Electrophysiologic Characteristics of Atrial Tachycardia Recurrence: Relevance to Catheter Ablation Strategies in Adults with Congenital Heart Disease

ABSTRACT Background Catheter ablation outcomes for adults with congenital heart disease (ACHD) are described, but recurrence mechanisms remain largely unknown. Objective To identify the electrophysiologic characteristics of AT recurrence in ACHD. Methods ACHD atrial tachycardia (AT) procedures over a 10-year period were explored for AT or atrial fibrillation (AF) recurrence. Results At 299 procedures in 250 ACHD (mean age 39 +/- 15 years, 52% male), 464 ATs (360 intra-atrial reentrant tachycardia [IART], 104 focal AT [FAT], median 2 ATs/procedure) were targeted. Complete (n=256, 86%) or partial (n=37, 12%) success was achieved in 98% of procedures. Over 3.0 years, 67 patients (27%) developed AT/AF recurrence after the index procedure. Recurrent vs index tachycardias were more often FAT (38% vs 19%, p Conclusion After catheter ablation in ACHD, repeat ATs were frequently focal, requiring isoproterenol administration, or involved IART within the PVA or atrial septum. Negative factors were partial success, index PVA substrate and remote history of AF. These data support aggressive, pharmacologic provocation to eliminate all inducible tachycardias and co-existing PVA substrates at index procedures for ACHD.