The heart beats in all of us. It reacts to effort and stress in identical fashion. The pathways the electrical impulses travel however are different in each of us. These differences are due to genetics, or can be the result of damage tot he heart tissue.
Damaged tissue can be the result of a heart attack, or a severe illness such as rheumatic fever.
It is these differences that individualizes the reactions of the heart to our environment. Yet, the basic function of the heart is the same in everyone. Like many of the man made pumps of today, The heart runs on electricity. It is the interruption of these electrical signals that are the underlying cause of arrhythmia. Arrhythmia is a disturbance in the heart rhythm beat due to the interference with its electrical pathways.