Idiopathic hypertrophic subaortic stenosis (IHSS) is a disease characterized by marked hypertrophy of the left ventricle, involving in particular the interventricular septum and the left ventricular outflow tract.

Idiopathic hypertrophic subaortic stenosis (IHSS), or hypertrophic obstructive cardiomyopathy (HOCM), is one of the few common diseases virtually unknown 20 years ago.

It is concluded that an increase in heart rate tends to exaggerate circulatory abnormalities in idiopathic hypertrophic subaortic stenosis and provides a simple and useful diagnostic test for differentiation of the dynamic and fixed forms of obstruction to left ventricular outflow.

Genetically inherited heart muscle disease associated with left ventricular hypertrophy (LVH), myocyte disarray, small vessel disease (narrowing of intramural coronary arteries by medial thickening), and fibrosis.

The resutts of surgery in 43 patients with idiopathic hypertrophic subaortic stenosis are reported. Twenty-eight patients were male and 15 female; their mean age was 34 years. Dyspnea, angina pectoris and dizziness or syncope were the most common symptoms, in de- creasing frequency.

The clinical and hemodynamic features of a case of idiopathic hypertrophic subaortic stenosis are presented. Criteria for its clinical recognition are assessed and current concepts of its pathophysiology are briefly reviewed, with confirmation of a recently described technique for its hemodynamic detection.

With the delineation of its clinical, hemodynamic, angiocardiographic and anatomic features, idiopathic hypertrophic subaortic stenosis emerges as a specific entity which can be distinguished preoperatively from discrete valvular and subvalvular aortic stenosis.

BRENT L. B., ABURANO A., FISHER D. L., MORAN T. J., MYERS J. D., TAYLOR W. J. Familial muscular subaortic stenosis: an unrecognized form of "idiopathic heart diseases," with clinical and autopsy observations.

hypertrophic subaortic stenosis (idiopathic hypertrophic subaortic stenosis) a cardiomyopathy of unknown cause, in which the left ventricle is hypertrophied and the cavity is small; it is marked by obstruction to left ventricular outflow.

pertrophic subaortic stenosis and provide the basis for a new, simple and useful diagnostic test for the detection of this disease. CLINICAL MATERIAL AND METHODS The results of hemodynamic studies in 15 patients form the basis for this report. The diagnosis of idiopathic hypertrophic subaortic stenosis was es-