The Relationship between the Presence of Fragmented QRS and Iron Overload Determined by Magnetic Resonance Imaging T2* in Patients with Beta‑thalassemia Major

Patients with beta-thalassemia major are categorized as high risk for cardiovascular complications due to myocardial iron overload that leads to reduce both systolic and diastolic function as well as cardiac arrhythmias. The present study aimed to assess the relationship between the presence of fragmented QRS and iron overload determined by magnetic resonance imaging (MRI) T2* in patients with beta-thalassemia major.

This cross-sectional study was performed on 71 consecutive patients with beta-thalassemia major that referred to Shahid Rajaei Heart Center in 2014 for assessing myocardial T2* using cardiac MRI. The cardiac MR T2* values and electrocardiograms (ECGs) of the patients were evaluated. The patients’ 12-lead surface ECGs were analyzed for the presence of fragmented QRS.

The presence of fragmented QRS was revealed in 19.7% of patients. The study showed the presence of a significant relationship between cardiac T2* value and fragmented QRS in ECG that the mean myocardial T2* in those with and without fragmented QRS was 11.46 ± 6.63 and 21.72 ± 9.49 (P < 0.001). Using the multivariable linear regression model, it was shown a significant association between the presence of fragmented QRS and myocardial T2* value (standardized beta = −0.318, P = 0.007). In those with fragmented QRS, a significant association was found between myocardial and liver T2* values [r = 0.677, P = 0.008.

A notable number of patients with beta-thalassemia major have fragmented QRS pattern in ECGs that is accompanied with lowering myocardial T2* value in these patients.