Hypertrophic apical cardiomyopathy: a subtype of hypertrophic cardiomyopathy

Abstract

This is the first report of hypertrophic apical cardiomyopathy outside of Japan. Electrocardiographic, vectorcardiographic, echocardiographic, hemodynamic and angiographic investigations support the view that this entity is a subset of hypertrophic cardiomyopathy that differs from hypertrophic obstructive cardiomyopathy and left-ventricular cavity obliteration. The ECG recorded giant negative T waves associated with prominent R waves in the precordial leads and septal Q waves were absent, with a normal mean QRS axis in the frontal plane. The vectorcardiogram showed a QRS loop oriented to the left anteriorly and inferiorly, while the T loop was characteristically discordant, elongated and situated in the right posterior quadrant. An M-mode ECG scan along the left-ventricular long axis revealed a marked increase in both septal and posterior wall thickness and excursions toward the apex. A characteristic spadelike configuration was observed in the left ventriculogram at end-diastole. Pressure studies at rest and after ventricular ectopic beats and isoproterenol provocation revealed no significant peak systolic pressure gradient within the left ventricle. This may have certain therapeutic implications.