Q. A 60-year-old man presents at your primary care clinic with complaints of exercise intolerance over the past month. He reports needing more frequent rest during activities he was previously able to perform without difficulty. He has a ten-year history of hypertension and has been consistently taking his prescribed medications. His temperature is 98.6°F (37°C), pulse is 90 beats per minute, blood pressure is 140/90 mmHg and respiratory rate is 14 per minute. Physical examination is normal. On auscultation, a single S2 heart sound with a loud mid-systolic ejection murmur is heard in the right second intercostal space. This murmur is radiating to the carotid arteries. Given the location and characteristics of this murmur, which heart valve is likely implicated, and what should be the initial course of action?