Characteristics of the limb circulation in hypertension.

The aim of this study was to investigate the effect of hypertension on the regulation of limb circulation. The study group consisted of 50 patients suffering from hypertension; in 21 cases the peripheral circulation was intact, while 29 patients had peripheral obliterative arterial disease (POAD) (clinical symptoms: intermittent claudication or rest pain). The control group consisted of 67 normotensive patients. In 33 subjects of the control group the peripheral circulation was intact, while 34 patients suffered from POAD (clinical symptoms: intermittent claudication or rest pain). The total limb blood flow (LBF) was measured by using venous isotope dilution technique. In hypertensive patients the limb vascular resistance (LVR) was markedly elevated, but the LBF remained in the normal range. In patients suffering from both hypertension and POAD the LVR was pathologically elevated and the LBF markedly diminished. After acute vasodilator therapy the LBF significantly increased, despite the drop in blood pressure owing to the extensive decrease of the LVR. It appears that in hypertension the elevation of the LVR is the most characteristic change of the limb circulation. The elevation of the arterial blood pressure has no favorable effect on the limb circulation, and the LBF compared with the blood pressure is relatively low.