What is the relationship between heart rate and stroke volume in cardiac output?

The relationship between heart rate and stroke volume is integral to understanding cardiac output, which is defined as the volume of blood the heart pumps per minute. Cardiac output is calculated by multiplying heart rate (the number of beats per minute) by stroke volume (the amount of blood pumped by the heart with each beat).

This means that as heart rate increases, or as stroke volume increases, the total cardiac output also increases in direct proportion to those changes. The direct multiplication reflects how these two factors work together to determine how effectively the heart can meet the body's demands for oxygen and nutrients.

Thus, asserting that they multiply to determine cardiac output accurately captures the combined effect of heart rate and stroke volume on overall cardiovascular function. This understanding is essential in various physiological contexts, particularly in assessing cardiovascular health and performance during different states of activity or rest.