title: QT interval dispersion analysis in patients with aortic valve stenosis: a prospective study.
abstract: OBJECTIVE
  QT interval dispersion (QTd) was analyzed in patients with aortic valve stenosis, and the relationship investigated between QTd, age, gender, hypertension, presence of significant coronary artery stenosis and left ventricular (LV) hypertrophy assessed by echocardiography. Results were also compared between survivors and patients who had cardiac arrest or died before, during or soon after cardiac surgery.
  
  
  METHODS
  The group comprised 535 consecutive patients (217 women, 318 men; mean age 59 +/- 11 years; range: 20-81 years) with significant aortic valve stenosis before valve replacement. The control group comprised 35 healthy subjects (12 women, 23 men; mean age 51 +/- 11 years; range: 28-74 years).
  
  
  RESULTS
  Mean QTd was 29 +/- 10 ms in controls and 59 +/- 24 ms in patients (p < 0.001). Gender had no impact on QTd. QTd was increased in men with significant coronary artery stenosis, and independently related strongly with ECG parameters (QTmax, heart rate) and weakly with age and degree of LV hypertrophy. In patients with cardiac arrest or those who died (n = 14), QTd was increased compared to that in survivors (71 +/- 22 versus 59 +/- 24 ms; p = 0.05), and QTd >70 ms was observed more frequently (p = 0.02; odds ratio 3.4, 1.16-10.0).
  
  
  CONCLUSIONS
  QTd is abnormally increased in two-thirds of patients with aortic valve stenosis, and is increased in men with concomitant coronary artery disease. QTd >70 ms significantly increased the risk of cardiac arrest or death perioperatively. QTd was only weakly related with age and degree of LV hypertrophy, but QTmax and heart rate had a greater impact. QT dispersion analysis has limited clinical value in patients with aortic stenosis.
authors.affiliation: Department of Valvular Heart Disease, The National Institute of Cardiology, Warsaw, Alpejska, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Orlowska-Baranowska
authors.forename: Rafal
authors.initials: R
authors.lastname: Baranowski
authors.forename: Dariusz
authors.initials: D
authors.lastname: Zakrzewski
authors.forename: Beata
authors.initials: B
authors.lastname: Kusmierczyk
authors.forename: Irena
authors.initials: I
authors.lastname: Rawczynska-Englert
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000175:diagnosis* / Q000401:mortality*; D016022:Case-Control Studies; D017023:Coronary Angiography; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006323:Heart Arrest / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D016019:Survival Analysis