Comparison of retrograde vs simultaneous ante/retrograde cold blood cardioplegia

To evaluate the homeostasis of myocardium during simultaneous continuous retrograde and antegrade cardioplegia vs retrograde continuous cardioplegia.40 patients who underwent elective operation of coronary arteries bypass grafting were randomly assigned to 2 groups: group one consisted of 24 patients who received retrograde continuous blood cardioplegia; group two consisted of 16 patients who received simultaneous continuous ante/retrograde cardioplegia. The following measurements were taken: acidosis, oxygen content, oxygen extraction and oxygen consumption; they were taken before and after cross-clamp releasing from coronary sinus effluent and from arterial line. Incidence of low cardiac output, ventricular fibrillation, raised cardiac enzymes and ischemic changes on ECG was noted.In simultaneous group such parameters as acidosis, oxygen content, oxygen extraction and myocardial oxygen consumption recovered after cross-clamping and changes of their values were respectively: 0.0005, 0.87 ml/100 ml, 0.098 and 1.4 ml/min. The same parameters didn't recovered in retrograde group and changes were respectively: 0.05 - p=0.2; 3.7 ml/100 ml - p=0.006, 0.29 p=0.006 and 7.4 ml/min - p=0.03. These changes were significant between groups.Metabolic viability of myocardium measured with oxygen utilisation is better preserved with simultaneous antegrade and retrograde cardioplegia.