Structural and functional alterations of the intramyocardial coronary arterioles in patients with arterial hypertension.

Abstract

BACKGROUNDIn hypertensive patients with angina pectoris, the coronary vasodilator reserve is frequently impaired despite a normal coronary angiogram. Experimental data indicate that structural alterations of the intramyocardial coronary vasculature contribute to an increased minimal coronary resistance and a diminished coronary flow reserve.METHODS AND RESULTSIn 14 patients (10 men and 4 women) with arterial hypertension and 8 normotensive subjects, minimal coronary resistance and vasodilator reserve (dipyridamole: 0.5 mg/kg body wt, gas chromatographic argon method) were determined after the angiographic exclusion of relevant coronary artery disease. Coronary reserve was depressed in hypertensive patients (2.7 +/- 2.3 vs 4.6 +/- 1.3, P < or = .05) due to increased minimal coronary resistance (0.64 +/- 30 vs 0.24 +/- 0.055 mm Hg.min.100 g.mL-1, p < or = 0.002). In right septal biopsies, mean external arteriolar diameter (21.6 +/- 2.3 vs 17.2 +/- 2.5 microns, P < or = .001), mean arteriolar wall area (271 ...