Management of surgical complete atrioventricular block in children.

Because there is disagreement concerning the efficacy of and indication for permanent pacemaker implantation in children with postoperative complete (third degree) atrioventricular (A-V) block, experience in the management of this problem at one institution was reviewed. Thirty-four patients with postoperative complete atrioventricular block were identified. They ranged in age from 4 months to 22 years and in weight from 4 to 60 kg and were evaluated from 1 month to 20 years postoperatively. Complete A-V block developed within 24 hours of operation in 28 of the 34 patients. A permanent pacemaker was implanted in 13 of the 28. Death occurred in 4 of these 13 patients and in 5 of the remaining 15 patients who did not have an artificial permanent pacemaker. Complete A-V block developed later than 1 day (2 days to 4 months) postoperatively in 6 of the 34 patients; all 6 of these patients survived, and only 3 required permanent pacemaker implantation. Intracardiac electrophysiologic studies were performed by 14 of the 34 patients. The site of complete block was above the His bundle in 5, within the His bundle in 2, and below the His bundle in 4; it was undetermined in 3. The results of intracardiac electrophysiologic studies are important in delineating the natural history of surgically induced complete A-V block and in the clinical management of this lesion. Permanent pacemaker implantation is indicated if complete A-V block persists longer than 2 weeks postoperatively and if the site of the block is within or below the bundle of His.