Left ventricular geometrical differences in dogs with various stages of myxomatous mitral valve disease.

Abstract

OBJECTIVES: To evaluate left ventricular geometry in dogs with various stages of myxomatous mitral valve disease. METHODS: Ninety-seven dogs with myxomatous mitral valve disease classified by the International Small Animal Cardiac Health Council system and 20 weight- and age-matched healthy dogs. Left ventricular long-axis to short-axis ratio, sphericity index in end-diastole and end-systole, left ventricular wall thickness to internal dimension ratio and relative wall thickness were assessed. RESULTS: The diastolic sphericity index was lower in classes Ib, II and III than in healthy dogs (P=0&#xb7;003, P<0&#xb7;001 and P<0&#xb7;001) and was also lower in class III than in classes Ia, Ib and class II dogs (P<0&#xb7;001, P<0&#xb7;001 and P=0&#xb7;002). The relative wall thickness was lower in classes II and III than in class Ia (P=0&#xb7;003 and P<0&#xb7;001), class Ib (P=0&#xb7;004 and P<0&#xb7;001), and healthy dogs (P<0&#xb7;001 and P<0&#xb7;001) and was also lower in class III than in class II (P=0&#xb7;005). CLINICAL SIGNIFICANCE: Sphericity index and relative wall thickness are simple methods for assessing left ventricular geometry using two-dimensional echocardiography that may be useful in myxomatous mitral valve disease dogs as part of risk stratification.