Normally, any electrical pulse engaging the heart muscle during each heart beat begins in the tissue called Sinus (SA node). This tissue has autonomic potential of generating such pulses.
This tissue is also known as natural pacemaker.
In some instances, for various reasons, electrical stimulation can be elicited from other sites in the heart, outside the Sinus, by cells that are under normal conditions not electrically active.
Usually, such impulse will be generated before the normal next impulse from the natural pacemaker, the Sinus, and it is therefore called “premature beat”.
Another name for such premature beats is Extra-Systole.
Premature beats can be generated from a supra-ventricular source (from sites located above the ventricles) or from sites located in the ventricles.
In many instances, the reason for the generation of such premature beats is unknown. They are more frequent under the influence of substances such as caffeine, nicotine or alcohol. They can be also associated with cardiac diseases.
Sometimes such premature beats can give a sensation of irregular pulse or of interruptions in the normal heart action.
Most extra systoles do not require medical treatment. The decision about initiating medical treatment for the suppression of premature beats will depend on the subjective feeling of the patient as well as on the cause for their appearance.