How is systolic blood pressure defined?

Systolic blood pressure is defined as the pressure in the arteries during heartbeats, specifically when the ventricles contract and pump blood into the aorta and other arteries. This phase of the cardiac cycle is known as systole. During systole, the heart's contraction generates a peak pressure in the arterial system, which is measured as systolic blood pressure. This measurement is critical as it reflects how well the heart is functioning and indicates the pressure exerted on arterial walls during the active phase of the heartbeat. Understanding systolic blood pressure is essential for assessing cardiovascular health and diagnosing conditions like hypertension.

In contrast, the pressure between heartbeats refers to diastolic blood pressure, which occurs when the heart is at rest and filling with blood. The average pressure in the arteries relates to mean arterial pressure but does not specifically represent systolic blood pressure. Finally, pressure in the veins relates to venous pressure, which is significantly different from arterial pressure and is not used to define systolic blood pressure.