Myocardial revascularization without cardiopulmonary bypass in pigs: a comparison between beta-blockers and...

The purpose of this study was to develop the surgical technique for internal mammary artery grafting on the beating heart. In 10 pigs, heart rate was reduced with esmolol (n = 5) or verapamil (n = 5). In addition, the anti-ischaemic and anti-arrhythmic potencies of these drugs were investigated. Haemodynamics, mechanical function and ischaemia-sensitive laboratory measurements were assessed perioperatively. There were no differences in pre-ischaemic data including ischaemic clamping time of the left anterior descending artery. At the end of ischaemia haemodynamic parameters were significantly lower in the esmolol-group (P < 0.05). In the verapamil-group, one pig died from ventricular fibrillation during ischaemia, and one showed fibrillation during reperfusion (P < 0.01). There were no differences in cardiac function or enzymes between the groups. Reduction of heart rate was provided by both drugs, but no conclusive evidence was provided with regard to additional anti-ischaemic and anti-arrhythmic protection.