Asymptomatic severe aortic stenosis: silence of the lambs?

A 62-year-old man with a past medical history presents to the cardiology clinic for evaluation after a routine echocardiogram obtained for evaluation of palpitations. His clinical history is remarkable for infrequent self-terminating episodes of regular rapid heartbeat over the last 2 months. The events are not associated with chest discomfort, dyspnea, lightheadedness, dizziness, or flushing. He denies any symptoms of rest or exertional chest discomfort or dyspnea, recent syncope or presyncopal sensations, or paroxysmal nocturnal dyspnea. He states that he has been reducing his physical activity over the last several years because of fatigue. His past medical history is remarkable for hyperlipidemia and erectile dysfunction. He has no drug allergies. His medications include a multivitamin, simvastatin, and tadalafil. He smokes 1 pack of cigarettes per day and has a >30 pack-year smoking history. He neither drinks alcohol nor uses illicit drugs. He is a retired store clerk.