Apical hypertrophic cardiomyopathy: clinical and metabolic studies.

Among the hypertrophic non-obstructive cardiomyopathies, a particular group of patients with concentric apical hypertrophy can be described. We studied seven patients (five men and two women) who underwent heart catheterization because they had giant negative T waves in the precordial leads. M-mode and two-dimensional echocardiograms revealed no obstruction within the outflow tract of the ventricle. Coronary angiography was normal in all cases. None of these patients demonstrated any significant peak systolic pressure gradient in the outflow tract. A characteristic spade-like configuration (concentric apical hypertrophy) was observed in the right anterior oblique ventriculogram at end diastole. The apical thickness reached 17.2 +/- 0.85 mm and was significantly greater than mid-anterior wall thickness (9.8 +/- 2.14 mm). In five cases, atrial pacing with coronary arterial and venous lactate sampling revealed abnormalities in myocardial metabolism. With a mean follow up of 43 months, three patients remain asymptomatic and one had heart failure. ECG abnormalities were unchanged and echocardiograms showed an increase of the septal and posterior wall thickness, suggesting a transformation in concentric diffuse hypertrophic cardiomyopathy.