EARLY POSTOPERATIVE ARRHYTHMIA AFTER CARDIAC SURGERY FOR CONGENITAL HEART DISEASES

Objective: Early post-operative arrhythmias are a known complication of cardiac surgery; however, there is a paucity of data specific to pediatric heart surgery. The purpose of this study was to evaluate the occurrence rate and type of early post-operative arrhythmias in children. Methods: Data were collected in a prospective observation of pediatric patients undergoing cardiac surgery between December 2001 and December 2005. All consecutive patients undergoing well-defined surgical procedures were prospectively evaluated for the occurrence rate and type of early post-operative arrhythmias that occurred in the ICU and during the postoperative hospital stay by means of continuous electrocardiographic monitoring in the intensive care unit and use of 24-hour Holter monitors. All the operations were performed by one surgeon throughout the study period. The procedures were performed with cardiopulmonary bypass (CPB) and moderate hypothermia (28-32o C) using anterograde crystalloid cardioplegia for myocardial protection. To determine the relationship between the age of the patients and the degree of post-operative arrhythmia, the patients were divided into 17 age groups. Results: Arrhythmias occurred in 231 of the 658 patients (35.01%). The most common types of arrhythmia were junctional rhythm (47), premature atrial contractions (PACs) (40), bradycardia (39), and premature ventricular contractions (PVCs) (28). The total correction operations for the tetralogy of Fallot (TOF), atrial septal defect (ASD) repair, and ventricular septal defect (VSD) repair were the procedures in which the most post-operative arrhythmias occurred. The occurrence rate of arrhythmias was higher in the infants (202-57 arrhythmia 30.69%) and in TOF (205-102 arrhythmia 46%). Post-operative atrioventricular (AV) block was observed in 18 (7%) patients, 10 of whom had a complete AV block (4%), comprising 4 VSD repairs, 4 TOF repairs, and 2 complete AV canal repairs, and 5 and 3 had second- and first- degree AV blocks, respectively. During the whole study period, 48 (21%) patients died because of a post-operative arrhythmia. The total number of deaths was 97 (15%).Conclusion: Approximately 1/3 of all the patients experienced cardiac arrhythmia during the early post-operative period after open heart surgery for congenital heart disease, and a higher occurrence rate of arrhythmias was found in the infants and cyanotic children. Junctional arrhythmia, PACs, bradycardia, and PVCs were the most frequent arrhythmias.