(P109) ATRIAL FIBRILLATION INDUCIBILITY AFTER PAROXYSMAL SUPRAVENTRICULAR TACHYCARDIA ABLATION

Background: Patients with these supraventricular tachycardias (SVT) exhibit a higher incidence of atrial fibrillation (AF). Data on the prevalence of AF inducibility following SVT ablation in patients without prior history of AF is limited. During the electrophysiological study, the inducibility of AF can be assessed by rapid atrial pacing. This study aims to identify features associated with AF inducibility and the the subsequent development of clinical AF in patients undergoing SVT ablation.

METHODS AND RESULTS: Patients who underwent an SVT ablation, were included. At baseline a standard clinical electrophysiology protocol was applied, which included post-ablation routine AF inducibility testing. This testing utilized decremental burst pacing form the coronary sinus catheter, employing the same protocol that had previously demonstrated clinical significance following pulmonary vein isolation. The median follow-up period was 381 days. AF was assessed clinically as well as through 12-lead electrocardiogram recordings and 24–48-hour ambulatory Holter recordings.
A total of 152 consecutive patients who underwent an AVNRT/AVRT ablation were evaluated. The median age was 53 years old (range: 18 to 90), with 92 being female (60.5%). AVNRT was diagnosed in 112 (73.6%) of the patients, whiled 40 patients (26.3%) exhibited arrhythmias related to an accessory pathway. AF was induced in 41 (27.0%) patients during the electrophysiology induction protocol. There was a trend toward for hypertension as a predictor of inducibility, but this was not statistically significant (P=0.06). Among patients with inducible AF during the procedure, 79% spontaneously converted to normal sinus rhythm, while the rest were managed with cardioversion. During a median follow-up of 381 days, six patients developed clinical AF (3.9%). Inducibility of AF at the SVT procedure was associated with the development of clinical AF (odds ratio= 6.17, 95% confidence interval 1.08- 35.08; p=0.04).

Conclusion: A significant proportion of patients undergoing SVT ablation have inducible AF but only a few have clinical AF in the first year of follow-up. Longer studies are needed to confirm whether inducibility is associated with future AF recurrence.