Right atrial versus aortic root perfusion with blood cardioplegia

The efficacy of coronary sinus cardioplegia administered into the right atrium has not been fully defined. Thirty-two consecutive patients undergoing elective myocardial revascularization were prospectively assigned to receive cold blood cardioplegia exclusively into the aortic root (15 patients) or the right atrium (17 patients). The two groups were similar with respect to age, ventricular function, severity of coronary disease, cross-clamp time, and mean infusate volume and temperature. Completeness of revascularization was greater in the aortic root cardioplegia group (p less than 0.007). The mean septal temperature and time to achieve electromechanical arrest was greater in the right atrial cardioplegia group (p less than 0.05). The right ventricular temperature and the release of myocardial isoenzyme were similar in both groups. Left and right ventricular stroke work index was preserved equally in both cohorts. Volume loading studies performed immediately after termination of bypass suggested better left ventricular function in the aortic root cardioplegia group. Myocardial performance with a loading challenge assessed late postoperatively was superior in the right atrial cardioplegia group (p less than 0.05). There were no differences between the groups with respect to clinical outcome. The data suggest that right atrial cardioplegia (1) possesses clinical safety equal to aortic root cardioplegia, (2) possesses inferior ventricular septal cooling, and (3) yields adequate preservation of both the right and left ventricles. We conclude that right atrial cardioplegia possesses no apparent advantage over aortic root delivery in the setting of elective myocardial revascularization.