What does the systolic value in a blood pressure measurement represent?

The systolic value in a blood pressure measurement represents the highest pressure in the arteries when the heart contracts and pumps blood into the circulation. During each heartbeat, the heart squeezes (contracts) to push blood out into the arteries, producing a maximum pressure which is recorded as the systolic pressure. This measurement reflects how well the heart is functioning in pumping blood and indicates the amount of work the heart is doing.

Understanding the aspects of blood pressure helps to clarify why other answers are not suitable. For instance, while the lowest pressure is indicative of diastolic pressure, and the average pressure relates to mean arterial pressure calculations, the defining characteristic of systolic pressure is its peak value during the cardiac cycle. The pressure when the heart is at rest pertains to when the heart chambers are filling with blood, corresponding to diastole, not systole. This distinction is fundamental in interpreting blood pressure readings accurately.