title: An increase in right atrial magnetic strength is a novel predictor of recurrence of atrial fibrillation after radiofrequency catheter ablation.
abstract: BACKGROUND
  Differences in electrical properties between left and right atria (LA and RA) after pulmonary vein isolation (PVI) for atrial fibrillation (AF) are currently poorly understood. Magnetocardiograms were used to investigate the effect of PVI on bi-atrial magnetic field changes and their relationship to clinical outcomes.
  
  
  RESULTS
  This study included 71 patients undergoing PVI for paroxysmal AF. Magnetocardiograms were recorded at baseline and 1 day, 8 weeks, and 24 weeks after ablation. Peak magnitude of LA and RA segments on P waves was separately compared before and after PVI. During a 16-month post-ablation period, 53 (75%) patients were free from AF recurrences. LA magnetic strength in patients without recurrence persistently decreased for 24 weeks and was significantly lower at 8 weeks than that in patients with recurrence (1.28±0.69 vs. 1.74±0.71 pico-Tesla, P=0.02). RA magnetic strength in patients with recurrence persistently rose for 24 weeks and was significantly higher at 8 weeks than that in patients without recurrence (2.17±0.82 vs. 3.00±1.12 pico-Tesla, P=0.001). Multivariate analysis showed RA magnetic strength at 8 weeks to be the strongest predictor of AF recurrence (odds ratio=3.335; 95% confidence interval=1.181-9.416; P=0.02).
  
  
  CONCLUSIONS
  PVI resulted in distinct changes in magnetic strength in both the LA and the RA. A persistent rise in RA magnetic strength might be a robust predictor of AF recurrence after ablation.
authors.affiliation: Division of Cardiovascular Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Sato
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yoshida
authors.forename: Kuniomi
authors.initials: K
authors.lastname: Ogata
authors.forename: Takeshi
authors.initials: T
authors.lastname: Inaba
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tada
authors.forename: Yukio
authors.initials: Y
authors.lastname: Sekiguchi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ito
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ishizu
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Seo
authors.forename: Iwao
authors.initials: I
authors.lastname: Yamaguchi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kandori
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Aonuma
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D016280:Atrial Function, Right; D017115:Catheter Ablation / Q000009:adverse effects*; D016009:Chi-Square Distribution; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006339:Heart Rate; D006801:Humans; D007564:Japan; D016015:Logistic Models; D060526:Magnetic Fields; D053798:Magnetocardiography; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome