EXTERNAL ELECTRIC CARDIVERSION

External electrical cardioversion is a procedure that allows you to interrupt a cardiac arrhythmia, such as atrial fibrillation, and restore normal sinus rhythm through a high-energy electrical shock. For this procedure, deep sedation is practiced to avoid the patient feeling unpleasant sensations. Cardioversion is effective in restoring sinus rhythm between 50 and 90% depending on the underlying heart disease and the duration of the arrhythmia. However, there is also the possibility that even if cardioversion is initially effective, there is a recurrence, even early, of the previous arrhythmia or the appearance of a new arrhythmia.

Cardioversion of atrial fibrillation

If you have an episode of symptomatic atrial fibrillation that does not respond to antiarrhythmic medications, your doctor may suggest a procedure called electrical cardioversion, which is designed to return your heart to a normal rhythm (sinus rhythm). This procedure is usually scheduled in advance and involves delivering a controlled electrical shock to your heart. The electrical impulse is strong enough to briefly stop the heart's electrical signals and allows the heart's natural pacemaker, the sinoatrial node, to resume normal activity and restore normal sinus rhythm. Electrical cardioversion is performed in a hospital using a machine called a defibrillator. Before cardioversion, you will be given an injection (anesthetic) that makes you drowsy because the procedure can be slightly uncomfortable. This way, you will not feel anything during the procedure. Be aware that even after successful cardioversion (which returns your heart rhythm to normal sinus rhythm), atrial fibrillation may return. This happens in about half of patients during the first year after the cardioversion procedure. The chances of atrial fibrillation returning depend on many factors, but are higher if you have other heart problems (including high blood pressure) and if you have had atrial fibrillation for more than 1 year.

Cardioversion can also be achieved with certain medications used to control the rhythm. This is called pharmacological cardioversion because instead of an electrical shock, medications are used to try to return the heart to a normal rhythm. This procedure is also done in a hospital. The patient is given this medication intravenously through an IV in their arm, and their heart rate is continuously monitored during the procedure. Before cardioversion, whether electrical or pharmacological, they will need to take a blood thinner for at least 1 month before the procedure. Alternatively, a transesophageal echocardiogram will be done to rule out the possibility of blood clots in the heart before cardioversion. To reduce the risk of stroke, they will need to continue taking the blood-thinning medication for at least 2 months after the cardioversion procedure. Depending on their overall risk of stroke, their doctor may ask them to continue taking the blood-thinning medication for the rest of their life.

Complications, although very rare, of external electrical cardioversion are: stroke, hemobolia, bradycardia.