Cardioplegic rearrest: clinical experience with 12 patients

Myocardial damage due to ischemic arrest occurs during aortic unclamping and early reoxygenation (reperfusion injury). Thus, surgeons may be reluctant to reinfuse cardioplegic agents if a second period of aortic cross-clamping is required at the end of cardiopulmonary bypass. Because of technical difficulties, 12 patients underwent two consecutive periods of cardioplegic arrest with an intervening period of reperfusion of the heart. All survived without complications. Myocardial biopsy specimens from three patients revealed some cellular edema. Serial enzyme levels measured postoperatively compared favourably with those of 12 other patients who had sustained a single period of multidose cardioplegic arrest. Postoperative hemodynamic measurements were similar to preoperative values. Although cardioplegic rearrest may appear safe in the human heart, further studies assessing hemodynamics, morphology and metabolism are necessary in order to delineate fully the changes that occur with this method of myocardial preservation.