Assessment of regional and global myocardial systolic function by 2D longitudinal speckle tracking in children with beta thalassemia major

Abstract

Background: Thalassemias constitute a group of chronic, inherited anemias that are transfusion dependent. Cardiac disease as a result of transfusional iron overload remains as the principal cause of death in these patients even though there have been lots of improvements in iron chelation therapy during the past 25 years. For this reason, it is recommended that regular cardiac evaluation should be done for all patients with thalassemia major. Objective: The present study was conducted with the primary objective to investigate the left ventricular (LV) myocardial function using conventional echocardiographic measures as well as two-dimensional (2D) speckle tracking in patients with beta-thalassemia major who received regular transfusions and chelation therapy. Methodology: This prospective observational study was conducted in the Department of Paediatrics, Sir Jamshedji Jeejeebhoy Group of Hospitals, Mumbai, over a period of 6 months from February 2012 to July 2012. The study comprised 25 consecutive cases of beta-thalassemia major who were diagnosed on the basis of hemoglobin electrophoresis and 25 controls with normal hemoglobin electrophoresis pattern. Patients with any congenital or acquired heart disease and also patients with heart disease of infectious, metabolic, autoimmune etiology were excluded from the study. 2D, M-mode, Doppler, and longitudinal speckle tracking echocardiographic assessment was performed in all the study cases and controls. Results: The mean age of beta-thalassemia group was 7.02 ± 3.00 years whereas the control group was 5.06 ± 3.62 years. The mean hemoglobin was 5.54 ± 1.30 g/dl in beta-thalassemia patients and 10.96 ± 1.36 g/dl in controls (P < 0.001). The thalassemia patients had lower LV ejection fraction (EF) (62.20 ± 7.93% vs. 66.40 ± 1.19%, P < 0.001) and lower global longitudinal strain (GLS) (−21.73 ± 3.68% vs. −26.80 ± 1.29%, P < 0.001) as compared to the controls. The age of the child, hemoglobin level, and serum ferritin level correlated with the LVEF and GLS. Conclusions: LV systolic dysfunction is common in patients with beta-thalassemia major. This is likely to be a consequence of chronic anemia as well as transfusional iron load, compounded by poor compliance to chelation therapy and sometimes nonavailability of proper cardiac monitoring. These findings suggest that even in young children with beta-thalassemia major, who are asymptomatic, serial echocardiography is warranted to permit early recognition of LV systolic dysfunction and timely initiation of appropriate cardioprotective therapy.