The hemodynamics in young patients with borderline hypertension.

Hemodynamics in supine position were studied echocardiographically in 56 young patients with borderline hypertension and 56 age-matched normotensive subjects. In hypertensive patients, the cardiac index (CI) did not increase, but the total peripheral resistance (TPR) increased significantly (p less than 0.005). The hypertensive patients were classified into 2 groups, according to the level of the CI. In patients in group A ("normal" CI), the CI, heart rate and the mean circumferential fiber shortening velocity (mVCF) were normal, but the TPR was increased significantly. In patients in group B ("high" CI), the CI, heart rate and the mVCF increased significantly (hyperkinetic state), but the TPR was normal. Plasma renin activity (PRA) was significantly higher in patients in group B than the normal subjects, but the level of PRA in patients in group A was normal. These findings support the hypothesis that sympathetic nervous activity increases in patients in group B, but not in those in group A. Therefore, this study provides evidence that the TPR is abnormal in patients with borderline hypertension, and an impaired neurogenic activity seems to be important in the early stage of hypertension, as in borderline hypertension associated with a hyperkinetic circulatory state (group B).