Having a left-atrial appendage occlusion device fitted is an alternative treatment to long-term anticoagulation.

In some circumstances, long-term anticoagulation with warfarin or direct oral anticoagulants (DOACs) may not be possible because of the high risk of bleeding complications, raised by other medical conditions. For example, if you have suffered bleeding in the stomach or bowel or had a stroke caused by bleeding then it may not be appropriate for you to take anticoagulants. 

Your case will be discussed at a multidisciplinary team (MDT) meeting, where other options for treatment will be explored. 

One option may be to close a part of the heart (the left-atrial appendage) where a clot is most likely (80–90% of the time) to occur. This method does not remove your risk of stroke, but it appears to be as effective as anticoagulation, without carrying the risk of bleeding complications. The left-atrial appendage is closed with a device (a 'plug') that stops blood from entering the appendage and by doing so stops blood clot formation, reducing the risk of stroke.

Before the procedure, and for up to six months after the procedure, you will be asked to take blood-thinning medication. If you are unable to take blood-thinning medication in this period, we will not be able to perform the procedure and an alternative approach may be recommended. 

The admission arrangements and procedure are similar to AF ablationLeft-atrial appendage is performed under general anaesthetic. Once you are anaesthetised, we will pass an ultrasound tube (transoesophageal echocardiogram (TOE) through the mouth to the oesophagus. This will help us to see if there are any clots in the left atrium, specifically in the small outpouch – the left-atrial appendage – which we are intending to close with a device. If there is a clot, the procedure will be abandoned and postponed until the clot has cleared with the help of blood-thinning medication.

If there is no clot we will go ahead with the procedure. We will place two small tubes into the veins at the top of your leg, near the groin area. These tubes allow us to pass through another tube (catheter) holding the device. This is then crossed from the right atrium, through a small punctured hole, to the left atrium. Using the TOE again, we will place the device in the best possible position in the left-atrial appendage, and it will remain there permanently. 

After your procedure, you will have an echocardiogram and be monitored by the clinical team. If you remain well, and your echo is clear, you will be discharged home.

You will be asked to come back in three months for a transesophageal echocardiogram (TOE), where we will check the device, and check for any clots in small gaps that may not have been filled in by the device at the time of the procedure.

Complications of a left-atrial appendage device ('plug')

  • 0.5 per cent (1 in 200) risk of stroke
  • 1 per cent (1 in 100) risk of peripheral vascular damage (damage to the veins/arteries in your groin), when we put the tubes in your groin
  • 1–2 per cent (1–2 in 100) risk of tamponade (bleeding around the heart) that needs urgent drainage and may require a blood transfusion
  • 0.2 per cent (1 in 500) risk of cardiac surgery
  • 0.2 per cent (1 in 500) risk of plug migration requiring cardiac surgery
  • 0.1 per cent (1 in 1000) risk of death

Atrial tachycardia is an abnormal heart rhythm which is usually seen in patients that have undergone heart surgery, have congenital heart defects or have undergone previous ablation procedures.

Atrial fibrillation is an abnormal heart rhythm. It is the most common heart rhythm disorder in the UK.

Arrhythmia team

The arrhythmia team includes: 

  • EP consultants
  • clinical nurse specialists
  • an arrhythmia pharmacist 
  • catheter laboratory technicians.  


Clinical nurse specialists

  • Beatrice Moloce, Royal Brompton Hospital

  • Harriet Fisher, Royal Brompton Hospital

  • Sue King, Harefield Hospital

  • Sally Deane, Harefield Hospital

Arrhythmia pharmacist

  • Carol Hayes


Harefield Hospital
01895 828979

Royal Brompton Hospital
020 7351 8364 

Useful links

If you want to know more about arrhythmia, here are some helpful organisations and websites: