What is cardiac output (CO)?

What is cardiac output (CO)?

• A. The amount of blood pumped by a single ventricle in a minute.
• B. The amount of blood pumped by the entire heart in a minute.
• C. The amount of blood returning to the heart per minute.
• D. The pressure generated during systole.

Answer: (A)

Cardiac output is the volume of blood the heart pumps per minute from one ventricle. It is determined by multiplying heart rate by stroke volume (CO = HR × SV), so it tells you how vigorously the heart is delivering blood to the body. In a healthy heart, the left ventricle and right ventricle pump equal amounts per minute, with the left ventricle driving systemic circulation and the right driving pulmonary circulation. The other ideas aren’t correct because venous return is the amount coming back to the heart, not what is ejected per minute, and systolic pressure is a pressure measure, not a volume. Resting CO is typically around 5 L/min, varying with heart rate and the amount of blood each beat ejects.

Cardiac output is the volume of blood the heart pumps per minute from one ventricle. It is determined by multiplying heart rate by stroke volume (CO = HR × SV), so it tells you how vigorously the heart is delivering blood to the body. In a healthy heart, the left ventricle and right ventricle pump equal amounts per minute, with the left ventricle driving systemic circulation and the right driving pulmonary circulation. The other ideas aren’t correct because venous return is the amount coming back to the heart, not what is ejected per minute, and systolic pressure is a pressure measure, not a volume. Resting CO is typically around 5 L/min, varying with heart rate and the amount of blood each beat ejects.