SUCCESSFUL MANAGEMENT OF JUNCTIONAL TACHYCARDIA BY HYPOTHERMIA AFTER CARDIAC OPERATIONS IN INFANTS

Background. Junctional ectopic tachycardia is an early postoperative c omplication after intracardiac repair of congenital heart disease, esp ecially in infants. Because of the high ventricular rate and the usual ly poor response to antiarrhythmic drugs, this condition is associated with a high morbidity and mortality. The purpose of this study was to assess the safety and efficacy of moderate body surface hypothermia i n the treatment of postoperative junctional ectopic tachycardia in inf ants. Methods. Six consecutive infants with postoperative junctional e ctopic tachycardia (mean age at operation, 14 weeks) were treated with surface cooling. The decision to start treatment was based on the def inition of a critical heart rate (180 to 200 beats/min) in the presenc e of junctional ectopic tachycardia diagnosed according to established criteria. Moderate hypothermia (rectal temperature between 32 degrees and 34 degrees C) was achieved by placing ice bags on the child's bod y surface. The patients were sedated, mechanically ventilated, and par alyzed. Results. Mean interval between diagnosis of tachycardia and in itiation of hypothermia was 4 hours. Rectal temperature was rapidly (w ithin 1 hour) lowered to 32 degrees to 34 degrees C in all 6 patients. This significantly lowered the tachycardia rate from 219 +/- 27 beats /min to 165 +/- 25 beats/min (mean +/- standard deviation; p < 0.001). Three patients with signs of low cardiac output had restoration of st able hemodynamics once the tachycardia rate had been decreased by hypo thermia. Cooling was maintained for a period of 24 to 88 hours (mean, 59 hours). No serious side effects were observed. Conclusions. Early i nstitution of moderate hypothermia by body surface cooling was a safe and efficient measure to control ventricular rate in infants with post operative junctional ectopic tachycardia.