Cardioversion

Cardioversion 

Patient Information

Cardiac Catheter Laboratory

• Author ID: PD
• Leaflet ref: Card 008
• Version: 9
• Leaflet title: Cardioversion
• Last review: September 2024
• Expiry date: September 2026

Introduction

If you have an abnormal hearth rhythm such as atrial fibrillation, your doctor may want you to have a treatment called cardioversion.  This treatment aims to get your abnormal heart rhythm back to normal.  You will be given a short-acting heavy sedation, so you will be asleep throughout the procedure.

The Clinician performing the procedure (this may be an Advanced Clinical Practitioner or sometimes a doctor) will put electrodes, stuck to large sticky pads, on your chest. The electrodes are connected to a defibrillator machine and will give you one or more controlled electric shocks to your chest wall. The whole procedure usually lasts about 20 minutes.

The defibrillator monitors your heart rhythm throughout the procedure, so the staff can see straight away if the cardioversion was successful.  You will usually only need to go to hospital for part of the day, although occasionally, some people need to stay overnight. 

You will have a pre assessment appointment prior to your admission, when the risks and benefits of the procedure will be explained, and you will have the opportunity to ask questions 

Admission 

Prior to your admission to the Cardiac Catheter Laboratory (CCL), you will have a blood test in the outpatient department and a blood form and instructions about this will be sent to you by post. 

When you arrive in the department, you will have an ECG to check your heart rhythm. Then the nurses will check your details. The clinician will explain the risks and benefits again and ask you to sign a consent form. You will have a cannula inserted into a vein in your arm through which sedation can be administered.   

A gown will be provided, however, you will be able to wear your own trousers/skirt so please wear something comfortable, such as tracksuit bottoms. Try to avoid wearing jeans. 

The clinician will perform the procedure and will be assisted by a trained nurse. 

The equipment used to perform the cardioversion is called a defibrillator. The defibrillator has two pads. One pad will be placed under your right collarbone, whilst the other pad will be placed under the lower end of your rib cage or on your back. You will also have your blood pressure monitored and be given oxygen via a face mask. You will then be sedated with a short acting medication, and once you are asleep, the defibrillator will be programmed to deliver a set of electric currents through the heart via the pads.

You will then be transferred back to the recovery area, where you will stay until you have fully recovered from the sedation. 

The nurse will sit you upright when fully recovered and provide you with a drink and a sandwich. The clinician will review your medication and make any necessary changes; your GP will be informed of the outcome of your cardioversion and any changes to your medication via a letter.  Within the next two to three hours, you will be allowed to go home, providing the clinician is satisfied with your recovery. Following the procedure, you will need to stay with a relative/friend overnight.

Someone will need to collect you from the department following your cardioversion, as you will not be permitted to drive for the next 48 hours.  It is advised that once at home, you rest for the remainder of the day. You will require someone to stay with you overnight. Daily activity, e.g. driving, shopping, housework and returning to work, can resume 48 hours at the earliest following the procedure.

Risks

Complications during or after cardioversion are not common.  The procedure is not always successful. If this is the case for you, the clinician will give you a plan before you leave the department.  You may get superficial burns/redness where the electrodes have been in contact with your skin; this usually resolves within a few days.

 It is essential to be on a blood thinner prior to your cardioversion; the Specialist Nurse will discuss this with you at your pre assessment appointment.  It is common for your heart to beat more slowly following a successful cardioversion; this is normal, but occasionally some people’s hearts beat a little too slowly. If this happens, the clinician will give you some medication to speed it up via the cannula in your arm. Some patients need to have a pacemaker following a cardioversion; however, this is very rare.

Although sedation is very safe, it is important to have an empty stomach prior to your procedure; details of when you may eat and drink will be sent to you with your appointment.

Benefits

Cardioversion doesn’t always restore normal heart rhythm. Sometimes it’s successful to start with, but then your abnormal heart rhythm comes back several days, weeks or even months later. If this happens, your doctor may want to repeat the cardioversion, or they may consider another treatment for you.