Which of the following is NOT a minor criterion in the Duke criteria for diagnosing infective endocarditis?

• A. Fever
• B. Predisposing condition
• C. Vascular phenomenon
• D. Endocardial involvement on echocardiography

Answer: (D)

Understanding the Duke criteria means recognizing which findings provide strong evidence of infective endocarditis (major criteria) versus those that merely raise suspicion (minor criteria). Major criteria include direct evidence of endocardial involvement, such as echocardiographic findings of vegetation, abscess, or new valvular regurgitation, or microbiologic data that meet specific criteria. Minor criteria are less specific and include fever, a predisposing heart condition or IV drug use, vascular phenomena, immunologic phenomena, and microbiologic evidence that doesn’t meet major criteria.

Endocardial involvement on echocardiography is a major criterion because it provides direct imaging confirmation of infection affecting the heart valves or endocardium. Fever, predisposing conditions, and vascular phenomena are all considered minor criteria since they are nonspecific clues rather than definitive proof of endocarditis.