Endocarditis is an infection of the inner lining of the heart (endocardium) and heart valves. It occurs when bacteria or other microbes enter the bloodstream and attach to damaged heart tissue. Infective endocarditis is a serious and potentially life-threatening condition that requires early diagnosis and aggressive antibiotic therapy.
Types of Endocarditis
- Acute infective endocarditis: Rapid onset, severe symptoms, caused by highly virulent organisms like Staphylococcus aureus.
- Subacute infective endocarditis: Slower onset, less severe, commonly caused by streptococci.
- Prosthetic valve endocarditis: Occurs in patients with artificial heart valves.
Risk Factors
- Damaged or artificial heart valves
- Congenital heart disease
- IV drug use
- Poor dental hygiene
- Previous endocarditis
- Long-term IV catheters
Common Causative Organisms
- Streptococcus viridans
- Staphylococcus aureus
- Enterococci
- HACEK group (fastidious gram-negative bacteria)
Symptoms
- Fever and chills
- Fatigue and weakness
- Shortness of breath
- Persistent cough
- Heart murmurs
- Weight loss
- Petechiae (tiny red spots)
Diagnosis
Diagnosis is based on clinical signs and specific investigations.
- Blood cultures – essential to identify organism
- Echocardiography (TTE/TEE) – detects vegetations
- ESR and CRP – raised in infection
- Duke criteria – standard diagnostic tool
Treatment
Endocarditis requires long-term, high-dose intravenous antibiotics. Therapy depends on the organism and valve type.
Empirical Therapy
- Native valve endocarditis: Vancomycin + ceftriaxone
- Prosthetic valve endocarditis: Vancomycin + gentamicin + rifampicin
Definitive Therapy (Based on Culture Results)
1. Streptococcal Endocarditis
- Ceftriaxone or penicillin G
- Gentamicin may be added in severe cases
2. Staphylococcal Endocarditis
- MSSA: Nafcillin or oxacillin
- MRSA: Vancomycin or daptomycin
3. Enterococcal Endocarditis
- Ampicillin + gentamicin
- Vancomycin if penicillin allergy
Treatment duration is typically 4–6 weeks.
When is Surgery Needed?
- Heart failure due to valve damage
- Large vegetations (>10 mm)
- Persistent infection despite antibiotics
- Prosthetic valve involvement
- Recurrent embolic events
Complications
- Heart failure
- Stroke
- Kidney damage
- Septic emboli
- Arrhythmias
Prophylaxis (Prevention)
Antibiotic prophylaxis is recommended for high-risk individuals undergoing dental or invasive procedures.
- Amoxicillin 1 hour before procedure
- If allergic: Clindamycin
Patient Counseling
- Complete full antibiotic course
- Maintain good dental hygiene
- Avoid IV drug use
- Inform doctors about heart valve disorders
- Seek immediate help for fever or breathlessness
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