Cardiac output is decreased by

The amount of blood pumped out of the hea per beat is the stroke volume, is about 70 mL.The output of the hea per unit of time is the cardiac output cardiac output = stroke voume*hea rate Therefore decrease in hea rate decrease cardiac outputIncrease in either of hea rate or stroke volume or both increase cardiac outputRef: Ganong's Review of Medical Physiology Twenty-Third Edition Page No:514