What are the signs and symptoms of endocarditis?

Signs and Symptoms of Infective Endocarditis

Fever is the hallmark sign of infective endocarditis, occurring in up to 90% of patients, typically accompanied by a new or changing heart murmur (present in up to 85% of cases) and embolic phenomena (present in up to 25% at diagnosis). 1, 2

Cardinal Clinical Features

Fever and Constitutional Symptoms

• Fever is present in up to 90% of patients and represents the most common presenting symptom 1, 2
• Systemic symptoms accompany fever including chills, poor appetite, and weight loss 2
• Important caveat: Fever may be absent in elderly patients, those who received antibiotics before evaluation, immunocompromised individuals, or infections with less virulent organisms 1, 2

Cardiac Manifestations

• New or changing heart murmur occurs in up to 85% of patients, most commonly due to valvular insufficiency 1, 2
• Heart failure can develop from acute valve destruction or progressive valvular damage 1
• The murmur may not be present at initial presentation, particularly in early disease 3

Embolic and Vascular Phenomena

• Embolic phenomena are present in up to 25% of patients at diagnosis 2
• Septic pulmonary infarcts and abscesses occur particularly in right-sided endocarditis 1
• Splinter hemorrhages, Janeway lesions, and Osler nodes are associated findings, though these classic peripheral stigmata are actually uncommon 2, 3

Organ-Specific Presentations

Ophthalmic Signs

• Roth spots (retinal hemorrhages with pale centers) serve as a significant diagnostic clue 1

Renal Manifestations

• Glomerulonephritis can occur as an immunological phenomenon 2

Neurological Complications

• Neurological findings may result from systemic emboli or bleeding mycotic aneurysms 4

High-Risk Presentations Requiring Immediate Consideration

Consider infective endocarditis in any patient with fever and the following risk factors:

• Prior endocarditis (the most common risk factor) 3
• Prosthetic valves or intracardiac devices 2
• Intravenous drug use (past or current) - a patient with IVDU and fever should immediately trigger consideration of IE 3
• Pre-existing valvular or congenital heart disease 2
• Poor oral hygiene or recent dental procedures 3
• Multiple sites of infection with atypical organisms 3

Critical Pitfalls to Avoid

• A negative echocardiogram (even TEE) does not rule out IE, particularly in early disease 2
• Patients may present with flu-like illness without obvious cardiac findings initially 3
• Persistent fever despite appropriate antimicrobial therapy often indicates complicated endocarditis with myocardial abscesses or other serious complications 5
• The classic peripheral stigmata (Roth spots, Janeway lesions, Osler nodes) are not common and their absence should not exclude the diagnosis 3

Diagnostic Approach When Signs Are Present

When clinical features suggest endocarditis:

• Obtain at least 3 sets of blood cultures from separate sites before initiating antimicrobial therapy 1
• Start with transthoracic echocardiography (TTE), then proceed to transesophageal echocardiography (TEE) if clinical suspicion remains high 1, 2
• Early involvement of a multidisciplinary team including cardiology and infectious disease specialists is highly recommended 2