الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Regular blood transfusion in patients of thalassemia major leads to left
ventricular remodeling which is a powerful risk factor for ventricular arrhythmias,
congestive heart failure and sudden death.
However, conventional echocardiography detects abnormalities in LV
systolic function only in the advanced irreversible stages when a clear LV
remodeling/hypertrophy is evident.
Preclinical alterations of LV systolic function have been demonstrated in
thalassemic patients with normal EF. Hence, early detection of such preclinical LV
changes represents a clinical finding that would justify aggressive chelation
therapy aiming at reducing cardiovascular risk.
2D STE is a new technique that enables assessment of regional myocardial
deformation by assessment of strain and strain rate. In contrast to TDI, 2D STE is
an angle-independent technique that may allow an accurate assessment of
segmental myocardial deformation.
This study was designed to evaluate LV systolic and diastolic functions in β-
thalassemia patients using 2D STE based longitudinal strain and strain rate
imaging and correlation with ferritin level.
75 individuals were enrolled, divided into two groups; group I (patients
group): included 50 thalassemic patients. group II (control group): included 25
healthy ages and sex matched volunteers free from cardiovascular risk factors.
Participants in the study were subjected to:
Full history taking, thorough clinical examination and 12 lead ECG.
2D Echocardiography, M-mode and Doppler examination were performed;
LV dimensions were measured including LVEDD, LVESD, IVSD,
LVPWD, LVMI and left ventricular ejection fraction.
Pulsed wave doppler echocardiography was performed for measuring mitral
inflow velocities. Mitral annular TDI was performed in the septal and lateral
mitral annuli.
Strain and strain rate values were measured by 2D STE.
Results of the current study showed that:
Regarding conventional echocardiographic parameters: LVESD, LA,
LVM, LVMI, LA/Ao and MAPSE in thalassemic patients highly
significantly exceeded that of controls.
Regarding the left ventricular systolic function as assessed by strain and
strain rate and LV ejection fraction:
No significant difference between the studied groups regarding LV ejection
fraction. The study showed subtle or subclinical impairment of LV systolic
function in thalassemic group as evidenced by highly significant reduction
of LV systolic longitudinal strain in patient group.
Moreover, significant reduction of LV strain was found in thalassemic
patients.
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Also, there was significant reduction of systolic strain rate values in
thalassemic patients compared with controls which confirms subtle
impairment of LV systolic function.
It was noted that, the systolic impairment in thalassemic patients detected by
strain and strain rate occurs earlier than impairment of ejection fraction that
results from changes in stroke volume and systolic pump performance.
Regarding the left ventricular diastolic function as measured by strain
rate and TDI:
The findings of this study indicated that significant LV diastolic impairment
was common in thalassemic group than control group, as shown by
significant difference of E/A ratio, and changes in TDI derived indices
namely E/e` ratio.
Regarding serum ferritin level:
The current study showed that serum ferritin level was higher in thalassemic
patients than controls and is negatively related to LVESD, LVEDD, global
LV systolic strain and global LV late diastolic strain rate but positively
related to LVMI.
Cutoff point of serum ferritin at which LV diastolic dysfunction starts to
occur is 3000 micrograms/l.
Cutoff point of serum ferritin at which LV systolic dysfunction starts to
occur is 4100 micrograms/l.