Assessment of myocardial viability using coronary zero flow pressure and fractional flow reserve in swine model of acute myocardial infarction

Abstract

Objective This study is to make into the swine model of acute myocardial infarction(AMI) and detect viable myocardium. Methods Thirteen swines， their pressure of aotic artery were measured through guiding wire and the distal pressure of left anterior descending(LAD)measured through coronary pressure wire， then calculated fractional flow reserve (FFR). Coronary blood flow velocity was recorded through coronary doppler wire and calculated zero flow pressure (Pzf). Blocked up distal of LAD by angioplasty balloon to establish the model of AMI. Calculated the FFR and Pzf repeadly. Analysis the difference of FFR and Pzf between before and after the model of AMI established. Taken out of those swines\'heart after executed them， sliced the cardiac muscle and dyed with TTc to detect the viable myocardium. Calculated the percent ratio of viable myocardium to the whole left ventrcular myocardium using image tool 3.0.Drawed the percent ratio of viable myocardium？Pzf coordinate graph and observed the relationship between them. Results Eleven swines were successfully established models of AMI by occlusion of the coronaries. 2 swines died of ventricular fibrillation after the coronaries were occluded 45 and 65 minutes respectively. The viable myocardium could be detected by TTc dyeing. After the model of AMI established， all FFR＜0.75 and the FFR of the models of AMI were less than before (P＜0.001) while the Pzf of the models of AMI were more than before (P＜0.001). The percent radio of viable myocardium were negative correlation with Pzf after the model of AMI established. Conclusions The swine model of AMI can be established by coronary occlusion with angioplasty balloon. FFR＜0.75 is a criterion to detect the viable myocardium and Pzf is an index that can predict the extent of viable myocardium after AMI.