Cardiac output is determined by which of the following?

Cardiac output is determined by which of the following?

• A. Heart rate x stroke volume
• B. Systolic pressure x diastolic pressure
• C. Stroke volume only
• D. Heart rate only

Answer: (A)

Cardiac output is the volume of blood the heart pumps each minute, and it is determined by heart rate and stroke volume. Heart rate is how many times the heart beats per minute, and stroke volume is how much blood is ejected with each beat. Multiply them together: cardiac output = heart rate × stroke volume. This gives flow in milliliters per minute (or liters per minute), reflecting both how often the heart beats and how much blood is moved with each beat. Why the other ideas don’t fit: systolic and diastolic pressures describe arterial pressures, not the amount of blood pumped per unit time. They aren’t a measure of pump output. Considering stroke volume alone ignores how frequently the heart beats, and considering heart rate alone ignores how much blood is released with each beat. The combination of rate and volume per beat provides the true measure of how much blood the heart pushes forward each minute.

Cardiac output is the volume of blood the heart pumps each minute, and it is determined by heart rate and stroke volume. Heart rate is how many times the heart beats per minute, and stroke volume is how much blood is ejected with each beat. Multiply them together: cardiac output = heart rate × stroke volume. This gives flow in milliliters per minute (or liters per minute), reflecting both how often the heart beats and how much blood is moved with each beat.

Why the other ideas don’t fit: systolic and diastolic pressures describe arterial pressures, not the amount of blood pumped per unit time. They aren’t a measure of pump output. Considering stroke volume alone ignores how frequently the heart beats, and considering heart rate alone ignores how much blood is released with each beat. The combination of rate and volume per beat provides the true measure of how much blood the heart pushes forward each minute.