The three major criteria for endocarditis include which items?

• A. Two positive blood cultures
• B. Positive transesophageal echocardiography
• C. A new murmur
• D. All of the above

Answer: (D)

The key idea is the Duke criteria used to classify infective endocarditis. Among the major criteria, there are two that reflect bacteremia and evidence of infection on the valve itself. Two positive blood cultures drawn appropriately, with typical organisms, show persistent bacteremia that seeds the heart valves. Transesophageal echocardiography provides direct evidence of endocardial involvement by revealing vegetations, valvular abscesses, or other intracardiac abnormalities. A new murmur represents new valvular regurgitation, which occurs when the infection damages the valve and causes regurgitant flow. Since all three findings meet the major criteria for endocarditis, the option that includes two positive blood cultures, positive TE echocardiography, and a new murmur is the best choice.