Heart & Thalassemia . R.Miri,MD, Interventional Cardiologist

Heart & Thalassemia Cardiac complications represent the primary cause of mortality / morbidity

Heart & Thalassemia iron is normally transported by transferrin in iron overload, transferrin becomes completely saturated, so free iron enters the cardiomyocytes  

Heart & Thalassemia Inside the cardiomyocytes, iron is stored in 3 different forms: ferritin Hemosiderin labile cellular iron Labile cellular iron is the most accessible to iron chelators but also the most toxic form, inducing cardiomyocyte apoptosis and finally, cardiac dysfunction.

Heart & Thalassemia The susceptibility to iron toxicity varies greatly among thalassemia cases patients with the same iron load present with various severity of cardiac injury.

Heart & Thalassemia

Heart & Thalassemia Early identification of ventricular dysfunction, before the appearance of symptoms, can alter the prognosis of these patients

Heart & Thalassemia cardiomyopathy that progressively leads to heart failure and death.

Heart & Thalassemia Cardiomyopathy phenotypes: Dilated phenotype, with left ventricular dilatation and impaired contractility(Viral Myocarditis) Restrictive phenotype, with restrictive left ventricular filling, pulmonary hypertension, and right heart failure( Iron Overload). 

dilated cardiomyopathy 4.5% of cases developed a clinical picture consistent with acute myocarditis at a mean age of 15±3 years, because of their repetitive exposure to a significant, transfusion-associated viral burden

Restrictive cardiomyopathy a) Due iron overload results from: ineffective erythropoiesis peripheral hemolysis increased intestinal iron absorption main cause is the repetitive blood transfusions b) anemia / bone marrow expansion cause volume overload and increased cardiac output, with consequent development of eccentric ventricular hypertrophy

Heart & Thalassemia Our study is an observational and cross sectional study including 145 patients with thalassemia major with no signs or symptoms of heart failure

Echo Measurment LV (end-diastolic / end-systolic) diameters & volumes IVS & LV posterior wall thicknesses (end-diastolic / end-systolic) LV ejection fraction LA volume Mitral early (E) & late (A) diastolic velocities E/A ratio isovolumetric relaxation time

LV diastolic function parameters early diastolic wave (E wave) late diastolic wave (A wave) deceleration time of E wave (DT) isovolumicrelaxation time (IVRT) E wave to A wave (E/A) ratio

LV systolic function parameters EF Sympsons Method

Echo Measurment LA volume indexed by body surface area was significantly higher suggests an increase in LVEDP, reflecting an alteration in diastolic function

independent predictor of Echo Measurment An study with 6,657 individuals showed that LA volume / body surface area ratio ≥ 34 ml/m² is an independent predictor of death heart failure atrial fibrillation ischemic stroke

LV diastolic function parameters higher E/A ratio were suggestive of restrictive diastolic pattern and consequently stiff LV wall

LV diastolic function parameters

LV diastolic function parameters the decreased DT of E wave related to the impaired relaxation of LV. The IVRT was shortened which is the reflection of the impaired LV relaxation pattern most probably caused by iron overload stiffness of LV wall.

LV systolic function evaluation: LV systolic posterior wall thickening was lower Simpson method showed LV systolic dysfunction

Pulmonary Hypertension Seen in 15% of the cases, evauated by TR PH results from : Hypercoagulability endothelial dysfunction reduce NO availability elastic tissue disorders lung tissue injury

Angiography In 13 of the 145 was done ,age:12-25 yr Normal coronaries arteries despite of severe iron disposition.