title: Electrophysiological characteristics related to outcome after catheter ablation of idiopathic ventricular arrhythmia originating from the papillary muscle in the left ventricle.
abstract: OBJECTIVE
  The electrophysiological properties associated with favorable outcome of radiofrequency catheter ablation (RFCA) for idiopathic ventricular arrhythmia (VA) originating from the papillary muscle (PM) remain unclear. The purpose of this study was to investigate the relationships of electrophysiological characteristics and predictors with the outcome of RFCA in patients with VAs originating from PM in the left ventricle (LV).
  
  
  METHODS
  Twelve (4.2%) of 284 consecutive patients with idiopathic VAs originating from LV PM were assessed. The electrophysiological data were compared between the patients in the successful group and patients in the recurrence group after RFCA.
  
  
  RESULTS
  In 12 patients with PM VAs, non-sustained ventricular tachycardias (VTs, n=6), sustained VTs (n=4) and premature ventricular complexes (n=2) were identified as the presenting arrhythmias. Seven of eight patients showing high-amplitude discrete potentials at the ablation site had a successful outcome (85.7%), while the remaining four patients who showed low-amplitude fractionated potentials at the ablation site experienced VA recurrence. The mean duration from onset to peak downstroke (Δt) on the unipolar electrogram was significantly longer in the successful group than in the recurrence group (58±8 ms vs. 37±9 ms, p=0.04). A slow downstroke >50 ms of the initial Q wave on the unipolar electrogram at ablation sites was also significantly associated with successful outcome (85.7% vs. 25.0%, p=0.03).
  
  
  CONCLUSIONS
  In PM VAs, the high-amplitude discrete potentials before QRS and slow downstroke of the initial Q wave on the unipolar electrogram at ablation sites were related to favorable outcome after RFCA.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Ban
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
authors.forename: Hyun-Soo
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
authors.forename: Dae-In
authors.initials: DI
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Hanyang University Guri Hospital, Guri, Korea.
authors.forename: Hwan-Cheol
authors.initials: HC
authors.lastname: Park
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
authors.forename: Jae-Seok
authors.initials: JS
authors.lastname: Park
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
authors.forename: Yasutsugu
authors.initials: Y
authors.lastname: Nagamoto
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
authors.forename: Jong-Il
authors.initials: JI
authors.lastname: Choi
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
authors.forename: Hong-Euy
authors.initials: HE
authors.lastname: Lim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
authors.forename: Sang-Weon
authors.initials: SW
authors.lastname: Park
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
authors.forename: Young-Hoon
authors.initials: YH
authors.lastname: Kim
keywords: Arrhythmia; Catheter ablation; Left ventricle; Papillary muscles