Abstract
Iron overload contributes to cardiac dysfunction in patients with beta thalassemia. Early heart iron overload can be quantified through cardiovascular magnetic resonance (CMR) T2*.
to clarify the value of tissue Doppler imaging (TDI) in early detection of global myocardial dysfunction in iron loaded thalassemia major patients diagnosed by CMR.
Two groups were included in the study; Group I: 69 asymptomatic thalassemia patients (28 females, 41 males), mean age 18.1±7.03 years (range 6 to 39 years), Group II (n=41) healthy normal controls matched for age and sex. Serum ferritin and CMR were performed to assess the degree of cardiac siderosis (T2*< 20 ms). Group I was subdivided into two subgroups; Group Ia (n=26) T2*<20ms and Group Ib (n=43) T2* >20ms. Conventional echocardiography and Doppler of LV, RV dimensions and functions and pulmonary artery pressure were evaluated. TDI measures included systolic and diastolic myocardial velocities (S', E', A' and E'/A') of the basal segments of septal, lateral LV and RV free walls.
Right ventricular diastolic function assessed by tricuspid annular E'/A' was positively correlated with T2* value; the lower tricuspid E'/A' ratio the lower T2* value (r = +0.366, P=0.002). Tricuspid annular A' was significantly higher in group Ia compared to group Ib (16.7 ±5.2cm/s versus 12.1 ±4.0cm/s, P<0.001). Tricuspid E'/A'<1 was common in group Ia compared to group Ib (19/26 (73.0%) versus 3/43 (6.97%), P=0.000). Group Ia (T2*<20ms) had high serum ferritin level compared to group Ib (T2*>20ms) (6,357±2478 microgram/L versus 2,965±2289 microgram/L (P<0.0001). By multivariate logistic regression analysis, right ventricular diastolic dysfunction (tricuspid E'/A'< 1) was associated with serum ferritin and T2* level of the thalassemic patient.
Pulsed tissue Doppler imaging (TDI) is a promising tool for quantitative assessment of myocardial function and early detection of right ventricular diastolic dysfunction in iron loaded beta thalassemia major patients assessed by cardiovascular magnetic resonance.
No relevant conflicts of interest to declare.
Author notes
Asterisk with author names denotes non-ASH members.
