Reduced peripheral and coronary vasomotion in systemic hypertension.

In 53 patients with a history of arterial hypertension and 16 normotensive control subjects, coronary blood flow reserve by means of the argon method, and peripheral vascular flow reserve by means of venous occlusion plethysmography, were studied. The coronary flow reserve, expressed as the ratio of coronary vascular resistance under resting conditions to the minimal coronary vascular resistance after the administration of dipyridamole, was 4.34 +/- 0.89 in the normotensive group and 2.18 +/- 0.60 in the hypertensive group. There was no significant difference in forearm peak flow after 3 min of arterial occlusion between normotensive and hypertensive patients, while the peripheral minimal vascular resistance was significantly higher in hypertensive patients (8.8 +/- 3.8 mmHg x ml.min-1 x 100 ml-1 tissue) as compared to normotensive subjects (6.37 +/- 2.37 mmHg x ml.min-1 x 100 ml-1 tissue). Parallel to the reduction in coronary reserve, the peripheral flow reserve, expressed as the ratio of peripheral resting vascular resistance to peripheral minimal vascular resistance after 3 min of arterial occlusion, was significantly lower (P less than 0.01) in hypertensive subjects (3.85 +/- 2.28) as compared to normotensive subjects (5.31 +/- 1.72). These data suggest that in hypertensives an impaired vasodilator reserve of both coronary and peripheral microcirculation exists.