Familial Myocardial Disease with and without Obstruction

Right and left heart catheterization, including selective cineangiocardiography, was performed in 20 of the 33 patients examined in a large Negro family. Fifteen had features compatible with the diagnosis of idiopathic hypertrophic subaortic stenosis. Sudden death has not occurred in this family. Many of the patients were young and were totally unaware of the heart disease, although 11 had symptoms of dyspnea on exertion. A large number of individuals in this family were found to be affected by a familial form of heart disease with similar clinical manifestations, but with a wide spectrum of hemodynamic and cineangiocardiographic abnormalities ranging from no obstruction to ventricular outflow and only mild indentation of the ventricular cavity to obstruction and marked narrowing of both ventricular outflow tracts. The patients with obstruction of the left ventricular outflow tract were older than those without obstruction. Therefore, this study provides further evidence that in families with myocardial disease, the presence or absence of outflow tract obstruction is merely a different manifestation of the same basic cardiac disease. This study has also demonstrated distinct left ventricular abnormalities quite early in life suggesting that the disease may be of congenital origin and that obstruction may be a function of the duration of the disease.