What is the amount of blood pumped out of a ventricle with each heartbeat called?

The amount of blood pumped out of a ventricle with each heartbeat is known as stroke volume. Stroke volume refers specifically to the volume of blood ejected from one ventricle during a single contraction. This measurement is crucial for understanding cardiac performance, as it directly reflects how effectively the heart is functioning during each beat.

Ejection fraction, which is often confused with stroke volume, is a percentage that measures the fraction of blood ejected from the ventricle relative to the total volume of blood that is in the ventricle just before contraction. While it provides valuable insight into cardiac function, it does not quantify the absolute volume of blood pumped per heartbeat.

Cardiac output, on the other hand, is the total volume of blood pumped by the heart per minute and is the product of stroke volume and heart rate. End diastolic volume refers to the amount of blood in a ventricle at the end of filling, just before contraction, which is an important factor but is not the same as the amount of blood ejected per heartbeat.

Understanding the distinction between these terms is essential for interpreting cardiovascular physiology correctly. Stroke volume provides a clear measure of the pump function of the heart, influencing overall cardiac output and cardiovascular health.