Automaticity speaking only about heart cells refers when cardiac pacing has the ability or property of depolarizing the myocardial cells creating heart beats spontaneously.
Explanation:
The spontaneous activity is initiated by specific cardiac cells that generate periodical electrical cycles. In the normal heart, automaticity is confined to the sinus node (remember that this is the natural pacemaker of the heart) and other conducting tissues. Cells that can reach the limit in the shortest amount of time have the greatest automaticity capacity since they can produce action potentials at a quicker rate than other cells.
