Classification and Clinical Features of Infective Endocarditis

Definition and Pathophysiology of Infective Endocarditis

Infective endocarditis (IE) is a serious condition characterized by infection of the heart's inner lining, usually affecting the heart valves. It is caused by bacterial or fungal pathogens that colonize the bloodstream and adhere to damaged endocardium.

Classification of Infective Endocarditis

1. Based on Cause

• Bacterial Endocarditis: Caused primarily by Staphylococcus aureus, Streptococcus viridans, and other species.
• Fungal Endocarditis: Less common but associated with immunocompromised patients.

2. Based on Mode of Acquisition

• Native Valve Endocarditis (NVE): Occurs in patients without prosthetic heart valves.
• Prosthetic Valve Endocarditis (PVE): Develops after valve replacement surgery.
• Intravenous Drug Use (IVDU) Endocarditis: Commonly affects the tricuspid valve.

Clinical Features of Infective Endocarditis

General Symptoms

• Fever with chills
• Fatigue and weakness
• Weight loss
• Night sweats

Cardiac Symptoms

• New or worsening heart murmur
• Heart failure symptoms (dyspnea, edema)

Embolic Manifestations

• Neurological: Stroke, brain abscesses
• Dermatological: Janeway lesions, Osler nodes
• Renal and Spleen: Renal infarcts, splenomegaly

Diagnosis and Management

Diagnosis involves blood cultures, echocardiography, and clinical scoring systems such as the Duke Criteria. Management includes targeted antibiotic therapy and surgical intervention in severe cases.