[Diagnosis and treatment of arrhythmias after Mustard-Brom operation for transposition of the great arteries (author's transl)].

Arrhythmias after Mustard's operation for transposition of the great arteries were studied in 96 patients operated upon between June 1965 and July 1979. All patients had sinus rhythm consistently before the operation. Surgical modifications aimed at preserving the sinoatrial (S-A) node have reduced but not avoided arrhythmias. During the follow-up period in 54 patients (56.25%) different arrhythmias were observed. Sick-sinus syndrome was detected as the most frequent rhythm disturbance. The highest incidence of arrhythmias was in the first 6 weeks after the operation. However, life-threatening arrhythmias and sudden death occurred even years after Mustard's operation. Overall, there were 31 deaths (32.3%) in which severe arrhythmias were involved. In 6 patients sudden death occurred 4 weeks to 3 years postoperatively, attributable to rhythm disturbances. In one patient who died from sick-sinus syndrome, the histologic features of the S-A nodal area were examined. The S-A node was replaced by dense connective tissue. In another patient who had recently undergone Mustard's operation, S-A nodal tissue was identified, but fresh hemorrhage was seen in and about the node. Different antiarrhythmic drugs were employed in the treatment of arrhythmias observed after Mustard's operation. In 34 patients (36.4%) temporary pacing was necessary. In case of failure of antiarrhythmic drugs, permanent pacing is the therapy of choice.