The heart is a muscle with four chambers that contract at regulated intervals to pump blood throughout the body. These contractions are generated by electricity that passes with very precise speeds through distinct pathways along the fibers of the heart muscle. This electricity originates from the heart's sinoatrial node, also known as the heart's pacemaker, which is found in the right atrium at the top half of the heart's upper right chamber. The rate of electrical current discharged by the sinoatrial node, together with nerve impulses and hormone levels in the blood, determines a person's heart rate or heart rhythm.

Arrhythmia Causes and Symptoms
Excessive alcohol use, cigarette smoking, caffeine, stress and intense exercise can produce a minor arrhythmia. But the most common and serious cause of arrhythmia is heart disease, with coronary artery disease, abnormal heart valve function and heart failure among the top triggers.

It is not unusual for an abnormal heart rhythm to go undetected because in some circumstances no symptoms arise. Frequently, a doctor will discover the problem during a routine examination without any patient symptoms. But normally, arrhythmias cause noticeable signs that may include:
-- Rapid heartbeat
-- Slow heartbeat
-- Chest pain
-- Fluttering in your chest
-- Shortness of breath
-- Extreme fatigue
-- Lightheadedness
-- Dizziness
-- Fainting

IRREGULAR HEARTBEAT TREATMENT
Treating arrhythmias will depend on the type of irregular heartbeat a person has, and how serious the case is. Some arrhythmias will not require treatment at all, while others necessitate major surgical procedures, medication and a change in lifestyle. Irregular heartbeat can be treated using Cardioversion, where an electrical current is applied across the heart’s chest wall to treat pulsed ventricular tachycardia (fast heartbeat caused by abnormal electrical impulses). Defibrillation, where even more electricity can be delivered, is used to remedy ventricular fibrillation, a condition where a confusion of electrical impulses trigger the heart's ventricles to quiver uncontrollably instead of pumping blood. Ventricular fibrillation is believed to be one of the causes of sudden cardiac death (SAD) that kills people each year. Cardiac pacing may also be applied for sufferers of bradycardia, or very slow hearbeats. This is usually indicated for arrhythmias caused by a drug overdose or myocardial infarction (heart attack). Sometimes, a pacemaker has to be inserted into the heart for patients who have severe bradycardia.