Cardiology > Endomyocardial Fibrosis

Background

Endomyocardial Fibrosis (EMF) is a restrictive cardiomyopathy characterized by fibrotic thickening of the endocardium, predominantly affecting the apical and inflow regions of one or both ventricles. This results in impaired ventricular filling, leading to diastolic dysfunction, atrioventricular valve regurgitation, and eventual heart failure. 

II) Classification/Types 

By Ventricular Involvement: 

• • Left Ventricular EMF 

• • Right Ventricular EMF 

• • Biventricular EMF 

By Etiology (Proposed): 

• • Idiopathic EMF: Most common, often endemic to certain regions. 

• • Secondary EMF: Associated with hypereosinophilic syndromes, parasitic infections, or autoimmune conditions. 

By Stage: 

• • Early Stage: Subclinical or mild symptoms 

• • Intermediate Stage: Fibrosis and restrictive physiology begin 

• • Advanced Stage: Severe restriction, heart failure, and valve regurgitation 

III) Pathophysiology 

EMF involves chronic inflammation leading to progressive fibrosis of the endocardium, typically starting at the ventricular apex and progressing toward the base. This fibrosis traps the chordae tendineae and impairs valve mobility, leading to atrioventricular valve regurgitation. The restricted ventricular compliance impairs diastolic filling, increases venous pressures, and causes systemic or pulmonary congestion depending on the ventricle involved. 

IV) Epidemiology 

• • Sex: Slight male predominance 

• • Age: Typically affects children and young adults 

• • Geography: Endemic in tropical regions, particularly sub-Saharan Africa, India, and South America 

• • Comorbidities: Eosinophilia, parasitic infections (e.g., filariasis, schistosomiasis), malnutrition 

Etiology

I) Causes 

• • Idiopathic (most common in endemic regions) 

• • Hypereosinophilic syndromes 

• • Parasitic infections (e.g., schistosomiasis, filariasis) 

• • Autoimmune diseases (e.g., Churg-Strauss) 

• • Malnutrition (low protein diets, cassava consumption) 

• • Genetic predisposition (under investigation) 

II) Risk Factors 

• • Living in endemic tropical areas 

• • Chronic parasitic infections 

• • Eosinophilia 

• • Poverty and malnutrition 

• • Children and young adults 

Clinical Presentation

I) History (Symptoms) 

• • Progressive dyspnea on exertion 

• • Orthopnea and paroxysmal nocturnal dyspnea (left-sided EMF) 

• • Ascites and peripheral edema (right-sided EMF) 

• • Fatigue, reduced exercise tolerance 

• • Palpitations (often due to atrial fibrillation) 

• • Weight loss in chronic cases 

II) Physical Exam (Signs) 

Vital Signs: 

• • Normal or low blood pressure 

• • Tachycardia 

Cardiac Exam: 

• • Loud S3 or S4 

• • Murmur of mitral or tricuspid regurgitation 

• • Jugular venous distention 

Pulmonary: 

• • Basal rales (left EMF) 

• • Signs of pulmonary hypertension 

Peripheral: 

• • Ascites, hepatomegaly (right EMF) 

• • Pedal edema 

• • Cachexia in advanced cases 

 Differential Diagnosis (DDx)

• • Restrictive cardiomyopathy (e.g., amyloidosis, sarcoidosis) 

• • Constrictive pericarditis 

• • Rheumatic mitral or tricuspid regurgitation 

• • Dilated cardiomyopathy 

• • Right heart failure due to pulmonary hypertension 

• • Tropical endomyocarditis 

Diagnostic Tests

Initial Tests: 

Transthoracic Echocardiogram (TTE): 

• • Apical fibrosis with obliteration of ventricular apex 

• • Atrioventricular valve regurgitation (mitral or tricuspid) 

• • Enlarged atria with preserved ventricular systolic function 

• • Diastolic dysfunction with restrictive filling pattern 

Electrocardiogram (ECG): 

• • Low voltage QRS 

• • Atrial fibrillation or flutter 

• • Nonspecific ST-T changes 

Chest X-ray: 

• • Cardiomegaly 

• • Pulmonary congestion (left EMF) 

• • Right atrial and ventricular enlargement (right EMF) 

Cardiac MRI: 

• • Confirms endocardial thickening and fibrosis 

• • Better tissue characterization than echo 

Laboratory Tests: 

• • Eosinophilia (often transient) 

• • Elevated BNP in advanced heart failure 

• • Rule out parasitic infections (stool ova and parasite, serologies) 

Endomyocardial Biopsy: 

• • Definitive diagnosis but rarely performed due to risk 

Cardiac Catheterization: 

• • Diastolic pressure equalization in both ventricles 

• • Elevated filling pressures 

• • Confirms restrictive physiology 

Treatment

I) Medical Management 

Heart Failure Management: 

• • Diuretics for fluid overload 

• • Salt restriction 

• • Aldosterone antagonists (e.g., spironolactone) 

Rate Control and Anticoagulation: 

• • Beta-blockers or calcium channel blockers for atrial fibrillation 

• • Anticoagulation if atrial fibrillation or intracardiac thrombus present 

Anti-inflammatory/Eosinophil Control (in early stage): 

• • Corticosteroids if eosinophilia present 

• • Antiparasitic agents if underlying infection is confirmed 

II) Interventional/Surgical 

Endocardial Decortication and Valve Repair/Replacement: 

• • Indicated in advanced disease with symptomatic valve regurgitation and restrictive physiology 

• • May improve symptoms and reduce atrial pressures 

• • High perioperative risk in advanced cases 

Patient Education, Screening, Vaccines

• • Educate about symptoms of worsening heart failure 

• • Encourage adherence to diuretics and follow-up visits 

• • Emphasize importance of antiparasitic treatment if applicable 

• • Nutritional counseling to prevent malnutrition 

• • Avoid strenuous physical activity 

Vaccinations: 

• • Influenza annually 

• • Pneumococcal vaccine 

• • COVID-19 vaccination 

Consults

• • Cardiology: All suspected or confirmed cases for diagnostic evaluation and long-term management 

• • Cardiothoracic Surgery: For surgical planning in advanced EMF 

• • Infectious Disease: If parasitic or eosinophilic etiology suspected 

• • Nutritionist: To address dietary deficiencies 

• • Primary Care/Internal Medicine: For comprehensive chronic disease management 

Follow-Up

• • Echocardiography: 

• • • Every 6–12 months to assess progression of fibrosis and valve function 

• • ECG monitoring: 

• • • To detect new-onset arrhythmias 

• • Functional Assessment: 

• • • NYHA classification at each visit 

• • Medication Review: 

• • • Adjust diuretics, anticoagulation, and rate control agents 

• • Reinforce Education: 

• • • Fluid restriction, signs of decompensation, and adherence