During examination of a 49-year-old male schoolteacher who presents with a swelling in the neck, palpation by a bounding pulse. Which test would be most likely to establish a possible cause of the underlying condition?

The pulse is bounding when the pulse pressure is magnified because of a wide difference between the systolic and diastolic pressure. It may be due to aortic incompetence, PDA, or noncardiac causes that result in increase in cardiac output and decreased peripheral resistance (e.g., hyperthyroidism, peripheral AV fistula, or anemia).