What does systolic blood pressure measure?

Systolic blood pressure specifically measures the pressure in the arteries during ventricular contraction. This occurs when the heart's ventricles contract and pump blood out into the arteries, causing a peak pressure in the arterial system. This measurement is crucial because it indicates how well the heart is able to deliver blood to the body while increasing the pressure in the arteries to ensure that blood flows efficiently.

Understanding this process is important for first responders as systolic blood pressure is a key indicator of cardiovascular health and can help assess a patient's overall condition in emergency situations. The other choices relate to different aspects of cardiovascular function, such as pressure during relaxation or in veins, but they do not accurately describe what systolic blood pressure measures.