What systems affect cardiac output?

Heart rate, volume: Cardiac output is affected by heart rate and the volume of blood pumped out of the heart in each heart beat (stroke volume). Factors that increase the heart rate (anxiety, fever, walking) increase cardiac output. Similarly, factors that increase volume of blood that heart pumps with each cycle increase cardiac output. High level athletes have very high stroke volume, because of conditioning.

All: All organ systems are related and can affect cardiac output.