An arrhythmia is a change in the rhythm of your heartbeat. When the heart beats too fast, it's called tachycardia. When it beats too slow, it's called bradycardia. An arrhythmia can also mean that your heart beats irregularly (skips a beat or has an extra beat). At some time or another, most people have felt their heart race or skip a beat. These occasional changes can be brought on by strong emotions or exercise. They usually are not a cause for alarm. Arrhythmias that occur more often or cause symptoms (see the box below) may be more serious and need to be discussed with your doctor.

Most arrhythmias are harmless, but some can be serious or even life threatening. When the heart rate is too slow, too fast, or irregular, the heart may not be able to pump enough blood to the body. Lack of blood flow can damage the brain, heart, and other organs.

Causes and Risk Factors of Heart Arrhythmia

Irregularities in the rhythm of the heart can be caused by many things, including disease (e.g., coronary artery disease, diabetes, cardiomyopathy), medications or drugs, an aging heart, metabolic problems; such as thyroid disease, or have no evident cause.

In a healthy person with a normal, healthy heart, it's unlikely for a sustained arrhythmia to develop without some outside trigger, such as an electrical shock or the use of illicit drugs. That's primarily because a healthy person's heart is free from any abnormal conditions, such as an area of scarred tissue.

The heart has its own natural built-in pacemaker, called the sinoatrial node (or sinus node). Electrical impulses are triggered here and travel through a system of nerve wiring around the heart, so different parts of the heart beat in a regular order to make it function efficiently as a pump.

Signs and Symptoms

Because arrhythmias can cause the heart to beat less effectively, blood flow to the brain and to the rest of the body can be interrupted. If the heart is beating too fast, the heart's chambers can't fill with the right amount of blood. If it's beating too slowly or irregularly, the right amount of blood can't be pumped out to the body. Because the body isn't getting the supply of blood it needs to run smoothly, these symptoms can occur

Lightheadedness

Dizziness

Fainting (syncope) or near fainting

Paleness

Sweating

Cardiac arrest

Palpitations (a feeling that your heart has skipped a beat or is beating too hard)

A slow heartbeat

Diagnosing Arrhythmias

Electrocardiographic techniques

An arrhythmia is considered documented if it can be recorded on an electrocardiogram (ECG or EKG.) This is the standard clinical tool for diagnosing arrhythmias. It records the relative timing of atrial and ventricular electrical events. It can be used to measure how long it takes for impulses to travel through the atria (the heart's upper chambers), AV conduction system and ventricles (the heart's two lower, pumping chambers).

What's the treatment?

An artificial pacemaker is an electronic device placed under the skin on the chest. It helps the heart maintain a regular beat, especially when the heart beats too slowly.
Cardiac defibrillation (very brief electric shock) can be used to stop an abnormal rhythm and restore a normal one.

Surgery

Sometimes, surgery is used to treat arrhythmia. Often this is done when surgery is already being performed for another reason, such as repair of a heart valve. One type of surgery for atrial fibrillation is called "maze" surgery. In this operation, the surgeon makes small cuts or burns in the atria, which prevent the spread of disorganized electrical signals.