TABLE II. Stages in the development of heart failure due to Chagas disease.

Stages *	Findings
A	Patients present no symptoms of heart failure and no structural heart disease (normal ECG and chest X-ray)
B1	Asymptomatic patients with ECG changes (arrhythmias or conduction disorders); mild echocardiographic contractile abnormalities with normal global ventricular function can also be present
B2	Patients with decreased left ventricular ejection fraction who have never had any signs or symptoms of heart failure
C	Patients with left ventricular dysfunction and prior or current symptoms of heart failure
D	Patients with symptoms of heart failure at rest, refractory to maximised medical therapy (NYHA IV) that require specialised and intensive interventions

*: I Latin American Guidelines for the diagnosis and treatment of Chagas heart disease: executive summary; ECG: electrocardiogram; NYHA: New York Heart Association.