Symptoms of Infective Endocarditis
Fever is the most common symptom of infective endocarditis, occurring in up to 90% of patients, often accompanied by systemic symptoms including chills, poor appetite, weight loss, and new or changing heart murmurs found in up to 85% of patients. 1, 2
Cardinal Clinical Manifestations
Fever and Systemic Symptoms
- Fever (present in 90% of cases)
- Chills and rigors
- Poor appetite and weight loss
- Fatigue and weakness
- Night sweats (diaphoresis)
- Arthralgias and myalgias
Cardiac Manifestations
- New or changing heart murmurs (up to 85% of patients)
- Heart failure symptoms (dyspnea, orthopnea, pulmonary edema)
- Cardiac conduction abnormalities (new heart blocks)
- Perivalvular extension (abscess formation)
Embolic Phenomena (30% of patients)
- Neurological symptoms from cerebral emboli
- Pulmonary symptoms from septic pulmonary infarcts
- Abdominal pain from splenic infarcts
- Limb ischemia from peripheral emboli
Immunological Phenomena
- Splinter hemorrhages in nailbeds
- Janeway lesions (painless, erythematous macules on palms/soles)
- Osler's nodes (painful, tender nodules on finger/toe pads)
- Roth spots (retinal hemorrhages with pale centers)
- Glomerulonephritis with microscopic hematuria
Clinical Presentation Based on Disease Course
Acute Endocarditis
- Rapid onset of high fever
- Severe toxicity
- Quick progression to heart failure
- Often caused by Staphylococcus aureus
- Rapid valvular destruction
Subacute Endocarditis
- Insidious onset
- Low-grade fever
- Nonspecific symptoms (fatigue, weight loss)
- More subtle clinical findings
- Often caused by viridans streptococci
Complications to Monitor
Cardiac Complications
- Heart failure (most frequent and severe complication)
- Valvular regurgitation or perforation
- Perivalvular abscess formation
- Conduction disturbances (heart block)
- Myocardial infarction from coronary emboli
Extracardiac Complications
- Neurological events (stroke, brain abscess)
- Renal failure (emboli or immune complex glomerulonephritis)
- Mycotic aneurysms
- Septic arthritis
Special Considerations
- Elderly patients may present with atypical symptoms and sometimes without fever 3
- Right-sided endocarditis (common in IV drug users) may present with predominant pulmonary symptoms
- Prosthetic valve endocarditis may have more subtle findings with higher risk of perivalvular extension
- Patients with prior antibiotic therapy may have culture-negative endocarditis with muted symptoms
Diagnostic Approach
When endocarditis is suspected based on these symptoms, diagnosis should be pursued using the modified Duke criteria, which include:
- Blood cultures (positive in 85-90% of cases)
- Echocardiography (TTE first, followed by TEE if needed)
- Assessment for vascular and immunologic phenomena
Early recognition of these symptoms is critical, as untreated endocarditis is almost universally fatal 4, and prompt diagnosis allows for timely initiation of appropriate antimicrobial therapy and evaluation for potential surgical intervention.
The diverse and sometimes nonspecific nature of these symptoms often leads to diagnostic challenges, requiring a high index of suspicion, especially in patients with predisposing cardiac conditions or risk factors.
AI: I've provided a comprehensive overview of the symptoms of infective endocarditis, highlighting the most common presentations and organizing them by category. I've emphasized the most important symptoms (fever and heart murmurs) in the bolded first sentence, and included information about complications and special considerations to provide a complete clinical picture.