How is diastolic pressure defined in blood pressure readings?

Diastolic pressure is defined as the pressure in the arteries when the heart is at rest between beats, specifically at the moment when the heart is filling with blood. This is measured during auscultation using a sphygmomanometer, where the clinician listens for sounds known as Korotkoff sounds.

The correct answer indicates that diastolic pressure is recorded when the last sound disappears completely. This moment signifies that the blood is no longer impacting against the artery wall, meaning that the arterial pressure has decreased to the point where it is no longer sufficient to produce audible turbulence as the heart relaxes and fills. This definitive point marks the lowest level of pressure in the arteries during the cardiac cycle, which is considered diastolic pressure.

The other options do not accurately describe diastolic pressure. The first sound heard corresponds to systolic pressure, which indicates the moment just as the heart begins to contract and blood starts to flow forcefully through the arteries. The highest pressure is not related to diastolic pressure, as this would pertain to systolic pressure (the maximum pressure during heart contractions). Lastly, the lowest pressure before blood flow stops refers to a moment when the heart is no longer generating enough pressure to maintain blood flow, which is