From the Guidelines
Normal cardiac output is 4 to 6 L/min at rest, depending on body size.
Cardiac Output Details
- Cardiac output is defined as the volume of blood ejected from the heart in liters per minute 1.
- This value can vary depending on several factors, including body size and physical activity level.
- At rest, a normal cardiac output is typically in the range of 4 to 6 L/min 1.
- It's worth noting that cardiac output can increase significantly during exercise, as the body requires more oxygen and nutrients to be delivered to the muscles 1.
- The American Heart Association provides guidelines for exercise testing and training, which includes information on cardiac output and other relevant physiological parameters 1.
From the Research
Definition of Cardiac Output
- Cardiac output is the amount of blood the heart pumps in 1 minute, and it is dependent on the heart rate, contractility, preload, and afterload 2
Normal Values of Cardiac Output
- Peak exercise cardiac output in healthy individuals is approximately 13.2 ± 3.5 L/min, with values ranging from 15.3 ± 3.3 L/min in men to 11.0 ± 2.0 L/min in women 3
- Normative reference values of cardiac output by pulsed-wave Doppler echocardiography in adults are:
- Lower limit: 3.3 L/min (females), 3.5 L/min (males)
- Upper limit: 7.3 L/min (females), 8.2 L/min (males) 4
- Cardiac output can also be estimated from blood pressure and heart rate using the Liljestrand & Zander formula, with moderate correlation to Modelflow-derived CO 5
Factors Influencing Cardiac Output
- Age: peak cardiac output and cardiac power output decrease with age, particularly in men 3, 6
- Gender: cardiac output values are generally higher in men than in women 3, 4
- Body size: cardiac output is higher in obese patients, but cardiac index (CI) is not significantly different between obese and non-obese patients 4