Image of the Week: Fever, heart murmur, and Janeway lesions

A 55-year-old woman presents with a low-grade fever, a new heart murmur, and Janeway lesions one week following a dental cleaning, and a preliminary diagnosis of infective endocarditis is made. Prophylactic antibiotics are administered prior to dental cleanings to prevent endocarditis in patients considered to be high-risk. Which of the following valvular conditions requires prophylactic antibiotics prior to ...