The Effects of Lidocaine on Reperfusion Ventricular Fibrillation During Coronary Artery – Bypass Graft Surgery

Myocardial protection with cardioplegia has resulted in significant improvement in the outcomes of cardiopulmonary bypass (CPB) in coronary artery bypass graft (CABG) procedure. However, subendocardial damage created by ischemic injury still remains a source of morbidity and mortality associated with CABG (1). Ventricular fibrillation (VF) occurring after releasing of aortic cross-clamp in the reperfusion phase of CABG surgery (reperfusion VF) is very common (74–96 %) (1-5). This complication is considered to be related with ischemia-induced increases in reentry and automaticity as well as the possibility of reperfusion injury (6-8). Reperfusion VF may adversely affect coronary blood flow and increase ventricular wall tension, which causes a further depletion of myocardial energy reserves in an energydepleted myocardium (2). It is estimated that reperfusion VF occurs as a result of increased myocardial wall stress and oxygen consumption besides diminished subendocardial blood flow and intramyocardial acidosis (9-12). Additional myocardial injury following defibrillation by direct current countershocks may worsen this situation (13,14). Therefore, it would be helpful for the patients’ recovery after the CABG (15).