How the heart works
The cardiac electrical system
The heart generates its own electrical signal, or impulse. This electrical impulse can be recorded by placing electrodes on the skin of the chest, thus producing the electrocardiogram (ECG, or EKG).
The heart’s electrical impulse arises in the upper portion of the right atrium and spreads across. As it spreads, it triggers the heart muscle to contract in a coordinated fashion. If the electrical signal becomes deranged in some way, the efficient pumping action of the heart may deteriorate, or stop altogether.
