence of abnormalities when obstruction is mild. PW Doppler can be used to identify the exact location of te obstruction but it is of little value otherwise in assessing the high velocity flow of aortic stenosis.

Question 77

AS: Move the gate along the outflow tract and into the aorta. Although there is a slight ……….. in velocity across the LV outflow tract as blood approaches …………….. in the normal heart, an ……………. signal will be seen when the high velocity flow secondary to the obstruction is met.

Answer 77

Move the gate along the outflow tract and into the aorta. Although there is a slight step up in velocity across the LV outflow tract as blood approaches the aortic valve in the normal heart, an aliased signal will be seen when the high velocity flow secondary to the obstruction is met.

Question 78

AS: CW Doppler will record the high velocity flow through the stenotic region, and the Bernoulli equation can be applied in order to calculate a pressure gradient.

Answer 78

CW Doppler will record the high velocity flow through the stenotic region, and the Bernoulli equation can be applied in order to calculate a pressure gradient.
The Doppler ultrasound beam needs to be as parallel with flow as possible in order to derive accurate measures of velocity.

Question 79

AS: Derivation from parallel by > …….. gracer using CW will significantly underestimate the severity of the obstruction.

Answer 79

Derivation from parallel by > 15-20 gracer using CW will significantly underestimate the severity of the obstruction.

Question 80

AS: the site of the stenosis does not always line up with the aortic walls, and the beam might not be placed parallel to the aortic walls as they usually are when interrogating aortic flow for other reasons. The outflow tract is typically aligned at an angle toward the …………. in the presence of subvalvular aortic stenosis, and all possible angles should be interrogated in order to determine what the highest velocity truly is.

Answer 80

the site of the stenosis does not always line up with the aortic walls, and the beam might not be placed parallel to the aortic walls as they usually are when interrogating aortic flow for other reasons. The outflow tract is typically aligned at an angle toward the mitral valve leaflets in the presence of subvalvular aortic stenosis, and all possible angles should be interrogated in order to determine what the highest velocity truly is. Fig 10.20

Question 81

PW Doppler can locate the site of obstruction

Answer 81

PW Doppler can locate the site of obstruction

Question 82

AS: The flow profile is somewhat different from that seen with normal aortic or outflow tract flow. How?

Answer 82

-Peak velocity is reached closer to the midpoint of ventricular systole as opposed to within the first third of systole.
Fig 10.21, 10.22

• The flow profile becomes more symmetrical as the pressure gradient increases.
• When dynamic obstruction is present, the flow profile is dagger shaped during acceleration. This late peaking velocity is a reflection of the reduction in outflow tract size as the septum contracts secondary to muscular obstruction or systolic anterior motion.

Question 83

AO flow profile in SAS:

Severe SAS:

• …………….. profile
• No longer rapid ……………..

Dynamic component
-………… peaking flow.

Answer 83

Severe SAS:

• rounded profile
• No longer rapid acceleration

Dynamic component
-Late peaking flow.

Question 84

Take care to record outflow tract and aortic flow and not …………….. flow when trying to obtain velocities for pressure gradients.

Answer 84

Take care to record outflow tract and aortic flow and not mitral regurgitant flow when trying to obtain velocities for pressure gradients.

CF Doppler helps localize the turbulent jet, but patient movement, respiratory movement, and motion of the heart itself can complicate matters, and a mitral regurgitant jet may inadvertently be recorded instead of outflow velocity.

Question 85

AS: How to differentiate MR from aortic flow?

This mistake is made more often when a nonimaging Doppler probe is used.

Answer 85

MR typically will start early in the systolic time period, and flow starts near the onset of the QRS complex. LV outflow and aortic flow typically will start later in systole coinciding with the latter part of the QRS complex. Fig 10.22

MR flow also lasts longer and extends well beyond the T wave since insufficiencies typically last into the isovolumic relaxation phase of diastole. Fig 10.22

Question 86

When MR is present, the pressure gradient of the regurgitant jet should be used, if possible, to confirm the pressure gradient obtained across the stenosis. Fig 10.22
A gradient across an aortic stenosis of 100 mmHg in a patient with a systolic blood pressure of at least 120 mmHg indicates LV pressure of at least …………. mmHg, and the velocity of MR should reflect this pressure and be approximately ……..m/s .

Answer 86

A gradient across an aortic stenosis of 100 mmHg in a patient with a systolic blood pressure of at least 120 mmHg indicates LV pressure of at least 220 mmHg, and the velocity of MR should reflect this pressure and be approximately 7 m/s (4 x 7 upphöjt i 2 = 196). This assumes that LA enlargement is minimal and atrial pressure is normal at least less than 10 mmHg.

Question 87

Aortic stenosis with a pressure gradient of less than …….. mm is considered mild in severity, and the animal may never show any clinical signs related to the disease. Pressure gradients between ………..and ……………. mmHg represent moderate obstruction to outflow, while gradients higher than this imply severe stenosis and carry a poorer prognosis for the animal.

Answer 87

Aortic stenosis with a pressure gradient of less than 50 mm is considered mild in severity, and the animal may never show any clinical signs related to the disease. Pressure gradients between 50 and 80 to 90 mmHg represent moderate obstruction to outflow, while gradients higher than this imply severe stenosis and carry a poorer prognosis for the animal.

Question 88

SAS severity based on PG

…… but ………… = severe

Answer 88

50 but 80-90 = severe

Question 89

There is controversy as to what velocity must be exceeded before the diagnosis of aortic stenosis can be made. The published reference ranges for normal aortic flow velocity range from 0.62-2.65 depending upon the study. These studies vary with regard to transducer location , sedation, and the use of angle correction. Velocity values defining AS range from…

Answer 89

> 1.70 m/s to >2.5 m/s.

There is general agreement that velocities exceeding 250 m7s are consistent with the presence of AS.

Question 90

Aortic velocities > 200 cm/s are uncommon in dogs, but may be seen in athletic animals or animals with slow heart rates, and a definitive decision that the animal in question is free from stenosis when flow velocities fall between 200 and 250 cm/s is typically not made. Velocities 1.7 to be abnormal.

Answer 90

Aortic velocities > 200 cm/s are uncommon in dogs, but may be seen in athletic animals or animals with slow heart rates, and a definitive decision that the animal in question is free from stenosis when flow velocities fall between 200 and 250 cm/s is typically not made. Velocities 1.7 to be abnormal.

Question 91

Subvalvular aortic stenosis is a progressive disease and severity may increase until the animal is full grown. A normal pressure gradient at several weeks of age or a mild pressure gradient at a young age therefore doe not represent the absence of disease or the presence of insignificant obstruction, as the disease may still progress to a severe level.

Answer 91

Subvalvular aortic stenosis is a progressive disease and severity may increase until the animal is full grown. A normal pressure gradient at several weeks of age or a mild pressure gradient at a young age therefore doe not represent the absence of disease or the presence of insignificant obstruction, as the disease may still progress to a severe level.

Question 92

AS: The pressure gradient obtained from Dopple echo is affected by stroke volume.Flow through the aorta and the size of the aortic orifice are important. A repeat study where gradients are lower may just indicate poorer flow through the aorta secondary to myocardial ……….. or more significant …………..resulting in lower forward flow.

Answer 92

A repeat study where gradients are lower may just indicate poorer flow through the aorta secondary to myocardial failure or more significant mitral insufficiency resulting in lower forward flow.

Question 93

AS: the velocity of flow is also affected by AI since the regurgitant volume is involved in the aortic …………

Answer 93

AS: the velocity of flow is also affected by AI since the regurgitant volume is involved in the aortic flow velocity. Fig 10.23

Mild AI will probably not affect the gradient to any great degree, but the moderate to severe regurgitations that sometimes present will overestimate the severity of the actual physical obstruction. The same applies to any other cardiac defect that adds volume to flow through the aorta.

Question 94

Do not base the diagnosis of AS on high velocity aortic flow alone. Why not?

Answer 94

PDA may be found in conjunction with AS, and the severity of the stenosis cannot be accurately determined until the ductus has been closed.

Question 95

Aorta flow velocity:
PG affected by:

• Low output such as due to myocardial failure: Decreases PG
• Increased stroke volume: AI, PDA: Increases PG

Answer 95

• Low output such as due to myocardial failure: Decreases PG

- Increased stroke volume: AI, PDA: Increases PG

Question 96

Pulmonic stenosis:

Occurs with high incidence in the following breeds:

Answer 96

Bullmastiff
Beagle
Bulldog
Boxer
Spaniel
Keeshond
Schnauzer
Chihuahua
Terrier breeds

Question 97

Tidholm found that the overall incidence of PS in one study of 151 dogs with congenital disease to be 20%. It has been reported in cat as well.

Answer 97

Tidholm found that the overall incidence of PS in one study of 151 dogs with congenital disease to be 20%. It has been reported in cat as well.

Question 98

Pulmonary stenosis is typically …………, but fixed ………… constriction may occur by itself or in conjunction with the ………stenosis.

Answer 98

Pulmonary stenosis is typically valvular, but fixed subvalvular constriction may occur by itself or in conjunction with the valvular stenosis.

Question 99

Subvalvular obstruction as a dynamic component may also develop secondary to compensatory …………..

Answer 99

Subvalvular obstruction as a dynamic component may also develop secondary to compensatory hypertrophy.

Question 100

………………stenosis rarely occurs. Even rarer is pulmonary stenosis that involves the ………… of the pulmonary artery.

Answer 100

Supravalvular stenosis rarely occurs. Even rarer is pulmonary stenosis that involves the branches of the pulmonary artery.

Question 101

PS: Valvular and subvalvular pulmonary stenosis usually develop to their peak pressure gradient early in life and do not increase in severity as the animal matures as subaortic stenosis does.

Answer 101

Valvular and subvalvular pulmonary stenosis usually develop to their peak pressure gradient early in life and do not increase in severity as the animal matures as subaortic stenosis does.

Question 102

PS: 2D evaluation:

4 different views are available to image the pulmonary valves and artery: Which ones?

Answer 102

The right parasternal transverse and oblique views, and the left cranial long axis and transverse pulmonary artery views.
The site for the clearest valvular image varies from animal to animal, and all should be used in evaluating dogs with pulmonary stenosis.

Question 103

PS: The features of pulmonary stenosis include?

Answer 103

RV hypertrophy, abnormal pulmonary valves or outflow tract, poststenotic dilation of the main pulmonary artery segment, and possible right atrial and right ventricular dilation.

Question 104

There are 2 types of valvular pulmonic stenosis; usually both are referred to as dysplasia of the cusps. they are typed as?

Answer 104

One involves thick immobile cusps, the other involves fusion of the peripheral edges of the semilunar valves. Type 1 (A) and 2 (B)

The 2 forms are not mutually exclusive, and thick immobile cusps can coexist with commissural fusion.

Question 105

PS: Features of type 1 (A)

Answer 105

Type 1 (or A) is typified by commissural fusion. The semilunar cusps have not separated completely resulting in doming of the valves. Fig 10.24 This means that the body of the valvular curve toward the walls of the pulmonary artery as flow pushes them to the side during systole while the edges of the cusps remain in the center of the artery and stay in close approximation to each other throughout the cardiac cycle. Freeze-frame imaging of the leaflets show that the leaflets do not move toward the wall of the artery, as they normally would, creating a hammock-like appearance of the valves within the pulmonary artery during systole. Severity of the stenosis is related to the degree of commissural fusion. The cusps show little if any thickening, a normal annular size, and a post stenotic dilation.

Question 106

Features of type 2 (B)?

Answer 106

When type 2 (or B) valvular dysplasia is present, the cusps will appear visibly thickened and immobile, there may be a hypoplasia of the annulus and cusps, and at times, a subvalvular ring may be present.

Question 107

Type I PS: Commissural fusion

Type II PS: Valvluar dysplasia
Hypoplastic annulus

Not mutually exclusive.

Answer 107

Type I PS: Commissural fusion

Type II PS: Valvluar dysplasia
Hypoplastic annulus

Not mutually exclusive.

Question 108

Infundibular hypertrophy may be part of the………. esion or may appear as a secondary change after ……………… hypertrophy develops.

Answer 108

Infundibular hypertrophy may be part of the congenital lesion or may appear as a secondary change after concentric hypertrophy develops.

The vast majority (96%) of dogs in a study that include 29 animals had subvalvular hypertrophy. Increased muscle thickness is seen within the RV outflow tract. Fig 10.26. This is best seen on right or left parasternal transverse views. Color-flow Doppler can define the narrow outflow tract.

Question 109

Color-flow Doppler helps define infundibular stenosis.

Answer 109

Color-flow Doppler helps define infundibular stenosis.

Question 110

A hypoplastic pulmonary artery or annulus is recognized by comparing the diameter of the pulmonary artery at the level of the valve to the diameter of the aorta. A ratio of pulmonary artery to aorta is…… in normal canine hearts.

Answer 110

0.8-1.15

The aortic diameter is measured from the right parasternal long-axis outflow view, and the pulmonary artery annulus is measured on right or left parasternal transverse views. The diameter is measured at cusp insertion.

Question 111

Supraventricular stenosis is rare.

Answer 111

Supraventricular stenosis is rare.

Question 112

The poststenotic dilation seen with pulmonary stenosis is best appreciated on right or left parasternal transverse views of the pulmonary artery. The pulmonary artery will become wider ………..to the valve.
This is different from the pulmonary artery dilation seen with ………….

Answer 112

The poststenotic dilation seen with pulmonary stenosis is best appreciated on right or left parasternal transverse views of the pulmonary artery. The pulmonary artery will become wider distal to the valve.

This is different from the pulmonary artery dilation seen with PH, PDA or other

Question 113

The width of the artery at the level of the stenotic pulmonary valve will be normal or smaller than normal if the annulus is hypo plastic. The dilation occurs beyond the valves. Fig 10.25 c
With volume overload or pulmonary hypertension, the artery will be dilated at the level of the valve and usually remain dilated to the same degree distal to the valve. The dilated pulmonary artery segment may be seen as a prominent …………… on right parasternal long-axis views below the aorta at the base of the LA (Fig 10.27). The degree of pulmonary artery dilation does not appear to correlate with the severity of the obstruction.

Answer 113

The dilated pulmonary artery segment may be seen as a prominent …………… on right parasternal long-axis views below the aorta at the base of the LA (Fig 10.27). The degree of pulmonary artery dilation does not appear to correlate with the severity of the obstruction.

Question 114

Dilation of PA

Poststenotic due to PS:

• Valve diameter ………….
• ………… distal to valve

Pulmonary hypertension or shunt:

• Valve diameter …………..
• ……….. MPA including valve level dilated.

Answer 114

Poststenotic:

• Valve diameter normal or small
• Dilation distal to valve

Pulmonary hypertension or shunt:

• Valve diameter large
• Entire MPA including valve level dilated.

Question 115

PS: The afterload created by the obstruction to flow causes the right ventricular wall and inter ventricular septum to hypertrophy. Severe septal hypertrophy may contribute to …..?

Answer 115

Dynamic outflow obstruction in both the right and LV chambers. The hypertrophy is concentric, and a small ventricular chamber is seen. Fig 10.28

Question 116

PS: Increases in chamber size suggests that significant tricuspid or pulmonary insufficiencies are present or possibly a shunt coexists with the pulmonary stenosis. The elevated ………. pressure causes flattening of the septum, and paradoxical septal motion may be seen. The paradoxical motion that occurs during systole is typically subtle unless the volume overload is significant in which case …………. flattening is seen as well.

Answer 116

Increases in chamber size suggests that significant tricuspid or pulmonary insufficiencies are present or possibly a shunt coexists with the pulmonary stenosis. The elevated systolic pressure causes flattening of the septum, and paradoxical septal motion may be seen. Fig 6.4, 6.5

The paradoxical motion that occurs during systole is typically subtle unless the volume overload is significant in which case diastolic flattening is seen as well.

Question 117

RA dilation is reported in dogs and cats with PS: This may be secondary to?

Answer 117

Diastolic or systolic dysfunction, or it may be secondary to tricuspid insufficiency caused by concurrent dysplasia. Fig 10.29

Question 118

Almost …..% of dogs with pulmonary stenosis have some degree of TR.

Answer 118

Almost 50% of dogs with pulmonary stenosis have some degree of TR.

Question 119

When the pulmonary stenosis is moderate to severe, there will be a decrease in LV chamber size secondary to ………………

Answer 119

When the pulmonary stenosis is moderate to severe, there will be a decrease in LV chamber size secondary to decreased RV cardiac output. The LV chamber will appear to be concentrically hypertrophied. Fig 10.28, 10.29

Question 120

When the pulmonary stenosis is moderate to severe, there will be a decrease in LV chamber size secondary to decreased RV cardiac output. The LV chamber will appear to be concentrically hypertrophied. LV wall and septal thicknesses will be higher than normal, and chamber size will be small. This is …………. since it is a …………..-related change with lack of stretch on the cardiac muscle fibers.

Answer 120

This is pseudo-hypertrophy since it is a preload-related change with lack of stretch on the cardiac muscle fibers.

Question 121

PS: The LV chamber will appear to be concentrically hypertrophied. The inter ventricular septum will bow down toward the LV chamber since right-sided pressure will exceed left-sided pressure, and paradoxical septal motion may be present.The LA will also be smaller than expected.

Answer 121

The LV chamber will appear to be concentrically hypertrophied. The inter ventricular septum will bow down toward the LV chamber since right-sided pressure will exceed left-sided pressure, and paradoxical septal motion may be present.The LA will also be smaller than expected.

Question 122

LVH seen with PS:
……….. hypertrophy
Secondary to poor ……….
May cause …………..

Answer 122

Pseudo hypertrophy
Secondary to poor preload
May cause SAM.

Question 123

Systolic anterior mitral (SAM) valve motion may be seen in patients with elevated right ventricular pressure caused by pulmonic stenosis, Tetralogy of Fallot, and pulmonary hypertension. All of these disease processes may result in LV volume ………………, and the abnormal LV …………… is thought to be the cause of the SAM.

Answer 123

All of these disease processes may result in LV volume contraction, and the abnormal LV geometry is thought to be the cause of the SAM.
Even when flow velocity is normal, the flow profile shows late peaking velocity secondary to the SAM.

Question 124

………….. and ………. dogs with PS may have abnormal coronary arteries.

Answer 124

Bulldogs and Boxers with PS may have abnormal coronary arteries.

Question 125

Bulldogs and Boxers with PS may have abnormal coronary arteries. A single right coronary artery is found that divides into 2 branches shortly after leaving the ………………….. One brach supplies blood to the ………… as usual, while the other supplies blood to the ………….. via an aberrant pathway.

Answer 125

A single right coronary artery is found that divides into 2 branches shortly after leaving the right coronary ostium. One brach supplies blood to the right ventricle as usual, while the other supplies blood to the left ventricle via an aberrant pathway.

Question 126

Bulldogs and Boxers with PS may have abnormal coronary arteries.

One brach supplies blood to the right ventricle as usual, while the other supplies blood to the left ventricle via an aberrant pathway. The pathway this aberrant vessel takes may be ………. to the pulmonary artery, ……….the pulmonary artery and aorta, or …………… to the aorta (Fig 10.30, 10.31)

Answer 126

The pathway this aberrant vessel takes may be cranial to the pulmonary artery, between the pulmonary artery and aorta, or caudal to the aorta (Fig 10.30, 10.31)

Question 127

Identification of a normal left coronary artery is important when balloon valvuloplasty or a patch graft procedure is considered since these procedures may cause ……………..

Answer 127

Identification of a normal left coronary artery is important when balloon valvuloplasty or a patch graft procedure is considered since these procedures may cause rupture of the aberrant artery or ischemia and possible infarct within the LV chamber.

Question 128

The aberrant coronary artery may constrict the pulmonary valve annulus or the subvalvuar area creating a stenosis that leads to ……………

Answer 128

The aberrant coronary artery may constrict the pulmonary valve annulus or the subvalvuar area creating a stenosis that leads to right ventricular hypertrophy with growth and maturation of the dog.

When this occurs, color-flow Doppler will show the turbulence associated with the obstruction begin at the level of the aberrant artery, not the valve.

Question 129

The aberrant coronary artery may constrict the pulmonary valve annulus or the subvalvuar area creating a stenosis that leads to right ventricular hypertrophy with growth and maturation of the dog.

When this occurs, color-flow Doppler will show …………?

Answer 129

When this occurs, color-flow Doppler will show the turbulence associated with the obstruction begin at the level of the aberrant artery, not the valve.
One imaging plane to see the normal left coronary artery on is a right parasternal transverse view at the level of the aortic valve, LA, left auricle, and pulmonic valve. Fig 10.32.

Question 130

aberrant coronary artery: Looking at the junction between the left auricular appendage and the pulmonary artery, fan the crystals up toward the pulmonary valve, and down away from it. The normal left coronary arty is seen exiting the left coronary ostium and coursing through the muscle just above the auricular appendage and just below the pulmonary valve. Be sure to identify the coronary artery as it leaves the aorta because the space between the auricle and right ventricular wall can mimic the artery. A blind end or blunted ostium at the location of a normal coronary artery is seen completely crossing over the pulmonary artery after it leaves the aorta. Cranial let transverse images of the aorta and pulmonary artery may also show the normal left coronary artery. Fan the transducer cranial and caudal while viewing the pulmonary artery and the coronary vessel is seen leaving the aorta, crossing under the pulmonary valve to the right side of the sector image. Fig 10.33

Answer 130

aberrant coronary artery: Looking at the junction between the left auricular appendage and the pulmonary artery, fan the crystals up toward the pulmonary valve, and down away from it. The normal left coronary arty is seen exiting the left coronary ostium and coursing through the muscle just above the auricular appendage and just below the pulmonary valve. Be sure to identify the coronary artery as it leaves the aorta because the space between the auricle and right ventricular wall can mimic the artery. A blind end or blunted ostium at the location of a normal coronary artery is seen completely crossing over the pulmonary artery after it leaves the aorta. Cranial let transverse images of the aorta and pulmonary artery may also show the normal left coronary artery. Fan the transducer cranial and caudal while viewing the pulmonary artery and the coronary vessel is seen leaving the aorta, crossing under the pulmonary valve to the right side of the sector image. Fig 10.33

Question 131

aberrant coronary artery: Right parasternal long-axis images of the LV outflow tract also provide a window to the normal left coronary artery. Fan the transducer between a good inflow outflow view and one with just the outflow tract. The normal coronary artery is seen leaving the aorta and running through the myocardium toward the LV chamber.

Answer 131

aberrant coronary artery: Right parasternal long-axis images of the LV outflow tract also provide a window to the normal left coronary artery. Fan the transducer between a good inflow outflow view and one with just the outflow tract. The normal coronary artery is seen leaving the aorta and running through the myocardium toward the LV chamber.

Question 132

Aberrant left coronary artery:
Primarily seen in …………..
May create ………… and ……………

Answer 132

Primarily seen in bulldogs

May create constriction and stenosis.

Question 133

PS: Spectral Doppler evaluation:
Will show high velocity flow. Fig 10.34. Use whatever view that provides the highest flow velocities. On right parasternal transverse views, the pulmonary artery is typically curved away from the Doppler cursor, so use the modified long-axis view of the LV and pulmonary artery to provide parallel alignment with flow. Left cranial long-or short-axis views may also provide good alignment with flow.

Answer 133

Spectral Doppler evaluation:
Will show high velocity flow. Fig 10.34. Use whatever view that provides the highest flow velocities. On right parasternal transverse views, the pulmonary artery is typically curved away from the Doppler cursor, so use the modified long-axis view of the LV and pulmonary artery to provide parallel alignment with flow. Left cranial long-or short-axis views may also provide good alignment with flow.

Question 134

PS: A pulsed-wave gate can be placed within the outflow tract in order to determine if any subvalvular obstruction is present if 2D images are inconclusive. There will be a ……….. if any obstruction is present as the gate is moved from the subvalvular area to the valve.

Answer 134

There will be a step up in velocity if any obstruction is present as the gate is moved from the subvalvular area to the valve.

Question 135

Normal pulmonary artery flow is typically

Answer 135

Normal pulmonary artery flow is typically

Question 136

The assessment of severity is similar to that used in aortic stenosis.

….. mmHg but ….. mmHg = severe

Answer 136

50 mmHg but 75 mmHg = severe

More severe stenosis has a higher mortality rate.

Question 137

PS: When dynamic outflow obstruction exists, a …………. flow profile similar to that found in dynamic ……………… and hypertrophic cardiomyopathy is seen.

Answer 137

When dynamic outflow obstruction exists, a dagger-shaped flow profile similar to that found in dynamic subaortic stenosis and hypertrophic cardiomyopathy is seen.

Question 138

PS: When TR is present, the regurgitant jet should be interrogation with a Doppler beam to help confirm the pressure gradient obtained across the pulmonary valve. Fig 10.35.

Answer 138

When TR is present, the regurgitant jet should be interrogation with a Doppler beam to help confirm the pressure gradient obtained across the pulmonary valve. Fig 10.35.

A TR jet may also be used to derive the only pressure gradient if difficulty is encountered getting a pulmonary flow profile.

Question 139

PS: A TR jet with flow velocities of 4.33 cm/sec for instance signifies that RV systolic pressures are at least 75 mmHg. If pulmonary artery pressure is close to normal at around 20 mmHg, the a pressure gradient of ……. mmHg can be applied to the pulmonary stenosis (right ventricular pressure is 55 higher than the pulmonary artery pressure of 20).

Answer 139

If pulmonary artery pressure is close to normal at around 20 mmHg, the a pressure gradient of 55 mmHg can be applied to the pulmonary stenosis (right ventricular pressure is 55 higher than the pulmonary artery pressure of 20).

Question 140

PS: A measurement of diastolic ante grade flow through the stenosis has been used to assess significance of main pulmonary artery stenosis (supravalvular stenosis) in cats with normal pulmonary valve anatomy. Diastolic ante grade flow through the stenosis is graded based upon how long it persists. The start of diastole in this study was defined as the end of the T wave. No diastolic regurgitant flow is a grade of 0, diastolic flow that occurs through 50% or less of the diastolic time period, diastolic flow that occurs throughout more than 50% but less than 100% of the diastolic time period is a grade 2, and flow that persists thorough diastole is a grade 3.

Answer 140

A measurement of diastolic ante grade flow through the stenosis has been used to assess significance of main pulmonary artery stenosis (supravalvular stenosis) in cats with normal pulmonary valve anatomy. Diastolic ante grade flow through the stenosis is graded based upon how long it persists. The start of diastole in this study was defined as the end of the T wave. No diastolic regurgitant flow is a grade of 0, diastolic flow that occurs through 50% or less of the diastolic time period, diastolic flow that occurs throughout more than 50% but less than 100% of the diastolic time period is a grade 2, and flow that persists thorough diastole is a grade 3

Question 141

The pressure half-time of the diastolic regurgitant flow has also been analyzed in these same cats with main pulmonary artery stenosis and normal pulmonary valves.

This measures the time of diastolic decay (slope) from the peak velocity at the beginning of diastole (end of the ……….) to the beginning of systole or the baseline if flow was less than grade 3.

Both of these measurements, pressure half-time and grade of diastolic ante grade flow correlate well with the severity of the pulmonary stenosis and has better separation between moderate and severe disease than systolic or diastolic pressure gradient did when compared to 2D changes and clinical signs.

Answer 141

This measures the time of diastolic decay (slope) from the peak velocity at the beginning of diastole (end of the T wave) to the beginning of systole or the baseline if flow was less than grade 3.

Both of these measurements, pressure half-time and grade of diastolic ante grade flow correlate well with the severity of the pulmonary stenosis and has better separation between moderate and severe disease than systolic or diastolic pressure gradient did when compared to 2D changes and clinical signs.

Question 142

Either a diastolic pressure half-time of antegrade flow through the stenosis of > …….. msec or a diastolic antegrade flow time of grade …… was consistent with severe pulmonary stenosis in these cats.

Answer 142

Either a diastolic pressure half-time of antegrade flow through the stenosis of > 100 msec or a diastolic antegrade flow time of grade 3 was consistent with severe pulmonary stenosis in these cats.

Question 143

PS: Color-Flow Doppler evaluation: Helps define the extent.

Answer 143

Helps define the extent of obstruction. The mosaic pattern associated with turbulence and high velocity will start at the level of the valve when valvular obstruction is present.

Question 144

PS: Color-Flow Doppler evaluation: The outflow tract will be defined by the aliased color-flow signal when either fixed or dynamic subvalvular obstruction is present.

Answer 144

Color-Flow Doppler evaluation: The outflow tract will be defined by the aliased color-flow signal when either fixed or dynamic subvalvular obstruction is present.

Question 145

PS: Color-Flow Doppler: The width of the outflow tract and the valvular orifice are well defined with color but usually overestimate ………….

Answer 145

the size of the stenotic area.

Question 146

When CF-Doppler is available; use it to help align the spectral Doppler beam properly

Answer 146

When CF-Doppler is available; use it to help align the spectral Doppler beam properly

Question 147

PS: The pulmonary artery stenosis diameter to pulmonary artery valve diameter has been used to assess severity of artery stenosis and clinical significance in cats. These cats had normal pulmonary valve anatomy and stenosis within the artery or its branches. Where are the measurements made?

Answer 147

At the largest diameter (vena contracta) of the stenosis and at the pulmonary valve on right or left parasternal transverse imaging planes of the pulmonary artery.

Question 148

PS: How is vena contracta defined?

Answer 148

By color-flow Doppler as the largest area through which blood flows at the level of the stenosis.

Question 149

PS: The pulmonary artery stenosis diameter to pulmonary artery valve diameter ratio is used to determine severity of the stenosis. The smaller the ratio the more severe the stenosis was felt to be. Cats with obstruction to flow of greater than 60 mmHg had vena contracta diameter to pulmonary valve diameter ratios of

Answer 149

Cats with obstruction to flow of greater than 60 mmHg had vena contracta diameter to pulmonary valve diameter ratios of

Question 150

As with aortic stenosis, volume through the pulmonary artery affects the derived pressure gradient. Any shunt that adds volume or the presence of significant pulmonic insufficiency adds………….and………….to the pulmonary artery flow profile. The pressure gradient will ………………….. reflect the degree of physical obstruction.

Answer 150

As with aortic stenosis, volume through the pulmonary artery affects the derived pressure gradient. Any shunt that adds volume or the presence of significant pulmonic insufficiency adds volume and velocity to the pulmonary artery flow profile. Fig 10.36. The pressure gradient will not truly reflect the degree of physical obstruction.

Question 151

Double-chamber RV and infundibular stenosis:
The …………… is the smooth muscular portion of the right ventricular chamber that separates the tricuspid valve from the pulmonary artery.

Answer 151

The crista supraventricularis is the smooth muscular portion of the right ventricular chamber that separates the tricuspid valve from the pulmonary artery.

Question 152

The crista supraventricularis can be seen on transverse views of the heart base above the aorta between the tips of the tricuspid valve and the pulmonary valve. A stenosis in this area of the RV separates the chamber into 2 sections; Which ones?

Answer 152

A high pressure proximal chamber and a low pressure disal chamber between the obstructive lesion and the pulmonary valve. The obstruction can be created by a fibrous or fibromuscular ridge of tissue, a muscular bundle, or both, which extends across the RV chamber at the level of or close to the supraventricularis.

Question 153

An obstruction in the crista supraventricularis area creates an orifice of variable size for flow between the ………… and …………….portions of the RV chamber.

Answer 153

An obstruction in the crista supraventricularis area creates an orifice of variable size for flow between the high pressure and low pressure portions of the RV chamber.

Question 154

Obstruction in the crista supraventricularis area: There is confusion regarding the terminology used to name this defect. Names include?

Answer 154

Infundibular obstruction
Midventricular obstruction
Double-chambered RV (DCRV).

Regardless name, they all create the same pathophysiologic changes within the heart as valvular pulmonary stenosis does.

Question 155

Midventricular obstruction or double-chambered RV are typically described as more …………. in nature and occur at the junction of the supraventricularis and the ………………, while infundibular obstruction is usually described as a ………………… located proximal to the pulmonic valve. All of these are often associated with other congenital defects including VSD, AD, TD, pulmonic valvular stenosis, and subaortic stenosis.

Answer 155

Midventricular obstruction or double-chambered RV are typically described as more muscular in nature and occur at the junction of the supraventricularis and the RV outflow tract, while infundibular obstruction is usually described as a discrete fibrous band located proximal to the pulmonic valve. All of these are often associated with other congenital defects including VSD, AD, TD, pulmonic valvular stenosis, and subaortic stenosis.

The high pressure within the proximal chamber can create significant tricuspid insufficiency even without the presence of structural tricuspid valve disease.
There appears to be a propensity for this congenital defect in Golden retrievers, Boxers, and Siberian Huskies.

Question 156

Midventricular stenosis or DCRV:
-Found at junction of RV and ………..

Subvalvular or infundibular stenosis:
-Closer to ………. in RVOT

Answer 156

Midventricular stenosis or DCRV:
-Found at junction of RV and supraventricularis

Subvalvular or infundibular stenosis:
-Closer to PV in RVOT

Question 157

Midventricular stenosis or DCRV.
2D and Doppler evaluation:

The obstruction is identified on echo images from slightly oblique right or left parasternal transverse views of the heart base or on modified (foreshortened) left apical views of the right ventricular chamber. Fig 10.37, 10.38.

Answer 157

The obstruction is identified on echo images from slightly oblique right or left parasternal transverse views of the heart base or on modified (foreshortened) left apical views of the right ventricular chamber. Fig 10.37, 10.38.

Question 158

Midventricular stenosis or DCRV:
Identification of turbulent flow within the RV chamber proximal to the RV outflow tract should prompt angling of the transducer into nonstandard imaging planes in order to identify the source of the abnormal flow. Fig 10.39, 10.40

Answer 158

Midventricular stenosis or DCRV:
Identification of turbulent flow within the RV chamber proximal to the RV outflow tract should prompt angling of the transducer into nonstandard imaging planes in order to identify the source of the abnormal flow. Fig 10.39, 10.40

Question 159

Midventricular stenosis or DCRV features:
A turbulent jet within the RV chamber, distinct fibromuscular, or muscular tissue at the level of the turbulent flow, and hypertrophy of the RV wall proximal to the obstructive lesion, which is absent distal to the muscular bundle, and turbulent flow are identifying features of this form of RV obstruction to outflow.

Answer 159

A turbulent jet within the RV chamber, distinct fibromuscular, or muscular tissue at the level of the turbulent flow, and hypertrophy of the RV wall proximal to the obstructive lesion, which is absent distal to the muscular bundle, and turbulent flow are identifying features of this form of RV obstruction to outflow.

Question 160

Features Midventricular stenosis or DCRV:

• ………………. band in RV
• Abrupt ………………….. of RVH in RV
• Turbulent color flow in ……….RV

Answer 160

• Fibromuscular band in RV
• Abrupt cessation of RVH in RV
• Turbulent color flow in mid RV

Question 161

Features Midventricular stenosis: Flow through the obstruction is usually somewhat perpendicular to the Doppler beam on transverse imaging planes, and manipulation of the imaging plane in order to align the beam with the high velocity jet is required. This can be done by twisting away from standard transverse planes toward the long axis on the right or left and using color flow to help align the obstruction and turbulent flow with the Doppler beam. Another successful imaging plane is a foreshortened apical 4 ch view, one that is usually somewhere between a true apical position and a cranial transverse view. Spectral flow of the stenosis from this imaging plane will be in an ……. direction on the display.

Answer 161

Spectral flow of the stenosis from this imaging plane will be in an upward direction on the display.
Fig 10.40.

Question 162

Midventricular stenosis: In cases where good alignment with the obstruction is not possible, tricuspid regurgitant flow can be used to determine the pressure gradient between the high pressure proximal chamber and the right atrium. This provides some idea of severity.

For example, if the tricuspid regurgitant jet has a velocity of 5 m/sec, the proximal chamber must have a pressure of at least ,,,,,,,, mmHg (…………….) more than the RA. If RA pressure is 0 then the proximal chamber has a pressure of a least ………mmHg. Assuming normal RV pressure in the distal chamber of about 20 mmHg (barring any other congenital defect), the pressure gradient across the stenotic area can be estimated at around ………. mmHg.

Answer 162

For example, if the tricuspid regurgitant jet has a velocity of 5 m/sec, the proximal chamber must have a pressure of at least 100 mmHg (4x 5 upphöjt i 2) more than the RA. If RA pressure is 0 then the proximal chamber has a pressure of a least 100 mmHg. Assuming normal RV pressure in the distal chamber of about 20 mmHg (barring any other congenital defect), the pressure gradient across the stenotic area can be estimated at around 80 mmHg.

Question 163

Cats with infundibular hypertrophy and obstruction almost all have evidence of …?

Answer 163

Cats with infundibular hypertrophy and obstruction almost all have evidence of small LV chambers and LV outflow obstruction with LV infundibular hypertrophy and evidence of SAM in some.

The causes of the LVOT obstruction is not clear. It is hypothesized that it may be hypertrophic cardiomyopathy or volume contraction. Cats with severe infundibular obstruction to outflow had RVOT diameter to pulmonary valve diameter ratios of

Question 164

Infundibular hypertrophy and obstruction: This defect is easily missed or can be confused with a …………………. The turbulent flow associated with a mid ventricular obstruction on transverse right parasternal imaging planes is close to the same location that shunted blood from a ………… enters the right ventricular chamber.

It can also be misdiagnosed as …………….. if a CW Doppler cursor is partially aligned with the mid ventricular turbulent jet.

Answer 164

The turbulent flow associated with a mid ventricular obstruction on transverse right parasternal imaging planes is close to the same location that shunted blood from a ventricular septal defect enters the right ventricular chamber.

It can also be misdiagnosed as valvular pulmonic stenosis if a CW Doppler cursor is partially aligned with the mid ventricular turbulent jet.

Use structural changes within the right side of the heart to help identify the presence of a possible mid ventricular of infundibular obstruction. An abrupt decrease in hypertrophy within the RV chamber or outflow tract should be a clue that a mid ventricular or infundibular obstruction exists and use color-flow Doppler to help identify the origination of turbulence.

Question 165

………. obstructions:
Mitral stenosis.
Rare congenital abnormality in dogs and cats. It has a high incidence in the …….breeds.

Answer 165

Bull terrier and Newfoundland .

Question 166

Mitral stenosis: It may occur as a single entity or in combination with other defects.Concomitant defects in dogs and cats include?

Answer 166

Subaortic stenosis,
patent ductus arteriosus
pulmonic stenosis
mitral valve dysplasia

Mitral stenosis development as an acquired lesion in animals, as seen in people, cannot be confirmed.

Question 167

Mitral stenosis has varying morphologies, which may include…

Answer 167

• Thickened leaflets with hypertrophied papillary muscles
• A supravalvular ring
• Billowing leaflets with abnormal chordae all attached to one papillary muscle creating a tunnel
• Hypoplastic valves.

Question 168

Mitral stenosis: characteristic echo findings?

M-mode,

Answer 168

• M-mode echo shows thick mitral leaflets, parallel motion of the anterior and posterior mitral valve leaflets (concordant motion),
• prolonged mitral valve EF slope,
• A dilated LA.

Fig 10.41.

Question 169

Mitral stenosis: characteristic echo findings? 2D findings include?

Answer 169

A dilated LA
Doming of the mitral valve leaflets
Reduced excursion of either or both mitral leaflets
Thick mitral valve leaflets
Possibly a supravalvular ring

Fig 10.42, 10.43, 10.44

Question 170

Mitral stenosis: characteristic echo findings? Doppler findings:

Answer 170

A pressure gradient, increased pressure half-time, and possibly mitral insufficiency are present on Doppler exam of mitral stenosis

Question 171

Features Mitral stenosis:

Answer 171

Concordant MV motion
Doming of MV leaflets
Reduced EF slope
Prolonged PHT
High PG
Dilated LA

Question 172

Doming of MV leaflets:

Answer 172

When the tips of the mitral valve point toward each other as opposed to pointing toward the LV chamber during maximal mitral valve excursion the leaflets are said to dome: a sign of mitral stenosis. May imply fusion of the valve leaflets.

Question 173

Mitral stenosis:
M-mode: Concordant mitral valve motion means ………..l, the posterior and anterior leaflets …………….. …………………………….. This is seen when there is commissural fusion of the leaflets and is easy to document on M-mode images.

Answer 173

Concordant mitral valve motion means the leaflets move in parallel, the posterior and anterior leaflets do not move away from each other as they normally do. The posterior leaflet will move upward toward the septum at the same time the anterior leaflets does. This is seen when there is commissural fusion of the leaflets and is easy to document on M-mode images. Fig 10.41

Question 174

Mitral stenosis: 2D evaluation:

2D images show doming of the mitral valve leaflets when there is fusion of the cusps. This means?

Answer 174

The tips of the leaflet will point toward each otter at maximal opening. The body of the anterior leaflet will bow or dome up toward the outflow tract, and sometimes the posterior leaflet domes toward the free wall of the LV. Fig 10.42, 10.43

Question 175

Mitral stenosis: Fusion of the mitral leaflets also reduces the anterior and posterior excursion of leaflets during diastole. In order to document the reduced excursion during diastole; look at ………… and not ……………………. To document this on M-mode images, the M-mode cursor must be positioned at the …………………….. The mitral valve EF slope will be ……….

Answer 175

Fusion of the mitral leaflets also reduces the anterior and posterior excursion of leaflets during diastole. In order to document the reduced excursion during diastole; look at the tips of the leaflets and not along the body of the leaflets where the septal leaflet will billow up toward the outflow tract and the parietal leaflet billows down to the free wall. To document this on M-mode images, the M-mode cursor must be positioned at the tips of the leaflets. The mitral valve EF slope will be reduced.

Question 176

Mitral stenosis: The finding of concordant motion is diagnostic of mitral stenosis. What about reduced EF slope and reduced excursion?

Answer 176

The latter two are not specific for the disease.

Reduced excursion may be seen in the presence of aortic insufficiency, a common finding in dogs with subaortic stenosis. Almost one half of dogs with mitral stenosis in one report also had subaortic stenosis. Poor inflow into the LV for any reason will also reduce mitral valve motion and excursion.

Question 177

Mitral stenosis: ……………………… will differentiate reduced motion secondary to AI or reduced flow from poor excursion secondary to mitral stenosis.

Answer 177

Doming of the body of the leaflets will differentiate reduced motion secondary to AI or reduced flow from poor excursion secondary to mitral stenosis.

Question 178

Mitral stenosis: Reduced ventricular ……………….may be a cause of delayed early diastolic mitral valve closure. This is often seen in heart disease resulting in LV hypertrophy. There are also reports of mitral stenosis in man in which concordant mitral valve motion is not present or may not be evident.

Answer 178

Reduced ventricular compliance may be a cause of delayed early diastolic mitral valve closure. This is often seen in heart disease resulting in LV hypertrophy. There are also reports of mitral stenosis in man in which concordant mitral valve motion is not present or may not be evident.

Question 179

Mitral stenosis: A thick mitral valve is usually present with mitral stenosis but may also be seen with …………..(4).

Answer 179

A thick mitral valve is usually present with mitral stenosis but may also be seen with dysplastic valves, subaortic stenosis, and acquired degenerative or infective lesions.

Question 180

A thick mitral valve is usually present with mitral stenosis but may also be seen with dysplastic valves, subaortic stenosis, and acquired degenerative or infective lesions.

The diagnosis of mitral stenosis as opposed to these other differentials can be made when the other features of stenosis are present including?

Answer 180

Doming
Reduced EF slope
Concordant diastolic motion
Increased pressure half-time

Question 181

Mitral stenosis: Restriction to LV filling causes LA pressure to increase and the LA to ……… Elevation in pressure secondary to increased output due to excitement or exercise may exacerbate the clinical signs associated with mitral stenosis.

Answer 181

Restriction to LV filling causes LA pressure to increase and the LA to dilate. Fig 10.43. Elevation in pressure secondary to increased output due to excitement or exercise may exacerbate the clinical signs associated with mitral stenosis.

Question 182

Mitral stenosis: The development of atrial arrhythmias, especially atrial fibrillation, will ……….flow into the ventricle and elevate ……………….. The degree of LA dilation is affected not only by the obstruction to LV inflow but also by the degree of …………… if present.

Answer 182

The development of atrial arrhythmias, especially atrial fibrillation, will decrease flow into the ventricle and elevate atrial pressure. The degree of LA dilation is affected not only by the obstruction to LV inflow but also by the degree of mitral insufficiency if present.

Question 183

Chronic elevation in LA and pulmonary venous pressure will lead to chronic interstitial changes within the pulmonary arterioles and secondary pulmonary hypertension. Pulmonary hypertension affects the right side of the heart, and echo evidence of pulmonary hypertension includes?

Answer 183

RV and pulmonary artery dilation
RV hypertrophy
Tricuspid insufficiency
Changes in the pulmonary flow profile.

When hypertension becomes significant, decrease in LV preload may alleviate some of the symptoms of mitral stenosis.

Question 184

Mitral valve area in man is measured directly from transverse images of the mitral valve. Normal mitral valve area in the dog is?

Answer 184

3.69 +/- 1.42

Fig 10.45

Question 185

Problems om direct measurement of mitral valve area includes?

Answer 185

Poor resolution
Improper selection of the frame for measurement
Gain settings.

When the transverse image is not perpendicular to the mitral valve and an oblique view is used, the size of the mitral valve leaflets must be seen in cross section otherwise the orifice size will be overestimated secondary to billowing of the body of the leaflets.

Question 186

Color-flow Doppler evaluation in mitral stenosis patients:
The narrow mitral orifice secondary to commissural fusion of the mitral valve creates an ………… color jet flowing into the LV during diastole representative of increased velocity and turbulence. Fig 10.46

Answer 186

The narrow mitral orifice secondary to commissural fusion of the mitral valve creates an aliased color jet flowing into the LV during diastole representative of increased velocity and turbulence. Fig 10.46

Question 187

Mitral stenosis: When aortic valve or outflow tract pathology is also present, be sure to differentiate this mitral jet from diastolic aortic insufficiency with the outflow tract. Systolic aliased signals may also be seen since many of many of these patients also have mitral insufficiency.

Answer 187

When aortic valve or outflow tract pathology is also present, be sure to differentiate this mitral jet from diastolic aortic insufficiency with the outflow tract. Systolic aliased signals may also be seen since many of many of these patients also have mitral insufficiency.

Question 188

Mitral stenosis:
Spectral Doppler of mitral inflow shows …………… profiles with …………. early diastolic slopes or lack of closure during early diastole.

Answer 188

Spectral Doppler of mitral inflow shows high velocity flow profiles with reduced early diastolic slopes or lack of closure during early diastole.

Question 189

Mitral stenosis:The inflow profile is recorded from apical four or five-chamber views of the heart. The reduced slope reflects delayed normal early diastolic closure because of?.

Answer 189

Because of a persistent pressure differential between the LA and LV. Fig 10.47

Question 190

Spectral Doppler of mitral inflow shows high velocity flow profiles with reduced early diastolic slopes or lack of closure during early diastole. Measurement of the slope provides a calculation of pressure half-time. Pressyre half-time is the …?

Answer 190

The time required for pressure to decrease to 1/2 its peak value.

Question 191

Normal pressure half-times in the dogs and cats are?

Answer 191

In dogs: 29 +/- 8 msec (

Question 192

Mitral stenosis: The longer the pressure half-time, the more severe the stenosis.

Answer 192

Mitral stenosis: The longer the pressure half-time, the more severe the stenosis.

Question 193

Normally during early ventricular filling, the LV pressure …….. and left atrial pressure ………. resulting in a rapid ………….. of the E peak on transmitral flow profiles when the pressure gradient between the 2 chambers rapidly equalizes.

Answer 193

Normally during early ventricular filling, the LV pressure rises and left atrial pressure decreases resulting in a rapid deceleration of the E peak on transmitral flow profiles when the pressure gradient between the 2 chambers rapidly equalizes.

Question 194

Normally during early ventricular filling, the LV pressure rises and left atrial pressure decreases resulting in a rapid deceleration of the E peak on transmitral flow profiles when the pressure gradient between the 2 chambers rapidly equalizes. What about in patients with mitral stenosis?

Answer 194

With mitral stenosis: the more severe the restriction to LV inflow, the longer the pressure gradient is maintained between the 2 chambers and the slower the decline of the MV E peak pressure during early diastolic filling.

Question 195

Pressure half-times in mitral stenosis usually exceed 90 msec in man and may be much higher. Reported pressure half-times exceed 80 msec in cats and ran to 330 msec in dogs with mitral stenosis.

Answer 195

Pressure half-times in mitral stenosis usually exceed 90 msec in man and may be much higher. Reported pressure half-times exceed 80 msec in cats and ran to 330 msec in dogs with mitral stenosis.

Question 196

PHT and MS:

Increased PHT (pressure half time) = ……………. PG between LV and LA

Normal PHT- canine: 29 +/- 8 msec (

Answer 196

Increased PHT (pressure half time) = persistent PG between LV and LA

Normal PHT- canine: 29 +/- 8 msec (

Question 197

The severity of stenosis correlates directly with pressure half-time (PHT). The ………. the PHT, the more severe the stenosis is.

Answer 197

The severity of stenosis correlates directly with pressure half-time (PHT). The longer the PHT, the more severe the stenosis is.

Question 198

Pressure half-time is affected by a variety of other factors (than mitral stenosis) including?

Answer 198

The presence of aortic insufficiency and

irregular heart rhythms.

Question 199

The velocity across the stenosis is directly dependent upon left ventricular pressures. In the presence of aortic insufficiency, LV diastolic pressure increases more rapidly secondary to this second source of blood volume, especially if the insufficiency is …………., and pressure half-time will …………….. correspondingly despite the presence of possibly severe mitral stenosis.

Answer 199

The velocity across the stenosis is directly dependent upon left ventricular pressures. In the presence of aortic insufficiency, LV diastolic pressure increases more rapidly secondary to this second source of blood volume, especially if the insufficiency is acute, and pressure half-time will decrease correspondingly despite the presence of possibly severe mitral stenosis.

Question 200

When measuring half-time; follow the actual outline of …. to …. slope. If the slope has a curve, follow the curve while tracing the slope. The ….. wave should also be ignored if present, a sweep speed of 100 mm/sec should be used for greater accuracy, and average at least …… beats. If the animal is in atrial fibrillation or has another irregular rhythm, average the half-times of 5 to 10 beats.

Answer 200

When measuring half-time; follow the actual outline of E to F slope. If the slope has a curve, follow the curve while tracing the slope. The A wave should also be ignored if present, a sweep speed of 100 mm/sec should be used for greater accuracy, and average at least 3 beats. If the animal is in atrial fibrillation or has another irregular rhythm, average the half-times of 5 to 10 beats.

Question 201

Mitral valve area can be calculated using pressure half-time (PHT). Fig 10.47. This info is used to determine…?

Answer 201

The timing of surgical intervention and is of lesser value at this time in animals. Apply Equation 10.5 to calculate an orifice area.

Area = 220/P upphöjt i 1/2

where PHT is measured in msec, and the area is reported as cm upphöjt i 2.

Question 202

Mitral stenosis creates an obstruction to inflow that results in ……………

Answer 202

elevated LA pressures.

Question 203

MS: The Bernouslli equation can be applied to peak or mean mitral inflow velocities to determine the pressure gradient. The more………… the stenosis, the higher the gradient.

Answer 203

The Bernouslli equation can be applied to peak or mean mitral inflow velocities to determine the pressure gradient. The more restrictive the stenosis, the higher the gradient.

Question 204

MS: ………….pressure gradients are considered more accurate i the assessment of severity of mitral stenosis. The flow profile is traced, and ………….. gradients are calculated by the equipment.

Answer 204

Mean pressure gradients are considered more accurate i the assessment of severity of mitral stenosis. The flow profile is traced, and mean gradients are calculated by the equipment.
Fig 10.48.

Question 205

Some studies have even shown that Doppler -derived gradients for mitral stenosis are more accurate then invasive catheterization methods. Normal dogs should have a peak mitral valve E velocity of ………, and pressure gradients less than …. mmHg between the LA and LV during diastole. A peak gradient greater than this suggests ………….

Answer 205

Some studies have even shown that Doppler -derived gradients for mitral stenosis are more accurate then invasive catheterization methods. Normal dogs should have a peak mitral valve E velocity of 1.1, and pressure gradients less than 5 mmHg between the LA and LV during diastole. A peak gradient greater than this suggests the presence of mitral stenosis. Fig 10.49.

Question 206

Mitral stenosis:

…… PG more accurate than …… PG.

Answer 206

Mean PG more accurate than peak PG.

Question 207

Pressure gradients for any given orifice area are influenced by?

Answer 207

The amount of volume flowing through it. Therefore, animals with mitral stenosis and significant mitral insufficiency will have higher pressure gradients than animals with the same valvular area and little or no mitral insufficiency. Similarly, low flow states will underestimate the pressure gradient.

Question 208

Elevations in left ventricular diastolic pressure secondary to aortic insufficiency or poor LV compliance will also ………. the derived gradient for any given stenotic area.

Answer 208

Elevations in left ventricular diastolic pressure secondary to aortic insufficiency or poor LV compliance will also reduce the derived gradient for any given stenotic area.

Question 209

Radial LV wall motion has been assessed with color tissue Doppler imaging in a dog with mitral stenosis. No abnormalities from normal were found in this Bull terrier suggesting that systolic and diastolic function were normal.There was also no discordant motion between the endocardium and epicardium.

Answer 209

Radial LV wall motion has been assessed with color tissue Doppler imaging in a dog with mitral stenosis. No abnormalities from normal were found in this Bull terrier suggesting that systolic and diastolic function were normal.There was also no discordant motion between the endocardium and epicardium

Question 210

It is obvious that any one given features of mitral stenosis cannot be used to make the diagnosis. A combination of features plus characteristic real-time images consistent with reduced ……………, …………, thickened leaflets, abnormal chordae, supravalvular rings, etc, will provide accuracy in diagnosis the presence of mitral stenosis correctly even if the assessment of severity is sometimes not possible.

Answer 210

A combination of features plus characteristic real-time images consistent with reduced mitral valvular motion, doming, thickened leaflets, abnormal chordae, supravalvular rings, etc, will provide accuracy in diagnosis the presence of mitral stenosis correctly even if the assessment of severity is sometimes not possible.

Question 211

Tricuspid stenosis:
Isolated congenital tricuspid stenosis is uncommon, and there are rare reports of it in a …………..r and a ………………. in veterinary medicine.

What is seen more often?

Answer 211

Isolated congenital tricuspid stenosis is uncommon, and there are rare reports of it in a Labrador retriever and a Chesapeake Bay retriever in veterinary medicine.

Tricuspid stenosis in conjunction with tricuspid dysplasia is seen more often.

Question 212

2D and M-mode evaluation:
The features of tricuspid stenosis are similar to those seen with mitral stenosis. There is ………… of the leaflets, reduced ……………. of the valve tips, ……………. motion of the anterior and septal leaflets, a dilated ……., and often, tricuspid …………… The free edges of the valve are …………… displaced, but the ……….. is not displaced. Fig 10.49.

Answer 212

There is doming of the leaflets, reduced excursion of the valve tips, concordant motion of the anterior and septal leaflets, a dilated RA, and often, tricuspid insufficiency. The free edges of the valve are apically displaced, but the annulus is not displaced. Fig 10.49.

Question 213

Tricupsid stenosis: The RV will be dilated if there is tricuspid insufficiency, but will be normal or small if there is no valvular regurgitation.

Answer 213

The RV will be dilated if there is tricuspid insufficiency, but will be normal or small if there is no valvular regurgitation.

Question 214

TS: The tricuspid valve may be nodular, thick, and can be ………….. with short chordae tendinae and abnormal papillary muscles.

Answer 214

The tricuspid valve may be nodular, thick, and can be dysplastic with short chordae tendinae and abnormal papillary muscles. Fig 10.50.

Right to left shunting through a patent foramen oval may exist when right atrial pressure is high enough.

Question 215

Features TS?

Answer 215

Concordant TV motion
Doming of TV leaflets
Reduced EF slope
Prolonged PHT
High PG
Dilated RA
Possible patent foramen

Question 216

M-mode images of TS show:

Answer 216

Paradoxical septal motion where the septum move down toward the LV chamber during diastole secondary to elevated diastolic pressure in the right side of the heart relative to the left.

Question 217

TS: The parietal leaflet of the tricuspid valve will show slow deceleration time because of delayed equilibration of pressure between the RA and ventricle.

Answer 217

The parietal leaflet of the tricuspid valve will show slow deceleration time because of delayed equilibration of pressure between the RA and ventricle.

Question 218

TS: Normally RV pressure……….. rapidly and RA pressure ………. rapidly during early diastole giving the E peak of tricuspid valve motion a rapid ………….. time.

Answer 218

Normally RV pressure increases rapidly and RA pressure decreases rapidly during early diastole giving the E peak of tricuspid valve motion a rapid deceleration time.

Question 219

TS: the LV chamber may be smaller than normal because of poor RV forward stroke volume if the animal is in right-sided CHF and because of the …………….

Answer 219

the LV chamber may be smaller than normal because of poor RV forward stroke volume if the animal is in right-sided CHF and because of the paradoxical septal motion.

Question 220

TS: Color-flow Doppler shows turbulent flow passing through a visibly small orifice. The turbulent signal starts at the …….. of the tricuspid valve leaflets during …………… Fig 10.51.

Answer 220

Color-flow Doppler shows turbulent flow passing through a visibly small orifice. The turbulent signal starts at the tips of the tricuspid valve leaflets during diastole. Fig 10.51.

Question 221

TS: There is no turbulence during systole unless the valve is also ……….

Answer 221

There is no turbulence during systole unless the valve is also insufficient.

Question 222

TS: Spectral Doppler shows high velocity flow greater than ……. m/s and slow ………… during early diastole resulting in a ………..pressure half-time.

Answer 222

Spectral Doppler shows high velocity flow greater than 1.0 m/s and slow deceleration during early diastole resulting in a long pressure half-time. Figure 10.52

Question 223

TS: Use color-flow Doppler to define the imaging plane that align the Doppler cursor along the right ventricular inflow pathway. This imaging plane may be the ……………….

Answer 223

Use color-flow Doppler to define the imaging plane that align the Doppler cursor along the right ventricular inflow pathway. This imaging plane may be the left apical 4 or 5 ch view, a modification of the apical view, or a right parasternal transverse plane.

Question 224

TS: Peak flow velocity is increased in order to maintain normal flow volume through the valve (based upon the continuity equation) and is proportionate to the degree of stenosis. Deceleration of flow during early diastole will be ………. because of the increased time for RV and RA pressure to equalize.

Answer 224

Peak flow velocity is increased in order to maintain normal flow volume through the valve (based upon the continuity equation) and is proportionate to the degree of stenosis. Deceleration of flow during early diastole will be slow because of the increased time for RV and RA pressure to equalize.

Question 225

TS: If right atrial pressure is not very elevated for instance, then it would not take long for the pressure gradient between the atrium and ventricle to diminish as in normal transvalvular flow where we see a rapid deceleration rate of flow during early (E wave) diastole.

Answer 225

If right atrial pressure is not very elevated for instance, then it would not take long for the pressure gradient between the atrium and ventricle to diminish as in normal transvalvular flow where we see a rapid deceleration rate of flow during early (E wave) diastole.

Question 226

The more stenotic and restricted flow is through the valve, the higher the …….. pressure and the longer it will take a pressure gradient to ……………

Answer 226

The more stenotic and restricted flow is through the valve, the higher the RA pressure and the longer it will take a pressure gradient to diminish.

Question 227

TS:Peak trans tricuspid flow velocity increases in response to the high …………. pressure and the effort to maintain normal ………………. flow. The increased flow velocity is proportionate to the severity of the …………

Answer 227

Peak trans tricuspid flow velocity increases in response to the high atrial pressure and the effort to maintain normal forward flow.
The increased flow velocity is proportionate to the severity of the stenosis.

Question 228

TS: Pressure in the right side of the heart is low and even a mean pressure gradient of …….. mmHg in humans suggests the presence of hemodynamically significant TS. Mean pressure gradient is calculated by tracing ………………..

Answer 228

Pressure in the right side of the heart is low and even a mean pressure gradient of 5 mmHg in humans suggests the presence of hemodynamically significant TS. Mean pressure gradient is calculated by tracing the flow velocity integral.

Question 229

TS: Mean PG in man > 5 mmHg = significant TS

Answer 229

TS: Mean PG in man > 5 mmHg = significant TS

Question 230

Cor triatriatum:
Refers to the division of the right or left atrium into cranial and caudal cambers. The membrane on the right side is a ……… of the embryonic right ………………… When the membrane is present within the RA, it is refereed to as for triatriatum dexter.

Answer 230

Refers to the division of the right or left atrium into cranial and caudal cambers. The membrane on the right side is a remnant of the embryonic right sinus venous valve. When the membrane is present within the RA, it is refereed to as for triatriatum dexter.

its presence within the LA is referred to as cor triatriatum sinister, and is the result of improper resorption of the common pulmonary veins during embryonic development.

Question 231

cor triatriatum dexter is typically dound in the …….. and cor triatriatum sinister is primarily found in …………

Answer 231

cor triatriatum dexter is typically dound in the dog, and cor triatriatum sinister is primarily found in cats.

Question 232

Although cor triatriatum may be the only defect present, associated problems include?

Answer 232

Tricupsid valve anomalies, pulmonic stenosis, PDA, patent foramen ovale, MR, persistent left cranial vena cava in man and dogs.

The patent foramen may shunt R-L if it is located within the high pressure chamber of for triatriatum dexter.

Question 233

Cor triatriatum dexter: Echo images of the right atrium show a membrane dividing the chamber into 2. This membrane restricts venous return into the right side of the heart by obstructing …………….. flow and possibly…………… flow.

Answer 233

This membrane restricts venous return into the right side of the heart by obstructing caudal vena cava flow and possibly coronary sinus flow.

Fig 10.53.

Question 234

Cor triatriatum dexter: The membrae varies in it location within the RA in man. The cranial chamber may receive either the ………… and ………. …… or only one of the …………

Answer 234

The cranial chamber may receive either the caudal and cranial vena cava or only one of the vena cava.

Question 235

Cor triatriatum dexter: The tricuspid valve may be within either chamber depending upon the site of the membrane and its angle through the atrium. The majority of dogs have a low pressure distal chamber that receives the ………….. vena cava and contains the tricuspid valve, and a proximal high pressure chamber that receives the ……….l vena cava and the coronary sinus. The tricuspid valve is located within the ……………chamber and may or may not be normal.

Answer 235

The majority of dogs have a low pressure distal chamber that receives the cranial vena cava and contains the tricuspid valve, and a proximal high pressure chamber that receives the caudal vena cava and the coronary sinus. The tricuspid valve is located within the distal chamber and may or may not be normal.

Question 236

Cor triatriatum dexter: Atypical angles and planes through the RA are sometimes necessary in order to visualize the membrane. The membrane may also form a ………… type of connection between the cranial and caudal chambers as opposed to forming a …………… into two chambers.

Answer 236

Atypical angles and planes through the RA are sometimes necessary in order to visualize the membrane. The membrane may also form a tunnel type of connection between the cranial and caudal chambers as opposed to forming a distinct division into two chambers.

Question 237

Cor triatriatum dexter: The perforation, which allows blood to flow from the cranial to the caudal chamber, varies in size and degree of obstruction to flow.It is often not apparent without color Doppler echo.

Answer 237

The perforation, which allows blood to flow from the cranial to the caudal chamber, varies in size and degree of obstruction to flow.It is often not apparent without color Doppler echo.

Question 238

Cor triatriatum dexter: The membrane may be seen on right parastenal transverse or 4 ch views that show the vena cava as well as on apical 4 and 5 ch views.

Answer 238

Cor triatriatum dexter: The membrane may be seen on right parastenal transverse or 4 ch views that show the vena cava as well as on apical 4 and 5 ch views.
Rotate and fan the transducer in multiple directions in order for the sound beam to interrogate all aspects of the RA.

Question 239

Spectral or color-flow Doppler can confirm the presence of obstruction. A pressure gradient between the 2 chambers will exist, and turbulent flow can be documented. A diffuse membrane with many fenestrations, the …………, is a variant of this defect, and in most cases this is not hemodynamically significant.

Answer 239

A diffuse membrane with many fenestrations, the Chiari network, is a variant of this defect, and in most cases this is not hemodynamically significant.

Question 240

Cor triatriatum dexter: The cranial chamber and vena cava will dilate if a significant obstruction to flow into the right side of the heart exists. The rest of the heart may appear perfectly normal.

Answer 240

The cranial chamber and vena cava will dilate if a significant obstruction to flow into the right side of the heart exists. The rest of the heart may appear perfectly normal.

Question 241

Any young animal with signs of ………. should be examined thoroughly for triatriatum dexter. As an isolated defect, no murmur is typically heard.

Answer 241

Any young animal with signs of right-sided heart failure should be examined thoroughly for triatriatum dexter. As an isolated defect, no murmur is typically heard.

Question 242

Cor triatriatum sinister:

The membrane divides the left atrium into cranial and caudal chambers.

Answer 242

The membrane divides the left atrium into cranial and caudal chambers. Fig 10.54.

Question 243

Cor triatriatum sinister: This membrane should be differentiated from?

Answer 243

Supravalvular mitral stenosis.

Question 244

How can cor triatriatum sinister be differentiated from supravalvular mitral stenosis?

Answer 244

The fibrous ring associated with mitral stenosis is always distal the fossa ovals, closer to the mitral valve, and inferior to the left auricular appendage.

The membrane of cor triatriatum sinister is located proximal to the fossa ovalis near the base of the atrium. The left auricular appendage is in the low pressure compartment of cor triatriatum sinister.

Question 245

Cor triatriatum sinister: The pulmonary veins typically empty into the …………. chamber (high pressure chamber) ,and the …………… chamber (low pressure chamber) contains the mitral valve and left auricular appendage.

Answer 245

The pulmonary veins typically empty into the proximal chamber (high pressure chamber) ,and the distal chamber (low pressure chamber) contains the mitral valve and left auricular appendage.

Question 246

Cor triatriatum sinister:
-Membrane: proximal to ………..
-Left auricular appendage is in
the ………….. pressure chamber, ……..to the membrane

Answer 246

-Membrane: proximal to fossa ovalis.
-Left auricular appendage is in
the low pressure chamber, distal to membrane

Question 247

Supravalvular mitral stenosis:

• Membrane: ……… to fossa ovalis.
• Left auricular appendage is in the ………. pressure chamber, ………… to the membrane.

Answer 247

• Membrane: Distal to fossa ovalis.

- Left auricular appendage is in the high pressure chamber, proximal to the membrane.

Question 248

Cor triatriatum sinister can be subcategorized into 3 types depending upon the shape and location of the membrane and its relationship with the pulmonary veins and interatrial septum. Which ones?

Answer 248

Type A, B and C

The type and location of the membrane plays a large role in resulting clinical signs and development of congestive heart failure. Doppler can confirm the presence of a pressure gradient. Significant gradients may lead to left heart failure and pulmonary hypertension.

Question 249

Type A cor triatriatum has a ……………membrane that connects the proximal and distal chambers. The pulmonary veins in this type of membrane may all enter the proximal chambers, or there may be anomalous drainage into the right atrium.

Answer 249

funnel-like membrane that connects the proximal and distal chambers. The pulmonary veins in this type of membrane may all enter the proximal chambers, or there may be anomalous drainage into the right atrium.

Question 250

Type B cor triatriatum has a ……….. membrane with the fossa ovalis located within the ……… chamber. Pulmonary veins may all enter the ……………….. chamber and blood shunts to the ………., or they may be divided between both portions of the atrium.

Answer 250

wedge-shaped membrane with the fossa ovalis located within the proximal chamber. Pulmonary veins may all enter the proximal chamber and blood shunts to the right atrium, or they may be divided between both portions of the atrium.

Question 251

Type C cor triatriatum sinister involves a …………..where the foramen oval is located in the ………….. chamber with all pulmonary veins entering the …………… pressure chamber.

Answer 251

involves a midline membrane where the foramen oval is located in the proximal chamber with all pulmonary veins entering the distal low pressure chamber.

Question 252

Tetralogy of Fallot:

The combination of ……………..creates a congenital anomaly

Answer 252

The combination of pulmonary stenosis, right ventricular hypertrophy, over-riding aorta, and ventricular septal defect creates a congenital anomaly

Question 253

Tetralogy of Fallot: When the pulmonic stenosis is severe enough to elevate right-sided systolic pressures beyond those found within the LV and systemic circulation, the blood will flow from …………….

Answer 253

When the pulmonic stenosis is severe enough to elevate right-sided systolic pressures beyond those found within the LV and systemic circulation, the blood will flow from right to left through the VSD.

Question 254

Not all animals with Tetralogy of Fallot have right to left shunting, and ………… tetralogies can occur.

Answer 254

Not all animals with Tetralogy of Fallot have right to left shunting, and acyanotic tetralogies can occur.

Question 255

Several canine breeds are predisposed to the development of Tetralogy of Fallot: such as?

Answer 255

Keeshonds and bulldogs

Also reported complex congenital defect in horses and cats.

Question 256

The pulmonic stenosis in animals with Tetralogy of Fallot is similar to isolated PS: the defect may be …………………. The majority of dogs appear to have valvular stenosis.

Answer 256

The pulmonic stenosis in animals with Tetralogy of Fallot is similar to isolated PS: the defect may be valvular, subvalvular or both. The majority of dogs appear to have valvular stenosis.

Question 257

Tetralogy of Fallot: Hypoplasia of the pulmonary artery is often present, and a poststenotic dilation is absent in most of these cases.

Answer 257

Hypoplasia of the pulmonary artery is often present, and a poststenotic dilation is absent in most of these cases.

Question 258

Tetralogy of Fallot: Spectral Doppler of pulmonary flow can document the degree of obstruction. Pressure gradients in excess of ………. are consistent with right to left shunting or bidirectional shunting.

Answer 258

Spectral Doppler of pulmonary flow can document the degree of obstruction. Pressure gradients in excess of 100 are consistent with right to left shunting or bidirectional shunting.

Question 259

Tetralogy of Fallot: When severe subvalvular stenosis or hypoplasia of the pulmonary valve annulus is present, it is sometimes difficult to obtain an adequate image of the pulmonary outflow tract and valve. Spectral Doppler of pulmonary artery flow is also often difficult to obtain in these animals. Color-flow Doppler will delineate the boundaries of the outflow tract and may help position of the Doppler cursor. Examine all 4 views for obtaining the pulmonary artery. If pulmonary flow cannot be obtained, check for tricuspid insufficiency as an alternative way to derive RV pressures.

Answer 259

When severe subvalvular stenosis or hypoplasia of the pulmonary valve annulus is present, it is sometimes difficult to obtain an adequate image of the pulmonary outflow tract and valve. Spectral Doppler of pulmonary artery flow is also often difficult to obtain in these animals. Color-flow Doppler will delineate the boundaries of the outflow tract and may help position of the Doppler cursor. Examine all 4 views for obtaining the pulmonary artery. If pulmonary flow cannot be obtained, check for tricuspid insufficiency as an alternative way to derive RV pressures.

Question 260

Tetralogy of Fallot: Severe RV hypertrophy is always present as a consequence of the pressure overload generated by the pulmonic stenosis. The right ventricular cavity is usually small unless …………….. are present.

Answer 260

Severe RV hypertrophy is always present as a consequence of the pressure overload generated by the pulmonic stenosis. The right ventricular cavity is usually small unless valvular regurgitation are present.

Question 261

Is LV chamber size big or small in Tetralogy of Fallot patients?

Answer 261

LV chamber size is also small secondary to poor preload when Tetralogy of Fallot is present regardless of whether the shunt is right to left or left to right.

Question 262

Tetralogy of Fallot: the LV will appear to be concentrically hypertrophied, and invasive studies of left ventricular pressures in dogs with Tetralogy of Fallot reveal LV pressures as low as ….. in some.

Answer 262

Tetralogy of Fallot: the LV will appear to be concentrically hypertrophied, and invasive studies of left ventricular pressures in dogs with Tetralogy of Fallot reveal LV pressures as low as 36 in some.

Question 263

A left to right shunt would typically volume overload the LV and sometimes the RV, but when a moderate to severe ……………. is present, there is decreased volume flowing through the ……………. and into the left side of the heart.

Answer 263

A left to right shunt would typically volume overload the LV and sometimes the RV, but when a moderate to severe pulmonic stenosis is present, there is decreased volume flowing through the pulmonary circulation and into the left side of the heart.

Question 264

Although logically a right to left shunt should volume overload the left ventricle, the ……………… causes the shunted blood to flow directly into the ………., and the left ventricle never receives the volume. The severe ……………, which must be present with right to left shunts, additionally results in decreased preload within the left ventricular chamber.

Answer 264

Although logically a right to left shunt should volume overload the left ventricle, the overriding aorta causes the shunted blood to flow directly into the aorta, and the left ventricle never receives the volume. The severe pulmonic stenosis, which must be present with right to left shunts, additionally results in decreased preload within the left ventricular chamber.

Question 265

Tetralogy of Fallot:

LV concentric hypertrophy pattern:
Why?

Answer 265

• Pseudohypertrophy

- Due to decreased preload.

Question 266

Tetralogy of Fallot: The VSD is usually very obvious and large. The interventricular septum is aligned with the center of the aorta. Fig 10.56.
Only when septa …………. is very severe will the defect become less obvious.

Answer 266

The VSD is usually very obvious and large. The interventricular septum is aligned with the center of the aorta. Fig 10.56.
Only when septa hypertrophy is very severe will the defect become less obvious.
Manipulating the transducer and sound beam in slightly different directions can help define whether the septum is indeed intact and whether the aorta is overriding.

Question 267

Tetralogy of Fallot: Color-flow and spectral Dopper will show shunting of blood across the defect no matter how hard it is to elucidate on RT images. The direction of shunting may be L-R and …………. on spectral displays, bidirectional …….. velocity flow, or R-L ……….. flow on spectral tracing.

Answer 267

The direction of shunting may be L-R and positive on spectral displays, bidirectional low velocity flow, or R-L negative flow on spectral tracing.
Fig 10.57

Pressure gradients are derived just as they are for isolated VSD.

Question 268

Tetralogy of Fallot: When a pressure gradient can be obtained from both the pulmonic stenosis and the VSD, they should make sense in that the gradient across the septal defect should reflect…………-sided pressures and the degree of ………………

Answer 268

When a pressure gradient can be obtained from both the pulmonic stenosis and the VSD, they should make sense in that the gradient across the septal defect should reflect right-sided pressures and the degree of pulmonic stenosis.

Question 269

Tetralogy of Fallot: A pulmonary stenosis gradient of 130 mmHg for instance, suggesting a RV pressure of approximately 140 to 150 mmHg, should be approximately .. to …. if systemic systolic pressure is 120 mmHg.

Answer 269

A pulmonary stenosis gradient of 130 mmHg for instance, suggesting a RV pressure of approximately 140 to 150 mmHg, should be approximately 20 to 30 if systemic systolic pressure is 120 mmHg.

Question 270

Tetralogy of Fallot: A dog with a blood pressure of 120 mmHg and a gradient of 60 mmHg across a L-R flowing septal defect suggests that right ventricular pressures are about …… mmHg, and the pulmonic stenosis would therefore have a gradient of approximately …. to ….. mmHg if pulmonary pressure are assumed to be about 10 to 20 mmHg.

Pulmonary pressure will typically be lower than the …. to …. mmHg present in healthy dogs because of the pulmonary stenosis however.

Answer 270

Tetralogy of Fallot: A dog with a blood pressure of 120 mmHg and a gradient of 60 mmHg across a L-R flowing septal defect suggests that right ventricular pressures are about 60 mmHg, and the pulmonic stenosis would therefore have a gradient of approximately 40 to 50 mmHg if pulmonary pressure are assumed to be about 10 to 20 mmHg.

Pulmonary pressure will typically be lower than the 20 to 25 mmHg present in healthy dogs because of the pulmonary stenosis however.

Question 271

Tetralogy of Fallot: When multiple defects are present, always cross-check the derived gradients. They should make sense, and if they do not, one of the gradients is in error.

Answer 271

When multiple defects are present, always cross-check the derived gradients. They should make sense, and if they do not, one of the gradients is in error.

Question 272

Tetralogy of Fallot: Bubble studies can document the presence of a right to left shunt across a VSD. Inject a milliliter or 2 of saline that has been shaken vigorously into a peripheral vein. The micro bubbles will appear echo dense on echocardiographic images, and they will be seen flowing into the LV outflow tract when a reverse shunt is present. When a left to right shunt is present, the defect is harder to document with bubble studies unless an area of …………. contrast is seen.

Answer 272

When a left to right shunt is present, the defect is harder to document with bubble studies unless an area of negative contrast is seen.

Question 273

Tetralogy of Fallot: Significant septal hypertrophy may at times create a secondary obstruction in the left ventricular outflow tract. Look for the following M-mode signs of obstruction:

Answer 273

Systolic anterior mitral valve motion and early systolic anterior aortic valve closure. Fig 10.58

Question 274

Tetralogy of Fallot: Spectral and color-flow Doppler may show aliased and high velocity signals when left-sided obstruction is present. A left-sided obstruction, if present, is usually ………. to the ventricular septal defect, and analysis of pressure gradients should reflect this. In other words, systemic pressures are used in assessing the shunt and RV pressures, not the LV pressures as is done with isolated ventricular septal defects.

Answer 274

Spectral and color-flow Doppler may show aliased and high velocity signals when left-sided obstruction is present. A left-sided obstruction, if present, is usually proximal to the ventricular septal defect, and analysis of pressure gradients should reflect this. In other words, systemic pressures are used in assessing the shunt and RV pressures, not the LV pressures as is done with isolated ventricular septal defects.