Cardioversion (delivery of a synchronized shock) is a medical procedure that helps to restore a normal heart rhythm in people with various types of arrhythmias (i.e., abnormal heartbeats). In cardioversion, electrodes are placed on the patient's chest which sends electric shocks to the heart. Cardioversion can also be performed with certain medications. Usually, cardioversion is a scheduled procedure that is performed in a hospital. After the procedure is performed the patient can return home on the same day. For many patients, cardioversion restores a normal heart rhythm promptly.

Cardioversion is usually used to treat atrial fibrillation or atrial flutter patients. These conditions occur when the electric signals do not travel properly through the upper chamber of the heart to make a normal heartbeat at a regular rate. Cardioversion helps medical professionals to promptly see if cardioversion has restored normal heartbeat successfully. Electric cardioversion takes less time than cardioversion that is performed solely with medications. It depends on the prescription of medical professionals whether the patient will receive cardioversion with medications or electric cardioversion1.

Cardioversion is referred to as defibrillation when it is performed in an emergency condition to prevent death due to cardiac arrest caused by potentially fatal ventricular arrhythmias. If atrial fibrillation remains untreated it can increase the risk of heart failure and stroke2.


Heart muscle contract due to electrical impulses. Normally each impulse travels in an ordered and standardized manner over nerves from atria to ventricles, each resulting in a heartbeat. Any change in the pattern of these nerve impulses causes abnormal heartbeat.

Preparing for cardioversion:

Normally doctors advise the patients not to eat or drink 8 hours before the procedure. If the patient takes medicine before the procedure usually then he/she should sip enough water only to swallow the pill. If the patient does not take any medicine, the doctor will tell if he/she needs any medication before the procedure.

Sometimes, before cardioversion, a procedure called a transesophageal echocardiogram (it checks if there are any blood clots in the heart) is performed on the patient. As blood clots can break away and can cause life-threatening complications. This again will be decided by the medical professional whether the patient needs a transesophageal echocardiogram procedure to be performed or not.

If after a transesophageal echo (TEE) test blood clots appear in the heart, then the cardioversion procedure will be delayed for three or four weeks. In that time the patient will take blood-thinning medications to reduce the risk of any mishap1.

During cardioversion:

After cardioversion:

Cardioversion is done on an outpatient basis, this means that the patient can return home on the same day when the procedure is done. The patient spends an hour or so in the recovery room where he/she is kept under examination for any complications.

The patient needs someone to drive him/her home, as the decision-making power is affected for a few hours after the procedure.

Even if no clots are found in the patient's heart, blood-thinning medications are given to the patient for at least some weeks after cardioversion is performed to avoid the formation of new clots.

Risks of cardioversion:

Risks associated with cardioversion are:


Cardioversion is the delivery of a synchronized shock to restore a normal heartbeat. The procedure takes a few minutes after the patient is sedated. Medications are provided to restore a normal heart rhythm however in electrical cardioversion electric shocks are delivered to the heart by the help of electrodes. In either of the cases, the patient is allowed to return home the same day. Cardioversion can sometimes worsen arrhythmias and can cause life-threatening complications.