---
title: Chagas cardiomyopathy
description: What Chagas disease (American trypanosomiasis) is, how the parasite damages the heart, what the symptoms are, how the infection is detected and treated, and when urgent help is needed.
type: disease
preset: right-bundle-branch-block
morePresets: [left-anterior-fascicular-block]
wiggers: false
aliases:
  - Chagas disease
  - Chagas heart disease
  - American trypanosomiasis
  - Trypanosoma cruzi
  - T. cruzi
sources:
  - tier: guideline
    org: who
    title: Chagas disease (also known as American trypanosomiasis)
    year: 2026
    url: https://www.who.int/news-room/fact-sheets/detail/chagas-disease-(american-trypanosomiasis)
  - tier: guideline
    org: minzdrav-rf
    title: Желудочковые нарушения ритма сердца. Внезапная сердечная смерть
    year: 2025
    doi: 10.15829/1560-4071-2025-6670
    url: https://cr.minzdrav.gov.ru/view-cr/569_2
  - tier: guideline
    org: esc
    title: 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death
    year: 2022
    doi: 10.1093/eurheartj/ehac262
    url: https://doi.org/10.1093/eurheartj/ehac262
  - tier: guideline
    org: esc
    title: 2023 ESC Guidelines for the management of cardiomyopathies
    year: 2023
    doi: 10.1093/eurheartj/ehad194
    url: https://doi.org/10.1093/eurheartj/ehad194
  - tier: reference
    org: msd-manuals
    title: Chagas Disease
    year: 2025
    url: https://www.msdmanuals.com/professional/infectious-diseases/extraintestinal-protozoa/chagas-disease
  - tier: reference
    org: msd-manuals
    title: Chagas Disease (Consumer Version)
    year: 2025
    url: https://www.msdmanuals.com/home/infections/parasitic-infections-extraintestinal-protozoa/chagas-disease
  - tier: review
    title: 'Chagas Cardiomyopathy: An Update of Current Clinical Knowledge and Management: A Scientific Statement From the American Heart Association'
    year: 2018
    doi: 10.1161/CIR.0000000000000599
    url: https://doi.org/10.1161/CIR.0000000000000599
sources_checked: 2026-10-13
review: null
---

Chagas disease, or American trypanosomiasis, is an infection caused by the parasite Trypanosoma cruzi, a single-celled protozoan.<Cite n={[1, 5]} /> It is named after the Brazilian physician Carlos Chagas, who first diagnosed it in a person in 1909.<Cite n={1} />

The disease occurs mainly in Latin America, but because people move between countries the infection is now also found in many other countries, including the United States, Canada and countries in Europe.<Cite n={1} /> It mainly affects the heart and the digestive tract.<Cite n={2} /> Years or decades after infection, some people develop cardiomyopathy: the heart becomes enlarged and weak, impulse conduction is disturbed and dangerous heart rhythm disorders appear.<Cite n={[1, 2, 6]} /> How the impulse normally travels through the heart is explained in the article on the [conduction system of the heart](../../anatomy/conduction-system/).

<Diagram name="chagas-cardiomyopathy">
  <p slot="normal">
    Normally all chambers of the heart are of normal size, and the impulse passes freely to the
    ventricles through the <Structure id="bundle-of-his">bundle of His</Structure>, its branches
    and the Purkinje network.<Cite n={2} /> The diagram marks the
    <Structure id="right-bundle-branch">right bundle branch</Structure> and the anterior fascicle
    of the <Structure id="left-bundle-branch">left bundle branch</Structure>: the places where
    conduction problems in Chagas disease most often begin.<Cite n={5} />
  </p>
  <p slot="disease">
    Heart involvement in Chagas disease usually begins with conduction abnormalities: right bundle
    branch block or left anterior fascicular block; the diagram marks both.<Cite n={5} /> Chronic
    cardiomyopathy often follows: all chambers of the heart enlarge, an aneurysm (a bulge of
    thinned wall) forms at the apex of the left ventricle, and damage to the conduction system
    progresses.<Cite n={5} />
  </p>
</Diagram>

## Why it happens

<Patient>

The parasite is carried by triatomine bugs, also called kissing bugs.<Cite n={[1, 2, 5]} /> They live in cracks in the walls and roofs of houses and outbuildings in rural and suburban areas, hide during the day and feed on animal and human blood at night.<Cite n={1} /> A bug usually bites an exposed area of skin, such as the face, and leaves its droppings close to the bite.<Cite n={1} /> The parasites enter the body when the person rubs the droppings into the itchy bite, other breaks in the skin, the eyes or the mouth.<Cite n={1} />

The infection can also be passed on in other ways: from mother to baby during pregnancy or birth, through food and drinks contaminated with the parasite, through blood transfusion, organ transplantation and laboratory accidents.<Cite n={[1, 5]} /> Infection through food typically causes outbreaks.<Cite n={1} /> In recent years, transmission from mother to baby has become the main route of infection worldwide.<Cite n={1} />

The parasite also lives in animals, such as opossums, armadillos, dogs, rats and many others.<Cite n={5} /> That is why the infection cannot be eradicated, and the public health aim is to stop it being passed on to people.<Cite n={1} />

</Patient>

<Student>

The infection has three stages: acute, chronic indeterminate (latent), and chronic with cardiac or gastrointestinal involvement.<Cite n={5} /> In the chronic phase the parasites are hidden mainly in the heart and digestive muscles.<Cite n={1} /> They are probably still present in chronic disease, and an autoimmune reaction may also contribute to organ damage.<Cite n={5} />

According to the Russian Ministry of Health guideline, cardiac involvement in the acute phase is acute [myocarditis](../myocarditis/), and in the chronic phase a cardiomyopathy with chronic heart failure develops.<Cite n={2} /> The 2023 ESC guidelines list Chagas disease among the non-genetic causes of [dilated cardiomyopathy](../dilated-cardiomyopathy/): an infectious cause, after parasitic myocarditis.<Cite n={4} />

</Student>

<HeartModel highlight={['left-ventricle', 'right-ventricle', 'left-atrium', 'right-atrium']} />

## Symptoms

<Patient>

The acute phase lasts about two months after infection.<Cite n={1} /> In most cases there are no symptoms, or they are mild and non-specific: fever, headache, enlarged lymph glands, pallor, muscle pain, difficulty breathing, swelling, and abdominal or chest pain.<Cite n={1} /> Much less often, a hardened skin lesion (chagoma) appears where the parasite entered, or the eyelids of one eye become swollen and purplish (Romaña's sign).<Cite n={[1, 5]} /> In most people the symptoms of the acute phase go away without treatment, but for a few, usually children, it is fatal, for example because of a severe infection of the heart causing heart failure.<Cite n={6} />

A long period without symptoms follows: the parasites are in the body, but the ECG and tests of the heart and digestive system are normal.<Cite n={6} /> Many people stay in this stage for the rest of their life.<Cite n={6} />

One to three decades after infection, some people develop heart problems, and some develop digestive or nervous system problems.<Cite n={1} /> The heart may become enlarged and weak, so the person tires easily and is short of breath.<Cite n={6} /> If the heart's electrical system is affected, there may be fainting, irregular heart rhythms and sudden cardiac arrest.<Cite n={6} /> The disease can lead to worsening [heart failure](../heart-failure/) and sudden death.<Cite n={1} /> When the oesophagus is affected, swallowing becomes difficult; when the colon is affected, there may be severe constipation.<Cite n={6} />

</Patient>

<Student>

Cardiac disease usually starts with conduction abnormalities: <Structure id="right-bundle-branch">right bundle branch</Structure> block or left anterior fascicular block.<Cite n={5} /> Chronic cardiomyopathy often follows, with enlargement (dilatation) of all chambers, apical aneurysms and progression of conduction system lesions.<Cite n={5} /> The disease is characterised both by conduction disorders up to complete [AV block](../av-block/) and by life-threatening ventricular arrhythmias.<Cite n={2} />

Patients may present with heart failure, syncope or thromboembolism; sudden death may occur from heart block or [ventricular arrhythmia](../ventricular-tachycardia/).<Cite n={5} /> An AHA scientific statement calls Chagas disease an important cause of heart failure, stroke, arrhythmia and sudden death.<Cite n={7} />

</Student>

## How it is diagnosed

<Patient>

In the acute phase there are many parasites in the blood: they can be seen in a blood smear under a microscope, or their genetic material (DNA) can be found in the blood.<Cite n={[5, 6]} /> Later the parasites are seldom seen in the blood, so two or more different blood tests for antibodies to the parasite are done.<Cite n={6} /> One antibody test can be positive in a person who is not infected, so a positive result is confirmed with a different test.<Cite n={6} />

If the infection is confirmed, the heart is checked: an [ECG](../../diagnostic/ecg/) and a chest X-ray, and an [echocardiogram](../../diagnostic/echocardiography/) if these show changes or there are symptoms suggesting heart disease.<Cite n={5} /> Difficulty swallowing or constipation leads to tests of the digestive tract.<Cite n={[5, 6]} /> Many infected people are identified when they donate blood.<Cite n={5} />

</Patient>

<Student>

Acute infection is confirmed by light microscopy of thin or thick blood smears.<Cite n={5} /> PCR is used when parasitaemia is likely to be high: in acute disease, in congenital infection, and after transmission via blood transfusion, transplantation or laboratory exposure.<Cite n={5} />

Chronic infection is confirmed serologically: positive results from at least two different serological tests are needed, ideally using different methods.<Cite n={5} /> Serological tests are sensitive but may give false-positive results, for example in leishmaniasis.<Cite n={5} /> After diagnosis, a person without symptoms has a screening ECG with a rhythm strip and a chest radiograph; abnormalities on these or symptoms suggesting heart disease lead to echocardiography.<Cite n={5} />

When examining a patient with ventricular arrhythmias, the Russian Ministry of Health guideline advises looking for signs of reversible causes, including skin manifestations of infectious diseases, among which it names Chagas disease.<Cite n={2} /> In the 2023 ESC guidelines, AV block in a patient with dilated cardiomyopathy is an ECG feature that should raise suspicion of myocarditis, especially Chagas disease, Lyme disease and diphtheria.<Cite n={4} />

</Student>

## How it is treated

<Patient>

There are two antiparasitic medicines against the parasite itself.<Cite n={[1, 6]} /> They kill the parasite and fully cure the disease if treatment starts early, in the acute phase, including when the infection was passed on from the mother.<Cite n={1} /> The longer a person has been infected, the less effective they are, and in older people side effects are more frequent and can be severe.<Cite n={1} />

In the chronic phase, treatment can prevent or slow the progression of the disease, so adults with the infection, especially those without symptoms, should be offered it.<Cite n={1} /> Girls and women of childbearing age are treated before or after pregnancy so that the infection is not passed on to the baby.<Cite n={1} /> These medicines are not given during pregnancy.<Cite n={[1, 5]} />

Antiparasitic medicines do not reverse heart or digestive tract damage that has already developed.<Cite n={[5, 6]} /> Heart damage is treated like the corresponding conditions: [heart failure](../heart-failure/) is treated, a pacemaker is fitted for heart block, antiarrhythmic medicines are used for rhythm disorders, and a heart transplant is also possible.<Cite n={[5, 6]} /> Lifelong follow-up is usually needed.<Cite n={1} /> The doctor decides which treatment is needed.

There is no vaccine against Chagas disease.<Cite n={1} /> Prevention includes spraying houses and the area around them with long-acting insecticides, improving houses, plastering walls and keeping homes clean so that bugs do not settle in them.<Cite n={[1, 5]} /> Bed nets and good hygiene when preparing, storing and eating food also help.<Cite n={1} /> Blood and organ donors are screened, as are newborns and other children of infected mothers.<Cite n={1} /> Travellers are rarely infected; the risk is lowered by not sleeping in adobe houses or by using a bed net, and by avoiding fresh sugar cane juice.<Cite n={5} />

</Patient>

<Student>

Antiparasitic treatment is indicated for acute, congenital and reactivated infection, and for children with chronic indeterminate infection.<Cite n={5} /> The younger the patient and the earlier treatment starts, the more likely parasitological cure is.<Cite n={5} /> Once signs of advanced cardiac or gastrointestinal disease appear, antiparasitic drugs are not recommended.<Cite n={5} /> The WHO advises offering treatment to adults with chronic infection, especially those without symptoms; in other cases the possible benefit is weighed against the duration of treatment and adverse reactions.<Cite n={1} />

In Chagas cardiomyopathy with symptomatic premature ventricular complexes or ventricular tachycardia, an antiarrhythmic drug should be considered to reduce the arrhythmia burden (IIa, C).<Cite n={[2, 3]} /> In recurrent symptomatic monomorphic VT or ICD shocks for it, when antiarrhythmic drugs are ineffective, contraindicated or not tolerated, catheter ablation in specialised centres should be considered (IIa, C).<Cite n={[2, 3]} /> In symptomatic VT when antiarrhythmic drugs are ineffective or not tolerated, implantation of a cardioverter-defibrillator may be considered (IIb, C).<Cite n={[2, 3]} /> The Russian Ministry of Health guideline notes that studies on the benefits and risks of an ICD in these patients are conflicting.<Cite n={2} />

</Student>

## When to call an ambulance

Chagas disease can lead to fainting, dangerous heart rhythm disorders, thromboembolism and sudden death from heart block or ventricular arrhythmia.<Cite n={5} /> The Russian Ministry of Health guideline advises calling an ambulance if an episode of arrhythmia comes with dizziness, weakness, feeling faint, loss of consciousness or a fast heartbeat.<Cite n={2} /> Severe shortness of breath is also a reason to call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK): this is the site's general safety rule, repeated at the bottom of every page. If a person suddenly collapses, does not respond and is not breathing normally, call the emergency number straight away and start resuscitation; how to do this is explained in the article on [ventricular fibrillation](../ventricular-fibrillation/). Other warning signs are described in the articles on [ventricular tachycardia](../ventricular-tachycardia/), [AV block](../av-block/) and [heart failure](../heart-failure/).

<Quiz />