Early postoperative arrhythmias after open-heart procedures in children with congenital heart disease.

OBJECTIVE: Evaluation of occurrence, clinical course, necessity of treatment, and outcome of early postoperative cardiac arrhythmias after open-heart surgery. DESIGN: Prospective study. SETTING: Tertiary pediatric intensive care and pediatric cardiology unit. PATIENTS: All consecutive pediatric patients undergoing cardiac surgery on cardiopulmonary bypass were studied for the occurrence of cardiac arrhythmias during the whole perioperative hospital stay. Measurements: All patients had continuous electrocardiographic monitoring (with memory function) during the whole intensive care stay. A 24-hr Holter recording was done thereafter in patients with arrhythmias. RESULTS: Of 310 patients studied, 83 (27%) had postoperative arrhythmias. The occurrence rate was not different whether surgical access was by atriotomy or ventriculotomy (26% vs. 28%, respectively). Infants (39%) and cyanotic patients (36%) had a higher occurrence rate of arrhythmias (p <.05). Arrhythmias were more common after prolonged cardiopulmonary bypass time and with higher postoperative maximum troponin serum levels. In addition, patients with hemodynamically significant residual findings after correction had an increased occurrence rate of arrhythmias (18 of 43; 42%; p <.01). Of the 83 children with arrhythmias, 53 (64%) required specific antiarrhythmic treatment. The use of antiarrhythmic drugs was required in only 7 of these patients. Only one patient (1.2% of patients with arrhythmias) died from arrhythmia. No major complications resulting from arrhythmias occurred during the postoperative clinical course in the other patients. CONCLUSIONS: Although they occur frequently, postoperative arrhythmias after open-heart procedures in children are associated with low morbidity and mortality.