Endomyocardial Fibrosis - Causes, Symptoms, Diagnosis, and Treatment

Introduction

Endomyocardial fibrosis, or EMF, is an idiopathic disease of the tropical as well as the subtropical parts of the world and is characterized by the development of restrictive cardiomyopathy and fibrotic changes in the endocardium, primarily affecting the cardiac apex. As of today, the exact etiological factor and cause of endomyocardial fibrosis remain unknown. The condition resembles eosinophilic cardiomyopathy as well as a hypereosinophilic syndrome, and thus endomyocardial fibrosis at times is considered a part of the disease process that includes eosinophilic endomyocardial fibrosis.

What Are the Causes of Endomyocardial Fibrosis?

The exact etiology behind endomyocardial fibrosis remains unknown to date. Endomyocardial fibrosis is generally seen in the lower sectors of society, and there is no bias between the two genders. There are several studies and clinical trials that have come up with a few of the possible causes of endomyocardial fibrosis. Mentioned below are a few of the causes of endomyocardial fibrosis.

• Eosinophilia (increased eosinophil count in the blood).

• Infections due to pathogens such as plasmodium species, microfilaria, Schistosoma, helminths, toxoplasma, and arbovirus.

• Environmental exposure.

• Cerium (a chemical element).

• Immunological changes.

• Anti-myosin antibodies.

• Rheumatic heart disease.

• Dressler syndrome.

• Post-cardiac transplant rejection.

• Genetics.

What Are the Signs and Symptoms of Endomyocardial Fibrosis?

The heart has four chambers- two upper sections, the right and left atrium, and two lower sections, the right and left ventricles. Parallel to four chambers, the heart has four valves: mitral, tricuspid, aortic, and pulmonary. Valves are a crucial part of the heart’s structure. They open and close as the blood passes through them. They mainly regulate the entry and exit of blood into the heart’s various chambers. The valves have flaps or leaflets that open and close. Valves with three leaflets open and close simultaneously. In order to avoid any sort of backflow of blood, the leaflets close, and vice versa is why they open.

Endomyocardial fibrosis, or EMF, involves both the right and left ventricles in half of the cases reported. The right ventricle is hardly involved in endomyocardial fibrosis. The primary characteristic of this condition- is fibrotic obliteration of the ventricle. The changes then lead to constrictive endocarditis. Endomyocardial fibrosis typically extends from the posterior leaflet of the mitral valve. Furthermore, in advanced stages, there is the presence of endocardial calcific deposits along with thrombus formation.

The clinical manifestations of endomyocardial fibrosis depend on the involvement of the cardiac chamber and the severity of the condition. Mentioned below are a few of the signs and symptoms of endomyocardial fibrosis.

• Acute carditis.

• Febrile illness.

• Cardiogenic shock.

• Heart failure.

• Arrhythmias.

• Thromboembolic disease.

• Ascites.

• Hepatomegaly (enlargement of the liver).

• Lower extremity edema.

• Elevated jugular venous pressure.

• Tricuspid regurgitation.

• Giant V waves.

• Rapid Y waves.

• Dyspnea (difficult or labored breathing).

• Fatigue.

• Cachexia (a condition characterized by severe weight loss, muscle wasting, weakness, and loss of appetite often seen in chronic illnesses).

• Orthopnea (shortness of breath or difficulty breathing when lying flat).

• Mitral regurgitation.

• Pulmonary hypertension.

• The abnormal rhythm of the heart.

• Palpitations.

• Distended neck veins.

• Abdominal swelling.

• Discomfort while sitting up.

• Shortness of breath.

• Chest pain.

• Fatigue.

• Dizziness.

• Palpable veins of the legs and ankles.

• Profuse sweating in the forehead, scalp, and palms.

• Increased urinary output.

• Dry cough.

• Bloated.

• Loss of appetite.

• Nausea.

• Hard abdomen.

• Decreased ability to perform exercises.

• Swelling of the stomach.

• Difficulty in thinking.

• Confusion.

• Memory loss.

• Disoriented feeling.

How to Diagnose Endomyocardial Fibrosis?

There are not a great number of diagnostic tests and assessment tools to determine the presence of endomyocardial fibrosis. A few of them are mentioned below.

• Electrocardiogram: In advanced stages of endomyocardial fibrosis, the QRS complexes, as well as the nonspecific ST and T, wave abnormalities, are usually observed along with atrioventricular blocks and intraventricular conduction delay. The right or left bundle branch blocks are additionally seen. Observation of left atrial enlargement with atrial arrhythmias is seen in advanced cases of endomyocardial fibrosis.

• Echocardiography: This is a diagnostic modality where the pathological hallmarks of the disease may be seen. Microbubble contrast helps in enhancing the left ventricle and thus allows better imaging quality. Furthermore, atrioventricular valve abnormalities can be identified along with the obliteration of the right ventricle and right atrial thrombi. Endomyocardial fibrosis of the posterior mitral valve leaflet can lead to a case of mitral regurgitation. The left and right-sided atrium show enlargement.

• Transmitral inflow using Doppler echocardiography.

• Isovolumetric relaxation time evaluation.

• Cardiac hemodynamics.

• Cardiac catheterization.

• Electron beam computed tomography scan.

• Cardiovascular magnetic resonance imaging.

• Imaging with late gadolinium enhancement.

• Contrast-enhanced magnetic resonance imaging.

• Chest x-ray.

• Stethoscopic examination revealing an abnormal murmur of the heart.

• Stress test.

How to Treat Endomyocardial Fibrosis?

The treatment and management of endomyocardial fibrosis are currently extremely challenging. Atrial fibrillation is one of the poorest prognostic factors. There is only a limited role that exists for immunosuppressive therapy. Symptomatic therapy may be provided through diuretic therapy. Patients suffering from endomyocardial fibrosis may benefit to a small extent from angiotensin-converting enzyme inhibitors as well as beta-blockers. Anticoagulation therapy is additionally recommended in endomyocardial fibrosis patients who have a thrombus. Surgery has the potential to drastically increase the rate of survival in patients with advanced heart failure. The most generally used management approach is endocardectomy which is along with valvular replacement. The prognosis for endomyocardial fibrosis is very poor because the incidence and chances of sudden cardiac death by arrhythmia or any kind of thromboembolic disease as well as end-stage heart failure, are usually very high. Thus, the mean rate of survival is roughly two years.

Conclusion

Endomyocardial fibrosis refers to the fibrotic changes that occur in the heart, which eventually hamper the smooth functioning of the cardiovascular system, especially the heart. This disease affects the innermost lining of the heart and the heart chambers called the endocardium. The causes are vast, with idiopathic being one of the factors. The signs and symptoms that the patient presents with are parallel to the underlying cardiovascular changes that are brought about due to the alterations in the endocardium. There are several diagnostic measures to determine the presence of the disease, along with a few management options. The surgical intersection is one of the most positive and promising management options for endomyocardial fibrosis.