Small vessel disease (SVD) in patients with unexplained ventricular arrhythmia and dilated congestive cardiomyopathy.

Small vessel coronary disease is not commonly found in endomyocardial biopsies (EMB) of nondiabetic patients with clinical evidence of ischemic heart disease, congestive heart failure, or ventricular arrhythmia (VA). In 166 patients studied by heart catheterization and multiple right ventricle EMB, we identified 4 patients with histologic evidence of small vessel disease and normal coronary arteriograms. Two patients were suffering from VA without an obvious cardiac cause. Of the other two, one initially showed frequent ventricular tachycardia attacks followed by congestive heart failure alone. In both patients, the cardiac chambers were dilated and the left ventricular function seriously impaired. In all four patients, the histologic examination of right EMB revealed a wall thickening of the precapillary arterioles and capillary vessels. At ultrastructural examination, an increased thickening (four or five times normal) of the subendothelial lamina and of the basement membrane of capillary pericytes was found. Degenerative changes of cardiac myocells were found in all cases.