What Is Electrical Cardioversion?

If medications are not able to control a persistent irregular heart rhythm (such as AF), cardioversion may be required. Cardioversion frequently restores a normal rhythm, although its effect may not be permanent. After a short-acting anesthesia is given, a machine (defibrillator/cardioverter/pacemaker) is used to deliver specific amounts of energy (an electric shock) through electrode patches placed on the chest to synchronize the heartbeat and restore a normal rhythm. Although this procedure only takes a few seconds, several attempts may be needed to restore a normal rhythm.

What Is Ablation Therapy?

Catheter ablation therapy is an option for people who cannot tolerate medications or when medications fail to maintain the normal heart rhythm.

Pulmonary vein antrum isolation: Research has shown that most atrial fibrillation signals come from the four pulmonary veins. During this procedure, special catheters are inserted into the heart. Two catheters are inserted into the right atrium and two into the left atrium.

A specialized viewing device called intracardiac echocardiography is used to visualize the left atrium during the procedure. One catheter in the left atrium is used to map or locate the abnormal impulses coming from the pulmonary veins. The other catheter is used to deliver the radiofrequency energy to create lesions outside the pulmonary veins. The procedure is repeated for all four pulmonary veins.

The lesions heal and within 4 to 8 weeks, form a circular scar around the pulmonary veins. The scar blocks any impulses firing from within the pulmonary veins, thereby "disconnecting" the pathway of the abnormal rhythm and curing atrial fibrillation.

Ablation of the AV node: During this procedure, the doctor applies radiofrequency energy to injure the AV node. The end result is a permanent, very slow heart rate, since the electrical impulses from the top chamber of the heart cannot travel down to the lower chamber. Therefore, the patient needs a permanent pacemaker to maintain an adequate heart rate.

What Is Device Therapy?

Implantable atrial defibrillator: a device used to treat AF symptoms. When the symptoms of AF occur, the person can turn on the device and treat the AF when appropriate and convenient. Or, the device can be set to operate automatically. The atrial defibrillator can be programmed to identify when a person is having an episode of atrial fibrillation. When it occurs, the device delivers low-dose energy to convert AF to a normal heart rhythm. This procedure improves atrial fibrillation symptoms, but does not cure the condition.

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