What happens to Korotkoff sounds during cuff deflation?

During cuff deflation, Korotkoff sounds are indicative of changes in blood flow as pressure in the cuff decreases. The sounds occur due to the turbulent flow of blood through the partially occluded artery. Initially, as the pressure gradually drops, these sounds begin as sharp and clear "thumps" which correspond to systolic blood pressure.

As the cuff continues to deflate, the sounds transition through different phases. The muffled whooshing sound indicates the point where the vessel is becoming less constricted but is still experiencing turbulent flow. This sound reflects the diastolic pressure as the artery is increasingly open, but the turbulence is still present, albeit in a less pronounced manner. Therefore, the change to a muffled whooshing sound during cuff deflation effectively captures this transitional phase of turbulent blood flow as pressure changes, thus emphasizing the correct interpretation of Korotkoff sounds in the context of blood pressure measurement.