Haemodynamic characteristics in elderly patients with isolated systolic hypertension.

Systemic arterial compliance, baroreflex sensitivity index and cardiac function were studied in elderly patients with isolated systolic hypertension (ISH, n = 12) comparing values with those of essential hypertensive patients (EHT, n = 12) and normotensive subjects (NT, n = 7) in the same age range. Systemic arterial compliance of the ISH group was markedly decreased. Baroreflex sensitivity indices of ISH and EHT were similarly decreased. Pre-ejection period index (PEPI) of ISH was normal, whereas PEPI of EHT was significantly longer than that of NT. These results demonstrate that of the haemodynamic characteristics of ISH, the predominant features are a decrease in compliance of large arteries with a disturbance of baroreflex sensitivity and normal cardiac function.