Three Dimensional Speckle Tracking Echocardiography (3D-STE) for Early Detection of Subtle Myocardial Deformation Dysfunction in Thalassemic Patients

Background: Among patients with beta-thalassemia early detection of transfusion-induced myocardial iron loading and its intervention with aggressive chelation therapy may delay or reverse heart failure. Three dimensional speckle tracking echocardiography (3D-STE) is a novel tool that may early detect myocardial affection in these patients.

Methods: Thirty-two thalassemic patients with a mean age of 18.1± 7.03 years and 30 aged matched healthy control subjects have been included in the study. Patients have been recruited from pediatric hematology clinics in both Cairo University, Egypt (n=18) and Padova University, Italy (n=14). 3D-STE was performed to all patients and control subjects in addition to the myocardial relaxometry T2* by cardiac MRI.

Results: The left ventricular ejection fraction (LVEF) derived from 3D echocardiography among the studied thalassemia patients was within normal range 62.5± 5.6%. Compared to the normal subjects, thalassemia patients had a statistical significant reduction of the left ventricular global longitudinal strain (-16.81± 0.93% vs -18.76 ± 1.12 %, p=0.001), the left ventricular global circumferential  strain (-10.56 ± 0.61% vs -11.83 ± 0.71 %, p=0.001 ) and the left ventricular global area strain (-20.13 ±1.18% vs -22.48 ±,1.29 %, p=0.001). No statistical significant correlation was found between the severity of myocardial iron overload measured by T2* and the measured left ventricular global strain.

Conclusion: In asymptomatic thalassemia patients with preserved left ventricular global systolic function 3D-STE derived strain can detect early subtle myocardial dysfunction. The observed subtle myocardial deformation dysfunction is not related to the extent of myocardial iron deposition.