Objective—To analyze velocities of the annulus of the left atrioventricular valve and left ventricular free wall (LVFW) in a large population of healthy cats by use of 2-dimensional color tissue Doppler imaging (TDI).
Animals—100 healthy cats (0.3 to 12.0 years old; weighing 1.0 to 8.0 kg) of 6 breeds.
Procedure—Radial myocardial velocities were recorded in an endocardial and epicardial segment, and longitudinal velocities were recorded in 2 LVFW segments (basal and apical) and in the annulus of the left atrioventricular valve.
Results—LVFW velocities were significantly higher in the endocardial than epicardial layers and significantly higher in the basal than apical segments. For systole, early diastole, and late diastole, mean ± SD radial myocardial velocity gradient (MVG), which was defined as the difference between endocardial and epicardial velocities, was 2.2 ± 0.7, 3.3 ± 1.3, and 1.8 ± 0.7 cm/s, respectively, and longitudinal MVG, which was defined as the difference between basal and apical velocities, was 2.7 ± 0.8, 3.1 ± 1.4, and 2.1 ± 0.9 cm/s, respectively. A breed effect was documented for several TDI variables; therefore, reference intervals for the TDI variables were determined for the 2 predominant breeds represented (Maine Coon and domestic shorthair cats).
Conclusions and Clinical Relevance—LVFW velocities in healthy cats decrease from the endocardium to the epicardium and from the base to apex, thus defining radial and longitudinal MVG. These indices could complement conventional analysis of left ventricular function and contribute to the early accurate detection of cardiomyopathy in cats.
Objective—To describe and analyze the left ventricular
free wall (LVFW) radial and longitudinal motions in
a population of healthy Maine Coon cats by use of
quantitative 2-dimensional color tissue Doppler imaging
Animals—23 healthy young Maine Coon cats (mean
± SD: age, 2.1 ± 0.9 years; weight, 5.0 ± 1.0 kg).
Procedure—TDI was performed by the same trained
observer (VC) on all cats. Radial LVFW velocities were
recorded in endocardial and epicardial LVFW segments,
and longitudinal velocities were recorded in
the mitral annulus and in basal and apical LVFW segments.
Isovolumic contraction and relaxation times
were calculated in each myocardial segment, and the
coefficients of variation (CVs; %) were determined for
each TDI parameter.
Results—LVFW velocities were significantly higher in
the endocardial layers than in the epicardial layers and
also significantly higher in the basal than in the apical
segments. Annular velocities were significantly higher
than basal myocardial velocities in systole and early
diastole. Coefficient of variation values were lower for
radial velocities, particularly in systole, and were also
lower for time intervals (16% to 22%) than for
myocardial velocities (19% to 62%).
Conclusions and Clinical Relevance—Because
Maine Coon cats are predisposed to an inherited
hypertrophic cardiomyopathy, which is a common
cause of death in this breed, TDI could provide a useful
tool for early detection of the disease. Tissue
Doppler imaging indices may complete the conventional
analysis of the left ventricular function in Maine
Coon cats. However, the usefulness of TDI indices in
the early detection of myocardial dysfunction needs
to be clarified. (Am J Vet Res 2005;66:1936–1942)
Objective—To determine left ventricular free wall
(LVFW) radial and longitudinal myocardial contraction
velocities in healthy dogs via quantitative 2-dimensional
color tissue Doppler imaging (TDI).
Procedure—TDI was used by a single trained observer
to measure radial and longitudinal myocardial
movement in the LVFW. Radial myocardial velocities
were recorded in segments in the endocardial and
epicardial layers of the LVFW, and longitudinal velocities
were recorded in segments at 3 levels (basal,
middle, apical) of the LVFW.
Results—LVFW velocities were higher in the endocardial
layers than in the epicardial layers. Left ventricular
free wall velocities were higher in the basal
segments than in the middle and apical segments.
Radial myocardial velocity gradients, defined as the
difference between endocardial and epicardial velocities,
were (mean ± SD) 2.5 ± 0.8 cm/s, 3.8 ± 1.5 cm/s,
and 2.3 ± 0.9 cm/s in systole, early diastole, and late
diastole, respectively. Longitudinal myocardial velocity
gradients, defined as the difference between basal
and apical velocities, were 5.9 ± 2.2 cm/s, 6.9 ± 2.5
cm/s, and 4.9 ± 1.7 cm/s in systole, early diastole, and
late diastole, respectively. A breed effect was detected
for several systolic and diastolic TDI variables. In all
segments, systolic velocities were independent of
Conclusions and Clinical Relevance—LVFW
myocardial velocities decreased from the endocardium
to the epicardium and from base to apex, thus
revealing intramyocardial radial and longitudinal velocity
gradients. These indices could enhance conventional
echocardiographic analysis of left ventricular
function in dogs. Breed-specific reference intervals
should be defined. (Am J Vet Res 2005;66:953–961)
Objective—To quantify radial and longitudinal left
ventricular free wall (LVFW) velocities in dogs during
the preclinical phase of Golden Retriever muscular
dystrophy (GRMD)-associated cardiomyopathy by use
of tissue Doppler imaging (TDI).
Animals—9 dogs with GRMD and 6 healthy control
Procedure—All dogs (< 3 years old) were examined
via conventional echocardiography and 2-dimensional
color TDI. Myocardial velocities in the LVFW were
recorded from right parasternal ventricular short-axis
(radial motion) and left apical 4-chamber (longitudinal
motion) views. Cardiac assessments via TDI included
maximal systolic and early and late diastolic LVFW
velocities in the endocardial and epicardial layers (for
radial motion) and in the basal and apical segments
(for longitudinal motion).
Results—No notable ventricular dilatation or alteration
of inotropism was detected in dogs with GRMD
via conventional echocardiography. Compared with
healthy dogs, endocardial velocities were significantly
decreased in dogs with GRMD, resulting in marked
decreases in radial myocardial velocity gradients during
systole and early and late diastole. Similarly, basal
and apical velocities were significantly decreased in
systole and the former also in early diastole, resulting
in significant decreases in the 2 corresponding longitudinal
myocardial velocity gradients. The radial epicardial
and longitudinal late diastolic velocities were
comparable in the 2 groups.
Conclusions and Clinical Relevance—Results indicated
that GRMD-associated cardiomyopathy in dogs
is associated with early marked dysfunction of both
radial and longitudinal LVFW motions. These combined
regional myocardial abnormalities might be useful
criteria for detection of dilated cardiomyopathy at
the preclinical stage of the disease in dogs. (Am J Vet
Objective—To measure the radial and longitudinal
velocities of several myocardial segments of the left
ventricular wall by use of tissue Doppler imaging (TDI)
in healthy cats and determine the repeatability and
reproducibility of the technique.
Animals—6 healthy cats.
Procedure—72 TDI examinations were performed
on 4 days by the same trained observer. Radial parameters
included left endocardial and epicardial
myocardial velocities. Longitudinal parameters
included left basal, middle, and apical myocardial
Results—All velocity profiles had 1 positive systolic
wave (S) and 2 negative diastolic waves (E and A).
Myocardial velocities were higher in the endocardial
than epicardial segments during the entire cardiac
cycle (systolic wave S, 4.4 ± 0.82 and 1.9 ± 0.55; diastolic
wave E, 9.7 ± 1.70 and 2.2 ± 0.74; and diastolic
wave A, 5.1 ± 1.56 and 1.4 ± 0.76, respectively).
Velocities were also higher in the basal than in the apical
segments (systolic wave S, 4.7 ± 0.76 and 0.2 ±
0.11; diastolic wave E, 9.7 ± 1.36 and 0.5 ± 0.17; and
diastolic wave A, 3.7 ± 1.51 and 0.2 ± 0.13, respectively).
The lowest within-day and between-day coefficients
of variation were observed in endocardial segments
(8.2% and 6.5% for systolic wave S and diastolic
wave E, respectively) and in the basal segment in
Conclusions and Clinical Relevance—Repeatability
and reproducibility of TDI were adequate for measurement
of longitudinal and radial left ventricular
motion in healthy awake cats. Validation of TDI is a
prerequisite before this new technique can be recommended
for clinical use. ( Am J Vet Res 2004;
Objective—To determine the intra- and interobserver variability of systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) measurements obtained with 2 indirect methods in awake dogs and percentage of successful measurements.
Animals—6 healthy conscious adult dogs.
Procedures—4 observers with different levels of training measured SAP and DAP on 4 days by use of Doppler ultrasonography (DU) and high-definition oscillometry (HDO). The examinations were randomized. Measurements for each technique were recorded 5 consecutive times, and mean values (total, 720 measurements) were used for statistical analysis.
Results—All within- and between-day coefficients of variation (CVs) for SAP were < 15% irrespective of the observer or method (HDO, 3.6% to 14.1%; DU, 4.1% to 12.4%). Conversely, half the CVs for DAP were > 15% with the highest within- and between-day CVs obtained by the least experienced observer by use of DU (19.5% and 25.9%, respectively). All attempts with HDO were successful, whereas DAP could not be measured by use of DU by the least experienced observer in 17% of attempts.
Conclusions and Clinical Relevance—SAP may be assessed in healthy dogs by use of DU and HDO with good repeatability and reproducibility after a short period of training. Conversely, the variability of DAP is higher and longer training is required to assess DAP via DU than via HDO.
To document RBC abnormalities in dogs with congenital ventricular outflow tract obstruction.
62 dogs with pulmonic stenosis (PS) or aortic stenosis (AS) and 20 control dogs were recruited.
The proportions of RBCs that were schistocytes, acanthocytes, and keratocytes were assessed. Complete blood cell counts were performed. Tested variables included hemoglobin concentration, hematocrit, and erythrocyte count.
Median (interquartile range [IQR]) peak systolic Doppler-derived trans-stenotic pressure gradient (∆P) values were 161 mm Hg (108 to 215 mm Hg) and 134 mm Hg (125 to 165 mm Hg) for dogs with PS and AS, respectively. Hematologic abnormalities were detected in most dogs with AS or PS (54/62 [87%]) versus 8/20 [40%] in control dogs, with schistocytes found in 40 of 62 (65%; median, 0.1% RBCs; IQR, 0% to 0.3%), acanthocytes in 29 of 62 (47%; median, 0.3% RBCs; IQR, 0% to 0.9%), keratocytes in 39 of 62 (63%; median, 0% RBCs; IQR, 0% to 0.2%), and hemolytic anemia in 4 dogs with PS. No significant association was identified between these abnormalities and ∆P. However, 3 of 4 dogs with anemia had a ∆P > 200 mm Hg (range, 242 to 340 mm Hg). The dog with the highest ∆P value also had the most severe anemia and schistocytosis, and both resolved after balloon valvuloplasty.
Poikilocytosis is common in dogs with congenital ventricular outflow tract obstruction, with anemia only observed in few dogs with high ∆P values.