Cardiology

Understanding Tropical Endomyocardial Fibrosis

At a Glance

Tropical endomyocardial fibrosis is a rare heart condition in which scar tissue stiffens the inner lining of one or both lower chambers. This limits blood filling and can cause heart-failure symptoms; the cause is not known but may involve inflammation, infections, environment, and genetics.

A diagnosis of Tropical Endomyocardial Fibrosis (EMF) can feel overwhelming, especially because it is a rare and often misunderstood condition. It frequently affects children, adolescents, and young adults in specific parts of the world, which adds a significant emotional weight for families and caregivers ^[1]^[2]. While the diagnosis is serious, understanding the biology of how the heart is changing is the first step in managing the journey ahead.

What is Tropical EMF?

Tropical Endomyocardial Fibrosis is a type of restrictive cardiomyopathy, a disease where the heart muscle may remain strong initially but becomes stiff ^[3]. In EMF, the inner lining of the heart’s lower chambers (ventricles) develops thick, tough scar tissue known as fibrosis ^[4].

This scarring usually begins at the very tip of the heart, called the apex, and can eventually fill up or “obliterate” the space inside the ventricle ^[1]. Because this scar tissue cannot stretch like healthy muscle, the heart cannot expand properly to fill with blood. This leads to a backup of pressure in the body or lungs, causing symptoms of heart failure even if the heart’s initial “squeeze” is normal ^[5].

Who is Affected?

EMF is primarily found in tropical regions across the globe, particularly in Sub-Saharan Africa, South Asia (especially parts of India), and South America (such as Brazil and Colombia) ^[1]^[6].

Age: It most commonly affects children and teenagers. In some historically studied areas like Yaoundé, the median age at diagnosis was just 10 years old ^[2]. However, it is also seen in adults, with some patients diagnosed in their 20s through their 60s ^[7].
Setting: Most people diagnosed with EMF come from rural, lower-income areas, often in tropical forest zones ^[8]^[1].
Impact: In some historically high-prevalence rural communities (like regions of Mozambique), EMF has been responsible for up to 20% of all heart failure cases, though this does not represent universal national prevalence ^[9].

How the Disease Progresses

The biological mechanism of EMF is thought to involve overlapping features, though not every patient experiences an identical timeline ^[3]^[6]:

Inflammation and Injury: The process is hypothesized to begin with an inflammatory response that damages the endocardium (the inner lining of the heart).
Clot Formation: In response to this damage, small blood clots (thrombi) may form on the injured surface ^[4].
Fibrosis (Scarring): Over time, dense, permanent scar tissue replaces the inflammation. This tissue can also pull on the heart’s valves, causing them to leak ^[6].

The disease can affect the right ventricle, the left ventricle, or both. When the right side is heavily scarred, it often leads to a swollen abdomen (ascites); when the left side is affected, it more commonly causes fluid in the lungs and shortness of breath ^[10].

Investigating the Causes

Researchers have spent decades trying to pinpoint exactly why some people develop this scarring while others in the same environment do not. Currently, there is no single proven cause; instead, doctors believe it may result from a combination of factors ^[6]^[11]. Please be explicitly reassured that you did not cause this disease through your diet or living conditions.

Factor	What the Research Says
Eosinophils	These are a type of white blood cell involved in allergies and parasite defense. While high levels (eosinophilia) can damage the heart, they aren’t found in every EMF patient, so their exact role is still debated ^[12]^[13].
Diet (Cassava)	A diet heavy in cassava or other tubers has been observationally linked to EMF in some studies, but it has not been proven to be a direct cause ^[8]^[14].
Parasites	Infections like schistosomiasis or other tropical parasites are frequently found in EMF patients. They may trigger the initial inflammation that leads to scarring ^[15].
Poverty/Environment	EMF is observationally associated with poverty and living in rural tropical areas. Factors like poor nutrition or specific minerals in the soil/water may play a role ^[6]^[16].
Genetics	Some researchers suspect a genetic “vulnerability” that makes certain people’s hearts more likely to scar when exposed to environmental triggers ^[11].

Current medical consensus views EMF as a “multi-factorial” disease, meaning several of these triggers likely work together ^[6]. While the “why” is still being researched, modern imaging like Echocardiography and Cardiac MRI allows doctors to see the scarring clearly and create a management plan tailored to how the disease has affected your heart ^[10]^[17].

Common questions in this guide

What is tropical endomyocardial fibrosis, and how does it affect the heart?

Tropical endomyocardial fibrosis is a rare form of restrictive cardiomyopathy. Scar tissue develops along the inner lining of one or both lower heart chambers, often beginning at the tip of the heart, and makes it harder for the chambers to expand and fill with blood.

What symptoms can tropical EMF cause?

Symptoms depend partly on which side of the heart is affected. Scarring of the right ventricle can cause abdominal swelling from fluid buildup, while left-sided disease can cause fluid in the lungs and shortness of breath; either side can contribute to heart-failure symptoms.

What causes tropical endomyocardial fibrosis?

There is no single proven cause. Researchers think inflammation and small blood clots may lead to permanent scarring, with possible contributions from parasitic infections, environmental or nutritional exposures, and genetic susceptibility.

How do doctors look for endomyocardial fibrosis?

Echocardiography and cardiac MRI can show scarring, narrowing or obliteration of the ventricular tip, and whether the right ventricle, left ventricle, or both are involved. Doctors may also review symptoms, travel or residence history, parasite exposure, and blood findings such as eosinophil levels.

Does everyone with tropical EMF have high eosinophils or a parasite infection?

No. High eosinophil levels are not found in every person with EMF, and although parasitic infections are often found in affected patients, their exact role is uncertain. A clinician can decide whether parasite testing is appropriate based on the person's history and findings.

What should I ask about treatment or surgery for tropical EMF?

Management depends on the extent of scarring, which ventricles are involved, valve leakage, blood clots, and signs of heart failure. A specialist team can explain whether evaluation at an experienced center or a procedure such as endocardial decortication should be considered.

Get notified when new evidence is published on Tropical endomyocardial fibrosis.

We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.

Key takeaways

Tropical EMF is a restrictive heart condition in which scar tissue develops along the inner lining of one or both ventricles, often beginning at the heart’s apex and limiting filling.
The disease may affect the right ventricle, left ventricle, or both, causing problems such as abdominal fluid buildup, fluid in the lungs, shortness of breath, or other heart-failure symptoms.
No single cause has been proven; inflammation, parasitic infections, environmental or nutritional exposures, eosinophilia, and genetic susceptibility may contribute, and the disease is not known to be caused by a patient’s choices.
Echocardiography and cardiac MRI help doctors assess the scar tissue, apical obliteration, ventricular involvement, and effects on heart function.
Specialist evaluation may include checking for blood clots, valve leakage, active inflammation, and signs of heart failure when planning management.

References (17)

1
Comprehensive Assessment of Endomyocardial Fibrosis with Cardiac MRI: Morphology, Function, and Tissue Characterization.
de Carvalho FP, Azevedo CF
Radiographics : a review publication of the Radiological Society of North America, Inc 2020; (40(2)):336-353 doi:10.1148/rg.2020190148.
PMID: 32004118
2
[Endomyocardial fibrosis in Cameroon: Echocardiographic and clinical description of a pediatric series in Yaoundé].
Chelo D, Nguefack F, Menanga AP, et al.
Archives de pediatrie : organe officiel de la Societe francaise de pediatrie 2016; (23(2)):128-35.
PMID: 26724978
3
Cardiac involvement in hypereosinophilia.
Roblová L, Kuchynka P, Kuchař J, Paleček T
Vnitrni lekarstvi 2020; (66(3)):44-49.
PMID: 32972164
4
Left ventricle endomyocardial fibrosis: a case report.
Soares RR, Avelar MCM, Zanetti SL, et al.
Journal of medical case reports 2023; (17(1)):361 doi:10.1186/s13256-023-04056-z.
PMID: 37568222
5
Endomyocardial fibrosis: a restrictive cardiomyopathy in developing countries.
Vásquez-Rodríguez JF, Medina-Mur RI, Giraldo LE, et al.
Archivos de cardiologia de Mexico 2021; (91(2)):196-201 doi:10.24875/ACM.20000150.
PMID: 33887758
6
Tropical Endomyocardial Fibrosis: Natural History, Challenges, and Perspectives.
Grimaldi A, Mocumbi AO, Freers J, et al.
Circulation 2016; (133(24)):2503-15 doi:10.1161/CIRCULATIONAHA.115.021178.
PMID: 27297343
7
Endomyocardial fibrosis in Sudan: clinical and echocardiographic features.
Khalil SI, Khalil S, Tigani SE, Saad HA
Cardiovascular journal of Africa 2017; (28(4)):208-214 doi:10.5830/CVJA-2016-079.
PMID: 28906536
8
Endomyocardial fibrosis in Sub Saharan Africa: The geographical origin, socioeconomic status, and dietary habits of cases reported in Yaounde, Cameroon.
Chelo D, Nguefack F, Mbassi Awa HD, Kingue S
Annals of pediatric cardiology 2015; (8(3)):202-9 doi:10.4103/0974-2069.164693.
PMID: 26556966
9
Endomyocardial fibrosis: past, present, and future.
Duraes AR, de Souza Lima Bitar Y, Roever L, Neto MG
Heart failure reviews 2020; (25(5)):725-730 doi:10.1007/s10741-019-09848-4.
PMID: 31414216
10
Application of Routine Echocardiography Combined with Contrast-Enhanced Echocardiography in the Diagnosis of Endomyocardial Fibrosis.
Wu B, Yang Y, Zhao P
Discovery medicine 2023; (35(179)):1052-1063 doi:10.24976/Discov.Med.202335179.101.
PMID: 38058070
11
Challenges in addressing the knowledge gap on endomyocardial fibrosis through community-based studies.
Mbanze J, Cumbane B, Jive R, Mocumbi A
Cardiovascular diagnosis and therapy 2020; (10(2)):279-288 doi:10.21037/cdt.2019.08.07.
PMID: 32420110
12
Eosinophilia to endomyocardial fibrosis: Documentation of a case.
Bhasin D, Gupta SK, Arava S, Kothari SS
Annals of pediatric cardiology 2018; (11(2)):207-210 doi:10.4103/apc.APC_143_17.
PMID: 29922022
13
Structural and functional cardiac changes in endomyocardial fibrosis treated with endomyocardial resection: Disease progression captured by multimodality imaging.
Gibson GT, Majure DT, Hartman A, et al.
Echocardiography (Mount Kisco, N.Y.) 2021; (38(9)):1641-1646 doi:10.1111/echo.15153.
PMID: 34296459
14
Geographical variation in the clinical presentation of endomyocardial fibrosis in India?
Gupta PN, Kunju SM, Rajan B, et al.
Indian heart journal 2018; (70(1)):56-65 doi:10.1016/j.ihj.2016.12.015.
PMID: 29455789
15
Parasitic infections and the development of endomyocardial fibrosis: systematic review of case reports and case series.
Aizeque A, Kihunyu AM, Odusola OD, et al.
Tropical medicine and health 2025; (53(1)):112 doi:10.1186/s41182-025-00793-7.
PMID: 40836258
16
Endomyocardial fibrosis of the right ventricle in a patient with schistosomiasis: a case report.
Espinoza Romero C, Lima ICV, Hotta VT, et al.
European heart journal. Case reports 2022; (6(8)):ytac312 doi:10.1093/ehjcr/ytac312.
PMID: 35949701
17
An Unusual Cause of Unstable Angina: Endomyocardial Fibrosis.
Tapia Martínez M, Velasco EB, Romano M, et al.
European journal of case reports in internal medicine 2025; (12(12)):005878 doi:10.12890/2025_005878.
PMID: 41377797

This page is for informational purposes only and does not constitute medical advice. A cardiologist or specialist team should interpret your symptoms and heart imaging and guide decisions about testing and treatment.