The association between myocardial iron load and ventricular repolarization parameters in asymptomatic beta-thalassemia patients

Abstract

Previous studies have demonstrated impaired ventricular repolarization in patients with β-TM. However, the effect of iron overload with cardiac T 2 * magnetic resonance imaging (MRI) on cardiac repolarization remains unclear yet. We aimed to examine relationship between repolarization parameters and iron loading using cardiac T 2 * MRI in asymptomatic β-TM patients. Twenty-two β-TM patients and 22 age- and gender-matched healthy controls were enrolled to the study. From the 12-lead surface electrocardiography, regional and transmyocardial repolarization parameters were evaluated manually by two experienced cardiologists. All patients were also undergone MRI for cardiac T 2 * evaluation. Cardiac T 2 * score <20msec was considered as iron overload status. Of the QT parameters, QT duration, corrected QT interval, and QT peak duration were significantly longer in the β-TM group compared to the healthy controls. T p - T e and T p - T e dispersions were also significantly prolonged in β-TM group compared to healthy controls. (T p - T e) / QT was similar between groups. There was no correlation between repolarization parameters and cardiac T 2 * MRI values. In conclusion, although repolarization parameters were prolonged in asymptomatic β-TM patients compared with control, we could not find any relation between ECG findings and cardiac iron load. Copyright © 2012 Mehmet Kayrak et al.