title: QT dispersion in patients with rheumatic mitral stenosis and its relation with echocardiographic findings and serum NT-proBNP levels.
abstract: OBJECTIVE
  We evaluated the value of QT interval dispersion in patients with rheumatic mitral stenosis (MS) in association with echocardiographic parameters and serum N-terminal pro brain natriuretic peptide (NT-proBNP) levels.
  
  
  METHODS
  The study consisted of 46 patients (39 women, 7 men; mean age 46.9±9.7 years) with moderate-to-severe rheumatic MS. All patients underwent echocardiographic examination. Blood samples for NT-proBNP were collected immediately after ECG recording. QT interval and QRS complex were measured manually on standard 12-lead surface ECGs. Electrocardiographic and echocardiographic findings and serum NT-proBNP levels were compared with those of a control group consisting of 30 healthy subjects (26 women, 4 men; mean age 46.1±7.3 years).
  
  
  RESULTS
  Compared to controls, serum NT-proBNP levels were significantly higher in MS patients (284.6±206.5 vs. 70.2±9.3 pg/ml, p<0.001). The mean QT interval, QTc interval, and QT dispersion were significantly prolonged in MS patients compared to controls (378±25 vs. 349±21, 420±22 vs. 401±19, and 61±21 vs. 38±15 msec, respectively; p<0.005). QT and QTc dispersions were negatively correlated with mitral valve area (QT: r=-0.311, p=0.03; QTc: r=-0.327, p=0.02), and positively correlated with serum NT-proBNP level (QT: r=0.583, p<0.001; QTc: r=0.637, p<0.001). QTc dispersion was also an independent predictor of serum NT-proBNP level in regression analysis (β=0.330, p=0.03).
  
  
  CONCLUSIONS
  Our results indicate that QT dispersion is related to the echocardiographic degree of rheumatic mitral valve disease and serum NT-proBNP levels in rheumatic MS. Being a noninvasive, easy, and inexpensive method, QT dispersion may be used as a complementary tool to the clinical and echocardiographic evaluation of patients with rheumatic MS.
authors.affiliation: Department of Cardiology, Cardiology Institute, İstanbul University, İstanbul, Turkey. kadriye11@yahoo.com.
authors.forename: Kadriye Orta
authors.initials: KO
authors.lastname: Kılıçkesmez
authors.forename: Gülsüm
authors.initials: G
authors.lastname: Bulut
authors.forename: Murat
authors.initials: M
authors.lastname: Başkurt
authors.forename: Uğur
authors.initials: U
authors.lastname: Coşkun
authors.forename: Ahmet
authors.initials: A
authors.lastname: Yıldız
authors.forename: Serdar
authors.initials: S
authors.lastname: Küçükoğlu
mesh_terms: D001145:Arrhythmias, Cardiac; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D012214:Rheumatic Heart Disease / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain