BENEFIT: Evaluation of the Use of Antiparasital Drug (Benznidazole) in the Treatment of Chronic Chagas' Disease

Inclusion Criteria:

• Consenting patients (between 18 and 75 years of age) with serological evidence ofChagas infection (any combination of 2 positive tests) and that have one or more ofthe following:

• Abnormal electrocardiogram with at least two components (complete RBBB or LBBB; leftanterior or posterior fascicular block; ventricular premature beat; first degreeatrioventricular [AV] block; Mobitz type I AV block; sinus bradycardia; primary ST-Tchanges; abnormal Q waves; low voltage QRS; or atrial fibrillation);

• Abnormal ECG (Mobitz type II, advanced or third degree AV block);

• Increased cardiothoracic ratio (> 0.50);

• Complex ventricular arrythmias on 24 hour ambulatory ECG monitoring;

• Evidence of regional wall motion abnormality or reduced global left ventricularsystolic function or increased left ventricular and diastolic diameter on 2D-Echo.

Exclusion Criteria: Patients will be excluded if having:

• NYHA heart failure class IV or decompensated heart failure

• Evidence of concomitant coronary artery disease (CAD) or other etiology of dilatedcardiomyopathy

• Previous treatment with antitrypanosomal agents or an accepted indication forantiparasitic therapy

• Inability to comply with follow-up visits

• History of severe alcohol abuse within 2 years

• Known chronic renal or hepatic insufficiency or hepatic insufficiency

• Pregnancy or breast feeding

• Megaesophagus with swallowing impairment

• Other severe disease significantly curtailing life expectancy