title: Nonischemic cardiomyopathy substrate and ventricular tachycardia in the setting of coronary artery disease.
abstract: BACKGROUND
  Patients with coronary artery disease (CAD) may have ventricular tachycardia (VT) from a separate nonischemic process. Catheter ablation in these patients can be misguided by abnormalities of coronary arteries.
  
  
  OBJECTIVE
  To identify (1) the prevalence of unanticipated nonischemic VT in patients with known CAD presenting with VT and (2) the substrate and VT characteristics of this unique subset of patients.
  
  
  METHODS
  We examined consecutive patients referred for VT catheter ablation who had a history of myocardial infarction and angiography documented CAD with presumed ischemic VT. Patients with low-voltage zones and/or VT origin inconsistent with CAD distribution were included for further analysis.
  
  
  RESULTS
  Of 732 patients, 9 (1.2%) (7 men; median age 74 years; ejection fraction 30%) fulfilled inclusion criteria. Endocardial left ventricular scar inconsistent with CAD distribution was found in 8 patients. In 1 patient, only epicardial left ventricular scar was found. The distribution of low voltage (<1.5 mV) was predominantly around the aortic and mitral valves. Thirty-one VTs were induced in 8 patients. Most VTs had right bundle branch block (68%); of these VTs, 67% had an R/S transition zone later than lead V4 consistent with basal VT origin. Epicardial ablation was necessary in 2 patients. During follow-up (30 [25-39] months), 7 of 9 patients (78%) were free of recurrent VT.
  
  
  CONCLUSIONS
  A small but important subgroup of patients with CAD and VT has a nonischemic substrate/etiology for VT. The presence of multiple VTs with basal origin suggests a potential nonischemic perivalvular substrate and possible need for epicardial VT ablation.
authors: Electrophysiology Section, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania; Cardiology Department, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
authors: Bashar
authors: B
authors: Aldhoon
authors: Wendy S
authors: WS
authors: Tzou
authors: Michael P
authors: MP
authors: Riley
authors: David
authors: D
authors: Lin
authors: David J
authors: DJ
authors: Callans
authors: Mathew D
authors: MD
authors: Hutchinson
authors: Sanjay
authors: S
authors: Dixit
authors: Fermin C
authors: FC
authors: Garcia
authors: Erica S
authors: ES
authors: Zado
authors: Francis E
authors: FE
authors: Marchlinski
mesh_terms: D000368:Aged; D018780:Body Surface Potential Mapping; D009202:Cardiomyopathies / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D017115:Catheter Ablation; D003324:Coronary Artery Disease / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D018153:Czech Republic / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D015995:Prevalence; D011379:Prognosis; D017180:Tachycardia, Ventricular / Q000150:complications* / Q000453:epidemiology / Q000601:surgery
keywords: Ablation; CAD; Coronary disease; EGM; ICD; LBBB; LV; LVOT; MI; MRI; Mapping; NICM; Nonischemic; RBBB; RV; VT; Ventricular tachycardia; coronary artery disease; electrogram; implantable cardioverter-defibrillator; left bundle branch block; left ventricle outflow tract; left ventricle/ventricular; magnetic resonance imaging; myocardial infarction; nonischemic cardiomyopathy; right bundle branch block; right ventricle/ventricular; ventricular tachycardia