Bedside evaluation of postoperative sinus node function in children

Abstract

Sinus node dysfunction in children frequently results from the surgical correction of congenital heart defects. We evaluated postoperative sinus node function at the bedside in 25 children by utilizing atrial epicardial electrodes which were placed near the sinus node at the time of operation. Sinoatrial conduction times (SACTs) and corrected sinus node recovery times (CSNRTs) were determined within 3 days of operation in each patient. Group 1 consisted of 20 patients (aged 1 month to 13 years) with normal postoperative sinus node function. Mean (+/- SD) SACTs and CSNRTs were 122 +/- 33 msec (range 61 to 187 msec) and 165 +/- 54 msec (range 52 to 253 msec), respectively. Preoperative evaluation of sinus node function during cardiac catheterization showed that preoperative and postoperative SACTs and CSNRTs were not significantly different (p greater than 0.05) in any of nine patients. Group 2 was composed of five children (aged 1 to 14 years) with postoperative sinus node dysfunction. Three had abnormal SACTs of 230 msec or greater and two children had first-degree sinus node entrance block. Two patients had prolonged CSNRTs. Electrocardiographic (ECG) monitoring revealed evidence of sinus node dysfunction in four of the five patients in Group 2. This report describes a simple and safe means of evaluating postoperative sinus node function at the bedside. The data are comparable to those obtained using more conventional methods during cardiac catheterization.