Characterization and comparison of rhythm disturbances after atrial or arterial switch surgeries for dextro-transposition of the great arteries: a long-term follow-up study

Abstract

Abstract Introduction and objectives Dextro-transposition of the great arteries (D-TGA) is a congenital heart disease (CHD) palliated with atrial switch (ATR-S) and, more recently, with arterial switch (ART-S). As late complications from ATR-S are expected, novel challenges from ART-S surgery arises. Our aim was to evaluate these patients’ (pts) arrhythmic disturbances after a long-term follow-up. Methods We retrospectively analyzed D-TGA pts born between 1974 and 2001 and followed in Adult CHD Outpatient Clinic at a tertiary care hospital. Clinical records were used to collect pts data. Results A total of 79 pts were enrolled with a mean follow-up time after surgery of 27±6 years. Pts median age was 27 years-old and 46% were female. 54% were submitted to ATR-S, while 46% underwent ART-S; median age at intervention was 13 months and 10 days, respectively. Focusing arrhythmic events (Table 1), almost all ART-S pts remained in sinus rhythm versus 64% of ATR-S (p=0.002). The latter presented significantly higher frequencies of arrythmias (41% vs 3%, p < 0.001), mainly atrial flutter or fibrillation (26% vs 0%), as well as bradyarrhythmias (12% vs 0%). Chronotropic incompetence was also more frequent after ATR-S (46% vs 9%, p=0.011). Inversely, intraventricular (IV) conduction disturbances were more frequent after ART-S (54% vs 15%, p < 0.001), the majority due to incomplete right bundle branch block. Cardiac Implantable Electronic Devices (CIED) were implanted in 6 pts (5 pacemakers and 1 implantable cardioverter defibrillator) and 1 patient was submitted to catheter ablation of cavotricuspid isthmus, all of them from ATR-S group. The overall median time to first arrhythmia was 23±9 years. Conclusion ATR-S presented significantly fewer pts in sinus rhythm and higher rates of chronotropic incompetence, as well as need for CIED. Additionally, ATR-S pts had higher rates of arrhythmia development, namely supraventricular (SV) ones. These findings highlight the advantages of ART-S over ATR-S in reducing SV arrhythmias occurrence. Curiously, IV conduction disturbances, mainly incomplete right bundle brunch block, were more frequent after ART-S. This fact emphasizes the importance of long-term follow-up of all pts, regardless of the initial surgical approach, as ART-S pts were not arrhythmic-free. Our work raises awareness for arrhythmic disturbances in this subgroup of CHD pts, irrespective of surgical strategy adopted.Table 1