Papaverine hydrochloride as an adjunct to asanguinous cardioplegia, is it beneficial?

Papaverine hydrochloride was added to a standard asanguinous cardioplegic solution to study its effect on cardioplegic distribution by evaluating coronary resistance, myocardial temperature, and postoperative enzyme changes. Seventeen patients were randomized into a control group (8 patients) and a papaverine group (9 patients). All patients received 300 cc of a standard asanguinous cardioplegic solution into the aortic root after systemic cooling to 28 degrees C and measurement of septal temperature (To). The duration of infusion (t1), root pressure (p1), and septal temperature (T1) were recorded. All patients received a subsequent infusion of 200 cc of cardioplegia to which had been added either 10 cc normal saline (control group) or 1 mg papaverine hydrochloride in 10 cc normal saline (papaverine group). Time of infusion, root pressure, and septal temperature (t2, p2, T2) were recorded. Coronary resistance was calculated. Postoperative CPK and CPK-MB were recorded and compared. Mean high CPK in the papaverine group was 163 units and 182 units in the control group. There was no statistically significant difference in any parameter between groups. This study, in contradistinction to experience with animal research models, failed to demonstrate any significant value in adding papaverine hydrochloride to standard cardioplegic solutions.