title: Comparison of QT Dispersion With Left Ventricular Mass Index in Early Diagnosis of Cardiac Dysfunction in Patients With β-Thalassemia Major.
abstract: BACKGROUND
  In electrocardiography (ECG), QT is the interval between the onset of Q wave to the end of the T wave. This interval may be a sign of changes in the ventricular structure in hematologic disorders such as thalassemia major.
  
  
  OBJECTIVE
  The main goal of this study was to compare the diagnostic value of corrected QT dispersion (QTcd) and QT dispersion (QTd) with left ventricular mass (LVM) and left ventricular mass index (LVMI) as well as to determine their sensitivity and specificity in early detection of the cardiac involvement in patients with β-thalassemia major.
  
  
  METHODS
  In a case-control study, 60 patients older than ten years of age with thalassemia major who received regular blood transfusion and iron chelators were selected as the case group and were compared with 60 healthy age- and sex-matched subjects. All patients had myocardial performance index (MPI) of more than 0.5 and MPI for controls was less than 0.5. Echocardiography and ECG were performed for both groups and data were analyzed using appropriate statistical tests.
  
  
  RESULTS
  The mean age of cases and controls were 16 ± 2.8 and 16.08 ± 3.01 years, respectively. Male to female ratio was 33:27 in case group and 31:29 in the control group. LVMI in the case group was greater than control group. QTd and QTcd were larger in case group than in control group. The sensitivity and specificity of LVM, LVMI, QTd, and QTcd were as follows: 88.3%, 77.1%; 86.7%, 80%; 93.8%, 80%; and 91.7%, 86.7%, respectively.
  
  
  CONCLUSIONS
  This study showed acceptable sensitivity and specificity of QTcd and QTd in comparison to LVMI; it seems that standard ECG can be used for early diagnosis of cardiac involvement in asymptomatic patients with thalassemia major.
authors.affiliation: Children and Adolescents' Health Research Center, Zahedan University of Medical Sciences, Zahedan, IR Iran.
authors.forename: Noor Mohammad
authors.initials: NM
authors.lastname: Noori
authors.affiliation: Children and Adolescents' Health Research Center, Zahedan University of Medical Sciences, Zahedan, IR Iran.
authors.forename: Maziar
authors.initials: M
authors.lastname: Mahjoubifard
authors.affiliation: Children and Adolescents' Health Research Center, Zahedan University of Medical Sciences, Zahedan, IR Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Mohammadi
authors.affiliation: Tracheal Diseases Research Center, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Jahangiri Fard
authors.affiliation: Zahedan University of Medical Sciences, Zahedan, IR Iran.
authors.forename: Abdolhossein
authors.initials: A
authors.lastname: Abassi
authors.affiliation: Tracheal Diseases Research Center, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Behrooz
authors.initials: B
authors.lastname: Farzanegan
keywords: Beta-Thalassemia; Cardiac involvement; Echocardiography; Electrocardiography