Abstract
A form of cardiomyopathy displaying myocardial fiber disarray and ventricular septal hypertrophy is presented as a cause of sudden death in patients. The pattern of myocardial fibers is found embryologically, but is presented to be a genetically transmitted myocardial defect. Diagnosis is verified with echocardiography, but is not demonstrable on plain chest X-ray. Surgical myotomy or myectomy corrects thickening of the ventricular septum.