Evaluation of size, function, and hemodynamics Flashcards
Subjective assessment: Right parasternal long-axis LV outflow view:
When a clear right ventricular wall is seen; its thickness is usually about ………… the thickness of the LV free wall
When a clear right ventricular wall is seen; its thickness is usually about 1/3 to 1/2 the thickness of the LV free wall.
An increase in right ventricular wall thickness suggests the presence of right ventricular hypertrophy. Fig 4.1
The interventricular septum is typically slightly …………… than the LV free wall in dogs and cats.
The interventricular septum is typically slightly thicker than the LV free wall in dogs and cats.
In the presence of right ventricular hypertrophy, the interventricular septum may also be hypertrophied so compare the right ventricular wall to the …………
In the presence of right ventricular hypertrophy, the interventricular septum may also be hypertrophied so compare the right ventricular wall to the LV free wall.
When quantitative measurements reveal a thin LV wall, then the relationship of right ventricular wall thickness to the left ventricular wall thickness should be reevaluated.
Left ventricular outflow view: subjective assessment in dogs:
There is no curving of the IVS (should be straight) IVS and LVW are similar in size. IVS does not extend into LVOT RW wall is about 1/2 thickness of LVW RV chamber size is about 1/3 of LV chamber size LA and AO are similar in size MV excursion almost to IVS There are no valvular lesion
Displacement of the IVS toward the left side of the heart tends to indicate ….
Right ventricular volume or pressure overload, or in some cases may be a manifestation of left ventricular hypertrophy. Fig 4.4
Many normal cats have a slight upward ………. of the interventricular septum (Fig 4.5).
Many normal cats have a slight upward curve of the interventricular septum (Fig 4.5).
The base of the inter ventricular septum in normal cats tends to protrude into the left ventricular outflow tract slightly.
Biventricular dilation often keeps the pressure relationship between both ventricles the same, and bowing of the septum will not be present.
Biventricular dilation often keeps the pressure relationship between both ventricles the same, and bowing of the septum will not be present.
The relationship of right ventricular size to left ventricular size in a normal heart should be approximately …..to ………
The relationship of right ventricular size to left ventricular size in a normal heart should be approximately 1 to 3.
Fig 4.1, 4.6
The interventricular septum in all animals but cats should also not extend into the left ventricular outflow tract.
The width of the outflow tract should be about the same as the wist of the ………….
The interventricular septum in all animals but cats should also not extend into the left ventricular outflow tract.
The width of the outflow tract should be about the same as the wist of the aortic root. Fig 4.7.
The relationship of wall thicknesses and chamber sizes are different in neonates.
The relationship of wall thicknesses and chamber sizes are different in neonates.
Right ventricular wall thickness is as great or greater than LV wall thickness in all neonates, and the volume may remain large for several weeks.
Assessment of cardiac size in neonates is often a challenge, and unless there is clear pathology, re-evaluation of the heart may be necessary after the animal is 3-6 months old.
Assessment of cardiac size in neonates is often a challenge, and unless there is clear pathology, re-evaluation of the heart may be necessary after the animal is 3-6 months old.
Left ventricular outflow view: Assessment cats:
Slight bowing of the IVS is possible IVS and LVW are similar in size IVS extends slightly into LVOT RV wall is about 1/2 thickness of LVW RV chamber size is about 1/3 of LV chamber size LA is up to 1,7 times size of the Ao MV excursion is almost to IVS There are no valvular lesions.
Cats tend to have a larger atrium with respect to the aorta than dogs, and the visual ratio of left atrium to aorta may be 1,6 to 1,0 in healthy cats.
Cats tend to have a larger atrium with respect to the aorta than dogs, and the visual ratio of left atrium to aorta may be 1,6 to 1,0 in healthy cats.
Fig 4,5 and 4,7
The ratio of left atrium to aorta in all animals can be deceiving if the aortic root itself is small or large, and so this ratio is only a rough assessment of atrial size.
The ratio of left atrium to aorta in all animals can be deceiving if the aortic root itself is small or large, and so this ratio is only a rough assessment of atrial size.
Left atrial size …………… within hours after birth as the ductus and foramen close resulting in …………….. atrial volume so echo exams even at several weeks of age should show the same left atrial to aortic root ration as that seen in mature animals.
Left atrial size decreases within hours after birth as the ductus and foramen close resulting in decreased atrial volume so echo exams even at several weeks gf age should show the same left atrial to aortic root ration as that seen in mature animals.
The tip of the septal mitral valve leaflet should almost touch the ventricular septum during diastole. There should be no ……………or ……………… shape to the leaflet at end diastole.
The tip of the septal mitral valve leaflet should almost touch the ventricular septum during diastole. There should be no convex or concave shape to the leaflet at end diastole.
Fig 4.8
An abnormal shape at end diastole cold indicate ….(3)?
….decreased LV ejection fraction, severe aortic insufficiency, or mitral stenosis.
The valve itself should appear to be the same thickness throughout its length from the base of the leaflet, where it attaches near the aortic root, to its tip. When is this best assessed?
During diastole when the valve is wide open and not during systole when the leaflet edges are touching each other and may appear thick.
Do not mistake chordae teninae for lesions as they extend from the leaflets especially when the valve is closed. (Fig 4.9).
Smoke-like echoes of circulating blood have been reported in experimental healthy seated dogs. It is seen more readily with high frequency transducers than low frequency transducers in the same animal because of increased lateral and longitudinal resolution. It has not been reported in clinically healthy unseated or unanesthetized dogs…..(är väl inte så?).
Smoke-like echoes of circulating blood have been reported in experimental healthy seated dogs. It is seen more readily with high frequency transducers than low frequency transducers in the same animal because of increased lateral and longitudinal resolution. It has not been reported in clinically healthy unseated or unanesthetized dogs…..(är väl inte så?).
Right parasternal long-axis four chamber view:
Right ventricular chamber size appears slightly larger in right parasternal long-axis four chamber views than in the right parasternal inflow outflow long-axis plane, but the ………..relationship with the left ventricle should still predominate.
Right parasternal long-axis four chamber view.
Right ventricular chamber size appears slightly larger in right parasternal long-axis four chamber views than in the right parasternal inflow outflow long-axis plane, but the 1-to-3 relationship with the left ventricle should still predominate.
Right parasternal long-axis four chamber view: The interventricular septum should extend straight to the apex of the heart, parallel to the LV wall with only a slight deviation to the right at the ……. of the septum near the …………………
The inter ventricular septum should extend straight to the apex of the heart, parallel to the LV wall with only a slight deviation to the right at the base of the septum near the mitral valve annulus. Fig 4.10.
Right parasternal long-axis four chamber view assessment:
- There is not curving of the IAS or IVS
- There are no valvular lesions.
Right parasternal long-axis four chamber view assessment:
-The atrial septum should also be straight with no curvature to the right or left side of the heart.
-There is often a thinner area midway along the atrial septum that at times looks like an opening.
This thin area of tissue is the …………… , the membrane that closed the foramen ovale.
-The atrial septum should also be straight with no curvature to the right or left side of the heart.
-There is often a thinner area midway along the atrial septum that at times looks like an opening. Fig 4.11
This thin area of tissue is the fossa ovals, the membrane that closed the foramen ovale.
The right atrium may appear somewhat smaller than the left atrium in this view.
Right parasternal long-axis four chamber view assessment:
The tricuspid annulus is slightly closer to the ……… of the heart than the mitral annulus but not by more than a millimeter or two.
The tricuspid annulus is slightly closer to the apex of the heart than the mitral annulus but not by more than a millimeter or two.
Right parasternal long-axis four chamber view assessment:
Right ventricular to left ventricular free wall thickness ratios are often easier to visualize in this image plane and should be about …….to……….
Right ventricular to left ventricular free wall thickness ratios are often easier to visualize in this image plane and should be about 0.5 to 1.0
The 4 ch view of the heart is excellent for examination of the arterioventricular valves. Valve thickness should remain the same from the base of the leaflet to its tip. The closed AV valve should have a …………. cure toward the ventricular chamber as they extend from the annulus.
The 4 ch view of the heart is excellent for examination of the arterioventricular valves. Valve thickness should remain the same from the base of the leaflet to its tip. The closed AV valve should have a concave cure toward the ventricular chamber as they extend from the annulus. Fig 4.10
Right parasternal transverse left ventricle: How should a good transverse view of the LV chamber at the level of the papillary muscles be?
Uniform shortening
Circular outer shape
Round and symmetrical
Mushroom LV internal shape
The papillary muscles should be symmetrical and similar in size,
The septum should not be flattened.
The septum and free wall, excluding the papillary muscles, should be similar in size in small animals.
Right ventricular pressure or volume overload often flatten the septum creating a triangular-shaped LV chamber.
Right ventricular pressure or volume overload often flatten the septum creating a triangular-shaped LV chamber.
The right ventricular chamber should be ………….. in all animals.
The right ventricular chamber should be crescent-shaped in all animals.
Transverse sections of papillary muscles and trabecular irregularities on the right ventricular side of the septum are common and normal in this view. Fig 4.13, 4.14
Right parasternal transverse heart base:
Diameters of the ……… and pulmonary artery at the level of their valves should be similar on right parasternal transverse images of the heart base.
Diameters of the aorta and pulmonary artery at the level of their valves should be similar on right parasternal transverse images of the heart base.
Fig 4.15
Enlargement of the pulmonary artery may be seen with ……….. or ………………..
Enlargement of the pulmonary artery may be seen with poststenotic dilation or volume overload.
Pulmonary valve cusps often have a slight …………….. curvature to them.
Pulmonary valve cusps often have a slight upward curvature to them.
Should there be any change in diameter of the pulmonary artery from the level of the pulmonary valve to the bifurcation?
There should be no change in diameter of the pulmonary artery from the level of the pulmonary valve to the bifurcation.
Diameters of the aorta and left atrium in the dog should also be fairly close to the same size at the right parasternal transverse heart base:
Diameters of the aorta and left atrium in the dog should also be fairly close to the same size at the right parasternal transverse heart base.
The cat has a larger left atrium compared to the aorta.
Quantitative measurement of size:
The use of tissue harmonic imaging, although it enhances images, does lead to small increase in ……?
The use of tissue harmonic imaging, although it enhances images, does lead to small increase in measurements of wall and septal thicknesses and small decreases in chamber sizes. These differences are probably minimal but should be kept in mind.
Reference ranges in this book are derived from fundamental imaging.
Measurements of cardiac size obtained from 2D images involve freezing the image at?
End diastole and at end systole.
End diastole is identified as the largest LV dimension just before or as the mitral valve?
The mitral valve closes?
End systolic frames are identified as the smallest ventricular chamber size just before the mitral valve …..
The mitral valve opens?
Measurements of chamber size are obtained from the endocardial surface of the ventricular septum to the endocardial surface of the LV wall.
Measurements of chamber size are obtained from the endocardial surface of the ventricular septum to the endocardial surface of the LV wall.
This is called the trailing edge to leading edge method.
Left ventricular wall measurements are taken from …..?
Left ventricular wall measurements are taken from the top of the wall, including the endocardial surface to the top of the pericardial sac.
Septal measurement however are made from …………?
Septal measurement however are made from the trailing edge of the right side of the septum to the trailing edge of the LV side of the septum.
Therefore, the line defining the top of the inter ventricular septum is not included in the septal thickness measurement.
Are measuring planes similar for dogs and cats?
Yes. The only exception involves measurement of the LV wall, septum, and chamber from the right parasternal long-axis view in the dog. The measurements in dogs were derived from images that do not have a well-defined aorta, while the measurements in cats were obtained from standard LV inflow imaging planes.
Left ventricular chamber, wall, and septum:
Measurements of the minor dimension through the LV chamber are made from a right parasternal long-axis view that includes part of the LV outflow tract and aortic valve, the left atrium, and mitral valve.
Measurements of the minor dimension through the LV chamber are made from a right parasternal long-axis view that includes part of the LV outflow tract and aortic valve, the left atrium, and mitral valve.
Fig 4.17.
A line perpendicular to the septum and the wall just beyond the tips of the mitral valves at the largest LV dimension when they are wide open is used to identify the measurement location for this LV diameter.
Advance the image until the largest and smallest chamber sizes corresponding to diastolic and systolic dimensions respectively are identified.
The minor chamber size may also be measured from the right parasternal short-axis view of the heart at the level of the chordae tendinae. Fig 4.18.
The minor chamber size may also be measured from the right parasternal short-axis view of the heart at the level of the chordae tendinae. Fig 4.18.
A line connecting the septum and wall, dividing the ventricle into equal and symmetrical image halves is used to identify measuring points. The line should be perpendicular to a line connecting the chordae on each side of the image.
Wall and septal thicknesses are measured from either long-or short-axis imaging planes along the same lines used to measure ventricular chamber dimensions. The trailing edge method is used for the septum, and the leading edge method is used for the wall.
Wall and septal thicknesses are measured from either long-or short-axis imaging planes along the same lines used to measure ventricular chamber dimensions. The trailing edge method is used for the septum, and the leading edge method is used for the wall.
Can LV length be measured using M-mode
LV lenght is a measurement that does not have a corresponding M-mode parameter.
LV length measurement is obtained from ..?
The right parasternal long–axis four chamber view or a modified right parasternal long-axis LV outflow view where the LA is no longer visible and only a portion of the ascending aorta is seen.
A clear definition of the LV apex should be seen.
On the 4 chamber plane, a line defining the mitral annulus is drawn.
The measurement of LV length is then made along a line connecting the apex to the point that bisects the annulus equally Fig 4.19
On the 4 chamber plane, a line defining the mitral annulus is drawn.
The measurement of LV length is then made along a line connecting the apex to the point that bisects the annulus equally Fig 4.19
The measurement of LV length is then made along a line connecting the apex to the point that bisects the annulus equally.
On the modified view, 2 slightly different locations may be used to measure LV length. How?
A reference line defining the aortic annulus is drawn.
Fig 4.20.
One measurement extends from the apex of the LV to a point midway across the aortic valve.
Another measurement can be taken along a line that extends from the apex to the point where the aortic valve and mitral valve meet.
Can left parasternal apical 4 ch views also be used to measure LV length on?
Left parasternal apical 4 ch views can also be used to measure LV length. Fig 4.21.
A reference line is drawn along the ventricular side of the mitral annulus. The length is measured along a line extending from the apex to a point that bisects the reference line in half.
LV mass.
Cardiac hypertrophy usually involves an increase in …..
LV wall thickness.
It is not always visibly apparanct since there may be wall thinning as the heart dilated. This increase in mass can be quantified by several methods, including angiography, M-mode echo, and 2 D echo.
M-mode echo assumes a hypertrophy pattern that remains consistent ………………..
M-mode echo assumes a hypertrophy pattern that remains consistent throughout the heart.
2 D assessment of the LV mass has proven to be superior to M-mode measurement of mass because the entire geometry of the heart is taken into consideration.
2D methods of determining mass have been tested in the dog and proven to be quite accurate with a correlation coefficient of 0.98 between echo determined ventricular mass and necropsy determined mass in dogs.
2 D assessment of the LV mass has proven to be superior to M-mode measurement of mass because the entire geometry of the heart is taken into consideration.
2D methods of determining mass have been tested in the dog and proven to be quite accurate with a correlation coefficient of 0.98 between echo determined ventricular mass and necropsy determined mass in dogs.
Is there an effect of sex on ventricular mass?
No, but there is significant curvilinear or second order correlation between BW and ventricular mass in dogs.
Mass determination is an involved process, and it is not routinely performed during a clinical exam. How can this be measured?
External and internal volumes of the heart are measured, and the difference between the 2 should equal myocardial volume.
The myocardial volume is the multiplied by density in order to calculate ventricular mass.
Mass should remain constant throughout the cardiac cycles, and does so with a high correlation (0.92) between measurements taken in diastole and systole in the dog.
Mass should remain constant throughout the cardiac cycles, and does so with a high correlation (0.92) between measurements taken in diastole and systole in the dog.
Papillary muscles and trabecula are easier to differentiate and eliminate in endocardial traces when they are made during diastole however.
Measurements are taken in diastole just before atrial contraction. This created the least amount of cardiac motion and the best visualization of muscle boundaries.
Only one method of mass determination using the long-axis and transverse views will be described here, but 2 methods of measurement for mass determination have been studied in the dog. One is based on an assumption that the heart is shaped like a truncated ellipse. The other uses basically the same approach to mass determination but follows a simpler area length methodology. Is one more accurate than the other?
Neither is more accurate than the other.
The truncated ellipse has proven to eb accurate in both normal and hypertrophied canine hearts and during both diastole and systole. Fig 4.22.
How is volume determined?
Volume is determined from the longest possible apical 4-ch view of the heart.
This method of analysis requires measurements of chamber size to be taken along 3 directions on the apical 4 ch view.
Fig 4.22:
The minor axis is located at the tip of the papillary muscles at the point of chordal attachment (b).
The long axis of the heart is divide into both a semi major (a) and a truncated semi major axis (d).
Fig 4.22:
The minor axis is located at the tip of the papillary muscles at the point of chordal attachment (b).
The long axis of the heart is divide into both a semi major (a) and a truncated semi major axis (d).
Fig 4.22: The minor axis is the dividing line between the semi major axis and the truncated semi major axis.
The minor axis is also represented by the diameter of the LV on both long-and short-axis views of the heart at the level of the chordae.
Fig 4.22: The minor axis is the dividing line between the semi major axis and the truncated semi major axis.
The minor axis is also represented by the diameter of the LV on both long-and short-axis views of the heart at the level of the chordae.
Fig 4.22:
In addition to the measurements of LV length and width, wall thickness (t) is measured. On the transverse plane at the tips of papillary muscles, both the epicardial and endocardial surfaces are traced. The papillary muscles and any trabeculae are not included in the trace.
Subtracting the systolic area from the diastolic area gives a mean wall thickness measurement. All the measurements are inserted into the equation shown in fig 4.22 to calculate volume.
In addition to the measurements of LV length and width, wall thickness (t) is measured. On the transverse plane at the tips of papillary muscles, both the epicardial and endocardial surfaces are traced. The papillary muscles and any trabeculae are not included in the trace.
Subtracting the systolic area from the diastolic area gives a mean wall thickness measurement. All the measurements are inserted into the equation shown in fig 4.22 to calculate volume.
The equation calculated volume of the LV when the epicardium is traced and volume of the ventricle when the endocardium is traced.
Subtracting the 2 volumes results in volume of the ventricular myocardium. Mass is then calculated by multiplying the volume by myocardial specific gravity, which is?
Mass = 1.05 V
The echo derived mass has an excellent correlation with post mortem mass (r = 0.98) in dogs.
Once echo mass is determined, the value is inserted into a regression equation that correlates echo-derived mass to actual post mortem mass as follows?
Echo mass =
0.9 (actual weight) + 4.2
Where actual weight is in kg.
Aorta and left atrium:
Left atrial size can be measured from the ?
Right parastenral long-axis 4 ch view in the dog. Fig 4.19
A reference line connecting the mitral annulus is drawn on the atrial side of the valve. The anterior posterior dimension of the LA is measured by drawing a line that as closely as possible bisects the atrium into equal halves and is parallel to the line defining the annulus.
A reference line connecting the mitral annulus is drawn on the atrial side of the valve. The anterior posterior dimension of the LA is measured by drawing a line that as closely as possible bisects the atrium into equal halves and is parallel to the line defining the annulus.
An apical basilar dimension may also be measured on 2D images. How is this done?
By drawing a line perpendicular to the line defining the annulus and again dividing the atria as closely as possible into equal halves. Fig. 4.19. The apical basilar measurement extends from the base of the atrium to the reference line, and not the valve leaflet themselves.
The LA in dogs may also be measured on…?
Left parasternal apical 4 ch views, which maximize LA size. Fig 4.21
This plane may be slightly different than the one used to measure LV length since each chamber should be maximized for the parameter to be measured.
Left parasternal apical 4 ch views:
A line defining the mitral annulus on the atrial side is used as a reference for the other measuring points. The basal apical measurement is made from a line that as closely as possible divides the atrium into equal halves and is perpendicular to the reference line. The basal apical measurement starts at the base of the atrial septum and stops at the reference line. A lateral medial measurement can also be made. This is done from aline that divides the atrium into equal halves and is parallel to the reference line at the annulus.
A line defining the mitral annulus on the atrial side is used as a reference for the other measuring points. The basal apical measurement is made from a line that as closely as possible divides the atrium into equal halves and is perpendicular to the reference line. The basal apical measurement starts at the base of the atrial septum and stops at the reference line. A lateral medial measurement can also be made. This is done from aline that divides the atrium into equal halves and is parallel to the reference line at the annulus.
Which view is used instead of the long-axis 4 ch view to measure LA size in cats?
The long-axis LV inflow outflow view.
The frame just before mitral valve opening is used. The largest LA dimension is measured along a line that is parallel to the mitral annulus.
Aortic root size from right parasternal long-axis are made at both the level of the valve and at the maximum distance across the sinus of Valsalva.
Fig 4.23
Which imaging plane is use to measure LA size in dog and cat?
The transverse image at the level of the aorta and LA.
All 3 aortic valve cusps must be seen with symmetry. In other words, all cusps should be relaivel equal in size. This assures that the image is a s close to a true transverse imaging plane as possible.
The left auricular appendage and atrial septum should also be clearly seen.
The frame just after aortic valve closure is selected, and the LA is measured along a line that is an extension of the line that defines the junction between the non coronary and left coronary cusps.
The frame just after aortic valve closure is selected, and the LA is measured along a line that is an extension of the line that defines the junction between the non coronary and left coronary cusps.
Fig 4.24
The area of the LA may be obtained from any of these planes. Fig 4.24, 4.25. Trace the endocardial surface of the LA along the inside of the mitral valve and exclude the pulmonary veins.
The area of the LA may be obtained from any of these planes. Fig 4.24, 4.25. Trace the endocardial surface of the LA along the inside of the mitral valve and exclude the pulmonary veins.
Area calculation of the aortic root is made at the level of the valves on transverse images.
2D transverse heart base: LA/AO: Image
- All 3 aortic valve cusps seen
- Good atrial septum seen
- Good left auricle seen
- First frame just after AO valve closes
2D transverse heart base:
Measurement location:
- Measure AO along line defined by the non coronary and right coronary cusps
- Measure LA along line defined by non coronary and left coronary cusps.
- Internal dimensions.
Aortic root measurements are made from a right parasternal long-axis view that maximizes the aorta at the expense of the left atrium. Fig 4.23
Aortic root measurements are made from a right parasternal long-axis view that maximizes the aorta at the expense of the left atrium. Fig 4.23
A well-defined aorta and 2 valve cusps should be seen.
A line defining the annulus is used to measure the aortic diameter. Additionally, the distance across the sinus of Valsalva can also be measured.
The largest dimension is selected and is measured along a line parallel to the one defining the aortic valve annulus.
The left parasternal long-axis LV outflow view is also used to measure aortic root size. The annulus is measured on the aortic side of the valve, and this is also used as a reference line. Fig 4.26.
The left parasternal long-axis LV outflow view is also used to measure aortic root size. The annulus is measured on the aortic side of the valve, and this is also used as a reference line. Fig 4.26.
The ascending aorta distal to the sinus may also be measured.
Divide the measurement of the sinus of Valsalva in half and measure the ascending aorta that far away from the line that defined the measurement for the sinus.
Planimetry of the aorta is done on either the right or left parasternal transverse views of the aorta. Fig 4.24. Trace along the internal surface of the aorta at the level of the aortic valve cusps.
Planimetry of the aorta is done on either the right or left parasternal transverse views of the aorta. Fig 4.24. Trace along the internal surface of the aorta at the level of the aortic valve cusps.
Right ventricular chamber measurement is typically obtained from the ….
Apical 4 ch view.
Measurement of the right ventricular chamber is made across the width of the tricuspid valve annulus and the ….. ventricular chamber, and length is measured from the annulus to the apex.
Measurement of the right ventricular chamber is made across the width of the tricuspid valve annulus and the mid ventricular chamber, and length is measured from the annulus to the apex.
Normal reference ranges of the right ventricular chamber are limited in animals, but linear changes in size can be used in the individual animal.
Normal reference ranges of the right ventricular chamber are limited in animals, but linear changes in size can be used in the individual animal.
Wall thickness of the right ventricular chamber is measured from parasternal 2 D 4 ch images at the level of the tricuspid valve chordae tendinae. Be careful not to include trabeculae.
Wall thickness of the right ventricular chamber is measured from parasternal 2 D 4 ch images at the level of the tricuspid valve chordae tendinae. Be careful not to include trabeculae.
Evaluation of quantitative measurements:
Parameters of ventricular size correlate to …………….
Evaluation of quantitative measurements:
Parameters of ventricular size correlate to body surface area (BSA).
Ratios of LA to aorta and wall thickness to chamber size do not correlate with body size, nor does any parameter of function.
Ratios of LA to aorta and wall thickness to chamber size do not correlate with body size, nor does any parameter of function.
Evaluation of quantitative measurements: DOGS: Systolic and diastolic dimensions derived from short-axis views tend to be slightly……than those obtained from long-axis views, but the difference is not significant and the correlation between chamber sizes and wall thicknesses obtained from long-versus short-axis images are high with correlation coefficients of 0.93 for diastolic dimensions, 0.88 for systolic dimensions, 0,95 for diastolic wall thickness, and 0.86 for systolic wall thickness.
greater
Evaluation of quantitative measurements: DOGS:
Septal thickness measurements also show no significant difference between imaging planes, but the correlation coefficients were slightly lower.
Septal thickness measurements also show no significant difference between imaging planes, but the correlation coefficients were slightly lower.
Evaluation of quantitative measurements: DOGS:
There are also no sign differences between measurements taken from right or left parasternal imaging planes for the LA and aorta.
There are also no sign differences between measurements taken from right or left parasternal imaging planes for the LA and aorta.
Evaluation of quantitative measurements: DOGS: Ventricular lengths during diastole and systole show no sign differences between any of the three measuring techniques on right parasternal images.
Ventricular lengths during diastole and systole show no sign differences between any of the three measuring techniques on right parasternal images.
However, the right parasternal images were much better than left parasternal images for measuring length since the left parasternal images tended to foreshorten the ventricular chamber.
Evaluation of quantitative measurements: Cats:
Mean values from long-and short-axis planes are not sign different. There is no sign correlation between BSA or weight and parameters of cardiac size in the cat. This is probably due to the small weight range within the adult cat population.
Mean values from long-and short-axis planes are not sign different. There is no sign correlation between BSA or weight and parameters of cardiac size in the cat. This is probably due to the small weight range within the adult cat population.
2D and M-mode measurements in cats are very similar, bot the closet relationshop appears between measurements taken from 2D short axis measurements and M-mode values.
2D and M-mode measurements in cats are very similar, bot the closet relationshop appears between measurements taken from 2D short axis measurements and M-mode values.
(M-modes in the reported sutyd were however, not obtained with 2D guidance.
Measurement and assessment of M-mode images.
Recommendations in man set by?
The american society of echocardiography (ASE).
The same guidelines are followed for veterinary species.
The guidelines are made because they generated the least variability among human echocardiographers.
The ASE recommends that all diastolic measurements should be made at the …….of the QRS complex.
onset
Value of using the ECG for timing and measurements purposes?
Using the ECG for timing and measurements purposes assures consistency in measuring methods among examiners as well as providing greater accuracy in comparing measurements from serial examinations in the same patient.
When an ECG is not recorded on the M-mode image, use the largest ventricular dimension for diastolic measurements.
When an ECG is not recorded on the M-mode image, use the largest ventricular dimension for diastolic measurements.
In man, very little difference is found between measurements made by the beginning of the QRS complex and those made at the largest ventricular dimension except in children where there is a greater increase in dimension at the very end of diastole.
The ASE also adheres to a measuring method referred to as the leading edge theory. This means?
This means that measurements are mad from leading or top edge of one structure to the leading edge of the next structure.
Value of the leading edge theory?
This helps eliminate any variability in boundary thickness created by different ultrasound equipment as well as differences in gain settings, both of which may increase the perceived thickness of structures.
The ASE recommends making measurements at end-respiration. At least 3-5 cardiac cycles should be used, and averaged for each measurement. Value of this strategy?
This should negate any effects of respiration and changes in filling secondary to sinus arrhythmias.
M-modes may be obtained and measured from long-or short-axis views. Studies comparing M-mode values to 2D measurements found better correlation between short-axis M-mode and 2D measurements but the M-modes were not obtained with RT guidance.
M-modes may be obtained and measured from long-or short-axis views. Studies comparing M-mode values to 2D measurements found better correlation between short-axis M-mode and 2D measurements but the M-modes were not obtained with RT guidance.
Care to obtain very specific sites and planes when placing the M-mode cursor over cardiac structures on either the long or short-axis views should yield similar values. Normal values have been generated using both methods.
Care to obtain very specific sites and planes when placing the M-mode cursor over cardiac structures on either the long or short-axis views should yield similar values. Normal values have been generated using both methods.
The goals when obtaining 2D images for generation of M-mode images are to maximize LV size on long-axis LV outflow and to minimize it on transverse LV views.
The goals when obtaining 2D images for generation of M-mode images are to maximize LV size on long-axis LV outflow and to minimize it on transverse LV views.
What is anatomic M-mode?
Anatomic M-mode is the ability of ultrasound technology to create M-modes from saved echo 2D video lopps.
The cursor can be manipulated to align across the 2D structures in directions different from the axis of the ultrasound beam. Anatomical M-mode can be superior to conventional M-mode if the 2D image is of high enough quality and if the angle of correction is less than 30 grader.
All parameters of chamber size and wall thickness in the dog have a linear or logarithmic relationship with weight and BSA. Is the correlation coefficients for these cardiac dimensions with weight or body surface area similar?
The correlation coefficients for these cardiac dimensions with weight or body surface area are very similar.
The difference in actual measurements is minimal with most predictions for normal ranges falling within 2 mm of each other when using either method.
In order to make application of the data easier in the adult dog, the appendix includes charts with normal ranges for each parameter at each BSA. weights corresponding to each BSA are included in the charts. See appendix.
Is there a correlation between feline heart dimensions and body size?
There is a correlation between feline heart dimensions and body size, but the correlation is weak, probably due to the small degree of variation in weight.
Values corresponding to cardiac parameter ro BSA or weight are generally not used, and a single reference range for each variable is used for all cats.
Values corresponding to cardiac parameter ro BSA or weight are generally not used, and a single reference range for each variable is used for all cats.
Cardiac dimensions obviously must increase as an animal grows, and several studies have been performed in puppies with established growth-related changes in cardiac dimensions and function. Which dimension is the only one increasing with advancing age after the animal reaches maturity?
Only the left ventricular wall thickness. All other parameters appear to remain static during the aging process.
Some puppies have there owns reference values. Such as Bull Mastiffs
Spanish masitff
English pointer
Portugese water dog.
Inverse relationships exist for HR and weight, LV systolic and diastolic dimensions, and LA size. The effect of HR on ventricular dimension is ……however.
Nominal
Each individual M-mode measurement of size and function is just one piece of the puzzle and should not be used alone when making an echo interpretation. All the onto should be put tighter and analyzed as a whole. The entire set of data should fit tighter logically. If some info does not fit the puzzle, technical error maybe a factor, but just as likely another problem is present that has not been identified.
Each individual M-mode measurement of size and function is just one piece of the puzzle and should not be used alone when making an echo interpretation. All the onto should be put tighter and analyzed as a whole. The entire set of data should fit tighter logically. If some info does not fit the puzzle, technical error maybe a factor, but just as likely another problem is present that has not been identified.
Left ventricular M-modes are obtained from 2D images with the cursor placed ………….?
Left ventricular M-modes are obtained from 2D images with the cursor placed between the papillary muscles and the tip of the mitral valve leaflets. Fig 4.27
This location is easier to identify on long-axis LV inflow outflow images.
Maximize the length and width of the LV chamber when using the long-axis view.
How should you know that the longest, widest left ventricular chamber has been obtained?
When the septum and left ventricular wall are parallel to each other on the long-axis image, the longest, widest left ventricular chamber has been obtained, even if the apex of the heart is not in the sector image.
Make sure that the aortic valve is seen and that mitral valve is moving well when using this imaging plane to generate M-modes. The cursor should be perpendicular to the LV wall.
M-mode measurement of the LV: From the long axis:
LV inflow outflow vies Maximize length and width of LV No curve to LV wall Good MV motion Aortic valve in middle of aorta
M-mode measurement of the LV: From the short axis:
Level of chordae tendinae
Smallest symmetrical chamber
See a good RV
When a transverse image is used to create LV M-mode, fan the transducer between the level of the papillary muscles and the mitral valve until a good image of the …… are obtained within a symmetrical circular LV chamber. Obtain the ………. LV chamber at the level of the chordae.
When a transverse image is used to create LV M-mode, fan the transducer between the level of the papillary muscles and the mitral valve until a good image of the chordae are obtained within a symmetrical circular LV chamber. Obtain the smallest LV chamber at the level of the chordae.
This assures that the image is obtained along the true transverse image.
M-mode measurement of the LV: From the short axis:
If the imaging plane is oblique to the true transverse plane of the LV chamber, the diameter will be ………
If the imaging plane is oblique to the true transverse plane of the LV chamber, the diameter will be larger.
M-mode measurement of the LV: From the short axis:
The right ventricular chamber should be seen at the top of the sector image with enough space to show a clearly defined top to the interventricualr septum.
The right ventricular chamber should be seen at the top of the sector image with enough space to show a clearly defined top to the interventricualr septum.
If the right ventricle is not appreciated well, the transducer is probably too …..
close to the apex of the heart.
Twist the transducer to the long axis; if the apex is higher on the sector image than the base of the heart, the transducer is too close to the apex and not under the middle of the heart.
The M-mode cursor should bisect the left ventricular chamber into equal and symmetrical halves, and be perpendicular to a line that connects the chordae tendinae.
The M-mode cursor should bisect the left ventricular chamber into equal and symmetrical halves, and be perpendicular to a line that connects the chordae tendinae.
The M-mode image can show some chordae teninae within the left ventricular chamber. Fig 4.28-4.29.
The M-mode image can show some chordae teninae within the left ventricular chamber. Fig 4.28-4.29.
In small animals like kittens and very young puppies, the distance between the mitral valve and papillary muscles is often much closer and more mitral valve is recorded in M-modes of the LV.
The recommendation by the ASE is to …………..?
The recommendation by the ASE is to record and measure the LV at the level of the mitral valve tips/chordae in young children and infants.
This may be necessary in many puppies and kittens although no standard have been set.
When LV images are not oriented on the sector to allow perpendicular placement of the M-mode cursor to the septum and LV free wall, more accurate measurements of size and function will be obtained from the 2D image itself.
When LV images are not oriented on the sector to allow perpendicular placement of the M-mode cursor to the septum and LV free wall, more accurate measurements of size and function will be obtained from the 2D image itself.
Use a cine loop if available and advance the loop frame by frame until the largest and smallest LV dimensions are identified for measurements.
While the ASE recommend measuring diastolic chamber dimensions at the ……………., the recommendation for measurement of systolic chamber size is at the ………………. Fig 4.30
While the ASE recommend measuring diastolic chamber dimensions at the beginning of the QRS complex, the recommendation for measurement of systolic chamber size is at the peak downward point of septal motion. Fig 4.30
The free wall should be used when septal motion is abnormal.
Measurements should be made straight up or down from whatever point is selected, do not move diagonally across the ventricular chamber from septum to wall.
Measurements should be made straight up or down from whatever point is selected, do not move diagonally across the ventricular chamber from septum to wall.
Diastolic and systolic LV chamber measurements are made from the top of the …………. surface of the LV side of the septum to the top of the ……………..
Diastolic and systolic LV chamber measurements are made from the top of the endocardial surface of the LV side of the septum to the top of the LV free wall.
Therefore, a small amount of septal thickness is included in LV chamber dimension measurements.
Free wall and septal thciknesses are measured along the same lines that chamber dimensions are obtained. The inter ventricular septum is measured from ……………………to the……………. during both systole and diastole.
Free wall and septal thciknesses are measured along the same lines that chamber dimensions are obtained. The inter ventricular septum is measured from the top of the septum to the top of the endocardial surface at the bottom of the septum during both systole and diastole.
The LV free wall measurement starts at …………. and goes down to ……………defining the …………………
The LV free wall measurement starts at the top of the LV wall and goes down to the top of the bright line defining the pericardial sac.
Wall and septal excursion measurements are sometimes made from M-mode images. These measure the greatest distance the wall makes upward during systole and the septum
Wall and septal excursion measurements are sometimes made from M-mode images. These measure the greatest distance the wall makes upward during systole and the septum makes downward during systole.
Fig 4.31 shows an appropriate M-mode image for measurement. Clear boundaries are present as well as some chordae within the LV chamber.
M-mode image for measurement. Clear boundaries are present as well as some chordae within the LV chamber.
Measuring pitfalls:
Whenever images are not ideal or you are not comfortable with the M-mode cursor angle through the heart, it is better not to make the measurement than to base a diagnosis on potentially erroneous information.
Whenever images are not ideal or you are not comfortable with the M-mode cursor angle through the heart, it is better not to make the measurement than to base a diagnosis on potentially erroneous information.
Breathening can create many artifactual motion abnormalities on the M-mode image.
Fig 4.32 shows how wall and septal motions are altered secondary to respiration.
This kind of motion is seen even if the animal is not panting.
Momentarily placing a hand over the animal’s nostrils while 3 or 4 cardiac cycles are recorded on the M-mode can usually eliminate this artifact.
Which is the most common problem during measurement of LV M_modes?
Defining septal and wall boundaries.
The ………….. side of the septum is the hardest to define?
The right ventricular side of the septum is the hardest to define?
Why is the right ventricular side difficult to define?
- Right ventricular hypertrophy with prominent papillary muscles and trabeculae
- Left ventricular dilation
- Poor technique
..all contricute to ambiguity in identifying the right side of the septum. Fig 4.33, 4.34
Take care to identify and separate the right ventricular papillary muscle from the septum.
When an M-mode has an ill-defined inter ventricular septum, move the image into a more horizontal position across the sector by sliding the transducer dorsal and cranial on the thorax in order to define the right ventricle and the septal boundaries better.
When an M-mode has an ill-defined inter ventricular septum, move the image into a more horizontal position across the sector by sliding the transducer dorsal and cranial on the thorax in order to define the right ventricle and the septal boundaries better.
The LV wall i usually easier to obtain on M-modes, but at times…………. or …………. may create ambiguous measuring points.
The LV wall i usually easier to obtain on M-modes, but at times chordae tendinae or papillary muscles may create ambiguous measuring points.
Papillary muscles appear as thick layers of muscles above the free wall, usually during systole, but sometimes throughout both phases of cardiac cycle. Fig 4.36.
Fig 4.35.
Chordae tendinae generally follow wall motion, but they have a ……………. upward rate of motion during systole.
slower
If wall thickness appears to be greater than septal thickness and 2D image do not support this finding, ……..is probably included in LV wall thickness measurements.
papillary muscle
Elongate the LV by rotating the transducer or by lifting the transducer into a more horizontal position, creating better mitral valve motion.
This will generally eliminate papillary muscle from the 2D image.
M-mode assessment.
LV diastolic dimension is used to determine the presence or absence of LV volume overload.
Can systolic dimensions be used to assess the presence or absence of dilation?
Systolic dimensions are a reflection of systolic function in the heart and should not be used to assess the presence or absence of dilation.
The same principle applies to wall and septal thickness measurements.
The presence or absence of hypertrophy should be determined from ……
diastolic measurements of thickness.
Systolic measurements are a reflection of systolic function, so increased thickness during systole may simple reflect increased function as opposed to ……
hypertrophy.
Hypertrophy does increase systolic thickness but the effect of increased systolic function cannot be separated from the effects of hypertrophy.
Evaluation of chamber size: use……dimension
diastplic LV
Assessment of wall thickness
Use diastolic VS and LVW thicknesses
Use LVW to LVd ratio
Can right ventricular wall thickness and chamber size be measured from LV M-modes?
Yes, but there is a great variability in these measurements because of a low ratio of wall thickness to chamber size creating high wall stress.
Hearts with aortic stenosis or systemic hypertension should have increased wall thickness to chamber size ratios. The hypertrophy is an appropriate compensatory mechanism in response to the high …………. thus normalizing wall stress.
The hypertrophy is an appropriate compensatory mechanism in response to the high after load thus normalizing wall stress.
In the dog and cat, the inter ventricular septum is typically only slightly ………… than the free wall.
thicker
……………have increased LV dimensions and wall thicknesses compared to other dogs of the same weight. This difference exists whether the greyhound is a racing or a non racing animal.
Greyhounds
In man, the effects of exercise on the heart regress after several weeks of non exercising, but the increased dimensions and hypertrophy persist in these greyhounds despite a sedentary lifestyle.
Measurements of wall and septal excursions are a reflection of volume changes within the ventricular chamber. Greater volume changes create …………. wall and septal excursion than smaller volume changes.
Greater volume changes create greater wall and septal excursion than smaller volume changes.
When the LV is volume contracted for any reason, wall motion abnormalities become evident, which can mimic cardiac disease.
If measruemtnes of ventricular size are smaller than normal and the animal is possibly dehydrated, or has any reason to be volume contracted, repeat the echo exam after the volume depleted state has been corrected.
Mitral valve:
Before the advent of Doppler echo, the mitral valve M-mode was analyzed for rate of opening and closing as well as excursion distances. How are the normal ranges for these parameters. Why?
Very wide since the effects of HR and pressure differentials on how fast or slow the valve opens and closes are pronounced.
2D and Doppler echo have provided greater accuracy in assessing movement and flow through the valve.
Mitral valve M-modes are still valuable however, for detecting subtle movement alterations created by altered flow through and around the valve.
………………….. and ……………. are 2 findings that are easily seen on M-mode images and in the absence of Doppler provide important hemodynamic info.
Systolic anterior motion and diastolic flutter are 2 findings that are easily seen on M-mode images and in the absence of Doppler provide important hemodynamic info.
One very consistent and popular mitral valve measurement is the EPSS
E point to septal separation = EPSS.
Fig 4.37.
The EPSS is the shortest distance from the E point of the …………… to the …………………
The EPSS is the shortest distance from the E point of the mitral valve to the ventricular septum
The EPSS measurement is easy to make and is an indicator of?
LV filling and function
Cardiac pathology may increase, decrease, or not affect EPSS, but EPSS has strong negative correlation to ……………….. in the absence of aortic and mitral insufficiencies.
Cardiac pathology may increase, decrease, or not affect EPSS, but EPSS has strong negative correlation to ejection fraction in the absence of aortic and mitral insufficiencies.
Fig 4.38
The EPSS has strong negative correlation to EF in the absence of aortic and mitral insufficiencies, which is based upon the fact that flow into the ventricle is equal to flow leaving the ventricle.
In the presence of high …………….. LV filling pressure, such as in DCM, flow from the LA to the LV is reduced and consequently flow out of the LV is also reduced.
In the presence of high diastolic LV filling pressure, such as in DCM, flow from the LA to the LV is reduced and consequently flow out of the LV is also reduced.
EPSS: Indicator of LV …… and ……….
EPSS: Indicator of LV filling and function
EPSS: Increased EPSS = ………………. ejection ejection fraction.
EPSS: Increased EPSS = decreased ejection ejection fraction.
Normal canine EPSS =
Studies in man and dogs have shown that EPSS accurately separates normal from abnormal LV ……………regardless of LV size when dilation is present.
accurately separates normal from abnormal LV function regardless of LV size when dilation is present.
……………., however, restricts valve motion and may decrease EPSS-
Hypertrophy
Is EPSS also valid for assessing LV function in the presence of abnormal septal motion?
Yes, EPSS is also valid for assessing LV function in the presence of abnormal septal motion.
Is body size generally considered when assessing normal EPSS value?
EPSS shows a very weak correlation to BSA and weight in some studies and no correlation in other, so body size is generally not considered when assessing normal EPSS value.
While an inverse correlation of EPSS to heart rate has been shown in one study, another shows no effects of breed, age, sex, mass, or HR on EPSS.
Any correlation is weak and is probably not significant enough to warrant adjustment of normal values for the animal’s weight or HR.
EPSS: E= …..
A= ………..
E= early diastolic mitral valve motion, A= Late diastolic mitral valve motion.
Left atrium and aorta measurement can be measured using M-mode: Left atrium is imaged on M-mode as the largest LA dimension at end-…………… from the top of the posterior aortic wall to the top of the pericardium. Fig 4.39
Left atrium is imaged on M-mode as the largest LA dimension at end systole from the top of the posterior aortic wall to the top of the pericardium. Fig 4.39
M-mode: Left atrial wall thickness is generally not recorded well, and the………….. provides a consistent easily visualized atrial boundary.
Left atrial wall thickness is generally not recorded well, and the pericardium provides a consistent easily visualized atrial boundary.
Although the LA may enlarge in planes other than that recorded for M-mode images, it is generally a clinically useful indicator of LA size. Why is it so?
because the LA can dilate in planes other than the ones used for this M-mode measurement, the absence of dilation should not be based upon this number alone. Evaluate 2D as well
The aorta is measured from the top of the anterior aortic wall to the top of the posterior wall at end-…………… Ideally 2 aortic valve cusps should be seen in order to minimize angle problems.
The aorta is measured from the top of the anterior aortic wall to the top of the posterior wall at end-diastole. Ideally 2 aortic valve cusps should be seen in order to minimize angle problems.
Left ventricular ejection time is measured at the aortic valve from the time it …………. to the time it …………… Fig 4.39.
Left ventricular ejection time is measured at the aortic valve from the time it opens to the time it closes. Fig 4.39.
A perfect aortic valve is not required, but clear definition of when it opens and when it closes is necessary.
Pre-ejection time can only be measured when an electrocardiogram is used on the echocardiogram. The measurement is made from the beginning of the …………… …………. to where the …………….valve opens.
This time period is very similar to the isovolumetric ………….. period where both the aortic and mitral valves are closed and the ventricle is building up enough pressure to open the aortic valves.
Pre-ejection time can only be measured when an electrocardiogram is used on the echocardiogram. The measurement is made from the beginning of the QRS complex to where the aortic valve opens. Fig 4.39.
This time period is very similar to the isovolumetric contraction period where both the aortic and mitral valves are closed and the ventricle is building up enough pressure to open the aortic valves.
There is a positive correlation between aortic and LA dimensions with weight and BSA, in dogs and cats, and a ratio of LA to ………….. size may be used as an indicator of how severe the atrial dilation is.
There is a positive correlation between aortic and LA dimensions with weight and BSA, in dogs and cats, and a ratio of LA to aortic root size may be used as an indicator of how severe the atrial dilation is.
It is wise to assess aortic root size before using the ratio (LA/Ao).
A small aorta may be seen in animals with …………. output failure, and the LA to aortic root ratio will reflect greater LA enlargement than is actually present.
A small aorta may be seen in animals with low output failure, and the LA to aortic root ratio will reflect greater LA enlargement than is actually present.
Left atrial size is very similar to aortic root size in dogs (range LA/Ao= 0.83-1.13), while in cats the left atrium may be much larger than the aorta (range LA/Ao 0.88-1.79)
Left atrial size is very similar to aortic root size in dogs (range LA/Ao= 0.83-1.13), while in cats the left atrium may be much larger than the aorta (range LA/Ao 0.88-1.79)
Ratio indices:
There are instances when the subjective assessment of ventricular and atrial size do not match. This is especially true in ……? (3)
giant and small breeds and in overweight animals.
M-mode ratio indices may be more accurate in such unusual body types.
M-mode dimensions of each parameter are divided by either?
the pure aortic root M-mode measurement or a weight-based aortic value.
The weight-based aortic index is calculated as follows:?
AOw = kW upphöjt i 1/3.
where W = weight in kg
k = a constant for each species
(dogs 0 0.795, cats 0.567)
The constant was derived from the average value in each species of the raw aortic root measurement divide by W upphöjt i 1/3.
The weight-based aortic root measurement is similar to using BSA as a correlation except that it is a ………… assessment versus an …………… assessment.
The weight-based aortic root measurement is similar to using BSA as a correlation except that it is a linear assessment versus an area assessment.
BSA is calculated as ….?
BSA = kW upphöjt i 2/3.
where k is a constant in dogs equaling 0.101 and weight is in kg.
Se s 185: ex of the weighed assessment method.
se s 185: ex of the weighed assessment method.
The normal range for weighted LV size in diastole is?
1.305-1.861
Se s 185 for an ex of the M-mode aortic measurement without consideration for weight.
This method of evaluation seems superior to raw M-mode measures when compared to studies that used linear regr analysis of parameter to BW or BSA. The study was published prior to logarithmic correlation f M-mode parameters to weight in dogs.
In dogs, the weight-based aortic indices seem superior to raw aortic root rations in that smaller ranges and standard deviations are found.
Using aortic root ratio indices in cats did not add any more accuracy to measurements, presumably because of the narrow weight range, but weight based ratios did result in good adjustments for size.
Some advantages that ratio indices probably have over linear correlated M-mode parameters is that they may be more accurate for different somatotypes and even within breeds that vary greatly in weight but not body types. (i.e Irish Wolfhounds).
Some advantages that ratio indices probably have over linear correlated M-mode parameters is that they may be more accurate for different somatotypes and even within breeds that vary greatly in weight but not body types. (i.e Irish Wolfhounds).
They may also allow direct comparison between patiens of differing size and body type in the same way that fractional shortening and volume indices are used.
This method may also be more accurate in overweight animals and in the highly trained athletic dog.
Measurement and assessment of spectral doppler flow:
Doppler examination has the ability to provide info about?
Direction, velocity, character, and timing of blood flow.
Thereby allowing definitive diagnostics in most cardiac examinations.
Although the measurements of Doppler may appear intimidating, the equipment performs most of the calculations.
Remember to interrogate multiple views when possible for all valvular flows since the imaging planes for best Doppler alignment varies from animal to animal.
Although the measurements of Doppler may appear intimidating, the equipment performs most of the calculations.
Remember to interrogate multiple views when possible for all valvular flows since the imaging planes for best Doppler alignment varies from animal to animal.
Measurement:
Peak velocity is simply measured by placing a caliper at..?
the apex of maximal upward or downward motion. fig 4.40.
The velocity is displayed in cm per sec (cm/sec) or m7sec.
What is the velocity time integral (VTI), flow velocity integral (FVI) or time velocity integral (TVI)?
Tracing the flow profile provides a measure of mean velocity throughout the flow period, and is called the velocity time integral VTI, flow velocity integral (FVI) or time velocity integral (TVI)?
Fig 4.41
Flow velocity integral is directly proportional to the?
stroke volume
The flow integral is calculated by tracing the flow profile with a trackball or joystick. Fig 4.41.
Once the entire flow profile is traced, the FVI is displayed on the monitor in cm. The area under the flow velocity curve represents the?
The distance a volume of blood travels.
It is used with the area of the vessel or valve the blood is flowing through in order to calculate stroke volume.
Systolic time intervals can be measured from…………….?
Systolic time intervals can be measured from aortic and pulmonary flow profiles.
Left and right ventricular ejection times (LVET and RVET) are measured from the ……….. to the …………. at the baseline.
This is also called?
Left and right ventricular ejection times (LVET and RVET) are measured from the onset of flow to the end of flow at the baseline (fig 4.42).
This is also called flow time (FT).
Time to peak (TTP) flow (also called acceleration time (AT) is measured from the ………. to the point of ……………………
Time to peak (TTP) flow (also called acceleration time (AT) is measured from the onset of flow to the point of maximal velocity. Fig 4.43
These 2 systolic time periods are then divided to yield a variable that indicated what ………………..
These 2 systolic time periods are then divided to yield a variable that indicated what fraction of time is spent in reaching maximal velocity (TTP/FT).
Pre-ejection periods are measured from the onset of ………. to the onset of ………………
Pre-ejection periods are measured from the onset of the QRS complex to the onset of systolic flow.
Diastolic time intervals:
The isovolumetric relaxation time (IVRT) is measured by placing a CW or PW signal in the ………………..on apical 4 or 5 ch imaging planes near the ………………. and recording part of both the ………… profile and the ………………flow profile.
Diastolic time intervals:
The isovolumetric relaxation time (IVRT) is measured by placing a CW or PW signal in the left ventricular outflow tract on apical 4 or 5 ch imaging planes near the mitral valve and recording part of both the aortic flow profile and the transmittal flow profile. Fig 4.44
The time interval from ……….. flow to the …………………….. flow corresponds to the isovolumetric relaxation time period.
The time interval from cessation of aortic flow to the beginning of transmittal flow corresponds to the isovolumetric relaxation time period. Fig 4.45.
When left ventricular pressure drops below LA pressure, the mitral valve …….
When left ventricular pressure drops below LA pressure, the mitral valve opens.
Evaluation: there is little or no correlation between peak velocities for flow across the 4 valves with age, sex, or breed in the dog. Several studies have found that HR and weight do affect flow velocities while others have not.
The studies that showed an effect of body mass and heart rate on flow velocities reveal than in general, decreases in mass and increases in HR increased flow velocity.
Physical factors that increase Doppler flow velocities: (3)
Increasing HR
Inspiration
Decreasing weight
Age, sex, and breed have no effect.
Aortic flow profiles are negative and have a ……….. acceleration compared to the ……………deceleration rate.
Aortic flow profiles are negative and have a rapid acceleration compared to the slower deceleration rate.
This gives the normal aortic flow profile an asymmetric appearance. Fig 3.45.
Aortic flow: Peak velocity should be reached during the first ……. of systole
Peak velocity should be reached during the first third of systole
Peak velocities obtained from PW and CW examinations are only slightly different. The discrepancy may be secondary to Doppler angle.
Peak velocities obtained from PW and CW examinations are only slightly different. The discrepancy may be secondary to Doppler angle.
Most normal healthy dogs ave aortic flow velocities less than 200 cm/sec.
There is agreement that flows above 250 cm/sec are abnormal, but flows that fall within the 200 to 250 cm/sec range are equivocal.
Most normal healthy dogs ave aortic flow velocities less than 200 cm/sec.
There is agreement that flows above 250 cm/sec are abnormal, but flows that fall within the 200 to 250 cm/sec range are equivocal.
Other aspects of the echo exam will have to be used in order to determine if disease is present.
Can flow velcotieis be affected be heart rate?
Yes. Fast heart rates will increase peak and mean velocities.
Aortic flow is characterized by?
Rapid acceleration:
-Early peaking max velocity
Slower deceleration
Shorter ejection time than PA
Longer PEP than PA
Pulmonary flow is characterized by?
More symmetrical profile
-peak velocity in middle third of ejection period.
Pulmonary artery flow profiles are also negative in all the views that can be obtained in animals. It has a very …………. shape with very …………….acceleration and deceleration rates.
Pulmonary artery flow profiles are also negative in all the views that can be obtained in animals. It has a very symmetrical shape with very similar acceleration and deceleration rates. Fig 3.48
Often pulmonary flow displays a ………….. peak as opposed to the …….. peak velocity of aortic flow.
Often pulmonary flow displays a rounded peak as opposed to the pointed peak velocity of aortic flow.
Peak velocity of pulmonary flow is reached approximately …….. way through ejection, and in the dog the mean ratio of time to peak velocity to total ejection time is ……………..
Peak velocity of pulmonary flow is reached approximately half way through ejection, and in the dog the mean ratio of time to peak velocity to total ejection time is 0.43.
Peak pulmonary flow velocity in the dog is typically less than 130 cm/sec. This is lower than aortic flow presumably because of …..
Because of lower resistance within the pulmonary vascular system.
Pulmonary flow has a slightly …….. ejection time and …….. pre-ejection period compared to aortic flow because of the …….. after-load.
Pulmonary flow has a slightly longer ejection time and reduced pre-ejection period compared to aortic flow because of the reduced after-load.
Increased venous return with ………. increases pulmonary flow velocity during …………….
Respiration affecte flow within the right side of the heart. Increased venous return with inspiration increases pulmonary flow velocity during inspiration.
HR affects maximal velocity as does aortic flow. Faster heart rates in the dog increase velocity.
HR affects maximal velocity as does aortic flow. Faster heart rates in the dog increase velocity.
There is also a body mass effect on the right side of the heart. Increased body mass ………. the mean velocity.
Increased body mass decreases the mean velocity and is speculated to be secondary to decreased heart rate in larger dogs.
Systolic time intervals:
HR affects LVET, but the effect is minimized by normalizing the interval. The heart rate is multiplied by the slope of the regression line for heart rate versus the LVET, and this value is added to the measured LVET.
The heart rate is multiplied by the slope of the regression line for heart rate versus the LVET, and this value is added to the measured LVET.
This in effect allows LVET to be extrapolated to a HR of zero.
The slope of HR versus LVET is 0.55, and the resulting equation for HR corrected LVET, left ventricular ejection time index (LVETI) is as follows:
LVETI = LVET + (0.55 x HR)
Where HR should be measured from the R to R interval on the beat preceding the measured LVET.
The pre-ejection time period is very similar to the isovolumetric contration period where both the aortic and mitral valves are …….. and the ventricle is building up enough pressure to open the aortic valves.
closed
A ratio of PEP to LVET is usually calculated in order to reduce the effects of …………..on LVET.
A ratio of PEP to LVET is usually calculated in order to reduce the effects of heart rate on LVET.
This is considered to be a more accurate indicator of LV function.
Velocity of circumferential fiber shortening is a calculation that incorporates the ejection time into the fractional shortening equation. This is a measure of how fast the LV shortens and is calculated as…?
Vcf = LVd-LVs/LVd x LVET
Where LVET is measured in seconds and chamber sizes are measured in cm.
Velocity of circumferential shortening (VCF) may be divided by HR and multiplied by 100 in order to reduce the effects of rate on this systolic time interval.
Because of the strong effect of HR on systolic time intervals, several beats should be measured and averaged.
Because of the strong effect of HR on systolic time intervals, several beats should be measured and averaged.
In animals with atrial fibrillation or marked sinus arrhythmia, many beats should be measured and more than 10 is recommended.
Time intervals measured from the longest cardiac cycles tend to be the most accurate indicators of LV function when HR are variable. Avoid measuring during ventricular or supraventricular premature complexes of the beats that follow them.
Mitral valve flow: transmitral flow profiles in all planes are …………….., and when heart rates are slow enough, the …… phases of LV filling are displayed.
Mitral valve flow: transmitral flow profiles in all planes are positive, and when heart rates are slow enough, the 2 phases of LV filling are displayed.
Fig 3.52
Once HR exceed ca ……., the 2 phases begin to overlap and rates greater than ……… beats per minute shown no separation of filling phases.
Once HR exceed ca 125, the 2 phases begin to overlap and rates greater than 200 beats per minute shown no separation of filling phases.
The early phase of ventricular filling extends from mitral valve ………….. to peak ventricular ……………. and is called the E peak just as it is on M-mode images of the mitral valve.
The early phase of ventricular filling extends from mitral valve opening to peak ventricular filling and is called the E peak just as it is on M-mode images of the mitral valve.
Flow into the left ventricle during atrial contraction is represented by the …… point of the mitral inflow profile.
Flow into the left ventricle during atrial contraction is represented by the A point of the mitral inflow profile.
The E-peak should have a higher velocity than the A peak in the normal heart. The E:A ratio is always greater than one in the normal canine heart, but both slow HR and high HR bring the E:A ratio closer to
…
1
Increased volume associated with atrial contraction in animals with slow HR………… the A flow velocity ……………. the difference in E and A velocities.
Increased volume associated with atrial contraction in animals with slow HR increases the A flow velocity minimizing the difference in E and A velocities.
Rapid HR ………….. the E velocity secondary to decreased early ventricular filling volume and ………….. flow associated with the atrial contraction.
Rapid HR decrease the E velocity secondary to decreased early ventricular filling volume and increases flow associated with the atrial contraction.
Transmitral flow velocity is measured at the peak of both E and A points. Fig 4.46.
Transmitral flow is affected by?(3)
Preload
Myocardial relaxation
Heart rate
Fig 4.46
Deceleration time after rapid ventricular filling is ……?
Deceleration time after rapid ventricular filling is the time from point of maximal E velocity along its deceleration slope to the baseline.
Fig 4.46
The peak filling rare and flow deceleration are influenced by several factors including…?
Isovolumic relaxation
The pressure gradient from LA to LV
Ventricular compliance
Changes in relaxation affect ………..filling of the LV chamber while changes in compliance affect …………….. diastolic filling of the ventricle.
Changes in relaxation affect early filling of the LV chamber while changes in compliance affect late diastolic filling of the ventricle.
E wave velocity is increased with increased …….. pressure, decreased …….. pressure secondary to increased rate of relaxation, and ………. mitral valve area.
E wave velocity is increased with increased LA pressure, decreased LV pressure secondary to increased rate of relaxation, and small mitral valve area.
Early filling is decreased by ……. atrial pressure, ……… rate of relaxation, and ……… compliance, or a ………. valve area.
Early filling is decreased by low atrial pressure, decreased rate of relaxation, and increased compliance, or a large valve area.
Conditions that decrease early filling of the LV chamber, decreasing transmittal E wave amplitude, usually result in …………..A wave velocity because late diastole contributes more to total LV filling.
Conditions that decrease early filling of the LV chamber, decreasing transmittal E wave amplitude, usually result in increased A wave velocity because late diastole contributes more to total LV filling.
MV E velocity increases with? (4)
Increased LA pressure
Increased rate of LV relaxation
Decreased LV compliance
Small mitral valve area
MV E velocity decreases with? (3)
Decreased LA pressure
Impaired relaxation
Increased LV compliance
Increased HR is one of the factors resulting in a greater contribution to LV filing in …….. diastole during the atrial contraction
Increased HR is one of the factors resulting in a greater contribution to LV filing in late diastole during the atrial contraction
Faster HR can also result in superimposed E and A waves as the ……….. time period becomes shorted.
Faster HR can also result in superimposed E and A waves as the diastolic time period becomes shorted.
BW and BSA do not affect transmitral flow, but ……. is a major factor in altering transmittal flow profiles.
BW and BSA do not affect transmitral flow, but age is a major factor in altering transmittal flow profiles.
While E deceleration time does not change with age in cats as it does in man, there are weak correlations with age and other transmittal flow parameters.
While E deceleration time does not change with age in cats as it does in man, there are weak correlations with age and other transmittal flow parameters.
Mitral valve E wave velocity ………… and A wave velocity ………….. with age and the E/A ratio ………… as a result.
Mitral valve E wave velocity decreases and A wave velocity increases with age and the E/A ratio decreases as a result.
Transmitral valve E dec time increases and E/A ………in dogs over the age of 10 when compared to dogs less than 6 years of age.
Transmitral valve E dec time increases and E/A decreases in dogs over the age of 10 when compared to dogs less than 6 years of age.
BW ……………. transmitral valve E deceleration time and A duration.
BW increases transmitral valve E deceleration time and A duration.
Increases in heart rate …….. mitral valve E deceleration time in dogs. Sex has no effect on mitral valve flow velocity or time intervals.
Increases in heart rate increase mitral valve E deceleration time in dogs. Sex has no effect on mitral valve flow velocity or time intervals.
Trans tricuspid flow profiles are similar to mitral flow profiles with 2 phases to ventricular filling and is always ………… in the planes used for Doppler interrogation.
Trans tricuspid flow profiles are similar to mitral flow profiles with 2 phases to ventricular filling and is always positive in the planes used for Doppler interrogation.
Tricupsid flow velocities are lower than mitral flow velocities, probably because of ?
Tricupsid flow velocities are lower than mitral flow velocities, probably because of the reduced pressure drop from right atrium to right ventricle when compared to the pressure change from the LA to the LV.
Peak tricuspid E velocity varies with respiration. Inspiration ……… peak flow velocity while expiration ………. E flow velocities.
Peak tricuspid E velocity varies with respiration. Inspiration increases peak flow velocity while expiration decreases E flow velocities.
The E/A ratio therefore increases with inspiration and decreases with expiration.
The E/A ratio can even be less than 1 under appropriate conditions in a normal heart with ratios ranging from 0.69 to 3.08 in the dog
The ratio can even be less than 1 under appropriate conditions in a normal heart with ratios ranging from 0.69 to 3.08 in the dog
As with LV inflow rapid heart rate…….. A velocity
increase
TV E velcotity:
E ………….. with inspiration
E …………. with expiration
E increases with inspiration
E decreases with expiration
Pulmonary venous flow is continuous and phasic into the LA chamber
Pulmonary venous flow is continuous and phasic into the LA chamber. Fig 3.59
LA filling occurs predominantly during …………. when the mitral valve is closed. .
LA filling occurs predominantly during systole when the mitral valve is closed.
The velocity of this systolic flow is directly related to mean LA pressure.
During diastole when the mitral valve is open, blood flow into the ….. is directly related to flow moving into the …. and occurs at the same time as early transmittal valve flow (E wave)
During diastole when the mitral valve is open, blood flow into the LA is directly related to flow moving into the LV and occurs at the same time as early transmittal valve flow (E wave)
During atrial contraction there is reverse flow into the pulmonary veins, and the degree of this is affected by ……..
During atrial contraction there is reverse flow into the pulmonary veins, and the degree of this is affected by:
End diastolic LA pressure,
LA function,
LV compliance, and
Heart rate and rhythm.
Fig 4.47
The ratio of transmittal valve A duration to pulmonary vein Ar is correlated to …… filling pressure and ventricular compliance.
The ratio of transmittal valve A duration to pulmonary vein Ar is correlated to LV filling pressure and ventricular compliance.
Partial fusion of the mitral valve E and A waves does not invalidate this correlation.
Pulmonary vein:
D occurs at the same time as MV …………
Ar occurs at the same time as MV …….
D occurs at the same time as MV E
Ar occurs at the same time as MV A
There is a significant positive correlation between pulmonary venous S wave peak velocity and systolic fraction with ……… in cats.
There is a significant positive correlation between pulmonary venous S wave peak velocity and systolic fraction with age in cats
There is also a sign positive correlation between age and HR and pulmonary vein S velocity in cats.
There is no association between age and pulmonary D or Ar velocity in cats.
There is however a positive correlation between age and pulmonary vein Ar velocity in cats.
Dogs have a significant positive association between ….. and pulmonary vein Ar velocity and a negative correlation between age and Ar duration. These relationships were only present in dogs greater than 10 years.
Dogs have a significant positive association between age and pulmonary vein Ar velocity and a negative correlation between age and Ar duration. These relationships were only present in dogs greater than 10 years.
Increased …….. increases S and Ar velocity, and increased BW increases Ar duration in dogs.
Increased heart rate increases S and Ar velocity, and increased BW increases Ar duration in dogs.
Pulmonary vein flow-feline:
S wave velocity ……… with increased HR and age
Ar wave duration ……….. with age
S wave velocity increases with increased HR and age
Ar wave duration increases with age
Pulmonary vein flow-canine (
Ar velocity increases with increased age
Ar duration decreases with increased age.
Isovolumetric relaxation time:
Ventricular relaxation is indirectly measured from IVRT. Delayed relaxation is reflected in …….. IVRT.
Ventricular relaxation is indirectly measured from IVRT. Delayed relaxation is reflected in longer IVRT.
As atrial pressure increase however, the IVRT parameter will become less useful as it becomes “……………
As atrial pressure increase however, the IVRT parameter will become less useful as it becomes “normalized”.
IVRT is also affected by increased systolic aortic pressure and decreased LA pressure, both of which will ………..the IVRT and not truly reflect impaired relaxation.
IVRT is also affected by increased systolic aortic pressure and decreased LA pressure, both of which will prolong the IVRT and not truly reflect impaired relaxation.
HR is positively correlated with IVRT in man, but its effects on IVRT are variable in dogs and cats.
HR is positively correlated with IVRT in man, but its effects on IVRT are variable in dogs and cats.
BW and age do not significantly affect this parameter in cats.
The relationship between age and increasing IVRT in cats has an r2 value of 0.18.
IVRT increases with? (3)
Decreased LA pressure
Increased AO pressure
Delayed relaxation
The left auricle fills during ventricular ………. and empties during atrial …………. late in diastole.
The left auricle fills during ventricular systole and empties during atrial contraction late in diastole.
Fig 3.64
There are other flows recoded at the PW Doppler site at the junction of the left auricle and atrium, but they are inconsistently recorded.
Feline auricular emptying velocity ranges from 0.19-1.0 m/sec, and filling velocity ranges from 0.24-0.93 m/sec
Feline auricular emptying velocity ranges from 0.19-1.0 m/sec, and filling velocity ranges from 0.24-0.93 m/sec
There is a very weak correlation between left auricular flow and LA area or diameter in cats.
Age, HR, weight, sex, and blood pressure have no effect on left auricular flow.
Stasis of blood flow is associated with lower than normal auricular flow and predisposition toward thrombus formation.
There is a very weak correlation between left auricular flow and LA area or diameter in cats.
Age, HR, weight, sex, and blood pressure have no effect on left auricular flow.
Stasis of blood flow is associated with lower than normal auricular flow and predisposition toward thrombus formation.
Measurement and assessment of TDI:
TDI provides info regarding myocardial velocity in selected areas of the myocardium. A PW gate placed over the myocardium shows …………?
TDI provides info regarding myocardial velocity in selected areas of the myocardium. A PW gate placed over the myocardium shows both systolic and diastolic myocardial motion, which i sussed to evaluate diastolic and systolic function.
Fig 3.67
Using either color-tissue Doppler or PW tissue Doppler yields the same myocardial motions: which ones?
- A positive systolic motion: Sm or S´
- An early diastolic motion: Em or E´
- A late diastolic motion: Am or A´
- They also provide measurements of IVRT and IVCT
Color TDI must be analyzed off line. One or more PW gates may be placed anywhere over the color sector on the stored TDI video loop and wall motion is displayed.
Color TDI must be analyzed off line. One or more PW gates may be placed anywhere over the color sector on the stored TDI video loop and wall motion is displayed.
……. TDI is instantaneously generated during the exam by placing the PW gates over the color TDI sector.
PW TDI is instantaneously generated during the exam by placing the PW gates over the color TDI sector.
Peak Sm, Em, and Am velocity are measured. Fig 4.48
Peak Sm, Em, and Am velocity are measured. Fig 4.48
Color TDI also allows multiple PW gates to be placed over the color TDI sector during off-line analysis.
Gradients of color TDI Sm, Em, and Am can be obtained between basal and apical sections of myocardium on apical views or between epicardial and endocardial locations on transverse and parasternal long-axis views.
Gradients of color TDI Sm, Em, and Am can be obtained between basal and apical sections of myocardium on apical views or between epicardial and endocardial locations on transverse and parasternal long-axis views.
Fig 4.49
Isovolumic relaxation time is measured from the end of …. to the beginning of ….
Isovolumic relaxation time is measured from the end of Sm to the beginning of Em.
Isovolumic contraction time is measured from the end of ….. to the beginning of ……..
Isovolumic contraction time is measured from the end of Am to the beginning of Sm.
Fig 4.50
Assessment:
Are Color TDI and PW TDI measurements interchangeable?
No, each modality has its own set of reference values.
Color TDI evaluates ………. myocardial velocity while PW TDI measures ………. myocardial velocity in a segment of myocardium.
Color TDI evaluates mean myocardial velocity while PW TDI measures peak myocardial velocity in a segment of myocardium.
Color TDI is also recorded at ……. fram rates than PW TDI: These factors cause color TDI values to be lower than PW TDI values.
Color TDI is also recorded at lower fram rates than PW TDI: These factors cause color TDI values to be lower than PW TDI values.
Color TDI velocities are therefore …..than PW TDI velocities.
lower
Reference values are not interchangeable.
Reference values are not interchangeable.
