What is cardiac output?

Cardiac output is fundamentally defined as the volume of blood that the heart pumps per minute. This measurement is critical in assessing the efficiency and performance of the heart, as it indicates how well the heart is supplying blood to the body. Cardiac output is influenced by heart rate (the number of beats per minute) and stroke volume (the amount of blood ejected by the heart with each contraction).

Understanding cardiac output is essential for assessing various cardiac conditions and overall health, as it plays a key role in determining how well tissues and organs are perfused with oxygen and nutrients. In contrast to other concepts, such as the volume of blood in the heart at rest or the pressure of blood in the arteries, cardiac output specifically quantifies the heart's activity in circulating blood, making it a vital sign of cardiovascular health. Therefore, the correct definition emphasizes its role as a dynamic measure of heart performance rather than static volumes or pressures.