Cardioversion (DCCV) in Kent and London
Electric cardioversion is a medical procedure to reset the heart rhythm to normal. It may be used to treat many heart rhythm problems including atrial fibrillation, atrial flutter and atrial tachycardia. It may also be peformed as an emergency procedure to treat life-threatening ventricular arrhythmias if the heart is not pumping enough blood. The procedure is carried out under general anaesthetic or heavy sedation.
You can read more below about the procedure as carried out by Dr Idris Harding to treat arrhythmias for patients in Kent and London.
What is a cardioversion? - When to see a cardiologist - Reasons for a cardioversion - Getting ready - On the day - Recovery - Complications - FAQs
What is a Cardioversion?
Direct current cardioversion (“DC cardioversion”, or “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.
During DCCV, a brief electric current is applied across the chest to cause a moment of electrical silence within the heart, allowing the normal heart rhythm to start again.
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 usually be discharged soon afterwards.
Most cardioversions are to treat arrhythmias such as atrial fibrillation, atrial tachycardia and atrial flutter. It can also be used to treat more dangerous rhythms such as ventricular tachycardia and ventricular fibrillation.
When to See a Cardiologist
Symptoms such as palpitatiions, a fast or irregular pulse, breathlessness and chest tightness may be caused by a heart rhythm problem.
A cardiologist - in particular a cardiac electrophysiologist (heart rhythm specialist) - can use tests to confirm whether the heart is in an abnormal rhythm some, or all of, the time.
If an arrhythmia problem is constant, then a cardiologist may recommend a direct current cardioversion (DCCV) to return the heart rhythm to normal.
Reasons for a Cardioversion
DCCV is the most reliable way to return the heart rhythm to normal. Cardioversion for atrial fibrillation can improve symptoms related to this arrhythmia. The same procedure can be used to treat atrial flutter, atrial tachycardia and ventricular arrhythmias. Often, chemical cardioversion (using drugs to reset the heart rhythm) will be used first and only if this fails will electric cardioversion be needed.
Patients may also undergo cardioversion as part of a larger procedure, for example SVT ablation or pacemaker implantation.
Sometimes a DCCV may be used as part of a “trial of sinus rhythm” to test whether returning to a normal rhythm causes any difference in symptoms. This approach is used if it unclear whether the heart rhythm is the cause of symptoms.
Getting Ready
Any patient having a cardioversion for AFib or any other arrhythmia, will want to increase the chance of remaining in a normal rhythm for as long as possible afterwards. Heart rhythm abnormalities are made more likely by being overweight, drinking too much alcohol and uncontrolled medical conditions such as high blood pressure, obstructive sleep apnoea and thyroid problems.
Preparing for a cardioversion may involve tests and treatments to reduce anything that could cause the heart rhythm problem to return.
On The Day
Cardioversion is carried out under general anaesthetic or heavy sedation. Driving is not recommended immediately afterwards and patients should make arrangements to be accompanied away from hospital after the procedure.
Although preparation and pre-op checks may take a while, the procedure itself only takes a few moments. Electrical contacts are placed on the chest. Hairy patients may need to shave beforehand. Sometimes, the electrical contacts are placed on the back as well as the front of the chest. The patient is then made unconscious using anaesthetic drugs, either breathed in, or injected into a vein. Once the patient is deeply unconscious, an electric shock is delivered across the chest and the patient then gradually wakes up again. The whole process usually takes 10 minutes or so.
Recovery
Recovering from a cardioversion is usually very rapid. Patients may discharged an hour or less after regaining consciousness from the procedure. A low heart rate immediately after the procedure is very common. Patients with a low pulse will be monitored for longer before being let home.
Sedative drugs are used during the procedure and therefore patients should not drive on the day of the procedure. Some hospitals will insist that patients do not travel home alone due to the small risk of confusion, stumbling or unsteadiness after a sedative or anaesthetic.
Complications
There is a small risk of stroke during or after the procedure to due dislodging of blood clots from within the heart which can stravel to the brain. 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.
FAQs on Cardioversion
Can you die during cardioversion?
Deaths due to cardioversion are very rare. Studies that have followed patients with atrial fibrillation treated with or without cardioversion have generally found that death rates are very similar for patients whether or not they have the procedure.
How to stay in sinus rhythm after cardioversion?
Up to 70% of patients with atrial fibrillation will go back into the arrhythmia within a year of cardioversion. The risk of relapse can be reduced significantly by using drugs that promote a normal heart rhythm (“anti-arrhythmics”). Treatment of the cause of atrial fibrillation is also important to improve the chances of maintaining normal sinus rhythm. For example if poor blood pressure control, untreated thyroid disease or obstructive sleep apnoea has caused AF then these should be addressed before or alongside cardioversion. Lifestyle changes can have large impacts on the risk of returning to AF. Weight loss, avoiding alcohol and taking regular exercise have all been shown to reduce the risk of return to atrial fibrillation.
What should you not do after cardioversion?
On the day of the procedure you should not drive or operate heavy machinery, or undertake any other activity that would be risky if you were to suddenly become dizzy, lightheaded, unsteady or unwell. In the longer term it is advised to minimise behaviours that increase the chance of relapse into arrhythmia. For example heavy drinking, recreational drug use, and high stress situations are all best avoided. It is particularly important not to interrupt taking anticoagulant drugs (blood thinners) after a cardioversion unless recommended to do so by a healthcare professional who is familiar with the procedure and with your medical history. Stopping anticoagulant drugs inappropriately - or even missing doses - can increase the risk of stroke.
Do they stop your heart during cardioversion?
This is a common misunderstanding. The heart is not “stopped” by the application of the controlled direct current (DC shock) across the chest. In fact this merely resets the electrical activity of the heart for an instant, allowing the normal heart rhythm to resume.