A 32-year-old asymptomatic woman has a rapidly rising, forceful pulse that collapses quickly. Which of the following is the most likely diagnosis?

This pulse is seen in aortic regurgitation.The pressure in diastole is usually 50 mm Hg or lower. This is known as a water hammer or Corrigan's pulse. A bisferiens pulse (in the bisferiens wave form there are two pressure peaks) may be present as well. Systolic blood pressure is elevated.