title: Unipolar peak-negative voltage as an endocardial electrographic characteristic to predict overlying abnormal epicardial substrates in patients with right epicardial ventricular tachycardia.
abstract: BACKGROUND
  The characteristics of endocardial electrograms needed to detect the overlying abnormal epicardial substrates in arrhythmogenic right ventricular cardiomyopathy with epicardial ventricular tachycardia (VT) remain unclear. This study investigated which of the endocardial electrogram characteristics could predict the overlying abnormal epicardial substrates.
  
  
  RESULTS
  In 20 consecutive patients (median age: 46 years, 11 men) undergoing epicardial VT ablation, detailed endocardial and epicardial mappings were obtained by using the CARTO 3 system. The endocardial electrographic characteristics (unipolar peak-to-peak voltage, unipolar peak-negative-voltage, bipolar voltage, and bipolar electrogram duration) of the opposite endocardium and epicardium in RV were retrospectively investigated (N = 1,697 paired points, 84 ± 60 pairs/patient). Endocardial predictors of the presence of epicardial dense scar (<0.5 mV), low voltage zones (LVZ; ≤1.5 mV), and ablation targets (by using activation mapping, entrainment mapping, and pace mapping) were analyzed.
  
  
  RESULTS
  In the multivariable analysis, (1) unipolar peak-negative voltage independently predicted the presence of epicardial LVZ, epicardial dense scar, and ablation targets; (2) bipolar voltage could not predict epicardial lesions; and (3) bipolar electrogram duration predicted epicardial LVZ, but not dense scar or ablation targets. The endocardial unipolar peak-negative voltage of <1.66 mV (89% sensitivity and 53% specificity) was the optimal cutoff point for predicting epicardial dense scar.
  
  
  CONCLUSIONS
  In patients with RV epicardial VT, the presence of unipolar peak-negative voltage of <1.66 mV in the endocardium predicted the presence of epicardial dense scar (<0.5 mV) and potential ablation targets in the overlying epicardium.
authors: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Division of Cardiology, Department of Medicine, Mackay Memorial Hospital, Taipei, Taiwan; Department of Medicine, Mackay Medical College and Mackay Medicine Nursing and Management College, Taipei, Taiwan.
authors: Po-Ching
authors: PC
authors: Chi
authors: Yenn-Jiang
authors: YJ
authors: Lin
authors: Shih-Lin
authors: SL
authors: Chang
authors: Li-Wei
authors: LW
authors: Lo
authors: Yu-Feng
authors: YF
authors: Hu
authors: Tze-Fan
authors: TF
authors: Chao
authors: Fa-Po
authors: FP
authors: Chung
authors: Jonan
authors: J
authors: Liao
authors: Ta-Chuan
authors: TC
authors: Tuan
authors: Jen-Yuan
authors: JY
authors: Kuo
authors: Jin-Long
authors: JL
authors: Huang
authors: Shih-Ann
authors: SA
authors: Chen
mesh_terms: D018780:Body Surface Potential Mapping / Q000379:methods*; D004699:Endocardium / Q000503:physiopathology*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000503:physiopathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000503:physiopathology*
keywords: arrhythmogenic right ventricular cardiomyopathy; catheter ablation; endocardial unipolar electrocardiogram; epicardial low voltage zone; epicardial scar; ventricular tachycardia