A 62-Year-Old Man Comes to the Office for Decreased Exercise

A 62-year-old man comes to the office for decreased exercise tolerance. Over the past six months, he has noticed progressively worsening shortness of breath while mild exertion. He also becomes short of breath when lying in bed at night. His temperature is 36.4°C (97.5°F) , pulse is 85/min, respirations are 18/min, and blood pressure is 156/55 mm Hg. Cardiac examination shows a high-pitched, decrescendo murmur that occurs immediately after S2 and is heard best along the left sternal border. There is an S3 gallop. Carotid pulses are strong. Which of the following is the most likely diagnosis?

A) Aortic regurgitation
B) Aortic stenosis
C) Atrial septal defect
D) Coarctation of the aorta
E) Mitral regurgitation
F) Mitral stenosis
G) Pulmonary stenosis
H) Tricuspid regurgitation