Risk factors for postoperative atrial fibrillation in cardiac surgery

Introduction: The advent of new techniques of percutaneous intervention, the optimization of pharmacological behavior and the use of new surgical techniques (conventional, minimally invasive and video-assisted) have resulted in ever more difficult cases being treated in the operating room with an increase in the incidence of postoperative atrial fibrillation. Objectives: To analyze the association among some variables and the incidence of this arrhythmia in cardiovascular surgery. Method: A retrospective analysis was conducted with the last 100 patients of both sexes, aged 18 and over, operated in the Cardiovascular Surgery Service of CIMEQ Cardiology Hospital, between October 2008 and February 2010. 27 variables arranged in four groups were analyzed and their relationship with postoperative atrial fibrillation was determined. Results: 37% of the patients analyzed presented this type of atrial fibrillation, which was more frequent in patients with mixed (80%) and double valve disease (66.66 %). Of the clinical variables only previous atrial fibrillation, mitral valve disease, age over 65, hemodynamic instability, previous myocardial infarction and III or IV functional class were significant. None of the studied electrocardiographic variables were significantly associated with the occurrence of postoperative atrial fibrillation. All echocardiographic variables (dilated left ventricle and atrium, dilated right atrium and ejection fraction below 55 %), and six of the variables that are typical of surgery (cardiopulmonary bypass, recovery from cardiac arrest in atrial or ventricular fibrillation, use of amines in trans or postoperative period, over 120 minutes of aortic clamping, double valve disease and mixed cases) were significantly associated with the occurrence of this arrhythmia. Conclusions: The clinical variables highly associated with atrial fibrillation are less significant than the variables typical of surgery, in the case of postoperative atrial fibrillation.