Coronary flow velocity reserve and indices describing aortic distensibility in patients after coronary angiography

Abstract

Background: The purpose of this study was to assess the elastic properties of the descending aorta and the coronary flow velocity reserve (CFR) in patients after coronary angiography. Methods and patients: We recruited 112 subjects with stable angina pectoris without a previous myocardial infarction: 17 consecutive patients with anatomically normal coronary arteries, 24 patients with non-significant coronary artery disease (CAD), 31 patients with significant left anterior descending coronary artery (LAD) disease and 40 patients with multivessel disease (MVD). Transoesophageal echocardiography (TEE) is useful for evaluation of the elastic properties of the descending aorta. The physical behaviour of vessels in response to an intraluminal force is described by the elastic modulus ( E(p)) and Young's circumferential static elastic modulus ( E(s)). Coronary flow velocities can be measured in the LAD under baseline conditions and during dipyridamole stress. The CFR was calculated as the ratio of the average peak diastolic flow velocity during hyperaemia to that at rest. Results: The indices of aortic distensibility, CFR and mean CFR, were different in patients with LAD disease and in those with normal coronary angiograms. There were no further changes in these parameters in cases with MVD. In patients with non-significant CAD, the CFR, mean CFR and stiffness moduli lie between those for negative cases and those for patients with LAD disease/MVD. Conclusions: When there was significant stenosis of the LAD, the CFR was significantly decreased, while indices of aortic distensibility were increased as compared with the negative controls. Interestingly, not only the CFR, but also E(p) and E(s) displayed no further changes in cases with MVD as compared with LAD disease.