Cardiac Iron Overload Detection Using Longitudinal Strain in Asymptomatic Children with Beta Thalassemia Major

Background.Cardiomyopathy mediated by iron disposition in cardiomyocytes is a dreadful cause of morbidity and mortality in patients with beta thalassemia major (BTM). Conventional transthoracic echocardiography (TTE) parameters are preserved at late stages of cardiomyopathy induced by iron overload. Therefore, cardiac imaging modalities based on myocardial deformation such as strain imaging are used for early detection of cardiac iron overload.Aim.To demonstrate the contribution of longitudinal strain (LS) in early detection of cardiac iron overload in children with BTM.Methods.Sixty children (30 children with BTM and 30 healthy controls) were enrolled in this study. Conventional TTE study was performed in both patient and control groups. LV regional longitudinal strain (RLS) were determined and compared between the two study groups.Results.Mean age was 10.4 ± 5years in BTM group compared to 10.2 ± 5 years in control group (p=0.876). Compared to control group, there was no significant difference in conventional TTE parameters except for indexed left atrium (LA) area and volume. LA was significantly larger in BTM children (27.59 ±13.1ml/m² vs. 18.23 ± 4.33 ml/m², p=0.001). RLS was lower in anterior, septal and inferior walls in basal and middle segments of LV in BTM group while there was no significant difference in RLS in apical segment between the two groups (-27.30 ± 5.1 vs. -28.83 ± 4.33, p=0.22).Conclusion.In asymptomatic BMT children with normal conventional TTE parameters, LS could be used for the detection of subclinical myocardial dysfunction.