Cardiac output is calculated as which of the following?

Cardiac output is calculated as which of the following?

• A. Heart rate (pulse) multiplied by stroke volume
• B. Heart rate divided by stroke volume
• C. Stroke volume divided by heart rate
• D. Blood pressure times heart rate

Answer: (A)

Cardiac output is the amount of blood the heart pumps per minute. It depends on two things: how often the heart beats (heart rate) and how much blood is pumped with each beat (stroke volume). Multiply these together to get the volume per minute, with typical units of liters per minute. For example, 70 beats per minute with a stroke volume of about 75 mL per beat gives roughly 5.25 L/min. Dividing heart rate by stroke volume or involving blood pressure does not describe the volume pumped per minute, since CO is a rate that combines frequency and amount per beat.

Cardiac output is the amount of blood the heart pumps per minute. It depends on two things: how often the heart beats (heart rate) and how much blood is pumped with each beat (stroke volume). Multiply these together to get the volume per minute, with typical units of liters per minute. For example, 70 beats per minute with a stroke volume of about 75 mL per beat gives roughly 5.25 L/min. Dividing heart rate by stroke volume or involving blood pressure does not describe the volume pumped per minute, since CO is a rate that combines frequency and amount per beat.