Atopic Dictionary
The term "cardiac action" is used to describe the entire work performed by the heart. The main task of the heart is to pump blood through the vessels. We mainly use the term "cardiac action" to describe whether the heart beats rhythmically or arrhythmically (regularly or irregularly) and whether the heart beats too fast or too slow. If someone's heart beats regularly or evenly and just fast enough, we say that the cardiac action is rhythmic and normocardic.
