Effects of procaine-induced cardioplegia on myocardial ischemia, myocardial edema, and postarrest ventricular function. A comparison with potassium-induced cardioplegia and hypothermia.

The extent of myocardial protection afforded by a procaine cardioplegic solution during cardiac ischemia has been evaluated and compared with the protection seen using a potassium cardioplegic solution. An isolated cat heart model was employed, and ventricular function parameters, intramyocardial gas tensions, and postischemic myocardial edema were measured and compared following 60 minutes of induced ischemia at 37 degrees C. and 27 degrees C. There was no significant improvement in recovery of postarrest ventricular function when procaine cardioplegia was used during normothermic ischemia. When used at 27 degrees C., however, both cardioplegic solutions were associated with significantly better recovery of postarrest ventricular function, although there was less myocardial edema formation in the potassium-treated hearts. Results of this study indicate that procaine-induced cardioplegia provides myocardial protection during anoxic cardiac arrest which is additive to that afforded by hypothermia alone. In addition, procaine cardioplegia results in postarrest functional recovery which is similar to that seen with potassium cardioplegia.