What diastolic pressure is the blood pressure when the heart beats while pumping blood?

Diastolic pressure is the lower number in a blood pressure reading and represents the pressure in the arteries when the heart is at rest between beats, not when it is pumping. When the heart beats and pumps blood, the pressure measured is called systolic pressure. Therefore, diastolic pressure occurs during the relaxation phase of the cardiac cycle, not during the heart's pumping action.