HEMODYNAMIC AND METABOLIC EFFECTS OF GALLOPAMIL AS ADDITIVE TO CALCIUM-CONTAINING AND CALCIUM-FREE CARDIOPLEGIC SOLUTIONS IN MATURE PIG HEARTS

Myocardial haemodynamic and metabolic effects of the calcium-channel b locker gallopamil as additive to calcium-containing (St Thomas Hospita l, STH) and calcium-free (Bretschneider procaine-containing, BRT) crys talloid cardioplegic solutions were evaluated. Adult pig hearts (weigh t 0.330 +/- 0.033 kg) were randomized to four groups and perfused with 1 litre of cold (4 degrees C) cardioplegic solution; group A: BRT wit hout gallopamil, n = 9, group B: BRT with gallopamil (0.4 mu M), n = 8 , group C: gallopamil-free STH, n = 8, and group D: STH with gallopami l (0.4 mu M), n = 8. After storage at 4 degrees C for 6 hours the hear ts were reperfused with blood/Ringer solution in a modified Langendorf f model for 60 min. Developed left ventricular pressure, rate-pressure product and +dP/dt were lower in gallopamil-treated hearts during rep erfusion (p < 0.05), as were oxygen extraction and oxygen uptake (p < 0.05) and lactate release (p < 0.05). Myocardial blood flow was greate r in gallopamil-treated hearts (p < 0.05). In hearts comparable in siz e and anatomy to the human heart, gallopamil added to both cardioplegi c solutions reduced cardiac function and oxygen uptake despite increas ed myocardial blood flow. The findings suggest reduced myocardial prot ection after addition of gallopamil to cardioplegic solutions.