Collateral flow prevents unintentional myocardial ischemia during antegrade cardioplegia in patients undergoing coronary artery bypass grafting

Clinical application of power Doppler imaging to visualize coronary arteries in human beings

Supplementation of angiographic information during bypass procedures is an attractive goal for the echocardiographic researcher. Compared with color flow mapping, power Doppler imaging is superior in terms of identifying small vessels and noise suppression because of the use of Doppler signal strength for imaging. Although power Doppler imaging does not provide information about flow velocity or its direction, it does show detailed vessel flow in a static organ. Our study was designed to obtain angiographic images of the coronary artery by the use of power Doppler imaging in 31 patients during open heart surgery. During cold cardioplegic infusion, the epicardial coronary artery and the coronary artery within myocardium, such as the septal perforator, could be well visualized by power Doppler imaging. There was good correlation between the diameters of coronary arteries measured from power Doppler imaging and those from quantitative coronary angiography (r = 0.964, p < 0.0001). We obtained clear and accurate images of the coronary artery by using power Doppler imaging during cardiac standstill. These images might provide meaningful supplemental information to the operator, such as confirming the target coronary artery during the cardioplegia and choosing the appropriate arterial portion for a bypass operation.