Isolated right ventricular cardiomyopathy in a dog.

Right-sided heart failure was diagnosed in a young dog with clinical and pathologic features of isolated right ventricular cardiomyopathy. This disorder, also referred to as right ventricular dysplasia, is an infrequent cause of heart failure and sudden death in people. Echocardiography of this dog revealed right ventricular and right atrial dilatation and severe right ventricular systolic dysfunction. Left ventricular size and function were normal. Electrocardiography revealed ventricular bigeminy. The configuration of the ectopic beats was similar to that seen with left bundle branch block. The dog died suddenly, and histologic examination of the heart revealed fibroadipose replacement of right atrial and right ventricular myocardium.