Retrograde coronary sinus cardioplegia in myocardial revascularization: hemodynamic evaluation of the influence on the right-ventricular function.

The problem of the efficacy of right-ventricular protection with retrograde coronary sinus cardioplegia is studied. Sixty patients undergoing myocardial revascularization were prospectively assigned to receive cold St. Thomas' Hospital cardioplegia into the aortic root (30 patients) or retrogradely in the coronary sinus (30 patients). The two groups were similar concerning preoperative and operative data. The hemodynamic recovery postoperatively was good in both groups, the increase of the heart rate, the decrease of the mean aortic pressure and the right-ventricular stroke-work index were not significantly different in the two groups. However, right atrial pressure increased significantly (p less than 0.001) in patients who received cardioplegia anterogradely and decreased, but not significantly, in the retrograde group. The data suggest that the decrease of the right-ventricular stroke-work index in the anterograde group is related to a depressed contractility and in the group with retrograde delivery of cardioplegia to a decreased preload. There were no differences between the groups with respect to clinical outcome. We conclude that retrograde delivery of cardioplegia results in an excellent protection of the right-ventricular function in elective myocardial revascularization.