Effect of oxidative stress and serum Antioxidant level on the Cardiac function of thalassemic patients

Abstract

Thalassemia is the world's most common hereditary disease caused by mutations affecting synthesis of hemoglobin.

The cardiac damage is mainly attributed to excessive iron deposition through the formation of oxygen free radicals.

This study was carried out on 30 thalassemic patients 18 femal and 12 males, aged from 7 month, to 20 years, attending the Hematology clinic in Pediatric Hospital, Cairo University. They were subjected to laboratory investigation and echocardiographic evaluation. Data were compared with those obtained in I 0 age and sex-matched normal subjects. An increase in serum malonyldialdehyde (MDA), iron and ferritin levels were observed in patients, while serum total antioxidant level was comparable in patients and controls. The echocardiographic examanation revealed that there was increase in some cardiac dimension. Estemation of cardiac function revealed that there was abnormal left ventricular systolic and diastolic functions, as there was significantly decreased stroke volume (SV) and shortened aortic deceleration time in patient when compared to controls, as well as there was an increase in A wave, decreased EJA ratio and shortened IVRT in patient when compared to controls. Right ventricular systolic and diastolic function was also estemated, and revealed that severe pulmonary hypertension is a late complication in thalassemia, as there was comparable pulmonary flow parameters in patients and controls, however TR was a prominent finding in patients (P-value = 0.002) and PASP had a significantly higher mean value (27 ± 7.2) in relation to controls (21.2 ± 2.6). Correlation was done between echocardiographic data and serum totaf antioxidant, MDA and ferritin level. This illustrates that with decreased serum total antioxidant level, the pattern of that of heart failure with increase EJA ratio that lead to aortic dilatation. On the other hand with increased serum MDA level there was an increase in pulmonary artery diameter reflecting the effect of oxidative stress on the heart of thalassemic patients. The finding of this study also suggest that chelation therapy does not completely protect patients with thalassemia from myocardial damage due to iron related cardiac toxicity.