Mechanism of angina in patients with systemic hypertension and normal coronary angiogram

ABSTRACT

the purpose of this study was to investigate the changes in the coronary flow reserve in hypertensive patients with angina and normal coronary arteries, and its relation with coronary vasomotor response. the study population consisted of thirty hypertensive patients with angina and normal coronary angiogram [group I [non-LVH] n = 15 without left ventricular hypertrophy, group II [LVH] n = 15 with left ventricular hypertrophy and a matched healthy control group [group III n = 10]. Coronary velocity was monitored by means of transesophageal Doppler echocardiography basely and during infusion of [0.56 mg/kg per 4-minute] dipyridamole. Coronary flow reserve [CFR] was assessed as the ratio of mean diastolic velocity after dipyridamole and basal diastolic velocity. Coronary vasomotion was assessed by means of coronary catheterization as the changes in arterial caliber by acetylcholine and papaverine. Left ventricular mass, dimensions and function were measured by transthoracic echocardiography, Electrocardiography [ECG] changes were recorded by resting and exercise stress ECG. compared with the control group, CFR was decreased in both hypertensive groups [non-LVH = 1.56 +/- 0.22, LVH = 1.46 +/- 0.14, control = 3.49 +/- 0.60, P < 0.001]. The reduction in CFR depends on both an increase in resting coronary flow, and an impaired in maximal vasodilator capacity. Hypertensive patients who showed a positive exercise test have significant high resting mean diastolic coronary flow velocity [p < 0.01], and CFR showed positive correlation with exercise duration and rate-pressure product. Left ventricular mass had no effect on CFR, and wall stress was the major discriminating variable between non-LVH and LVH groups. imparied coronary flow reserve in hypertensive patients is the mechanism for the clinical syndrome of angina pectoris, abnormal electrocardigram but normal coronary arteries