Excitable cells

I wrote this post to answer some of the questions, I had as a medical student, when I first learned about cardiac arrhythmias. Mainly, what are the conditions required to initiate and maintain a reentrant arrhythmia ? That is, a state where the heart muscles are continuously activated by a self-sustaining loop, independent of the normal pace-making system. These arrhythmias can be benign, as with…