[Systolic anterior motion of the anterior mitral leaflet and/or the chordae tendinae in the elderly].

Systolic anterior motion of the anterior mitral leaflet and asymmetric septal hypertrophy (ASH) are characteristic features of hypertrophic obstructive cardiomyopathy (HOCM) on an echocardiogram. Among 9,670 patients over 60 years old examined by echocardiography from January, 1984 to October, 1990, 55 patients showed systolic anterior motion of the anterior mitral leaflet and/or the chordae tendinae (SAM). We investigated clinical features and morphological features of the left ventricle on an echocardiogram in the 55 patients with SAM. They were classified into three groups according to the degree of SAM. Thirty eight cases (group I) had no mitral and/or chordal-septal contact, 10 (group II) had brief contact (less than 30% on the echocardiographic systole) and 7 (group III) had prolonged contact (greater than or equal to 30%). Ages ranged from 60 to 99 with a mean age of 78.2 years. There were 19 males and 36 females and there was a predominance of females in each group. Thirty five cases had hypertension and 34 left ventricular hypertrophy on electrocardiograms. One case of group I, 3 of group II and 7 of group III had a clinical diagnosis of HOCM. In comparison with each group, the incidence of LVH (SV1 + RV5 greater than or equal to 35 mm) was 52% in group I, 90% in group II and 83% in group III and that of LVH (SV1 + RV5 greater than or equal to 70 mm) was 29%, 20% and 67%, respectively. On echocardiographic examination, the diastolic descent rate of the anterior mitral leaflet in the 3 groups was 36.1 +/- 13.1 mm/sec, 19.4 +/- 13.1 mm/sec and 10.7 +/- 11.8 mm/sec (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)