title: Angioplasty decreases prolonged QT dispersion in patients with angina pectoris but not in patients with prior myocardial infarction.
abstract: OBJECTIVE
  Prolonged QT dispersion (QTd) is shortened by successful percutaneous transluminal coronary angioplasty (PTCA) in patients with ischemic heart disease. Particularly, QTd plays an important role in the prognostication in patients with prior myocardial infarction (MI). However, whether the effect of PTCA on QTd differs in patients with and without prior MI is not clear, and this study sought to clarify this question.
  
  
  METHODS
  In 41 consecutive patients with ischemic heart disease, we measured QTd from a routine 12-lead electrocardiogram taken at 72 h before and after successful PTCA. Patients were divided into two groups based on the presence or absence of prior MI: Group 1 consisted of 24 patients with angina (61 +/- 11 years old) without prior MI and Group 2 was comprised of 17 patients (69 +/- 10 years old) with prior MI. QTd was calculated as the difference between the maximum and minimum QT and QT corrected for heart rate (QTc), using Bazett's formula for calculating QTcd. All measurements were obtained manually and blindly.
  
  
  RESULTS
  In Group 1, 15 of 24 patients (63%) demonstrated multivessel disease and 16 of 24 (67%) patients had high QTd > 60 ms. Percutaneous transluminal coronary angioplasty decreased QTd and QTcd in Group 1 (QTd, from 83 +/- 35 to 57 +/- 19 ms, p < 0.05 ; QTcd, from 89 +/- 37 to 63 +/- 33 ms, p < 0.05), whereas no changes were observed in Group 2 (QTd, from 73 +/- 25 to 69 +/- 22 ms, NS; QTcd, from 80 +/- 30 to 79 +/- 28 ms, NS). QTd is more sensitive to decrease by successful PTCA in patients with angina than in patients with prior MI.
  
  
  CONCLUSIONS
  The effect of successful PTCA on inhomogeneity of ventricular repolarization reflected by QTd in patients with prior MI is different from that in patients without prior MI.
authors.affiliation: National Defense Medical College, Internal Medicine-1, Tokorozawa, Saitama, Japan.
authors.forename: B
authors.initials: B
authors.lastname: Takase
authors.forename: T
authors.initials: T
authors.lastname: Tujimoto
authors.forename: K
authors.initials: K
authors.lastname: Kitamura
authors.forename: A
authors.initials: A
authors.lastname: Hamabe
authors.forename: A
authors.initials: A
authors.lastname: Uehata
authors.forename: I
authors.initials: I
authors.lastname: Kazusige
authors.forename: K
authors.initials: K
authors.lastname: Satomura
authors.forename: F
authors.initials: F
authors.lastname: Ohsuzu
authors.forename: A
authors.initials: A
authors.lastname: Kurita
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000150:complications* / Q000601:surgery; D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D003327:Coronary Disease / Q000150:complications / Q000628:therapy*; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000601:surgery; D016896:Treatment Outcome