Prospective trial of electroanatomically guided, irrigated catheter ablation of atrial tachycardia in patients with congenital heart disease.
BACKGROUND
Ablation success rates reported for atrial tachycardia (AT) patients with congenital heart disease (CHD) is lower than the rates reported for other varieties of supraventricular tachycardia. Retrospective studies suggest these rates might be increased by the use of irrigated radiofrequency (RF) ablation.


OBJECTIVE
The purpose of this study was to determine whether irrigated RF ablation increases ablation success rates in patients with CHD and AT.


METHODS
Patients were studied in a prospective, randomized, nonblinded manner. The operator was limited to use of randomized therapy (standard or irrigated ablation) for the first 6 minutes of RF application to each targeted arrhythmia. Lesion characteristics were recorded, and acute ablation success was ascertained. Structured clinical follow-up was performed over a 6-month period.


RESULTS
Forty-seven ATs were targeted in 26 patients; 72% of these ATs were ablated. Within the 6-minute randomization period, no difference in success rates of standard and irrigated catheters was noted. However, crossover from standard to irrigated ablation more likely was successful than vice versa (irrigated: 8 successes/8 attempts vs standard: 1 success/4 attempts, P = .018), and overall success was greater using irrigated catheters (66% vs 33%, P = .019). Mean delivered power was slightly higher in irrigated lesions (32.5 W vs 30.2 W, P = .025), and mean temperature was much lower (33.5 degrees C vs 59.3 degrees C, P < .001). A composite AT intensity score was significantly reduced compared with preablation values at 6-month follow-up of all patients.


CONCLUSIONS
Ablation of ATs in patients with CHD results in symptomatic improvement over short-term follow-up. Irrigated ablation may result in higher acute success rates in these patients.
Children's Hospital Boston, Massachusetts 02115, USA. john.triedman@cardio.chboston.org
John K
JK
Triedman
Janet M
JM
DeLucca
Mark E
ME
Alexander
Charles I
CI
Berul
Frank
F
Cecchin
Edward P
EP
Walsh
D000293:Adolescent; D000328:Adult; D017115:Catheter Ablation / Q000379:methods*; D003080:Cold Temperature; D018592:Cross-Over Studies; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013612:Tachycardia, Ectopic Atrial / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*; D007507:Therapeutic Irrigation; D016896:Treatment Outcome