While blood:
crystalloid cardioplegia is the clinical standard for patients undergoing
cardiopulmonary bypass (CPB), it has been postulated that whole blood minicardioplegia may benefit the severely injured heart by reducing cardioplegic volume, thereby reducing myocardial
edema. To test this hypothesis, we compared the cardioprotection of a popular 4:1 blood:
crystalloid cardioplegia to whole blood minicardioplegia (WB) in a porcine model of acute
myocardial ischemia. Yorkshire pigs (n = 20) were placed on atriofemoral bypass and subjected to 30 minutes of global normothermic
ischemia. Animals were randomized to receive either 4:1 cold
cardioplegia (n = 10) or WB cold
cardioplegia (n = 10) delivered antegrade continuously for 90 minutes. Baseline (BL) echocardiographic determination of left ventricular mass (LVM) was compared within groups for
cardiac edema (%) measured by histologic morphometrics. All (100%) animals receiving WB were successfully weaned off CPB, whereas only 40% of animals receiving 4:1 were successfully weaned off CPB.
Cardiac edema percentage (p < .004) and LVM (p < .05) were significantly decreased in the WB group compared with 4:1. WB
cardioplegia increases the number of hearts successfully weaned from CPB and decreases
cardiac edema in our porcine model of acute
myocardial ischemia. This finding implies whole blood
cardioplegia may be more protective in a select group of patients undergoing extended CPB time by decreasing myocardial
edema.