Atrial baffle procedures for complete transposition of the great arteries: natural course of sinus node dysfunction and risk factors for dysrhythmias and sudden death.

359 patients after the Mustard (275) or Senning (84) operations for transposition of the great arteries were followed-up for a mean of 103.7 (range 0.4 to 204) months. 259 patients had postoperative 24-h Holter recordings. In 129 Mustard children serial (mean 4.4) postoperative Holter recordings were available for evaluation. Criteria based on Holter and scalar electrocardiograms at normal sinus node functions were used for rhythm analysis. Postoperative dysrhythmias appeared in 70% of the patients: sinus node dysfunction in 62.8%, second or third degree atrioventricular block in 3.2%, sustained atrial tachycardia or atrial flutter in 4.5%, and significant ventricular arrhythmia (Lown 2-5) in 21.4%. The prevalence of sinus node dysfunction increased slightly from 50.8% during the first 2 postoperative years to 64.4% in patients more than 10 years postoperatively. Fifteen patients (4.2%) died suddenly during follow-up. By multivariate analysis severe tricuspid regurgitation and/or right ventricular dysfunction and uncontrolled supraventricular tachydysrhythmias were identified as the two significant risk factors for sudden death.