Clinical Medicine Insights: Blood Disorders

Background: Doppler echocardiographic studies of left ventricle (LV) systolic and diastolic function in patients with β-Thalassemia Major (β-TM) had shown different patterns of systolic and diastolic dysfunction.

Aim: This cross-sectional study was designed to study the LV systolic and diastolic function in patients with β-TM using Pulsed Doppler (PD) and Tissue Doppler (TD) echocardiography.

Methods: All patients were evaluated clinically and by echocardiography, The study included patients with β-TM (n = 38, age 15.7 ± 8.9 years) compared with an age-matched control group (n = 38, age 15.9 ± 8.9 years). The pulse Doppler indices were normalized for age and heart rate.

Results: Compared with control patients, M-Mode showed that patients with β-TM have thicker LV septal wall index (0.659 ± 0.23 vs. 0.446 ± 0.219 cm, P < 0.001), posterior wall index (0.659 ± 0.235 vs. 0.437 ± 0.214 cm, P < 0.01), and larger LVEDD index is (3.99 ± 0.48 vs. 2.170 ± 0.57 mm. P = 0.035). Pulsed Doppler showed high LV trans-mitral E wave velocity (70.818 ± 10.139 vs. 57.532 ± 10.139, p = 0.027) and E/A ratio (1.54 vs. 1.23, P < 0.01). The duration of Deceleration time (DT) and isovolumic relaxation time (IVRT) were significantly shorter in patients with β-TM (150.234 ± 20.0.23 vs. 167.123 ± 19.143 msec, P < 0.01) and (60.647 ± 6.77 vs. 75.474 ± 5.83 msec, P < 0.001), respectively. The ratio of transmitral E wave velocity to the tissue Doppler E wave at the basal septal mitral annulus E/Em- was significantly higher in β-TM group (14.024 ± 2.29 vs. 12.132 ± 1.82, P < 0.01). The Tissue Doppler systolic velocity (Sm) and the early diastolic velocity (Em) were significantly lower in β-TM group compared to control (4.31 ± 1.2 cm/s vs. 6.95 ± 2.1, P < 0.01 and 4.31 ± 2.7 cm/s vs. 5.82 ± 2.5, P < 0.01) respectively. The tricuspid valve velocity was significantly higher than controls (2.993 ± 0.569 vs. 1.93 ± 0.471 m/sec, respectively, P < 0.01). However, the LVEF% and fractional shortening were normal with no significant difference in both groups.

Conclusion: In this study, patients with β-thalassemia major compared with controls, have significantly thicker LV wall, and larger LV cavity and LV diastolic filling indices suggestive of restrictive pattern with a higher tricuspid valve velocity. These data showed that left ventricle diastolic indices are compromised initially in patients with β-thalassemia major.