DC Cardioversion

Arrhythmias are abnormal rhythms of heartbeats. If left untreated, heart contractions can become less efficient which increases the risk of blood clots and strokes.

Cardioversions are used as a treatment for arrhythmias such as atrial fibrillation, atrial flutters and tachycardias. Arrhythmias are accompanied by symptoms such as feeling faint, chest pain, loss of breath, low blood pressure or loss of consciousness.

A DC cardioversion (DCC) is a procedure aimed at converting an arrhythmia back to a normal heart rhythm. This is done in a hospital where you can be closely monitored to ensure your oxygen levels, blood pressure and heartbeat are stable. The procedure occurs under a general anaesthetic using a defibrillator which sends an electric signal or shock to your heart, through electrodes placed on your chest. This disrupts the irregular heartbeat, therefore, resulting in heartbeat being reset back to normal. The brief interruption of the arrhythmia gives the heart’s electrical system to restore a normal heartbeat.

What happens during the procedure?

Before the procedure, your doctor would likely have prescribed a blood-thinner or anticoagulant, such as Warfarin, which stops the blood clotting and reduces the risk of stroke. It is also likely that you will be prescribed anti-arrhythmic medication in the form of tablets before and after the procedure.

You will lie down and have two electrodes stuck to your chest and back. Once the general anaesthetic has kicked in, an electrical current is delivered to your heart through your chest.

After around 10 minutes, you should have fully recovered and be able to go home soon after.

What happens after the procedure?

Due to the nature of a general anaesthetic, it will likely be advised that you do not drive or work for a couple of days after your procedure. It is unlikely that you will feel unwell but it’s helpful to have someone on call for 24 hours after, should you have any side effects. After 48 hours, you should be able to gradually get back to your normal activity levels.

It is possible that a cardioversion won’t be successful the first time and, therefore, it is possible to have more than one. There is no limit to have many an individual can have but the decision for further procedures is guided by your doctor and the chance of success of future procedures. This is based on how quickly your arrhythmia returned, whether you experienced any side effects or whether there is a cause of your arrhythmia that can be treated directly.

Side Effects

Side effects are uncommon and usually temporary with cardioversions. However, they are not impossible.

You may experience headaches and light-headedness after your procedure due to the reduced blood pressure. You may also experience discomfort around the area on the chest where the shock was given.

The most common side effect is nausea which does not originate from the procedure itself, but the general anaesthetic.

Are there any risks with this procedure?

As always, there are risks related with heart procedures. These can include:

• A blood clot may dislodge and cause a stroke. As mentioned earlier, the doctor will likely prescribe anticoagulants to reduce this risk and there is currently only a 1% risk of this occurring.

• You may have a reaction to the sedative or general anaesthetic given before the procedure. However, this is rare.

• You may experience small burns on the chest and back from the electrodes.

• You may experience muscle ache across the chest and back due to the muscle contraction when the shock is delivered.

• The procedure may not work. However, it is possible to have a subsequent cardioversion.

• In very rare cases, the anti-arrhythmic medication can cause complications to your heartbeat further.