General Information

Cardioversion refers to the process of restoring the normal heart rhythm from an abnormal rhythm. Most elective cardioversions are performed to treat atrial fibrillation or atrial flutter - heart rhythm disturbances that originate in the upper chambers (atria) of the heart.

Why Do I Need a Cardioversion?

Normally, each heartbeat starts in the upper right chamber (right atrium) of the heart in a region containing specialised "pacemaker" cells. Each time these cells fire (usually 1 to 2 times per second) this electrical impulse is transmitted in an organised fashion throughout the heart resulting in a coordinated rhythmic heartbeat. In patients with atrial fibrillation, instead of the normal organised electrical activity, the atria fibrillate (or quiver) because of chaotic electrical activity that circulate throughout both atria. This can result in less efficient blood pumping and an irregular or fast heartbeat. Some patients have no symptoms, whereas others may feel rapid heart beating, shortness of breath or fatigue. Depending on your specific medical history and symptoms, you may be advised to have a cardioversion to return your heart to normal rhythm.

What Are the Different Types of Cardioversion?

Cardioversion can be chemical or electrical. Chemical cardioversion refers to taking anti-arrhythmia medication to restore the heart's rhythm to normal. Such medications work by altering the heart's electrical properties to suppress the abnormal heart rhythms and restore a normal rhythm. These medications are usually given as an outpatient but sometimes you may be admitted to hospital for this therapy. Electrical cardioversion (also known as direct-current or DC cardioversion) is a procedure whereby an electrical current (shock) is delivered through the chest wall to the heart under anaesthesia. The shock is delivered through special electrodes or paddles on the chest and sometimes the back. The purpose of the cardioversion is to interrupt the abnormal electrical circuit(s) in the heart and to restore a normal heartbeat. The delivered shock causes all the heart cells to contract simultaneously, thereby interrupting and terminating the abnormal electrical rhythm (typically fibrillation of the atria) without damaging the heart. The heart's electrical system then restores a normal heartbeat.

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