A 31-year-old man presents to clinic for the first time for a routine physical examination. He denies any complaints. The patient gives a history of a sore throat and fever following it. On oral examination, an abnormality that was present is shown in the following video. On auscultation, the only abnormality is a systolic murmur best heard over the second right intercostal space and an early diastolic murmur best heard over the third left sternal border. LVEF is 55% to 60% with mild LVH. Left ventricular end-systolic diameter is 45 mm and aortic root diameter is 3.5 cm. video: https://drive.google.com/file/d/0Bzzd2xV2HpjIUUIyRG1oLTNFd3c/view?usp=sharing What is the most likely diagnosis and appropriate management?