Which parasitic infection, if left untreated, can lead to cardiomyopathy and fatal cardiac arrhythmias in the United States?

Which parasitic infection, if left untreated, can lead to cardiomyopathy and fatal cardiac arrhythmias in the United States?

• A. American trypanosomiasis (Chagas disease)
• B. Giardiasis
• C. Toxoplasmosis
• D. Malaria

Answer: (A)

Chagas disease, caused by Trypanosoma cruzi, can progress from a mild initial infection to chronic cardiac involvement. In the chronic phase, the parasite persists in heart muscle and the autonomic nervous system, leading to inflammation and fibrotic damage that disrupts electrical conduction and weakens the myocardium. This often produces dilated cardiomyopathy, apical left ventricular aneurysm, and a range of conduction abnormalities and arrhythmias, which can be fatal. In the United States, Chagas disease isn’t endemic, but cases occur in immigrants and travelers, and untreated infection can silently progress to serious heart disease over years. The other parasitic infections listed do not typically cause cardiomyopathy or malignant arrhythmias: Giardia causes GI symptoms; Toxoplasma commonly affects the eyes or brain in specific settings; malaria presents with fever and anemia. When a patient has unexplained cardiomyopathy with a history suggestive of exposure to endemic areas, Chagas disease should be considered.

Chagas disease, caused by Trypanosoma cruzi, can progress from a mild initial infection to chronic cardiac involvement. In the chronic phase, the parasite persists in heart muscle and the autonomic nervous system, leading to inflammation and fibrotic damage that disrupts electrical conduction and weakens the myocardium. This often produces dilated cardiomyopathy, apical left ventricular aneurysm, and a range of conduction abnormalities and arrhythmias, which can be fatal.

In the United States, Chagas disease isn’t endemic, but cases occur in immigrants and travelers, and untreated infection can silently progress to serious heart disease over years. The other parasitic infections listed do not typically cause cardiomyopathy or malignant arrhythmias: Giardia causes GI symptoms; Toxoplasma commonly affects the eyes or brain in specific settings; malaria presents with fever and anemia. When a patient has unexplained cardiomyopathy with a history suggestive of exposure to endemic areas, Chagas disease should be considered.