title: Impact of atrial fibrillation ablation on cardiac sympathetic nervous system in patients with and without heart failure.
abstract: OBJECTIVE
  Catheter ablation of atrial fibrillation (AF) might influence the cardiac autonomic nervous system. To investigate the impact of catheter ablation on the sympathetic nervous function in AF patients with and without heart failure (HF) using cardiac iodine-123-metaiodobenzylguanidine ((123)I-mIBG) scintigraphy, and the association of this effect with AF recurrence.
  
  
  METHODS
  Forty consecutive patients (median age, 65 (54-69) years; male, 29) with paroxysmal (n=22) and persistent (n=18) AF who were scheduled for ablation were enrolled. Twelve (30%) of these patients also exhibited either stable HF, defined as an ejection fraction <40%, or a history of symptomatic HF. (123)I-mIBG scintigraphy was performed at baseline and 3months post-ablation. The heart-to-mediastinum ratio of (123)I-mIBG uptake at 15min (H/M15min) and 240min (H/M240min), as well as the washout rate (WR) were measured.
  
  
  RESULTS
  During an 11±4-month follow-up, AF recurrence was observed in 8 (20%) patients receiving no antiarrhythmic drugs. Patients with HF had a tendency toward a lower baseline H/M15min (1.91±0.06 vs. 2.05±0.04, p=0.07), significantly lower H/M240min (1.88±0.22 vs. 2.14±0.28, p=0.008), and higher WR (40.3±9.0 vs. 32.3±7.4, p=0.007). Post-ablation, WR decreased in patients with HF (40.2±8.5 to 29.0±8.9, p=0.02) but slightly increased in those without (32.0±7.4 to 34.6±10.3, p=0.04). WR post-ablation independently predicted AF recurrence (adjusted hazard ratio=1.14 for 1 percentage point increase in the WR, 95% coincidence interval=1.02-1.34, p=0.02).
  
  
  CONCLUSIONS
  AF ablation restores sympathetic nervous system status via attenuation of excessive adrenergic tone in HF patients. Elevated sympathetic nervous tone 3months post-ablation was a reliable predictor of AF recurrence.
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, Japan; Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki, Hyogo 660-8511, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Masuda
authors.affiliation: Division of Cardiology, Osaka Prefectural General Medical Center, 3-1-56 Mandai-Higashi Sumiyoshi-ku, Osaka 558-8558, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, Japan. Electronic address: mizuno@medone.med.osaka-u.ac.jp.
authors.forename: Hiroya
authors.initials: H
authors.lastname: Mizuno
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Minamiguchi
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, Japan.
authors.forename: Shozo
authors.initials: S
authors.lastname: Konishi
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, Japan.
authors.forename: Tomohito
authors.initials: T
authors.lastname: Ohtani
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Yamaguchi
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Okuyama
authors.affiliation: Kansai Rosai Hospital Cardiovascular Center, 3-1-69 Inabaso, Amagasaki, Hyogo 660-8511, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Uematsu
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sakata
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000294:innervation* / Q000503:physiopathology; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012008:Recurrence; D013318:Stroke Volume; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: Atrial fibrillation; Heart failure; Recurrence; Sympathetic nervous system