title: Reduction of the QT interval dispersion after aortic valve replacement reflects changes in electrical function rather than structural remodeling.
abstract: OBJECTIVE
  Factors related to changes of QT dispersion (QTd) after aortic valve replacement (AVR) in patients with aortic stenosis were analyzed.
  
  
  METHODS
  The prospective group comprised 121 consecutive patients (45 women, 76 men; mean age 58 +/- 11 years; range: 24-77 years) with significant aortic valve stenosis. Data (clinical, echocardiographic and electrocardiographic) were collected before and at least 16 months after AVR. QTd was measured in the standard ECG.
  
  
  RESULTS
  Before AVR, the mean QTd was 60 +/- 24 ms (QT(max) 424 +/- 40 ms). QTd was > 50 ms in 68% of patients, and > 70 ms in 30%. During postoperative follow up the mean QTd was 54 +/- 19 ms (QT(max) 368 +/- 36 ms) for all patients, and was > 50 ms in 58% of cases and > 70 ms in 13%. Postoperatively, QTd was decreased to < 70 ms in 27% of patients with a normalized left ventricular mass index (LVMI), and in 27% of those without any clinically significant reduction in left ventricular (LV) hypertrophy. In the multivariate analysis, QTd reduction was weakly related to the reduction in LV wall thickness (p = 0.09) and LVMI (p = 0.05). The reduction in QTd was more related to changes in T-wave amplitude in lead V5 (p = 0.004).
  
  
  CONCLUSIONS
  Following AVR for aortic stenosis, a decrease in QTd was observed, notably among patients with QTd > 70 ms. This reduction was only weakly related to the degree of reduction in cardiac hypertrophy, but a more important relationship was observed with changes in T-wave amplitude. These findings suggest that a reduction in QTd after AVR is reflective of changes in electrical function rather than structural remodeling.
authors.affiliation: Department of Valvular Heart Disease, National Institute of Cardiology, 04-628 Warsaw, Alpejska 42, Poland. rbaranowski@ikard.waw.pl
authors.forename: Ewa
authors.initials: E
authors.lastname: Orlowska-Baranowska
authors.forename: Rafal
authors.initials: R
authors.lastname: Baranowski
authors.forename: Beata
authors.initials: B
authors.lastname: Kusmierczyk
authors.forename: Janina
authors.initials: J
authors.lastname: Sepiska
mesh_terms: D000328:Adult; D000368:Aged; D001021:Aortic Valve / Q000503:physiopathology* / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000503:physiopathology* / Q000601:surgery*; D004562:Electrocardiography; D005260:Female; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D020257:Ventricular Remodeling