A HEMODYNAMIC STUDY OF HYPERTENSION INCLUDING OBSERVATIONS ON CORONARY BLOOD FLOW

Abstract

Hemodynamic data are presented for a series of 21 hypertensive subjects and these are compared with data from 30 normotenslve subjects. In the 14 subjects with Smithwick grade 1 and 2 hypertension (Group I) cardiac Index was normal, whereas in the 7 subjects with grades 3 and 4 hypertension (Group n), cardiac Index was reduced. Total peripheral vascular resistance was elevated in both groups of hypertensive subjects and was significantly higher in Group II than in Group I. Total pulmonary resistance was elevated only in the Group II subjects. The left ventricular work index was elevated in Group I hypertensive subjects, but normal in Group EL Right ventricular work index was normal in Group I but reduced in Group II. Coronary blood flow was normal in both groups as was myocardial oxygen consumption per 100 g: however, coronary vascular resistance is significantly elevated in both groups of hypertensive subjects. It is concluded that cardiac efficiency must be reduced in Group n, since myocardial oxygen consumption per unit of weight was normal, myocardial weight was high, and cardiac work was normal.