Myocardial protection in infant open heart surgery.

Myocardial protection was evaluated in 2 groups of 5 infants each undergoing correction of either tetralogy of Fallot (TOF) or subcristal ventricular septal defect (VSD). In group A, profound hypothermia and total circulatory arrest (PHTCA) was utilized. In group B, profound hypothermia and total circulatory arrest combined with potassium cardioplegia (PHTCA + K) was the method of protection used. The analysis was carried out by sequential measurements of clinical, electrocardiographic, enzymatic (CK-MB) and ultrastructural parameters. There were no operative deaths. One infant had a second operation for recurrent VSD. The average anoxic time was 35.4 min in group A (PHTCA) and 32.6 min in group B (PHTCA + K). Analysis of our data demonstrated that when potassium cardioplegia was added to PHTCA, there was less intraoperative myocardial damage according to physiological, ultrastructural and biochemical parameters than when profound hypothermia and total circulatory arrest was applied alone.