title: Electrocardiographic abnormalities and ventricular tachyarrhythmias after myocardial infarction.
abstract: OBJECTIVE
  To assess the association of electrocardiographic repolarization and depolarization patterns to vulnerability to ventricular tachyarrhythmias.
  
  
  METHODS
  In the present case-control study, a 12-lead ECG, signal-averaged ECG (SAECG), T-wave and QRS morphology, and T-wave alternans (TWA) were analyzed in post-MI patients with and without documented sustained ventricular tachycardia (VT) or fibrillation (VF) (VT/VF group, n=40, Non-VT/VF group, n=37, respectively) and healthy subjects (n=41).
  
  
  RESULTS
  The QRS complex duration, measured from standard ECG (128 +/- 32 ms vs. 102 +/- 21 ms, p<0.001) or SAECG (125 +/- 25 ms vs. 99 +/- 20 ms, p<0.001), was significantly longer in the VT/VF than Non-VT/VF group. Several T-wave morphology variables, e.g., the total cosine of the angle between the main vectors of T-wave and QRS loops (TCRT), were different in the VT/VF (-0.13 +/- 0.58) and Non-VT/VF group (-0.11 +/- 0.48) compared to the healthy controls (0.47 +/- 0.50, p<0.001). However, there were no significant differences in any of the T-wave morphology variables including TWA between the two post-MI groups.
  
  
  CONCLUSIONS
  Abnormalities in ventricular depolarization are more common among post-MI patients with prior VT/VF than in those without documented ventricular tachyarrhythmias. Abnormal T-wave morphology and TWA seem to reflect the heart disease rather than specifically vulnerability to VT/VF.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, University of Oulu , Oulu , Finland.
authors.forename: Miia K
authors.initials: MK
authors.lastname: Hyytinen-Oinas
authors.forename: Kari
authors.initials: K
authors.lastname: Ylitalo
authors.forename: Mari
authors.initials: M
authors.lastname: Karsikas
authors.forename: Tapio
authors.initials: T
authors.lastname: Seppänen
authors.forename: M J Pekka
authors.initials: MJ
authors.lastname: Raatikainen
authors.forename: Paavo
authors.initials: P
authors.lastname: Uusimaa
authors.forename: Heikki V
authors.initials: HV
authors.lastname: Huikuri
authors.forename: Juha S
authors.initials: JS
authors.lastname: Perkiömäki
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004562:Electrocardiography; D005260:Female; D005387:Finland; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D011237:Predictive Value of Tests; D012372:ROC Curve; D017180:Tachycardia, Ventricular / Q000209:etiology* / Q000503:physiopathology; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000209:etiology* / Q000503:physiopathology