What does 'stroke volume' refer to?

Stroke volume is the term used to describe the amount of blood that is pumped out of the heart during each contraction, specifically during ventricular systole. It is a critical measure in cardiovascular physiology as it directly impacts cardiac output, which is the total volume of blood the heart pumps in a minute. Stroke volume is influenced by various factors, including preload (the degree of strech of the heart muscles before contraction), afterload (the resistance the heart must overcome to eject blood), and contractility (the strength of the heart's contraction). Understanding stroke volume is essential for assessing a patient's cardiac function and overall hemodynamic status.

The other definitions provided do not align with the concept of stroke volume. Total blood volume pertains to the overall quantity of blood in the body, rather than the amount pumped per heartbeat. The difference between systolic and diastolic pressure defines blood pressure rather than stroke volume, while the volume of blood in the heart chambers at rest refers to end-diastolic volume, not specifically the volume ejected with each heartbeat.