What is Endomyocardial Fibrosis?
Endomyocardial fibrosis (EMF) is a condition that’s not so common in North America but can be frequently found in the developing world’s tropical and subtropical areas. This disease causes fibrosis, or the thickening and scarring, of the inner layer of the heart’s left and right ventricles, this results in a condition called restrictive cardiomyopathy which is a disease that restricts the heart’s ability to expand and fill with blood.
In parts of Africa where EMF is commonly found, it’s a significant reason for heart failure, accounting for around 20% of cases. At present, doctors aren’t sure of the exact cause or development process of the disease. However, its characteristics are similar to conditions like eosinophilic cardiomyopathy (a heart disease where a type of white blood cell called eosinophils become too numerous and cause damage) and hypereosinophilic syndrome (a group of conditions where eosinophils are overproduced).
Because of these similarities, it’s sometimes believed that EMF, along with another condition called Loffler endocarditis (an inflammation of the heart’s inner lining caused by eosinophil buildup), might be part of the same disease process.
What Causes Endomyocardial Fibrosis?
The exact cause of endomyocardial fibrosis (EMF), a heart condition where parts of the heart thicken and harden, is still not fully understood. However, there are several factors that experts believe might contribute to the development of this condition.
One factor is a high level of a type of white blood cell called eosinophils. This is similar to a condition called Loffler endocarditis, where chronic high levels of eosinophils cause damage and hardening in parts of the heart. However, not everyone with EMF has high levels of eosinophils.
Infections could be another factor. Some people think that certain parasites and viruses, including Plasmodium species, Microfilaria, Schistosoma, Helminths, arboviruses, and Toxoplasma, might contribute to EMF – but no one type of organism has been definitively linked to this condition.
Exposure to environmental substances like cerium, a chemical element found in certain soils and foods, could also be part of the story. Some areas where people develop EMF have high levels of this chemical.
Another factor could be the immune system. Some people with EMF have been found to have anti-myosin antibodies in their blood. However, anti-myosin antibodies can also be found in other heart conditions such as rheumatic heart disease, Dressler syndrome, and after a heart transplant rejection, so it’s not a definitive marker for EMF.
Lastly, there could be a genetic element or family history factor at play. It’s still not clear whether this is because of something specific in the genes, something in the environment that affects families, or a combination of both. These are all areas of ongoing research aiming at understanding EMF better.
Risk Factors and Frequency for Endomyocardial Fibrosis
Endomyocardial fibrosis, a heart disease, is predominantly found in warmer parts of the world like Africa, Asia, and South America. This disease generally impacts young adults who are less economically advantaged. Studies from Uganda suggest that it mostly affects people around 10 and 30 years of age. As for whether it affects men or women more, the research isn’t conclusive yet.
Signs and Symptoms of Endomyocardial Fibrosis
Endomyocardial fibrosis (EMF) is a heart condition whose symptoms depend on which part of the heart is affected and how severe the condition is. Initially, a person may experience a feverish illness, and in extreme cases, shock due to inadequate blood flow. If they survive the first phase, symptoms may progress into more chronic stages of the disease, typically leading to advanced complications such as heart failure, irregular heartbeats, and diseases caused by blood clots.
If EMF primarily affects the right side of the heart, typical symptoms can include:
- Fluid buildup in the abdomen (ascites)
- Enlarged liver (hepatomegaly)
- Swelling of the lower extremities
- Elevated neck vein pressure
- Backflow of blood from the right side of the heart to the right atrium (tricuspid regurgitation)
In contrast, if the left side of the heart is primarily affected, symptoms can include:
- Shortness of breath
- Fatigue
- Weight loss and muscle wasting (cachexia)
- Difficulty breathing while lying flat (orthopnea)
- Backflow of blood from the left side of the heart to the left atrium (mitral regurgitation) due to impact on certain heart structures
Additionally, symptoms of high blood pressure in the lungs and certain abnormal heart sounds often manifest in patients with EMF.
Testing for Endomyocardial Fibrosis
When it comes to diagnosing and understanding the advanced stages of Endomyocardial Fibrosis (EMF), a heart disease that affects the inner lining of the heart, doctors employ a number of methods to help them examine what’s going on in your body.
An electrocardiogram, a medical device that measures electrical activity of the heart, can help doctors spot unusual heart rhythms and heart muscle stress. In severe cases of EMF, the electrocardiogram might reveal low voltages and irregularities in the rhythm.
One of the most common ways of diagnosing EMF is Echocardiography, a test that uses sound waves to create pictures of the heart’s chambers, valves, walls and blood vessels. This method allows doctors to see issues such as blockages in the heart’s chambers and blood clots. They can also find anything unusual about your heart valves and observe the pattern of your blood flow. Echo contrast, a liquid that is injected into your bloodstream for better ultrasound visibility, improves the image quality for diagnosis.
Certain changes, such as thickening and stiffening in the ventricle walls, can also be seen on Echocardiography. If one side of the heart is worse than the other, this can create different issues. For example, in left-sided EMF, the ventricle’s pointy end (known as the apex) is unable to move freely due to thickening and stiffening. In this case, the base of the ventricle moves more to help the heart work.
An echocardiography technique called Transmitral inflow, Doppler echo is used to monitor the blood flow through the mitral valve, check for abnormalities and observe how well the heart is filled with blood.
Cardiac catheterization is a procedure used to diagnose issues in the heart’s chambers. It involves threading a thin tube through an artery or vein to the heart. This can be useful to check pressure and blood flow in the heart and identify any restrictions.
Electron Beam Computed Tomography Scanning or CT scan provides more detailed images and can show thickened or stiffened areas in the heart. It can also give doctors a preview into how the disease has affected the heart’s structure and impaired its function.
Cardiovascular Magnetic Resonance Imaging (MRI) is another method of viewing the heart in detail. Here, doctors use an MRI to find the affected areas in the heart, taking advantage of the contrast created by a dye injected into your veins.
A chest x-ray can provide information about the size of the heart, thickness of the heart walls and congestion in your chest, which could signify an underlying issue such as heart disease.
Finally, certain blood tests could provide extra information about your condition. For example, having a high number of a certain type of white blood cell (eosinophilia) or a lower than normal amount of protein in your blood (hypoalbuminemia) can be found in some patients with EMF.
Treatment Options for Endomyocardial Fibrosis
Treating patients with an advanced illness can be quite tough, as about one-third to half of them unfortunately pass away within two years. A heart condition known as atrial fibrillation often indicates a poorer outlook; however, strategies to control the heart rate can help ease symptoms for patients.
Immune-suppressing therapies only have a limited role in treating these cases. This is because the majority of the patients don’t seek help until it’s well past the point where something might be done about the initial inflammation of the heart muscle (myocarditis).
Fortunately, patients can still experience symptom relief thanks to diuretic therapy, which helps to reduce fluid build-up in the body. Patients could also see improvements from use of medication such as ACE inhibitors and beta-blockers. If medical imaging reveals a blood clot (thrombus), doctors might recommend anticoagulation therapy, which stops more blood clots from forming.
Surgery can also greatly help some patients, particularly those with severe heart failure. The most common surgical approach is endocardectomy, often combined with replacement of a heart valve if needed. Remember though, this sort of surgery comes with a substantial risk, as the death rates can be up to 15-20%. Despite this, for some patients, the potential benefits outweigh the risks.
What else can Endomyocardial Fibrosis be?
Here are some conditions that may affect the heart:
- Anthracycline toxicity
- Carcinoid heart disease
- Fabry disease
- Fatty infiltration
- Glycogen storage disease
- Gaucher disease
- Hurler disease
- Idiopathic cardiomyopathy (a disease without an identifiable cause)
- Metastatic cancers (cancers that have spread from their original location)
- Radiation
What to expect with Endomyocardial Fibrosis
The outlook for people with Endomyocardial Fibrosis (EMF), a rare heart condition, is unfortunately not very good. This is because there is a high chance of sudden death due to irregular heartbeat (arrhythmia), blockages in the blood vessels caused by blood clots (thromboembolic disease), or very severe heart failure. Because of these risks, on average, people with this condition tend to live for about 2 years after diagnosis.
