[Hypertrophic cardiomyopathy with ventricular septal hypertrophy localized to the apical region of the left ventricle (apical ASH)].

Clinical and morphologic features are described in a subgroup of 22 patients with hypertrophic cardiomyopathy, who showed ventricular septal hypertrophy localized to the apical region (apical asymmetric septal hypertrophy: apical ASH). All patients had ventricular septal thickness of 17 mm or less with an average of 13 +/- 3 mm in the M-mode echocardiograms. In contrast, the two-dimensional echocardiograms demonstrated septal hypertrophy localized to the apical region, with an average septal thickness of 20 +/- 3 mm at the mitral valve and papillary muscle levels. On the left ventriculogram, 82% of patients with apical ASH showed inward concavity of the right-inferior wall of the left ventricle, indicating hypertrophy of the ventricular septum. However, no patient showed spade-like appearance of the left ventricle and only two showed giant T wave inversion exceeding 10 mm. Echocardiographic examination performed in eight affected relatives revealed typical asymmetric septal hypertrophy (ASH) in four relatives, one of them showing a resting pressure gradient of 30 mmHg in the left ventricle. The remaining four relatives showed similar apical ASH. When compared with patients of typical ASH, patients with apical ASH demonstrated significantly greater cardiac size, left ventricular end-diastolic pressure, left atrial and left ventricular diameters and significantly lower percent fractional shortening. Atrial fibrillation, B bump of the mitral echogram and heart failure were more frequent in this subgroup of patients. Thus, apical ASH appeared to be a part of the morphologic spectrum of hypertrophic cardiomyopathy with ASH and to be a separate disease entity from apical hypertrophy previously described in Japan. Severely impaired diastolic performances associated with mild to moderately depressed systolic function of the left ventricle were the characteristic clinical features of the subgroup of patients with apical ASH.