Elderly patients with hypertrophic cardiomyopathy: a subset with distinctive left ventricular morphology and progressive clinical course late in life.

This report describes a subgroup of 52 elderly patients with obstructive hypertrophic cardiomyopathy in whom certain clinical and morphologic features differed importantly from those of many other patients with this disease. Ages ranged from 60 to 84 years (mean 69) and 45 [87%] were women. Echocardiographic examination showed a relatively small heart, having only modest ventricular septal hypertrophy associated with marked distortion of left ventricular outflow tract morphology. By virtue of selection, left ventricular outflow tract size at end-diastole was substantially reduced, and anterior displacement of the mitral valve within the left ventricular cavity was particularly marked. Sizable deposits of calcium in the region of the mitral anulus, posterior to the mitral valve, appeared to contribute to the outflow tract narrowing. Systolic anterior motion of the mitral valve was severe (with apposition of the mitral valve and ventricular septum) in 32 patients and more moderate in 20. The mechanism by which systolic contact between the mitral valve and septum occurred in most patients appeared to differ from that observed more typically in many other patients with hypertrophic cardiomyopathy; in most elderly study patients, anterior excursion of the mitral valve leaflets was relatively restricted, and systolic apposition between the mitral valve and septum resulted from a combination of anterior motion of the mitral valve and posterior excursion of the septum. The vast majority (50 of 52) of the patients remained asymptomatic (or only mildly symptomatic) for most of their lives and often did not develop severe and intractable symptoms until the 6th or 7th decade (ages 56 to 81 years; mean 66). Of the 49 patients with at least 1 year follow-up study, only 12 had improvement with pharmacologic therapy; however, 14 of the 18 patients who underwent ventricular septal myotomy-myectomy or mitral valve replacement obtained symptomatic benefit from operation. In conclusion, obstructive hypertrophic cardiomyopathy in many elderly (and predominantly female) patients may assume a distinctive morphologic appearance and a progressive clinical course. This subgroup of patients appears to constitute an important segment of the disease spectrum of hypertrophic cardiomyopathy of cardiac disease in the elderly that previously has not been precisely defined nor fully appreciated.