Primary Myocardial Disease

This study describes 18 patients from the University of Cincinnati Hospitals who died of congestive heart failure without clinical or pathologic evidence of a primary cause. Clinical features. Their ages were from 18 months to 68 years at death. Fourteen were male and four female; 11 were white and seven were Negro. Seven patients had heart failure for 5 years or more; three had heart failure for over 10 years. Seven patients were alcoholic and three had nutritional cirrhosis. Transient mitral or tricuspid systolic murmurs and apical protodiastolic gallop rhythms were common. Atrial fibrillation was present in six patients. The electrocardiograms revealed abnormal left axis deviation in three and left bundle-branch block in two. Right heart catheterization was performed in four of these patients and showed low cardiac output, increased arteriovenous oxygen difference, and elevation of pulmonary arterial, pulmonary wedge, right ventricular diastolic, and right atrial pressures. Pathologic features. Heart weights were over 500 Gm. in 13 patients; all 18 had left ventricular hypertrophy. Mural thrombi were present in 10; six had pulmonary emboli and three had systemic arterial emboli. One patient had gross myocardial scarring; only two had small accumulations of inflammatory cells in the myocardium. Ten had focal increase of elastic tissue. Primary myocardial disease may simulate coronary artery disease because of the abnormal electrocardiogram; it may simulate hypertensive heart disease because of elevation of diastolic blood pressure during heart failure in some patients; it may simulate pericardial effusion because of the poor cardiac pulsations, narrow pulse pressure, and paradoxical pulse. It may simulate rheumatic heart disease because of the apical systolic and diastolic murmurs, left atrial enlargement, and presence of Kerley lines. The cause is unknown. Only one patient in this group had a familial history of similar heart disease.