Cardioversion is a medical treatment that uses quick, low-energy shocks to restore a regular heart rhythm. It’s used to treat some types of irregular heartbeats, called arrhythmias in particular atrial fibrillation (AF). It is performed in hospital after six hours of fasting. It is sometimes performed after a transoesophageal echocardiogram (TOE). This is a procedure to check that it is safe to perform the cardioversion by passing an ultrasound probe into oesophageus. This procedure is performed by your cardiologist with an anaesthetist present to administer the relevant medications to ensure your comfort and safety.