What are the signs and symptoms of endocarditis?

Signs and Symptoms of Infective Endocarditis

Fever is the hallmark symptom of infective endocarditis, occurring in up to 90% of patients, typically accompanied by a heart murmur (present in up to 85% of cases), and embolic phenomena (present in up to 25% at diagnosis). 1

Cardinal Clinical Features

Constitutional Symptoms

• Fever remains the most common presenting symptom, though it may be absent in elderly patients, those who received antibiotics before evaluation, immunocompromised individuals, or infections with less virulent organisms 1
• Systemic symptoms include chills, anorexia, weight loss, and fatigue 1, 2
• Back pain can be a helpful diagnostic clue 2

Cardiac Manifestations

• New or changing heart murmur is found in up to 85% of patients, most commonly due to valvular insufficiency 3, 1
• Heart failure can develop from acute valve destruction or progressive valvular damage 3, 4
• Patients may present with acute decompensation or insidious onset 3

Embolic and Vascular Phenomena

• Embolic events occur in up to 25% of patients at diagnosis and can affect multiple organ systems 1
• Peripheral manifestations include:
  • Petechiae (search carefully during physical examination) 2
  • Splinter hemorrhages 1
  • Janeway lesions (though uncommon) 5
  • Osler nodes (though uncommon) 5

Immunologic Phenomena

• Roth spots on funduscopic examination 1, 2
• Glomerulonephritis with urinary abnormalities compatible with nephritis 1, 2
• Splenomegaly 2

Organ-Specific Presentations

Endocarditis can masquerade as various organ system disorders 2:

• Pulmonary: Particularly in right-sided endocarditis with septic pulmonary infarcts and abscesses 3
• Central nervous system: Embolic stroke, particularly associated with Streptococcus gallolyticus 4
• Renal: Acute renal failure and nephritis 4
• Ophthalmic: Roth spots 1
• Orthopedic: Back pain and musculoskeletal complaints 2
• Abdominal: Unusual presentations like left upper quadrant pain from splenic involvement 6

Laboratory Findings

• Anemia 2
• Elevated erythrocyte sedimentation rate 2
• Urinary abnormalities suggesting nephritis or embolization 2

Critical Pitfalls to Avoid

A negative echocardiogram, even transesophageal echocardiography (TEE), does not rule out infective endocarditis, particularly in early disease. 1

• Classic peripheral stigmata (Roth spots, Janeway lesions, Osler nodes) are actually uncommon and should not be relied upon for diagnosis 5
• Fever may be completely absent in high-risk populations, yet endocarditis can still be present 1
• Blood cultures may be negative if antibiotics were administered before collection 3
• Persistent fever despite appropriate antimicrobial therapy often indicates complicated endocarditis with myocardial abscesses, requiring urgent evaluation for cardiac surgery 7

High-Risk Clinical Scenarios Requiring Heightened Suspicion

• Intravenous drug users (past or current) presenting with fever should trigger immediate consideration of IE 5
• Patients with prosthetic valves or intracardiac devices 1
• Pre-existing valvular or congenital heart disease 1
• Healthcare-associated invasive procedures within 6 months before presentation 4
• Multiple sites of infection with atypical organisms 5
• Poor dentition 5

Immediate Evaluation Requirements

When infective endocarditis is suspected, obtain at least 3 sets of blood cultures from separate sites before initiating antimicrobial therapy 3, perform thorough cardiac auscultation with daily re-examination 2, and arrange echocardiography as the cornerstone diagnostic test, starting with transthoracic echocardiography (TTE) and proceeding to TEE if clinical suspicion remains high despite normal TTE 1.