Radiofrequency Catheter Ablation of Atrial Tachyarrhythmias in Adults with Repaired Congenital Heart Disease: Constraints from Multiple and New Arrhythmic Foci.
BACKGROUND
Radiofrequency catheter ablation (RFCA) for atrial tachyarrhythmias in postoperative congenital heart disease (CHD) patients has a low success rate and a high recurrence rate. This study explores the reasons for these constraints.


METHODS
A total of 49 consecutive postoperative CHD patients who received RFCA for atrial tachyarrhythmias between 1993 and 2010 were enrolled.


RESULTS
Overall, there were 86 RFCA procedures performed, 32 with the conventional method and 54 using CARTO-guided mapping. The interval between the operation and the first ablation was 13 years. Isthmus-dependent atrial flutter (AFL) was the most common type of tachycardia (37, 76%), followed by intra-atrial re-entry tachycardia (IART; 37%), and ectopic atrial tachycardia (EAT; 31%). By applying CARTO-guided mapping, the success rate was elevated compared to that of conventional ablation (84% vs. 56%, p = 0.006), but there was no improvement in the recurrence rate (22% vs. 28%, p = 0.75). Multiple atrial tachyarrhythmias occurred in 26 (53%) patients, and 17 presented during the initial electrophysiological study. The presence of multiple arrhythmias during the initial study predicted ablation failure or multiple ablations (11/17 vs. 3/32, p < 0.001). Among the 15 patients with new tachyarrhythmias, EAT and IART predominated. However, applying antiarrhythmia agents immediately following ablation may decrease arrhythmia recurrence (1/10 vs. 14/25, p = 0.02).


CONCLUSIONS
Although electroanatomical mapping improves the results of RFCA in atrial tachyarrhythmias, the recurrence rate remains high because of multiple and new atrial tachyarrhythmias. Therefore, short-term pharmacological treatment following RFCA for positive remodeling should be considered.


BACKGROUND
Ablation; Antiarrhythmia agents; Atrial tachyarrhythmia; Congenital heart disease; Multiple arrhythmias.
Department of Pediatrics and Internal Medicine, National Taiwan University Hospital, Taipei;
Shuenn-Nan
SN
Chiu
Department of Pediatrics and Internal Medicine, National Taiwan University Hospital, Taipei;
Jiunn-Lee
JL
Lin
Department of Pediatrics and Internal Medicine, National Taiwan University Hospital, Taipei;
Chia-Ti
CT
Tsai
Department of Pediatrics and Internal Medicine, National Taiwan University Hospital, Taipei;
Chih-Chieh
CC
Yu
Department of Pediatrics and Internal Medicine, National Taiwan University Hospital, Taipei;
Chun-Wei
CW
Lu
Department of Pediatrics and Internal Medicine, National Taiwan University Hospital, Taipei;
Chi-Wei
CW
Chang
Department of Pediatrics, Min-Sheng General Hospital, Taoyuan, Taiwan.
Chien-Chih
CC
Chang
Department of Pediatrics and Internal Medicine, National Taiwan University Hospital, Taipei;
Jou-Kou
JK
Wang
Department of Pediatrics and Internal Medicine, National Taiwan University Hospital, Taipei;
Mei-Hwan
MH
Wu