thaler chapter 1

1   The Basics

10

Electricity and the Heart

Electricity, an innate biologic electricity, is what makes the heart go. The EKG is nothing more than a recording of the heart’s electrical activity, and it is through perturbations in the normal electrical patterns that we are able to diagnose many different cardiac and noncardiac disorders. All You Need to Know About Cellular Electrophysiology in a Few Brief Paragraphs Cardiac cells, in their resting state, are electrically polarized; that is, their insides are negatively charged with respect to their outsides. This electrical polarity is maintained by membrane pumps that ensure the appropriate distribution of ions (primarily potassium, sodium, chloride, and calcium) necessary to keep the insides of these cells relatively electronegative. These ions pass into and out of the cell through special ion channels in the cell membrane.

The resting cardiac cell maintains its electrical polarity by means of a membrane pump. This pump requires a constant supply of energy, and the gentleman above, were he real rather than a metaphor, would soon be flat on his back.