What does diastolic blood pressure primarily reflect about the heart's condition?

Diastolic blood pressure primarily reflects the heart's condition during the phase when the heart is in a stage of filling, known as diastole. During this phase, the heart's chambers are relaxed, allowing the ventricles to fill with blood that is returning from the body and lungs.

This measurement indicates the pressure in the arteries when the heart is not actively pumping blood, providing important insights into the vascular resistance and overall cardiovascular health. A healthy diastolic pressure suggests that the heart can adequately fill with blood, which is essential for maintaining a sufficient stroke volume in the subsequent contraction phase. As such, diastolic blood pressure serves as a critical marker for assessing the heart's function and the state of the circulatory system.