What does the word 'systolic' refer to in the context of blood pressure?

The term 'systolic' specifically refers to the pressure in the arteries during ventricular contraction, which occurs when the heart pumps blood out into the systemic circulation. During this phase of the cardiac cycle, the ventricles are actively contracting, causing a significant increase in blood pressure as blood is expelled from the heart. This peak pressure measured during contraction is what clinicians refer to as the systolic blood pressure, typically represented as the top number in a blood pressure reading, for example, 120 in a reading of 120/80 mmHg.

Understanding this concept is critical for interpreting blood pressure readings accurately. The systolic pressure is a key indicator of cardiac function and overall circulatory health, highlighting the force exerted by the heart during its pumping action. This contrasts with other terms related to blood pressure, such as 'diastolic,' which pertains to the pressure when the ventricles are relaxed, or other ways to describe blood pressure that do not directly relate to the phase of the heart's contraction.