Pulmonary stenosis and impaired myocardial function.

Two young Black female patients with pulmonary valve stenosis and intact ventricular septa are presented in protracted congestive cardiac failure with severe tricuspid insufficiency and, in one, atrial fibrillation. Right ventricular systolic dysfunction was manifested by peak systolic pressures below systemic level, raised end-diastolic pressures and low cardiac output, but without right-to-left shunt. These findings are in strong contrast to those found in most patients with pulmonary stenosis of long standing, where persistent impairment of right ventricular function is diastolic with a high end-diastolic pressure and reversal of an interatrial shunt which result from poor right ventricular compliance. Evidence of left ventricular dysfunction was also present in both cases. Protracted heart failure in these patients is believed to have been the result of coincidental cardiomyopathy in a racial group highly predisposed to this disorder. A diagnostic appreciation of this phenomenon is important in the evaluation of heart disease in the Black, since cardiomyopathy may modify or even mask the features of the underlying disorder.