Dolcino A, et al. - In this retrospective study of 101 neonates (mean age = 6.1 ± 5.4 days) undergoing arterial switch surgery (ASO) with Custodiol cardioplegia (single-dose cold histidine-tryptophan-ketoglutarate cardioplegia), researchers focused on the link among myocardial no-flow duration, postoperative troponins, and postoperative outcomes. This inquiry was held at a single-institutional, tertiary pediatric cardiac surgery unit of a university hospital. The cardiopulmonary bypass duration and the temperature during cross-clamping were 108.7 ± 54.1 minutes and 31.1°C ± 1.7°C, respectively. The duration of mechanical ventilation and the length of intensive care unit stay was 4 (3-6) days and 7 (5-8) days, respectively. They reported the occurrence of delayed sternal closure in 32 (31.7%) patients and the reported deaths were nil. The myocardial no-flow duration averaged 62.3 ± 14.6 minutes and was found to be related to both troponin release and low cardiac output syndrome, as evaluated by the necessity for delayed sternal closure, irrespective of cardiopulmonary bypass duration and temperature. Findings are indicative of the possible inadequacy of single-dose Custodiol for prolonged cross-clamping durations without myocardial perfusion in neonates.