What are the factors that affect cardiac output?

Numerous: Cardiac output is determined by the product of heart rate and a stroke volume (the amount of blood ejected with each heartbeat). Stroke volume is affected by something called contractility which is the strength of the heart muscle contraction. Contractility can be improved with sympathetic tone (epinephrine) or medications (dobutamine and others).

Cardiac output: Stroke volume times heart rate equals cardiac output. Stroke volume relates to myocardial contractility, vascular resistance, vascular volume, anemia and metabolic state. There are subcomponents to all of these.