Prevalence of cardiomyopathy in apparently healthy cats

OBJECTIVE

To determine the prevalence of cardiomyopathy and the relationship between cardiomyopathy and heart murmurs in apparently healthy cats.

DESIGN

Cross-sectional study.

ANIMALS

103 privately owned, apparently healthy domestic cats.

PROCEDURES

Cats were physically and echocardiographically examined by 2 investigators independently. Left ventricular wall thickness was determined via 2-dimensional echocardiography in short-axis and long-axis planes. Left ventricular hypertrophy was identified when end-diastolic measurements of the interventricular septum or posterior wall were > or = 6 mm. Cats with left ventricular hypertrophy but without left ventricular dilatation were considered to have hypertrophic cardiomyopathy (HCM). The associations between heart murmurs and Doppler echocardiographic velocity profiles indicative of dynamic ventricular outflow tract obstruction were evaluated.

RESULTS

Heart murmurs were detected in 16 (15.5%; 95% confidence interval, 9.2% to 24.0%) cats; of these, 5 had cardiomyopathy. Cardiomyopathy was also identified in 16 (15.5%; 95% confidence interval, 9.2% to 24.0%) cats; 15 had HCM, and 1 had arrhythmogenic right ventricular cardiomyopathy. Of the cats with HCM, 11 had segmental left ventricular hypertrophy, 3 had diffuse left ventricular hypertrophy, and 1 had borderline left ventricular hypertrophy with marked systolic anterior motion of the mitral valve. Sensitivity and specificity of auscultatory detection of a heart murmur for diagnosing cardiomyopathy were 31% and 87%, respectively. Echocardiographic evidence of late systolic acceleration within ventricular outflow tracts was associated with the existence of a heart murmur.

CONCLUSIONS AND CLINICAL RELEVANCE

Cardiomyopathy was common in the healthy cats evaluated in this study. In apparently healthy cats, detection of a heart murmur is not a reliable indicator of cardiomyopathy.

Systolic anterior motion of the mitral valve associated with right ventricular systolic hypertension in 9 dogs

OBJECTIVES

To describe the zoographic and echocardiographic characteristics of canine patients in which systolic anterior motion of the mitral valve (SAM) was identified in association with right ventricular systolic hypertension (RVSH).

ANIMALS, MATERIALS AND METHODS

Medical records and digitally recorded echocardiographic examinations were reviewed for RVSH and two-dimensional (2DE) or M-mode echocardiographic evidence of SAM.

RESULTS

SAM was identified in association with RSVH in 9 patients; 5 had pulmonic stenosis, 2 had tetralogy of Fallot and 2, pulmonary hypertension. Relative to body weight, the end-diastolic and end-systolic left ventricular dimensions were subnormal in all patients. Hyperdynamic left ventricular systolic performance was identified in 8 of 9 patients. In 5 of the 9 patients, SAM was mild or moderate in degree. Left ventricular outflow tract (LVOT) obstruction and mitral valve regurgitation were documented by Doppler studies in only 3 of the 4 patients with marked SAM. However, late systolic acceleration within the LVOT was recorded in 2 additional patients for whom peak velocities were normal.

CONCLUSIONS

In the cases described here, the presence of SAM is likely explained by alterations in left ventricular geometry and function associated with diminished pulmonary venous return together with sympathetic activation resulting from subnormal stroke volume. Although the hemodynamic consequences were apparently minor, the association of SAM with right-sided heart disease might be of interest to those engaged in the practice of veterinary echocardiography.

Prevalence and incidence density of Mycobacterium leprae and Trypanosoma cruzi infections within a population of wild nine-banded armadillos

A total of 415 wild 9-banded armadillos from the East Atchafalaya River Levee (Point Coupee, LA) were collected over 4 years to estimate the incidence and prevalence of Mycobacterium leprae and Trypanosoma cruzi and to discern any relationship between the 2 agents. M. leprae infections were maintained at a high steady prevalence rate year to year averaging 19%. T. cruzi antibody prevalence remained relatively low, averaging 3.9%, and varied markedly between years. Prevalence rates were independent, with only 3 armadillos coinfected with both agents. M. leprae incidence density ranged from 0.47 to 3.5 cases per 1,000 animal-days, depending on case definition, confirming active intense transmission of M. leprae among armadillos. No incident T. cruzi cases were found. These infections seem to occur independently and may be used in comparisons to understand better factors that may influence transmission of these agents.