title: Signal-Averaged Electrocardiography as a Noninvasive Tool for Evaluating the Outcomes After Radiofrequency Catheter Ablation of Ventricular Tachycardia in Patients With Ischemic Heart Disease: Reassessment of an Old Tool.
abstract: Inducibility of ventricular tachycardia (VT) has limited ability to predict recurrent VT after catheter ablation (CA). We sought to correlate the signal-averaged ECG (SAECG) with the endocardial scar characteristics in patients with ischemic VTs. We suggest that successful CA can result in normalization of the SAECG.
  
  
  
  Fifty patients (42 male; aged 67±10 years, ejection fraction 34±12%) with ischemic VTs were prospectively enrolled. SAECG was performed before and after CA. Patients with at least 2 abnormal criteria (filtered QRS ≥114 ms; root mean square 40 <20 μV, and low-amplitude potentials 40 >38 ms) were defined as having positive SAECG. There was a linear correlation between endocardial scar area (<1.5 mV) and filtered QRS (r=0.414; P=0.003). CA resulted in normalization of the SAECG in 6 patients. In patients with filtered QRS ≤120 ms, 13 (40.6%) patients had normal SAECG after CA compared with 7 (21.9%) before ablation (P=0.034). Patients with normal or normalized SAECG after CA had better VT-free survival compared with those whose SAECG remained abnormal. Abnormal SAECG after CA was a predictor for VT recurrence: hazard ratio=3.64; P=0.039 for the overall population, and hazard ratio=5.80; P=0.022 for patients having QRS ≤120 ms.
  
  
  
  There is a significant correlation between the surface SAECG and endocardial scar size in patients with ischemic VTs. A successful CA can result in normalization of SAECG that is associated with more favorable long-term outcomes. SAECG can be useful to assess the procedural success of VT ablation.
authors.affiliation: From the Department of Cardiac Electrophysiology, Heart Center, University of Leipzig, Germany. dinov@gmx.de.
authors.forename: Borislav
authors.initials: B
authors.lastname: Dinov
authors.affiliation: From the Department of Cardiac Electrophysiology, Heart Center, University of Leipzig, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Bode
authors.affiliation: From the Department of Cardiac Electrophysiology, Heart Center, University of Leipzig, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Koenig
authors.affiliation: From the Department of Cardiac Electrophysiology, Heart Center, University of Leipzig, Germany.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Oebel
authors.affiliation: From the Department of Cardiac Electrophysiology, Heart Center, University of Leipzig, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Sommer
authors.affiliation: From the Department of Cardiac Electrophysiology, Heart Center, University of Leipzig, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bollmann
authors.affiliation: From the Department of Cardiac Electrophysiology, Heart Center, University of Leipzig, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Hindricks
authors.affiliation: From the Department of Cardiac Electrophysiology, Heart Center, University of Leipzig, Germany.
authors.forename: Arash
authors.initials: A
authors.lastname: Arya
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000368:Aged; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D056149:Epicardial Mapping; D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000150:complications*; D011446:Prospective Studies; D017180:Tachycardia, Ventricular / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome
keywords: ECG; catheter ablation; late potentials; signal-averaged ECG; ventricular tachycardia