A 63-year-old woman develops exertional angina and has had two episodes of syncope. Examination shows a systolic ejection murmur with radiation to the carotids and a soft S2. Which of the following is the most likely diagnosis?

Aortic stenosis is most likely to be associated with angina pectoris, syncope, and exertional dyspnea. Exertional syncope is caused by either systemic vasodilation in the presence of fixed or inadequate cardiac output, an arrhythmia, or both. Syncope at rest is most frequently a result of a transient ventricular tachyarrhythmia.