Reversible Subaortic Obstruction in Hypertensive Hypertrophic Cardiomyopathy

Abstract

We identified 4 patients with pulmonary vascular congestion, a small left ventricular cavity seen echocardiographically, and normal indexes of systolic function. All patients had noninvasive evidence of subaortic obstruction and obliteration of the left ventricular cavity on apexcardiography and external carotid pulse tracings when treated with digitalis preparations, diuretics, and afterload-reducing medications. Considerable symptomatic improvement and resolution of pulmonary congestion were achieved with the use of either verapamil or β-receptor antagonists. Such therapy effectively abolished the noninvasive evidence of subaortic obstruction. We conclude that a certain subset of hypertensive patients are pharmacologically susceptible to obliteration of the left ventricular cavity and subaortic obstruction. Echocardiography is helpful in identifying these patients who represent a therapeutic challenge because their condition improves with administration of β-receptor antagonists and verapamil, but deteriorates appreciably with conventional therapy of vasodilators and inotropic agents.