Myocardial Protection of Warm Cardioplegic Induction on the Isolated Perfused Rat Heart Model

Abstract

Myocardial protection through different cardioplegia approaches is an important issue for successful cardiovascular surgery. The objective of this prospective randomized study was to evaluate the effect of myocardial protection of warm (37°C) and cold (6°C) cardioplegic induction, respectively, using a Langendorff isolated rat heart perfusion model. Twenty-eight isolated rat hearts on the Langendorff perfusion model were randomly divided into two groups: group T (n = 14) received warm (37°C) cardioplegic induction, followed by cold (6°C) cardioplegia after ECG showed straight line; alternatively, group C (n = 14) received only cold cardioplegic induction. After undergoing ischemia for 80 min, both group T and group C received reperfusion with Krebs-Henseleit Buffer (KHB) for 40 min. An additional group A (n = 7) received KHB continuously for 120 min and served as the control group for the assessment of Na+/K+-ATPase activity. The coronary flow, concentration of creatine kinase (CK) in coronary effluent, and cardiac function were evaluated at different time periods. Na +/K+-ATPase activity was assessed at the end of reperfusion. The coronary flow, content of CK in coronary effluent, heart rate, dp/dtmax, and left ventricular peak pressure (LVPP) were significantly greater (p