title: QT Dispersion after Thrombolytic Therapy.
abstract: BACKGROUND
  QT dispersion (QTd) is equal to longer QTc minus shorter QTc measured by 12-lead electrocardiogram (ECG). QTd reflects inhomogeneity in repolarization of ventricular myocardium and because of easy and fast measurement of QTd, it can be used to predict high-risk patients for dysrhythmia after Acute Myocardial Infarction (AMI).
  
  
  OBJECTIVE
  This study aimed to assess the effect of thrombolytic therapy on QTd before and 1 hour and 4 days after beginning of thrombolytic therapy.
  
  
  METHODS
  The patients with chest pain and ST Elevated Myocardial Infarction (STEMI) that underwent thrombolytic therapy were enrolled into this study. Streptokinase was the thrombolytic agent in all the patients. Standard 12-lead (ECG) was evaluated before beginning of thrombolytic therapy (QTd 1) and 1 hour (QTd2) and 4 days (QTd3) after thrombolytic therapy. First, ECG was magnified × 10 for exact calculation of QT and QTd. After all, the variables were compared using one-way analysis of variance (ANOVA). Besides, P ≤ 0.05 was considered as statistically significant.
  
  
  RESULTS
  This study was conducted on 160 patients. The results revealed no significant differences among QTd 1, QTd 2, and QTd 3 (P > 0.05). At inferior AMI, however, a significant difference was observed among QTd1, QTd2, and QTd3 (P = 0.031).
  
  
  CONCLUSIONS
  Thrombolytic therapy had no significant effects on QTd. Thus, thrombolytic therapy does not increase the risk of arrhythmia.
authors.affiliation: Shahid Rajaee Heart Center, Tehran, IR Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Oni Heris
authors.affiliation: Cardiology Department, Urmia University of Medical Sciences, Urmia, IR Iran.
authors.forename: Behzad
authors.initials: B
authors.lastname: Rahimi
authors.affiliation: Emergency Medicine Department, Urmia University of Medical Sciences, Urmia, IR Iran.
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Faridaalaee
authors.affiliation: Cardiology Department, Urmia University of Medical Sciences, Urmia, IR Iran.
authors.forename: Mojgan
authors.initials: M
authors.lastname: Hajahmadi
authors.affiliation: Department of Biostatics, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Hojjat
authors.initials: H
authors.lastname: Sayyadi
authors.affiliation: Department of Anesthesiology, Madani Hospital, Tabriz University of Medical Sciences, Tabriz, IR Iran.
authors.forename: Bahman
authors.initials: B
authors.lastname: Naghipour
keywords: Electrocardiography; Myocardial Infarction; QT; Streptokinase; Thrombolysis