Which statement best describes cardiac output?

Which statement best describes cardiac output?

• A. Volume of blood pumped by the heart per minute
• B. Volume of blood in a vertical column
• C. Maximum flow velocity within the vessel lumen
• D. Hydrostatic pressure per minute

Answer: (A)

Cardiac output is the volume of blood pumped by the heart per minute. It is calculated by multiplying heart rate (beats per minute) by stroke volume (milliliters per beat). For example, 70 beats per minute with a stroke volume of about 70 mL per beat gives roughly 5 liters per minute. This measure reflects how well the heart is delivering blood to the body's tissues and can rise with exercise or fall in conditions like heart failure. The other ideas refer to different concepts—blood volume, the speed of blood flow in a vessel, or pressure per unit time—none of which describe how much blood the heart moves into the circulation each minute.

Cardiac output is the volume of blood pumped by the heart per minute. It is calculated by multiplying heart rate (beats per minute) by stroke volume (milliliters per beat). For example, 70 beats per minute with a stroke volume of about 70 mL per beat gives roughly 5 liters per minute. This measure reflects how well the heart is delivering blood to the body's tissues and can rise with exercise or fall in conditions like heart failure. The other ideas refer to different concepts—blood volume, the speed of blood flow in a vessel, or pressure per unit time—none of which describe how much blood the heart moves into the circulation each minute.