What is Electrical Cardioversion?

Electrical cardioversion is a procedure intended to re-establish the heart’s normal rhythm by passing a controlled electrical current across the chest. We are recommending you have this procedure as your heart is beating abnormally.

How will I benefit from this procedure?

Because your heart is beating abnormally, its pumping action may be reduced giving you symptoms such as breathlessness, reduced exercise tolerance and tiredness. By restoring your heart’s normal rhythm, symptoms can be improved. It may also be possible to reduce or discontinue some of your medication, but this will be decided after the procedure.

Will it be successful?

There is a greater chance of success if your heart has only been in abnormal rhythm for a short while, i.e. a few weeks. However, the effectiveness does vary from person to person. In some people the procedure will restore a normal heart rhythm initially, but it will revert back to Atrial Fibrillation/Flutter (an abnormal heart rhythm) at a later date. In some instances the procedure will not be successful at all.

The best results are seen in patients who have normal heart structures. The lowest success rates are seen in patients with structural heart impairment, for example, leaky valves or enlarged heart chambers. An echocardiogram will reveal any abnormalities.

Are there any risks?

As with any medical procedure, there are some potential risks. There is a small risk of complications arising from the general anaesthetic itself. Those particularly associated with cardioversion include:

  • A small risk of a major complication such as a heart attack or stroke.
  • Rarely, some patients may require a temporary pacing wire to be inserted if the heart beats too slowly.
  • Minor risk of slight skin burns to the chest from the adhesive pads used during the procedure. Should this happen, then hydrocortisone cream can be applied to ease any discomfort

Is cardioversion the only option?

You may decide not to proceed for a variety of reasons. In this case, your condition can be managed with medication and Warfarin treatment. This will control heart rate and alleviate some of your symptoms but you will need to take medication for life.

Will Warfarin always be necessary?

Generally yes. Because your heart is beating abnormally, small clots can develop in the chambers of the heart. Warfarin will thin your blood and will help to prevent clots developing. It is important to get the dose right which is why you will need frequent blood tests. Ideally the result should be between 2 and 3 for four consecutive weeks for the cardioversion to go ahead.

Please call the Arrhythmia Nurse Specialist on 01935 384884 if your INR (warfarin check) drops below 2 in the four weeks leading up to your cardioversion.

Pre Assessment in the Clinical Investigations Department, Level 3

Tuesday morning
You will be formally assessed by the BHF Arrhythmia Nurse Specialist or the deputy. Part of this assessment will include taking your blood pressure, recording your electrocardiogram (ECG) and having some blood samples taken. Please bring your Warfarin booklet with you and a list of current medication.

The cardioversion procedure will be explained to you and if you have any questions this will be an opportunity to discuss these. Your partner is welcome to attend if you wish.

Procedure in Day Theatre, Level 3

Nil by mouth from midnight
Friday morning – arrive at 8am
Please note: The time of your admission is not the time of the procedure. The anaesthetist will assess you, your consent for the procedure will be obtained and a small needle, called a Venflon, will be inserted into a vein in the back of your hand.

General Advice

  • Leave your car at home. Get someone to bring you into hospital and arrange for someone to take you home. You will normally be discharged between 12pm and 1pm.
  • You should have a responsible adult stay with you for 24 hours. If this is not possible, you may book a bed for an overnight stay. (Please advise us as soon as possible).
  • Do not bring in any valuables.
  • Do not wear jewellery (you can leave a wedding ring on).
  • Do not wear make-up or nail varnish.
  • If you are diabetic, do not take your usual medication on the morning of the procedure, but please bring it with you for after the cardioversion.
  • Continue with your usual medication including Warfarin. The only exception is Digoxin. This must be stopped 2 days before the procedure. Take the last dose on Wednesday. You will be advised about whether to continue with your other medication after the procedure.

Things to bring with you

  • Please bring any drugs or inhalers you may take as prescribed by your GP.
  • Dressing gown and slippers.
  • Magazines, newspaper or a book to read while you wait.

About your general anaesthetic

A general anaesthetic gives a state of controlled unconsciousness which stops you feeling pain and other sensations. Therefore, it is important to remember that although you will be receiving an electric shock, you will not be aware of it. Before your procedure, you are advised to give up smoking to reduce the risk of breathing problems.

If you have any loose teeth or crowns, you may need treatment beforehand from your dentist to reduce the risk of damage to your teeth. You will be asked to remove all jewellery except your wedding ring which will be covered by tape.

Theatre staff will check your identity again, asking your name, date of birth and other details on your medical records as a final check that you are having the right procedure. When you go into the theatre, monitoring equipment which measures your heart rate, blood pressure and oxygen levels will be attached to you. This is a routine procedure to keep you safe. A nurse will accompany you at all times, so if you have any worries or concerns please feel able to discuss them

After receiving a general anaesthetic

Your co-ordination may be affected and you may feel slightly muddled during the first 24-48 hours following discharge. It is therefore advisable:

  • To rest for a day or two.
  • To refrain from driving for 48 hours.
  • Not to use power tools, machinery or appliances which may cause harm or injury.
  • Not to make vital decisions or sign legal documents.
  • When rising to a sitting or standing position, do it slowly as you may become dizzy if you get up too quickly.

After your cardioversion

You will wake up very quickly. As soon as the nurse is happy with your condition, you will be offered a drink, then something to eat. An ECG would have been performed while you were still asleep so we can tell if the procedure was successful.

Follow-up arrangements

If the procedure was successful you will be sent an appointment to see the BHF Arrhythmia Nurse Specialist in 12 weeks. If the procedure was not successful you may be sent an appointment to see the Consultant. Until that time you will need to continue on Warfarin.

We would like you to have an ECG four weeks after your procedure to check your heart rhythm. A request form will be given to you on discharge. If you feel your heart rhythm has changed before your ECG appointment, please telephone the Clinical Investigations Department on 01935 384457.

Further information

If you have any queries or concerns, please contact the BHF Arrhythmia Nurse Specialist on 01935 384884 or telephone the Hospital switchboard on 01935 475122 and ask for Bleep No. 2885. Alternatively, out of hours, please contact the Coronary Care Unit on 01935 384429.

Leaflet No 02-14-101 02/12
Review date 02/14