Standard values of the cardiac output | Cardiac output per minute

Standard values of the cardiac output

The heart minute volume is given in the unit volume per minute, as the name suggests. In a healthy adult, the cardiac output is 3.5 – 5 liters per minute. The values vary depending on individual circumstances and current requirements. A pregnant woman, for example, has a higher cardiac output per minute than before her pregnancy because she has to provide additional care for the fetus in her abdomen.

Heart minute volume for athletes

For athletes, the cardiac output is increased. During exercise, it is possible that the cardiac output increases to 30 liters/minute. On the one hand, control mechanisms outside the heart are responsible for this.

At the site of central cardiovascular regulation in the brainstem, signals are received from the body by the vessels in the body. Adapted to these signals, reactions are sent out to the body. The contractile force of the heart increases, which raises the heart rate and allows the heart muscle cells to be excited more quickly.

On the other hand, the heart also reacts quickly to an increased need for transport. To achieve this, the heart muscle is first stretched more, allowing more blood to flow from the body into the heart and consequently more blood to be expelled. The enlargement of the ventricles and hypertrophy (an increase in cell volume) of the heart muscle, which often occurs in athletes, leads to a higher cardiac output not only under stress but also at rest.

In an adult, the cardiac output at rest is about 5 liters per minute. Under stress this value can quadruple for a short time. Heavily endurance-trained hearts can even pump over 30 liters per minute.

However, the heart can only maintain such high values for a short period of time. For a marathon runner, the heart beats about 150 times in one minute. About 100 ml of blood is pumped out of the heart per beat.

Multiplying the number of beats per minute by the beat volume gives the cardiac output per minute. In this case it is 15 liters per minute.If the runner ran the marathon within four hours, the heart would have to pump 3600 liters of blood within this time. For top athletes the value is probably even higher.