Long-Term Protective Effects of Single-Dose infusion of Warm Blood Cardioplegic Solution in a mini-pig model on the background of intraoperative anemia

Objectives The tolerable ischemic time for many cardioplegia solutions has not been established yet. The aim of this study was to estimate the effect of a single-dose of cardioplegia solution Normacor (solution No. 1) and to establish the tolerable ischemic time in a normothermic cardiopulmonary bypass mini-pig model on the background of intraoperative anemia. Methods Five female mini-pigs (34±3 kg, 6-month-old) were subjected to 180 min or 210 min of cardiac arrest by single-dose 400 ml Normacor cardioplegia (solution No. 1). A needle biopsy was taken from the left ventricle before the aortic cross-clamping and every 30 minutes after it. The restoration of left ventricle contractility was assessed by the clinical indicators, catecholamine support, morphological and immunohistochemical examination. Results The morphological signs of cardiomyocytes ischemia were found after 120 minutes of aortic cross-clamping. According to the content of succinate dehydrogenase and hypoxia-inducible factor, the signs of the cardiomyocytes ischemic injury onset were detected at the same time point. During the entire period of aortic cross-clamping atrial activity was observed in all cases. The proposed single-dose ischemic time for re-dosing of cardioplegia is 120 minutes or ventricular activity onset. Conclusions Safe and effective cardioprotection can be achieved with warm blood cardioplegia Normacor (solution No. 1) within 120 minutes for a single-dose infusion. Graphical Abstract