MYOCARDIAL PROTECTION OF COLD CRYSTALLOID AND WARM BLOOD CARDIOPLEGIA- A COMPARATIVE-STUDY

Twenty patients undergoing open-heart valvular operations were divided randomly into two groups. Intermittent perfusion of cold crystalloid (St. Thomas Hospital solution) with hypothermic cardiopulmonary bypass (CPB) in the hypothermic group and continuous administration of warm blood cardioplegia with normothermic CPB in the normothermic group wer e used respectively. The results of warm blood cardioplegia were super ior to those of cold crystalloid. 70% of patients treated with the war m technique had spontaneous return of normal sinus rhythm shortly afte r removal of the aortic cross-clamp, compared with only 10% of the hyp othermic group (P < 0.05). The extracorporeal support time from releas ing of aortic clamp to the weaning of CPB was significantly shorter in the normothermic group (33.50 +/- 3.78 min vs. 25.00 +/- 4.64 min, P < 0.05). The postoperative ventilation support time was also much shor ter than that of the hypothermic group (19.84 +/- 1.11 h vs. 38.98 +/- 16.55 h, P<0.05). More atrial beating occurred in the normothermic gr oup (80% vs. 20%, P < 0.05) during aortic clamping, and it is showed t hat continuous warm blood cardioplegia might not efficiently prevent t he atrium from damage.