Effect of Metoprolol on Thalassemia Cardiomyopathy

Inclusion Criteria: * documented LVEF \< 50% by echocardiography * B thalassemia * No decompensated heart failure for at least 4 weeks (hospitalization for CHF, worsening lower extremity edema, worsening dyspnea on exertion, , and orthopnea) * have no evidence of acute myocarditis and * hemoglobin level above 7 gr⁄dL. Exclusion Criteria: * pulse rate below 60/min * systolic blood pressure less than 90 mmHg * evidence of peripheral vascular disease * major depression, history of asthma, PR interval more than 240 msec, second or third degree AV block * major medical diseases including diabetes mellitus requiring insulin injection, hypothyroidism, hypoparathyroidism, chronic renal failure (glomerular filtration rate below 30 ml/min), hepatic cirrhosis, hepatitis-B and hepatitis-C, positive tests for human immunodeficiency virus, and other hemoglobinopathies