The Apex Cardiogram in Left Ventricular Outflow Tract Obstruction.

392 rest. In patients T.T. and M.J. the diagnosis was not suspected until cardiac catheterization. The former had a ventriculo-aortic gradient of 18 mm. Hg during exercise. In patients M.S., R.G., R.J., and M.P. the diagnosis had been suggested by clinical examination, since these patients presented many of the features characteristic of this condition.2 These four patients had a resting subvalvular pressure gradient ranging from 38 to 92 mm. Hg. In patient R.G. the diagnosis was confirmed at operation and subsequentIy at autopsy. Selective angiocardiography, carried out in two patients, demonstrated systolic narrowing of the outflow tract of the left ventricle. All six patients were in sinus rhythm, five had evidence of left ventricular hvpertrophy on the electrocardiogram and had mild to moderate enlargement of the left ventricle on roentgenographic examination. M.J. showed incomplete right bundle-branch block in the electrocardiogram; the heart was not enlarged on roentgenographic examination. Idiopathic Myocardial Hypertrophy. The patient with this condition was a 42-year-old man without valvular, hypertensive, or coronary artery disease. The diagnosis was made at cardiac catheterization with the aid of angiocardiography. At rest there was a 2-mm. Hg ventriculoaortic gradient but during an infusion of isoproterenol a gradient of 35 mm. Hg developed. The electrocardiogram showed normal sinus rhythm and left ventricular hypertrophy. Roentgenographic examination showed left ventricular enlargement. Valvular Aortic Stenosis. The 16 patients with this lesion ranged in age from 20 to 64 years: eight were men and eight were women. All were moderately to severely limited in activity as a result of congestive heart failure. All were in sinus rhythm and presented electrocairdiographic evidence of left ventricular hypertrophy. Left ventricular enlargement of varying degree was detected on roentgenographic and fluoroscopic examination. The diagnosis was proved in all patients at cardiac catheterization. The systolic mean gradient across the aortic valve ranged from 24 to 44 mm. Hg. In four patients the diagnosis was confirmed at operation and in two of them at postmortem examination. Methodls. The electrocardiogram, phonocardio-