Assessment of transmural distribution of myocardial perfusion by real-time myocardial contrast echocardiography / 中华超声影像学杂志

ABSTRACT

Objective To explore the practicability of real-time myocardial contrast echocardiography (MCE) in assessing the transmural distribution of myocardial perfusion. Methods Three grades of left anterior descending coronary artery(LAD) stenoses were created in 6 open-chest dogs. Stenoses reduced LAD flow by 50%, 75% and 90% of hyperemia guided by flow probe. Low-energy MCE were performed at baseline, hyperemia reduced by dipyridamole, three different stenoses, reperfusion and complete occlusion, respectively, during continuously infusion of SonoVue. Regions of interest(ROI) were placed individually within endocardial and epicardial layers and myocardial signal intensity-versus-time plots just after high-energy FLASH frames were fitted to an exponential function to obtain values of A, ?, A??. The corresponding transmural gradients, defined as endocardial-epicardial ratios of A (A-EER),?(?-EER) and A??(A??-EER) were also calculated. Results The transmural distributions of A,? and A?? were more or less homogeneous at baseline,hyperemia and 50% reduced LAD flow, with their transmural gradients near 1. When LAD flow was reduced by 75%,? and A?? from endocardial layer decreased (P