Evaluation of QT Interval in β Thalassemia Major Patients in Comparison with Control Group

BACKGROUND: Cardiac complications are the primary cause of death in patients with b thalassemia major. QTc interval is an indicator of variability of ventricular repolarization and is supposed to be prominent in high risk patients. The aim of this investigation was to evaluate the relationship between QTc interval in β thalassemia major in comparison with the control group. PATIENTS AND METHODS: Sixty β thalassemia major and intermadia patients were enrolled in this analytical cross-sectional study. Thalassemia major and intermadia patients with no clinical symptoms of cardiac disease underwent echocardiographic and stress tests. QTc interval, blood pressure, heart rate, and average serum ferritin levels were measured. Statistical analysis was performed using version 15 SPSS. RESULTS: Although there was no clinical or echocardiographic sign of cardiac disease and QTc intervals measured before the test were not significantly different between patients and control group (421.7 ± 29.6 vs. 412.4 ± 28.2, P = 0.06), we found that, during stress test, QTc intervals (452.7 ± 30.8 vs. 410.2 ± 26.2, P < 0.001) and heart rate (105 ± 15.1 vs. 89.7 ± 12.3, P < 0.001) were notably greater in β thalassemia major patients compared to the control group, respectively. CONCLUSION: We found augmented QTc intervals in this group of thalassemia major patients who have neither clinical nor electrocardiographic and gross echocardiographic signs of cardiac disease. QTc interval can be helpful in the cardiac assessment of thalassemia major patients.