Simultaneous antegrade/retrograde cardioplegia protects myocardium distal to a coronary occlusion: A study in isolated pig hearts

This study was designed to assess the effects of simultaneous antegrade/ret rograde cardioplegia (SARC) on myocardial perfusion and energy metabolism i n the region supported by the occluded left anterior descending artery (LAD ) in isolated pig hearts. It was found that injection of Gd-DTPA into the a orta during antegrade cardioplegia (AC) did not result in signal increase i n the LAD region on T-1-weighted images. During SARC, however, Gd-DTPA was detected in the LAD region with the contrast agent injected into the aorta and the coronary sinus (CS), respectively. This suggests that SARC delivere d blood cardioplegia to the jeopardized myocardium through both arterial an d venous perfusion routes. Moreover, localized P-31 spectra showed that occ lusion of the LAD during AC resulted in severe ischemic changes in the LAD myocardium and the abnormal metabolic changes were completely abolished by use of SARC. Finally, recovery of myocardial contractile function during re perfusion In the hearts subjected to SARC was significantly better compared to those arrested with AC alone. It was concluded that the myocardium dist al to a coronary occlusion can be fully protected by use of SARC. Published 2001 Wiley-Liss, Inc.(dagger).