Then there is the wonderful back-up on the
electrical system of the heart
SA Node, in the
Atrium, is the
pacemaker. It discharges, the signal travels, and activates the AV Node, from there going into the ventricles. But what if the SA Node fails? Surprisingly, if the AV Node does not receive a signal from the SA Node, it discharges by itself, and causes the heart to beat. Mind you, the heart beats at a much slower pace, referred to as Bradycardia, but it does keep beating.