A 35-year-old woman presents for a well-woman exam. She is without complaint, with BMI=22, and reports that she runs about 28 miles per week, 4-5 miles with each run, and has excellent exercise tolerance. She states, “I am in great health.” On physical examination, the NP notes a faint mid-systolic click followed by a grade 2/6 mid- to late-systolic murmur, best heard at the apex. No other abnormalities are noted. These findings are most suggestive ofA. aortic stenosisB. mit...