How is systolic blood pressure defined?

Systolic blood pressure is defined as the highest point reached during the contraction of the left ventricle, which is when the heart pumps blood into the arteries. During this phase of the cardiac cycle, the ventricles contract, creating a surge of blood that increases the pressure within the arteries. This peak pressure is what is recorded as systolic blood pressure and is crucial for understanding cardiovascular health.

The other definitions provided do not accurately describe systolic blood pressure. The lowest point during the heart's relaxation phase pertains to diastolic blood pressure, while average pressure throughout the cardiac cycle relates more to mean arterial pressure. The pressure in the arteries during diastole specifically describes the state between heartbeats when the heart is at rest. Each of these concepts plays a role in cardiovascular function, but they are distinct from the definition of systolic blood pressure.