When do Korotkoff sounds first become audible during BP measurement?

• A. At the first two consecutive beats, representing systolic pressure
• B. During cuff inflation
• C. At the end of systolic pressure
• D. Only during diastole

Answer: (A)

Korotkoff sounds are heard when the cuff pressure falls enough that the brachial artery opens enough to allow turbulent blood flow during the heart’s systole. As you deflate, the first tapping sound appears at the moment the cuff pressure is equal to the systolic pressure, marking the systolic value. In practice, many guidelines say this tapping should be audible on two consecutive heartbeats to confirm accuracy and avoid mistaking noise for a real sound. The sounds then continue and eventually disappear as the cuff pressure drops below diastolic pressure, which marks the diastolic value. So the first audible tapping during cuff deflation best corresponds to the systolic pressure.