Echocardiographic dimensions in borderline and sustained hypertension.

Echocardiographic dimensions and hemodynamic indexes were determined in 42 patients with borderline hypertension and in 22 with sustained hypertension and the results were compared with findings in 33 normal subjects. In patients with borderline hypertension the thickness of the interventricular septum (IVS) was significantly increased (P less than 0.001), whereas the posterior wall PW) thickness remained within normal range. The IVS/PW ratio was significantly elevated (P less than 0.001) and was correlated negatively with the cardiac index (P less than 0.01) and positively with the preejection period (P less than 0.01). In patients with sustained hypertension a symmetric cardiac hypertrophy was observed, and there was a significant positive correlation between the IVS/PW ratio and diastolic pressure (P less than 0.05). The study suggested that (1) in sustained hypertension the symmetric cardiac hypertrophy was secondary to a progressive increase in pressure load, whereas (2) in borderline hypertension the asymmetric cardiac hypertrophy could not be directly related to the level of blood pressure and was probably associated with abnormalities of the sympathetic nervous system.