"Estudo dos efeitos da estimulação atrial temporária na prevenção da fibrilação atrial no pós-operatório de cirurgia de revascularização do miocárdio com circulação extracorpórea"

Abstract

Background: The high prevalence (10 to 60%) of atrial fibrillation in postoperative period of cardiothoracic surgery contributes to increase morbidity and prolongation of hospital stay. The limited efficacy of pharmacological prophylactic strategies demands investigation of alternatives management such as atrial pacing to prevent the postoperative atrial fibrillation. Objective: To study the efficacy of temporary atrial pacing to prevent the atrial fibrillation during post-coronary artery bypass graft surgery (CABG) and to identify risk factors correlated to this event. Methods: Between august of 2002 and september of 2004, 240 patients were enrolled prospectively after coronary artery bypass graft surgery (CABG). At end of surgery epicardial right and left atrial pacing were implanted to 72hourstemporary stimulation. According to computadorized aleatorial sample, patients were randomised into three groups with 80 patients each one including: no-stimulated group (NE), right atrial pacing (AD) and biatrial pacing (BiA). The cardiac rhythm was post-72 hours-CABG by electrocardiogram registered and continuous video monitoring. The primary endpoints of study was atrial fibrillation rate within 72 hours after CAGB and the risk factors correlated to the event. For statistical analysis were used χ 2 test, Fisher exact test, Student´s t test , Wilcoxon test and Cox´s regression model. Odds ratio with corresponding 95% confidence interval (CI) were estimated. The significance value considered was 0.05 level. Results: There were 30 (12.5%) episodes of atrial fibrillation, 20 of them in NE, three in AD and seven in BiA. Fibrillation episodes was less common in AD (OR 0.18, 95% (CI) 0.05-0.60) and BiA (OR 0.43, CI 0.19-0.98) when compared to NE. In addition, age (OR 1.07, 95%CI 1.02-1.12), preoperative betabloker use (OR 3.32 , 95% CI 0.95-11.58) and atrial pacing (OR 0.03, 95% CI 0.005-0.29) were variables correlated to occurrence of atrial fibrillation. Conclusions: The temporary atrial pacing reduced the incidence of atrial fibrillation after the CABG surgery that was similar with right atrial and biatrial pacing. Older age was also a predictive factor to occurrence of atrial fibrillation.