Infectious endocarditis Quiz: Ace Your Exams

A 46-year-old woman presents to the emergency department with a 2-week history of fever, fatigue, and an erythematous rash over the palms and soles. Past medical history is significant for mitral valve prolapse. The patient has not traveled recently. She is sexually active and uses condoms consistently. Temperature is 38.8°C (101.8°F), blood pressure is 125/78 mm Hg, pulse is 88/min, respiratory rate is 18/min, and oxygen saturation is 96% on room air. On physical examination, the patient has several small erythematous non-tender macules over the palmar surface over the hands and on the plantar surface of the feet, and several reddish-brown lesions under the nail beds. Cardiac auscultation is significant for 4/6 late systolic murmur with mid systolic click best heard over the apex, which is a change from prior murmur 2/6. Blood cultures are drawn and a transthoracic echocardiogram (TTE) is performed which does not show vegetation. Which of the following is the best next step in the evaluation?