What are the symptoms of infective endocarditis?

Symptoms of Infective Endocarditis

Fever is the hallmark and most common symptom 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, 3

Cardinal Clinical Features

Constitutional Symptoms

• Fever is present in up to 90% of patients and represents the most common presenting symptom 1, 2, 3
• Systemic symptoms frequently accompany fever, including chills, poor appetite, and weight loss 1, 3
• Important caveat: Fever may be absent in elderly patients, after antibiotic pre-treatment, in immunocompromised patients, or in IE involving 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, 3
• Heart failure can develop from acute valve destruction or progressive valvular damage 2, 3
• Cardiac conduction abnormalities, including heart block, may indicate valve ring abscess 3

Embolic and Vascular Phenomena

• Embolic phenomena are present in up to 25% of patients at diagnosis 1, 3
• Splinter hemorrhages, Roth spots (retinal hemorrhages with pale centers), and Janeway lesions are classic vascular and immunological findings 1, 3
• Embolic stroke or transient ischemic attack can occur from septic emboli 3

Organ-Specific Presentations

Pulmonary Manifestations (Right-Sided IE)

• Persistent fever, bacteremia, and multiple septic pulmonary emboli are the usual manifestations of right-sided IE 4
• Chest pain, cough, or hemoptysis may occur from septic pulmonary infarcts and abscesses 4, 2, 3
• Isolated right heart failure is rare but can be caused by pulmonary hypertension or severe right-sided valvular regurgitation 4

Neurological Manifestations

• Neurological findings may result from systemic emboli or bleeding mycotic aneurysms 3
• Intracranial hemorrhage can result from bleeding mycotic aneurysms 3
• In neonates, neurological signs include seizures, hemiparesis, or apnea 4

Renal Manifestations

• Glomerulonephritis can occur as an immunological phenomenon 1, 3

Ophthalmic Signs

• Roth spots serve as a significant diagnostic clue 2, 3

Special Population Considerations

Neonatal Infective Endocarditis

• Clinical manifestations are variable and nonspecific, often indistinguishable from septicemia or congestive heart failure 4
• Feeding difficulties, respiratory distress, tachycardia, and hypotension are common 4
• Septic emboli resulting in osteomyelitis, meningitis, or pneumonia are common 4
• Notable absence: Osler nodes, Roth's spots, Janeway lesions, and splinter hemorrhages are not mentioned in neonatal cases 4

Intravenous Drug Users

• Should be suspected of having right-sided endocarditis when presenting with fever and pulmonary symptoms 3

Critical Diagnostic Caveats

• A negative echocardiogram (even TEE) does not rule out IE, particularly in early disease 1
• Persistent fever despite appropriate antibiotics should raise concern for complications such as valve ring abscess, mycotic aneurysm, or treatment failure 3
• Persistent bacteremia, especially with typical IE organisms like Staphylococcus aureus or viridans streptococci, should raise suspicion for infective endocarditis 3
• The clinical presentation can be highly variable and nonspecific, requiring a high index of suspicion 5, 6

When to Maintain High Clinical Suspicion

• Patients with prosthetic valves or intracardiac devices are at high risk 1
• Patients with pre-existing valvular or congenital heart disease are at high risk 1
• Intravenous drug users with fever and pulmonary symptoms 3
• Any patient with persistent bacteremia with typical IE organisms 3