1331 Clinical Significance of Early Recurrences of Atrial Tachycardia After Atrial Fibrillation Ablation JONG-IL CHOI, M.D., Ph.D., ∗ HUI-NAM PAK, M.D., Ph.D.,† JAE SEOK PARK, M.D., ∗ JAE JIN KWAK, M.D., ∗ YASUTSUGU NAGAMOTO, M.D., ∗ HONG EUY LIM, M.D., Ph.D., ∗ SANG WEON PARK, M.D., Ph.D., ∗ CHUN HWANG, M.D.,‡ and YOUNG-HOON KIM, M.D., Ph.D. ∗ From the ∗ Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Republic of Korea; †Yonsei University Health System, Seoul, Republic of Korea; and ‡Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, Indiana, USA Early Recurrence After AF Ablation. Background: Atrial tachycardia (AT) commonly recurs within 3 months after radiofrequency catheter ablation for atrial fibrillation (AF). However, it remains unclear whether early recurrence of atrial tachycardia (ERAT) predicts late recurrence of AF or AT. Methods: Of 352 consecutive patients who underwent circumferential pulmonary vein isolation with or without linear ablation(s) for AF, 56 patients (15.9%) with ERAT were identified by retrospective analysis. ERAT was defined as early relapse of AT within a 3-month blanking period after ablation. Results: During 21.7 ± 12.5 months, the rate of late recurrence was higher in patients with ERAT (41.1%) compared with those without ERAT (11.8%, P < 0.001). In a multivariable model, positive inducibility of AF or AT immediately after ablation (65.2% vs 36.4%, P = 0.046; odd ratio, 3.9; 95% confidence interval, 1.0– 14.6) and the number of patients who underwent cavotricuspid isthmus (CTI) ablation (73.9% vs 42.4%, P = 0.042; odd ratio, 4.5; 95% confidence interval, 1.1–19.5) were significantly related to late recurrence in the ERAT group. The duration of ablation (174.3 ± 62.3 vs 114.7 ± 39.5 minutes, P = 0.046) and the procedure time (329.3 ± 83.4 vs 279.2 ± 79.7 minutes, P = 0.027) were significantly longer in patients with late recurrence than in those without late recurrence following ERAT. Conclusions: The late recurrence rate is higher in the patients with ERAT compared with those without ERAT following AF ablation, and is more often noted in the patients who underwent CTI ablation and had a prolonged procedure time. Furthermore, inducibility of AF or AT immediately after ablation independently predicts late recurrence in patients with ERAT. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1331-1337, December 2010) atrial fibrillation, catheter ablation, early recurrence, atrial tachycardia Introduction Catheter ablation including pulmonary vein (PV) isolation is an effective treatment for patients with atrial fibrillation (AF). 1-4 The patients who experience an early recurrence of AF (ERAF) after catheter ablation of AF are significantly more likely to develop a late recurrence than those without an early recurrence. 5 However, AF often does not recur in pa- tients with ERAF during further follow-up; therefore, a brief period of antiarrhythmic drug (AAD) therapy may be more appropriate than an early repeated procedure for AF patients This study was presented as an oral abstract at the 30th Annual Scientific Sessions of the Heart Rhythm Society, Boston, Massachusetts, USA, May 2009. This work was supported by a Korea University Grant. No disclosures. Address for correspondence: Young-Hoon Kim, M.D., Ph.D., F.A.C.C., Di- vision of Cardiology, Korea University Medical Center, 126-1, 5ga, Anam- dong, Seongbuk-gu, Seoul 136-705, Republic of Korea. Fax: +82-2-927- 1478, E-mail: yhkmd@unitel.co.kr Manuscript received 27 November 2009; Revised manuscript received 22 March 2010; Accepted for publication 20 April 2010. doi: 10.1111/j.1540-8167.2010.01831.x who were highly symptomatic. 5 On the contrary, an early reablation may reduce the incidence of further recurrence. 6,7 Ablation of the AF may result in secondary atrial tachycar- dia (AT). 8,9 However, the long-term outcomes of early recur- rence of AT (ERAT) have not been clearly elucidated, and it remains unclear whether ERAT predicts late recurrence of AF or AT. Therefore, we evaluated whether ERAT within the blanking period of 3 months correlated with the long-term outcome and investigated the predictors of late recurrence in patients with ERAT following AF ablation. Methods Patient Population Data were retrospectively analyzed from 352 consecu- tive patients who underwent their first AF ablation including PV isolation from January 2004 to April 2008. We defined ERAT as an episode of AT or atrial flutter (AFL) that is documented by electrocardiography (ECG) and lasts at least 30 seconds, no matter whether its responsible mechanism is focal or reentry, within a 3-month blanking period after radiofrequency catheter ablation (RFCA). 10 AT was defined as a regular, supraventricular rhythm at a constant rate ≥100 beats/min with a cycle length ≥200 ms, and AFL referred regular tachycardia with rate ≥240 beats/min with a cycle length ≤250 ms lacking an isoelectric baseline. 11