Evaluation of the Correlation Between Electrocardiographic Abnormalities, Cardiac Iron Overload, and Magnetic Resonance T2* Values in Patients with Beta Thalassemia Major

Beta thalassemia major (β-TM) is an inherited blood disorder. Affected patients require frequent blood transfusions, leading to iron deposition and end organ damage, particularly myocardial dysfunction. A 12-lead ECG is a readily available tool that could be used to screen for conduction abnormalities and arrhythmias as a marker of worsening myocardial function.  A total of 108 β-TM patients were evaluated for correlation between abnormal findings on the surface ECG and severity of myocardial iron deposition in magnetic resonance imaging as measured by T2* levels.  Patients with T2* below 20 msec had significantly longer PR intervals, P wave durations, and QTc intervals. Patients with T2* below 10 msec had the longest QRS duration and QRS activation times. Atrial fibrillation was more prevalent in patients with lower T2* levels. With a decrease in T2*, the probability of notching of QRS in the limb and precordial leads increased.  Abnormal ECG is prevalent in β-TM patients, and the frequency of changes increases with the severity of iron overload. A 12-lead ECG is a valuable and readily available tool for the early assessment of myocardial damage and the implementation of a timely and appropriate management strategy.