title: [Effects of metoprolol on the signal averaged electrocardiogram and QT dispersion in acute myocardial infarction].
abstract: OBJECTIVE
  The determination of high risk patients for sudden death and sustained ventricular tachycardia after acute myocardial infarction constitutes the main goal to decrease morbidity and mortality. Every attempt that decreases the frequency of late potentials (LPs) on signal averaged ECG (SAECG) and corrected QT dispersion (QTc-d) may improve prognosis of patients. In this study, the effect of metoprolol on frequency of LPs and QTc-d was investigated.
  
  
  METHODS
  Thirty-five patients (mean age 53 +/- 9 years) with acute myocardial infarction who were not given thrombolytic therapy were enrolled. Patients in whom metoprolol was not administered formed group I (n = 20) and patients who were given metoprolol constituted group II (n = 15). Metoprolol was administered as an initial dose of 15 mg intravenously, following 6-8 hours 100 mg/d orally. To determine the frequency of LPs, SAECG records were performed on admission and at the end of the first week. At the same time, resting ECG recordings (12 leads, 50 mm/s) were obtained to calculate QTc-d. Variance analysis was used for statistical analysis.
  
  
  RESULTS
  In group I; frequency of LPs were found 30% on admission and at the end of the first week. In group II; frequency of LPs were 6% on admission and at the end of the first week there was no LPs. There was no statistically significant difference between two groups according to TQRS, RMS-40, LAS40 and QTc-d
  
  
  CONCLUSIONS
  Metoprolol decreases the frequency of LPs. It has no effect on cQT-d.
authors.affiliation: Adnan Menderes Universitesi Tip Fakültesi Kardiyoloji Anabilim Dali, Aydin. antekten@superonline.com
authors.forename: Tarkan
authors.initials: T
authors.lastname: Tekten
authors.forename: Ceyhun
authors.initials: C
authors.lastname: Ceyhan
authors.forename: O Alper
authors.initials: OA
authors.lastname: Onbaşili
authors.forename: Azem
authors.initials: A
authors.lastname: Akilli
authors.forename: Cüneyt
authors.initials: C
authors.lastname: Türkoğlu
mesh_terms: D000284:Administration, Oral; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D004334:Drug Administration Schedule; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D017180:Tachycardia, Ventricular / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents; D008790:Metoprolol