Prevalence and significance of asymmetric septal hypertrophy in hypertension: an echocardiographic and clinical study.

To assess the prevalence of asymmetric septal hypertrophy (ASH) in hypertensive patients, 613 echocardiographic examinations performed over a period of one year were reviewed. Asymmetric septal hypertrophy (defined by an echocardiographic interventricular septum to left ventricular free wall thickness ratio of greater than or equal to 1.3 and by the presence of suggestive two-dimensional echocardiographic abnormalities) was found in 28 patients (5%). Clinical characteristics of asymmetric septal hypertrophy were assessed in 101 patients who underwent a complete evaluation. Patients with asymmetric septal hypertrophy (n = 9) were compared with patients with echocardiographic symmetrical left ventricle hypertrophy (n = 38) and without left ventricular hypertrophy (n = 54). Our results indicate that neither the severity of hypertension, nor the renin-angiotensin system nor sympathetic nerve activity appear to be the primary determinants in the development of asymmetric septal hypertrophy.