Cardioversion (DCCV)
Who is offered a cardioversion
The cardioversion procedure
Complications of a cardioversion
Who Is Offered a Cardioversion
Direct current cardioversion (DCCV) is common medical procedure used to reset the heart rhythm, returning it to normal. Many thousands of people in the UK undergo cardioversion each year.
Most cardioversions are to treat arrhythmias such as atrial fibrillation and atrial tachycardia. Some doctors also use cardioversion to treat typical atrial flutter but the modern consensus and guidelines state that atrial flutter is generally best treated by an ablation.
Cardioversion may be used to test out whether a patient’s heart is capable of maintaining a normal rhythm, and for how long.
Cardioversion is not generally used for intermittent heart rhythm abnormalities such as attacks of supraventricular tachycardia, or paroxysmal atrial fibrillation (atrial fibrillation that comes and goes spontaneously). However, exceptions to this general rule exist.
The Cardioversion Procedure
Direct current cardioversion involves the application of a very brief, high energy electric shock across the chest. This temporarily interrupts the electrical activity of the heart allowing a the normal heart rhythm to “kick back in”.
Cardioversion is usually carried out under a very brief general anaesthetic administered by a specialist anaesthetist. In some circumstances it may also be carried out under sedation by a cardiac electrophysiologist.
Patients may also undergo cardioversion as part of a larger procedure, for example SVT ablation or pacemaker implantation. If a cardioversion is performed alone then this is usually a day case procedure and the patient will be discharged after a few hours’ observation.
How long the normal rhythm lasts after a cardioversion is not influenced by the cardioversion technique, but due to other factors, such as what caused the arrhythmia in the first place. Other treatments such as lifestyle changes, medications, and ablation procedures may be needed to reduce the chance of an arrhythmia coming back after a cardioversion.
Complications of Cardioversion
The main risk of the abrupt change in heart rhythm caused by a cardioversion is that this can lead to stroke via the formation of blood clots in the heart that travel to the brain and interrupt blood supply. For this reason, all patients except those at extremely low risk of stroke are asked to take an anticoagulant drug for some weeks before and after the procedure.
some patients experience a very slow heartbeat once the rhythm is returned to normal and in roughly one in every 200 patients this requires treatment with a pacemaker implant.
Other minor complications include pain across the chest and skin burns related to the application of electricity across the chest.