Obstructive cardiomyopathy simulating aortic stenosis.

Over the past few years there has been a gradual recognition that obstruction to outflow from the left ventricle may be determined by lesions other than fusion of the aortic valve cusps or congenital diaphragms below or above the cusps. This syndrome has been described by Brock (1957, 1959), under the title of Functional obstruction of the left ventricle, and he instances a patient in whom hypertension produced left ventricular hypertrophy that narrowed the outflow tract of the left ventricle in systole. Bercu et al. (1958) used the term Pseudo-aortic stenosis to describe a patient with apparent aortic stenosis who at autopsy had gross generalized ventricular hypertrophy only. Morrow and Braunwald (1959), under the heading Functional aortic stenosis, instance two patients with apparent sub-aortic stenosis who at open operation were found to have no anatomical obstruction. Recently Teare (1958), from autopsy studies, gave the first adequate description of Asymmetrical hypertrophy of the heart, a condition in which the interventricular septum in particular is grossly hypertrophied and bulges into both ventricular cavities. One of his cases presented with signs of mitral stenosis; another was studied by us during life and found to have signs of obstruction to right ventricular inflow tract, and fourteen members of her family also had heart disease with similar signs (Hollman et al., 1960). Fig. 1 shows the heart in one of these patients. We have now seen 8 patients in whom we believe that hypertrophy of the left ventricle of undetermined cause has caused obstruction to left ventricular outflow (pseudo-aortic stenosis). Some have had signs suggesting inflow obstruction of one or both ventricles in addition, and we propose the term Obstructive cardiomyopathy as being a suitable descriptive title for the whole group. In one of our patients the obstruction was successfully dealt with by open-heart surgery.