Infective endocarditis — structured clinical encounter

A nine-year-old previously well girl with a history of repaired tetralogy of Fallot presents to the emergency department with two weeks of low-grade fever, fatigue and anorexia, and one day of breathlessness on exertion. On examination she is febrile at 38.6 degrees, tachycardic at 110 beats per minute, and has a new harsh early diastolic murmur at the left sternal edge. Three sets of blood cultures drawn before antibiotics grow penicillin-susceptible viridans streptococci in all bottles. Echocardiography shows a mobile vegetation on the aortic valve with mild aortic regurgitation. A diagnosis of infective endocarditis is made. You are the paediatric registrar working through the assessment and management with the examiner.