What is a Catheter ablation?
Catheter ablation for common arrhythmias in adults or children uses radiofrequency energy delivered to cardiac tissues using a steerable ablation catheter passed through a vein in the leg under local anaesthetic and conscious sedation. Typical arrhythmias treated include all forms of supraventricular tachycardia, atrial flutter, and some forms of ventricular tachycardia.
How does it work?
Radiofrequency current is passed to the tip of the ablation catheter from a radiofrequency generator. This generator can deliver selected temperatures and radiofrequency energies. A temperature sensor in the tip of the catheter ensures that the required energy is delivered when the catheter is in contact with the selected heart tissue, and the energy is turned on. The radiofrequency ablation catheter is radio-opaque, and is positioned in the heart using x-rays in a catheter laboratory.
Before the procedure , a nurse will prep you by inserting an IV line with anaesthesia to prevent pain and potentially offer you a sedative to help you relax. You will be awake during the whole time. The area where the consultant will be working, usually the groin, will be cleaned and shaved.
The consultant will make a puncture into your skin to get to the blood vessel in your groin, and then insert a tube the size of a straw (sheath). He or she will then guide a catheter into the vessel through the sheath whilst following its position on a screen. You shouldn’t feel any pain, just some pressure on your groin.
After the catheter has been inserted, the consultant will then start inserting several long tubes called electrode catheters through the sheath. These electrode catheters are used to send small electrical impulses that will locate the abnormal tissue causing the arrhythmia. With the abnormal cells located, the consultant can now position the catheter in the exact place and send a painless radiofrequency signal to the tissue and destroy the abnormal cells.
Once the procedure is done you will be moved to a recovery room because the sheath needs to stay in your leg for several hours. A nurse will then guide on what you need to do at home for a speedy recovery.
What are the benefits?
The heart can develop abnormal cell which disrupt the regular heartbeat, leading to arrhythmias which leave you feeling faint, short of breath or weak. These arrhythmias can’t always be treated with medicine, or the treatment can cause side effects in some people which is why the consultant will recommend a catheter ablation.
For example, for supraventricular tachycardia (SVT), about 97% of patients are cured, with a 3-4% risk of recurrence of tachycardia.
How safe is the treatment?
There is a 1:200 risk of a pacemaker in certain specific cases, and a very low risk of serious complications. The risk of death is <1:20,000 cases. Most of the risks can appear from the use of catheters because the insertion might cause damage to the blood vessel or lead to an infection.
Catheter ablation is usually avoided if possible in children under the age of 6 years, mostly on the basis of their size and the desire to avoid x-ray exposure.