title: Discrete potentials guided radiofrequency ablation for idiopathic outflow tract ventricular arrhythmias.
abstract: OBJECTIVE
  Discrete potentials (DPs) have been recorded and targeted as the site of ablation of the outflow tract arrhythmias. The aim of the present study was to investigate the significance of DPs with respect to mapping and ablation for idiopathic outflow tract premature ventricular contractions (PVCs) or ventricular tachycardias (VTs).
  
  
  RESULTS
  Seventeen consecutive patients with idiopathic right or left ventricular outflow tract PVCs/VTs who underwent radiofrequency catheter ablation were included. Intracardiac electrograms during the mapping and ablation were analysed. During sinus rhythm, sharp high-frequency DPs that displayed double or multiple components were recorded following or buried in the local ventricular electrograms in all of the 17 patients, peak amplitude 0.51 ± 0.21 mV. The same potential was recorded prior to the local ventricular potential of the PVCs/VTs. Spontaneous reversal of the relationship of the DPs to the local ventricular electrogram during the arrhythmias was noted. The DPs were related to a region of low voltage showed by intracardiac high-density contact mapping. At the sites with DPs, lower unipolar and bipolar ventricular voltage of sinus beats were noted compared with the adjacent regions without DPs (unipolar: 6.1 ± 1.8 vs. 8.3 ± 2.3 mV, P < 0.05; bipolar: 0.62 ± 0.45 vs. 1.03 ± 0.60 mV, P < 0.05). The targeted DPs were still present in 12 patients after successful elimination of the ectopies. Discrete potentials were not present in seven controls.
  
  
  CONCLUSIONS
  Discrete potentials and related low-voltage regions were common in idiopathic outflow tract ventricular arrhythmias. Discrete potential- and substrate-guided ablation strategy will help to reduce the recurrence of idiopathic outflow tract arrhythmias.
authors.affiliation: Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China.
authors.forename: Enzhao
authors.initials: E
authors.lastname: Liu
authors.affiliation: Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China xugang_163com@163.com.
authors.forename: Gang
authors.initials: G
authors.lastname: Xu
authors.affiliation: Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China.
authors.forename: Tong
authors.initials: T
authors.lastname: Liu
authors.affiliation: Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China.
authors.forename: Lan
authors.initials: L
authors.lastname: Ye
authors.affiliation: Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China.
authors.forename: Qitong
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China.
authors.forename: Yanshu
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China.
authors.forename: Guangping
authors.initials: G
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D017115:Catheter Ablation / Q000379:methods*; D015331:Cohort Studies; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000601:surgery*; D018879:Ventricular Premature Complexes / Q000601:surgery*
keywords: Discrete potentials; Local voltage; Outflow tract; Ventricular arrhythmia