The Effects of Vitamin D on Myocardial Function Demonstrated by Speckle-Tracking Echocardiography in Children with Beta Thalassemia.

Objective: Beta thalassemia major is an inherited hemoglobin disorder resulting in chronic hemolytic anemia. Cardiac involvement is the main cause of death in patients. Speckle-tracking echocardiography is a feasible method for the evaluation of cardiac function via an assessment of the longitudinal deformation of the myocardium through the cardiac cycle. The aim of our study is to evaluate the association between vitamin D deficiency and deformation of the left ventricular myocardium measured by speckle-tracking echocardiography in children with thalassemia major.

Methods: In this prospective study, 33 thalassemic patients with vitamin D deficiency were enrolled. Cardiac magnetic resonance T2* value, conventional echocardiography, and speckle tracking, and also left ventricular longitudinal and circumferential strain values were measured. Myocardial functions of the patients with vitamin D deficiency or insufficiency were evaluated by speckle-tracking echocardiography before and after vitamin D replacement.

Results: The mean age of the patients was 15.4 ± 3.09 years. Vitamin D level was deficient in 30 (90%) and insufficient in 3 (10%) of them. Speckle-tracking analysis showed a significantly decreased absolute value of the left ventricular global longitudinal strain before vitamin D replacement. A significant improvement in the global longitudinal strain was detected after vitamin D replacement (P < 0.05). A statistically significant increase was observed in parameters showing left ventricular systolic and diastolic functions after vitamin D replacement.

Conclusion: Vitamin D deficiency is frequently observed and causes decreased contractility in thalassemic patients. In our study, we observed that our patients' cardiac functions had improved after vitamin D replacement therapy.