Cardioversion refers to the treatment used to restore a normal heart rhythm in patients with heart rhythm disturbances. It is often recommended to patients with atrial fibrillation and atrial flutter but can be performed for a variety of other heart rhythm disturbances.
Cardioversion can be achieved with medications or electrically.
Electrical cardioversion is a procedure during which a synchronised electrical current (DC shock) is delivered to the heart through the chest wall. This activates all the heart cells simultaneously, thereby interrupting and terminating abnormal electrical circuits in the heart so that a normal rhythm can resume. The current delivered is limited and can be repeated a few times if necessary without damaging the heart. Cardioversion doesn’t always permanently restore the heart’s normal rhythm. Sometimes it’s successful to start with, but reverts back to an abnormal heart rhythm days, weeks or even months later.
This is usually a day-case procedure that doesn’t require overnight admission. You will be given a general anaesthetic or heavy sedation so you will be asleep throughout the procedure.
A doctor or nurse will put electrodes, stuck to large sticky pads on your chest or your back. The electrodes are connected to a defibrillator machine and will give you one or more controlled electric shocks to your chest wall.
Your heart rhythm will be monitored by the defibrillator throughout the procedure and If the abnormal heart rhythm relapses after initial successful reversion, additional shocks (usually up to three)may be delivered.
Because you are asleep or heavily sedated most patients wake up with little recollection of events during the procedure.
In some patients, a more invasive version of electrical cardioversion called ‘internal cardioversion’ may be recommend by a cardiologist with expertise in the management of heart rhythm disorders (Electrophysiologist)
To minimize the risk, patients for this procedure are carefully selected. In general, electrical cardioversion is a very safe treatment. Some patients experience temporary minor skin irritation on the chest. There is also a very small risk associated with the use of sedatives and anaesthetic agents. Any other specific risks to you will be discussed with you before the procedure is done.