title: The value of the 12-lead electrocardiogram in localizing the scar in non-ischaemic cardiomyopathy.
abstract: OBJECTIVE
  Patients with non-ischaemic cardiomyopathy (NICM) and ventricular tachycardia can be categorized as anteroseptal (AS) or inferolateral (IL) scar sub-types based on imaging and voltage mapping studies. The aim of this study was to correlate the baseline electrocardiogram (ECG) with endo-epicardial voltage maps created during ablation procedures and identify the ECG characteristics that may help to distinguish the scar as AS or IL.
  
  
  RESULTS
  We assessed 108 baseline ECGs; 72 patients fulfilled criteria for dilated cardiomyopathy whereas 36 showed minimal structural abnormalities. Based on the unipolar low-voltage distribution, the scar pattern was classified as predominantly AS (n = 59) or IL (n = 49). Three ECG criteria (PR interval < 170 ms or QRS voltage in inferior leads <0.6 mV or a lateral q wave) resulted in 92% sensitivity and 90% specificity for predicting an IL pattern in patients with preserved ejection fraction (EF). The four-step algorithm for dilated cardiomyopathy included a paced ventricular rhythm or PR > 230 ms or QRS > 170 ms or an r ≤ 0.3 mV in V3 having 92 and 81% of sensitivity and specificity, respectively, in predicting AS scar pattern. A significant negative correlation was found between the extension of the endocardial unipolar low voltage area and left ventricular EF (rs= -0.719, P < 0.001). The extent of endocardial AS unipolar low voltage was correlated with PR interval and QRS duration (rs= 0.583 and rs= 0.680, P < 0.001, respectively) and the IL epicardial unipolar low voltage with the mean voltage of the limb leads (rs= -0.639, P < 0.001).
  
  
  CONCLUSIONS
  Baseline ECG features are well correlated with the distribution of unipolar voltage abnormalities in NICM and may help to predict the location of scar in this population.
authors.affiliation: Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Via Olgettina 60, Milan, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Oloriz
authors.affiliation: Cardiovascular Research Center, Maastricht, The Netherlands.
authors.forename: Hein J J
authors.initials: HJ
authors.lastname: Wellens
authors.affiliation: Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Via Olgettina 60, Milan, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Santagostino
authors.affiliation: Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Via Olgettina 60, Milan, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Trevisi
authors.affiliation: Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Via Olgettina 60, Milan, Italy.
authors.forename: John
authors.initials: J
authors.lastname: Silberbauer
authors.affiliation: Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Via Olgettina 60, Milan, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Peretto
authors.affiliation: Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Via Olgettina 60, Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Maccabelli
authors.affiliation: Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Via Olgettina 60, Milan, Italy dellabella.paolo@hsr.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Della Bella
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology*; D017115:Catheter Ablation; D002921:Cicatrix / Q000175:diagnosis* / Q000473:pathology; D004562:Electrocardiography; D004699:Endocardium / Q000503:physiopathology*; D056149:Epicardial Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D007558:Italy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000601:surgery*
keywords: Cardiomyopathy; Catheter ablation; Electroanatomic mapping; Electrocardiogram; Ventricular tachycardia