title: Minimal energy requirement for external cardioversion and catheter ablation for long-standing persistent atrial fibrillation.
abstract: The minimal energy requirement (Emin) for electrical cardioversion (ECV) reflects the atrial substrate in patients with long-standing persistent atrial fibrillation (L-PeAF), but the relationship between EminECV and radiofrequency catheter ablation (RFCA) has not yet been studied. We hypothesize that EminECV before ablation (EminECVpre) predicts clinical outcome of RFCA, and that catheter ablation reduces EminECVpost.
  
  
  
  We included 172 patients with L-PeAF who underwent RFCA (79.7% males, 57.5±10.0 years) due to AF recurrence after ECV with an anti-arrhythmic drug (AAD). ECV began with 70J (patch electrode on anterior-posterior position) and was serially increased to 100, 150, 200, and 250J until sinus rhythm was achieved, at an average 5.0±5.6 months before RFCA. After RFCA, ECV was repeated (ECVpost) in 42 patients with recurrent AF that was not controlled by AAD.
  
  
  
  (1) During 34.8±20.0 months of follow-up after RFCA, 103 patients (59.9%) showed clinical recurrence of AF after RFCA. EminECVpre was significantly higher in patients with recurrent AF (129.0±58.6J) than those who remained in sinus rhythm (94.2±39.4J, p<0.001). (2) EminECVpre ≥150J (HR=3.31, 95% CI 2.18-5.03, p<0.001) and left atrial volume index (HR=1.02, 95% CI 1.00-1.04, p=0.021) were significantly associated with post-RFCA recurrence. (3) Shorter post-RFCA recurrence timing was also independently related to EminECVpre (β=-0.147, 95% CI -0.20 to -0.09, p<0.001). (4) Among 103 patients with recurrent AF after RFCA, 42 AAD-resistant AF patients underwent ECVpost. EminECVpost (100.9±50.8J) was significantly lower than EminECVpre (130.0±66.1J, p=0.006).
  
  
  
  Higher EminECVpre was independently associated with clinical recurrence and earlier recurrence timing of AF after catheter ablation among patients with AAD-resistant L-PeAF. Catheter ablation for L-PeAF significantly reduces EminECV.
authors.affiliation: Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: In-Soo
authors.initials: IS
authors.lastname: Kim
authors.affiliation: Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Tae-Hoon
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Pil-Sung
authors.initials: PS
authors.lastname: Yang
authors.affiliation: Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Jae-Sun
authors.initials: JS
authors.lastname: Uhm
authors.affiliation: Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Boyoung
authors.initials: B
authors.lastname: Joung
authors.affiliation: Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Moon-Hyoung
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Yonsei University Health System, Seoul, Republic of Korea. Electronic address: hnpak@yuhs.ac.
authors.forename: Hui-Nam
authors.initials: HN
authors.lastname: Pak
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000628:therapy*; D016279:Atrial Function, Left / Q000502:physiology*; D017115:Catheter Ablation / Q000379:methods*; D004554:Electric Countershock / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents
keywords: Atrial fibrillation; Cardioversion; Catheter ablation; Recurrence