Abnormal cardiac output Decreased cardiac output 2021-01-15T12:56:38Z A decreased volume of blood pumped by the left and right ventricle, per unit time. Cardiac output (CO) is the product of the heart rate (HR), i.e. the number of heartbeats per minute (bpm), and the stroke volume (SV), which is the volume of blood pumped from the ventricle per beat.