Cardiac output is defined as which of the following?

Cardiac output is defined as which of the following?

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

Answer: (B)

Cardiac output is the volume of blood the heart pumps per minute. It reflects how effectively the heart moves blood into the circulation over time. You can think of it as the product of how much blood is ejected with each beat (stroke volume) and how many beats occur each minute (heart rate): CO = stroke volume × heart rate. The result is expressed in liters per minute. This differs from maximum flow velocity, which is just how fast blood moves through a vessel at a particular moment and doesn’t tell you how much blood is moved per minute. It also isn’t about hydrostatic pressure per minute, which isn’t a measure of the heart’s pumping rate, and not about the total blood volume in the body or a vertical column. So the key idea is the amount of blood the heart pushes into circulation each minute.

Cardiac output is the volume of blood the heart pumps per minute. It reflects how effectively the heart moves blood into the circulation over time. You can think of it as the product of how much blood is ejected with each beat (stroke volume) and how many beats occur each minute (heart rate): CO = stroke volume × heart rate. The result is expressed in liters per minute.

This differs from maximum flow velocity, which is just how fast blood moves through a vessel at a particular moment and doesn’t tell you how much blood is moved per minute. It also isn’t about hydrostatic pressure per minute, which isn’t a measure of the heart’s pumping rate, and not about the total blood volume in the body or a vertical column. So the key idea is the amount of blood the heart pushes into circulation each minute.