Coronary Flow Reserve Before and After Coronary Artery Bypass Surgery

The coronary sinus (CS) blood flow can be used as a non-invasive measure of cardiac perfusion. Besides transesophageal echocardiography, transthoracic echocardiography with Doppler flow measurement has been introduced as a feasible and reproducible method to determine the CS blood flow. The purpose of this study was to assess the coronary flow reserve (CFR) by transthoracic imaging of the CS flow in patients with coronary artery disease before and after coronary artery bypass graft surgery (CABG). Twenty-nine patients with coronary artery disease who were candidates for CABG were evaluated in this study. CFR was measured using the CS flow profile. Twenty-one patients, comprised of 15 men and 6 women at a mean age of 56.7 ± 9.1 years, were evaluated. All the patients had a pre-operative increase in their coronary blood flow during the dipyridamole stress test (mean CFR/beat=1.38±0.2, mean CFR/min=1.54±0.18). CFR was significantly higher in post-operative status (mean CFR/beat=2.25±0.45, mean CFR/min=2.55±0.43, p <0.001). Our study, in accordance with previous studies, denotes that a transthoracic measurement of CFR can be used as a feasible and reproducible method to monitor the changes in cardiac perfusion after revascularization