Carvedilol-Enriched Cold Oxygenated Blood Cardioplegia Improves Left Ventricular Diastolic Function After Weaning From Cardiopulmonary Bypass

To investigate whether adding carvedilol, a nonselective β- and selective α1-receptor blocking agent with antioxidant properties, to oxygenated blood cardioplegia improves myocardial function after weaning from bypass. A randomized controlled study. A university laboratory. Twenty anesthetized pigs, Norwegian Landrace. On cardiopulmonary bypass, cardiac arrest was induced with cold (12°C), oxygenated blood cardioplegia, enriched with carvedilol or vehicle, and repeated every 20 minutes. After 100 minutes, the heart was reperfused and weaned. Left ventricular function was evaluated with pressure-volume loops, local myocardial systolic strain, and strain rate from Speckle tracking analysis and multilayer short-axis tissue Doppler Imaging. In the carvedilol group, the load-independent logarithmic end-diastolic pressure volume relationship, β, decreased from 1 to 3 hours of reperfusion and was low, 0.028±0.004 v 0.042±0.007 (p