Cardioversion

Converting AF to a normal rhythm can be done in 2 ways: chemical and electrical cardioversion.

Patients who are more likely to get better:
• Patients younger than 65 years of age
• Patients who have had AF for a short time (less than 12 months)
• Patients with normal-sized atria and ventricles
• Patients who are having their first episode of AF

The medication work by blocking channels on blood vessels that allow ion travel. Amongst them are:
• flecainide
• beta-blockers
• amiodarone.

However, these come with a disadvantage:
They carry a small risk of causing other abnormal heart rhythms-- said to be pro-arrhythmic. Especially in patients with diseases of the heart muscle or coronary arteries, which are more life threatening than AF. Treatment with these medications often is initiated in the hospital while the patient's rhythm is continuously monitored for 24-72 hours.

The medication also brings about side effects. An example would be that amiodarone interacts with warfarin and increases the risk of bleeding. The most severe side effect of amiodarone is lung toxicity that potentially can be fatal.

Electrical cardioversion requires the administration of an electrical shock over the chest. This electrical shock stops the abnormal electrical activity of the heart for a brief moment and allows the normal heart rhythm to take over. Warfarin usually is given for 3 to 4 weeks prior to and after successful cardioversion.
95% success rate.

There is little utility in cardioverting stable patients with permanent atrial fibrillation, and the goal in this group is rate control.

Limitations:
Approximately 75% of patients successfully treated with electrical cardioversion experience a recurrence of AF within 12-24 months. Older patients with enlarged atria and ventricles who have had AF for a long time are especially prone to recurrences.

Internal cardioversion uses a device called an implantable cardioverter defibrillator (ICD). This device delivers an electric shock to your heart. An implantable cardiac defibrillator is placed in people who are at high risk of sudden cardiac death from dangerous arrhythmias such as ventricular tachycardia or ventricular fibrillation.