Stress testing and working capacity in Chagas' cardiomyopathy

Area of Science:

• Cardiology
• Infectious Diseases
• Exercise Physiology

Background:

• Chagas' disease is a parasitic infection with potential cardiac complications.
• Early diagnosis of Chagas' cardiomyopathy is crucial for timely intervention.
• Standard diagnostic procedures may not detect early-stage cardiac involvement.

Purpose of the Study:

• To evaluate the utility of exercise electrocardiogram (EKG) stress testing in early Chagas' disease diagnosis.
• To assess exercise EKG response and working capacity in patients with positive Chagas' serology.
• To determine the impact of digoxin on exercise-induced arrhythmias and working capacity.

Main Methods:

• Seventy patients with positive Chagas' disease serology underwent bicycle-ergometer stress testing.
• Exercise EKG monitored for arrhythmias and working capacity was measured.
• Digoxin was administered orally to a subset of patients to assess its effects.

Main Results:

• Exercise EKG identified information not obtainable through other diagnostic methods.
• Stress testing induced or exacerbated ventricular arrhythmias in some patients.
• Oral digoxin did not significantly increase exercise-induced ventricular extrasystoles and improved working capacity in most patients.

Conclusions:

• Exercise EKG stress testing is valuable for the early diagnosis of Chagas' cardiomyopathy.
• The test is particularly indicated for patients with Chagas' infection and early-stage cardiomyopathy.
• Measuring working capacity helps quantify functional impairment in individual patients.