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.Objectives: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.Patients and 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.

Comparison between brain natriuretic peptide and calcitonin gene-related peptide in children with dilated cardiomyopathy and controls

“… 14 15 Left ventricular mass index (LVMI) as a left heart parameter had significant different values in case and control groups. 16 15 The results of the late studies were similar with the present study findings. Noori reported that echocardiographic parameters of left ventricle such as ICT, MPI, ET, PEP/ET, DT, AT, IRT, LVEDD, LVESD, and EF in patients and control groups were significantly different.…”

Increased iron stores prolong the QT interval – a general population study including 20 261 individuals and meta‐analysis of thalassaemia major

“…Only case‐control studies, cross‐sectional studies and population‐based follow up studies with results on QT interval [mean (SD), measured by ECG] in cases (thalassaemia major patients) and controls (healthy individuals) were included. Eight studies fulfilled our criteria: Farahani et al (), Garadah et al (), Kayrak et al (), Magri et al (), Noori et al (), Oztarhan et al (), Russo et al () and Ulger et al (). The following data was extracted from each study: author, title, publication year, number of cases and controls, definition of cases, mean age of cases and controls, mean ferritin concentration of cases, mean QTc interval (SD) of cases and controls, and formula used for QT interval correction for heart rate.…”

“…Cardiovascular mortality is the leading cause of death in patients with secondary iron overload due to thalassaemia major and dependency of chronic blood transfusions (Borgna‐Pignatti et al , ). Studies have shown increased incidence of prolonged QT interval and sudden cardiac death among these patients(Yalcinkaya et al , ; Ulger et al , ; Detterich et al , ; Kayrak et al , ; Noori et al , ). As prolonged QT interval is a well‐known risk factor for development of ventricular tachycardia and sudden cardiac death, the association between increased iron stores and QT interval is worth further investigation.…”

P-Wave and QT Dispersion in Children With βeta-Thalassemia

“…Mittal [20] also in agreement with Noori NM et al who showed that QTd was larger in case group than in control group. This study showed acceptable sensitivity and specificity of QTd in comparison to LVMI and suggests that standard ECG can be used for early diagnosis of cardiac involvement in asymptomatic patients with thalassemia major [21].…”