title: Endocardial or epicardial ventricular tachycardia in nonischemic cardiomyopathy? The role of 12-lead ECG criteria in clinical practice.
abstract: BACKGROUND
  Specific 12-lead ECG criteria have been reported to predict an epicardial site of origin (SoO) of induced ventricular tachycardias (VTs) in left ventricular nonischemic cardiomyopathy.
  
  
  OBJECTIVE
  The purpose of this study was to (1) determine the value of ECG criteria to predict an epicardial SoO of clinically documented VTs, (2) analyze the effect of VT cycle length (CL) and antiarrhythmic drugs on the accuracy of ECG criteria, and (3) assess interobserver variability.
  
  
  METHODS
  In 36 consecutive patients with nonischemic left ventricular cardiomyopathy (age 58 ± 16 years, 75% male) who underwent combined endocardial/epicardial VT ablation, all clinically documented and induced right bundle branch block VTs were analyzed for previously reported ECG criteria to determine the SoO, as defined by ≥11/12 pace-map, concealed entrainment, and/or VT termination during ablation.
  
  
  RESULTS
  In 21 patients with clinically documented (25 mm/s) right bundle branch block VT, none of the ECG criteria differentiated between patients with and those without an epicardial SoO. In induced VTs (100 mm/s), 2 of 4 interval criteria differentiated between an endocardial and epicardial SoO for slow VTs (CL >350 ms) and 2 of 4 criteria in patients on amiodarone, but none for fast VTs (CL ≤350 ms) or patients off amiodarone. The Q wave in lead I was the most accurate criterion for an epicardial SoO (sensitivity 88%, specificity 80%). In both clinically documented and induced VTs, interobserver agreement was poor for pseudodelta wave and moderate for other criteria.
  
  
  CONCLUSIONS
  When applied to clinically documented VTs, no ECG criterion could differentiate between patients with and those without an epicardial SoO. Published interval-based ECG criteria do not apply to fast VTs and patients off amiodarone.
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Sebastiaan R D
authors.initials: SR
authors.lastname: Piers
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Marta de Riva
authors.initials: Mde R
authors.lastname: Silva
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Gijsbert F L
authors.initials: GF
authors.lastname: Kapel
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Serge A
authors.initials: SA
authors.lastname: Trines
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.affiliation: Department of Cardiology, Leiden University Medical Centre, Leiden, The Netherlands. Electronic address: K.Zeppenfeld@lumc.nl.
authors.forename: Katja
authors.initials: K
authors.lastname: Zeppenfeld
mesh_terms: D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D009202:Cardiomyopathies; D002547:Cerebral Palsy; D004562:Electrocardiography; D004567:Electrodes, Implanted; D022062:Electrophysiologic Techniques, Cardiac; D004699:Endocardium / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000473:pathology; D017180:Tachycardia, Ventricular / Q000175:diagnosis
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone
keywords: Catheter ablation; Electrocardiography; Epicardial; Nonischemic cardiomyopathy; Ventricular tachycardia