Non-invasive evaluation of coronary reserve - Assessment of coronary reserve in patients with coronary artery disease by transesophageal-Doppler echocardiography

We assessed coronary flow reserve using transesophageal Doppler echocardiog raphy in patients with coronary artery disease. The study included 33 coron ary artery disease patients who were undergoing coronary arteriography. The blood flow velocities of the left anterior descending artery before and af ter intravenous infusion (0.56 mg/min for 4 min) of dipyridamole were recor ded using transesophageal Doppler echocardiography. Fourteen normal healthy individuals, matched forage, served as a control group. The index of coron ary flow reserve, i.e. the ratio of dipyridamole to baseline maximum diasto lic velocity, was calculated. Maximal coronary flow reserve in coronary art ery disease patients was significantly lower than in the control group (1.4 +/-0.2 vs. 2.8+/-0.3, P<0.001). The coronary artery disease patients were c lassified into three groups: Group A included 10 patients with <50% left an terior descending artery stenosis; Group B included seven patients with 50- 69% left anterior descending artery stenosis; 16 patients with >70% left an terior descending artery stenosis constituted Group C. The maximum coronary flow reserve was significantly different for A vs. B and A vs. C. (A, 1.77 +/-0.18; B, 1.51+/-0.1; C, 1.28+/-0.24). A strong and significant correlati on was found between the maximum coronary flow reserve and the degree of pr oximal left anterior descending artery stenosis (r=0.78, P<0.001). Coronary artery disease patients without left anterior descending artery stenosis o n the arteriogram exhibited lower maximum coronary flow reserve compared to the control subjects (1.78+/-0.19 vs. 2.8+/-0.3, P=0.000). (C) 1999 Elsevi er Science Ireland Ltd. All rights reserved.