title: QT dispersion before and after coronary artery angioplasty: a case study from Iran.
abstract: OBJECTIVE
  In this study, we investigated the changes in QT dispersion (QTd) after successful coronary artery revascularization.
  
  
  BACKGROUND
  QTd, as a marker of regional variability of myocardial repolarization, increases following impaired myocardial perfusion and is associated with increased risk of ischemia-induced arrhythmia.
  
  
  METHODS
  In 45 consecutive patients (mean age 54.39±11.49 years) undergoing elective percutaneous coronary intervention (PCI), QTd was measured from a 12-lead electrocardiogram 6-12 hours before and 6 hours after the procedure. QTd was defined as the difference between maximum and minimum QT interval in the 12 leads. QT changes were analyzed regarding preoperative ejection fraction (EF), type and number of involved vessels, type and number of revascularized coronary arteries and history of Q-wave MI using SPSS software.
  
  
  RESULTS
  QTd significantly decreased postoperatively from 55.48±20.03 to 42.00±19.96 in the study population (P=0.001). Subgroup analyses showed that QTd did not decrease significantly in patients with two-vessel disease and those with low EF (<50%); however, the reduction was significant for other subgroups.
  
  
  CONCLUSIONS
  Successful PCI results in improved regional heterogeneity of myocardial repolarization, evidenced as decreased QTd after the procedure.
authors.affiliation: Ministry of Health and Medical Education, Tehran, Iran; Milad Hospital, Tehran, Iran. swt_f@yahoo.com
authors.forename: E
authors.initials: E
authors.lastname: Monshizadeh
authors.forename: H
authors.initials: H
authors.lastname: Arefi
authors.forename: M
authors.initials: M
authors.lastname: Moghadam
authors.forename: M
authors.initials: M
authors.lastname: Hassanijirdehi
mesh_terms: D000328:Adult; D015906:Angioplasty, Balloon, Coronary; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology* / Q000628:therapy*