Cardiac Resynchronisation Therapy

What is CRT?

Cardiac Resynchronisation Therapy (CRT), also known as biventricular pacing, is a pacemaker device. We bury it under the skin with leads that we pass down the veins into each of the bottom chambers of the heart (the ventricles). It uses small electrical impulses to stimulate the two bottom chambers of the heart to beat at the same time. This allows the heart to beat more efficiently.

Some people require an additional function that monitors your heart’s rhythm for dangerous fast rhythms. If it detects one, it can deliver a small electrical shock to shock your heart back into normal rhythm. We call this a cardiac resynchronisation defibrillator (CRT-D).

Why do I need a CRT?

We use a CRT device in patients with heart failure, meaning their heart is not pumping blood out as efficiently as it should. There are various causes, such as muscle damage from heart attacks or heart muscle disease (cardiomyopathies).

If your heart works as it should, both ventricles beat simultaneously, meaning your blood pumps efficiently throughout your body.

In addition, in a significant proportion of patients with heart failure, one side of the heart can beat out of sync with the other. Your cardiologist might call this a “bundle branch block”. This means that the blood cannot flow as efficiently throughout the body. You may feel more short of breath than you once did or develop fluid build-up in your legs.

Initially, we will try to control these symptoms with medications to take the pressure off the heart. But, if these aren’t working optimally, we may consider CRT.


Why do I need a defibrillator?

If your heart isn’t beating as well as it should, you may be at an increased risk of dangerously fast heart rhythms. These could make you feel faint and dizzy, lose consciousness, and, in very severe cases, could be fatal.

In some cases, you receive a CRT device that can monitor your heart rhythm for these dangerous rhythms. If it detects one, it can pace your heart rapidly or deliver a small electric shock to put your heart back into normal rhythm.

We will discuss the specific types of CRT with you and decide which is best together.


How is a CRT inserted?

We usually insert a CRT while you are still awake. You will receive sedation (medication to make you sleepy) and local anaesthetic (medication injected under the skin to numb the area).

We then make a cut in your chest, just below the collarbone, on the left side. From the veins in your chest, we pass leads down to the heart. Usually, there are three leads, but there may be two, depending on your case. Then, we make a pocket under the skin for the battery or generator.

Once the leads and the battery are connected, we close the wound with sutures (stitches). You will usually stay in the hospital overnight for monitoring.

Depending on the sutures we use, you may need to have them removed in 7-10 days by your GP’s practice nurse. The hospital staff will tell you if and when you need to do this.


How is a CRT pacemaker implanted?0:40

What are the risks of the procedure?

The main risks from the procedure are essentially the same as having a pacemaker implanted.

These include

  • Infection
  • Bleeding and bruising
  • Scratching the surface of the lung (pneumothorax)
  • Bleeding around the heart
  • The leads moving

We can treat almost all the complications at the same time. Occasionally, due to your anatomy, the lead to the left ventricle cannot be implanted. This may mean a further procedure or a different technique will be required to implant the lead.


How safe is cardiac resynchronisation therapy (CRT)?0:22

How long will it take to recover?

As already mentioned, you may need to have the stitches removed after 7-10 days. For the first week, you must keep the wound clean and dry to minimise the chances of the wound getting infected.

For the first six weeks, don’t lift your left arm above your shoulder – or right arm if the device is on the right side. It takes this long for the leads to become bedded and fixed into position.

If you move your arm, one of the leads could become dislodged and relocate, meaning it won’t work effectively. You may then need another procedure to put the lead back into the correct position.

Will I be able to drive?

You will have to stop driving for a while after the device is implanted and inform the DVLA that you have had the device implanted. The time you can’t drive depends on the type of device and the reasons we implanted it.


How long does recovery from a CRT procedure take?0:19

What is the follow-up?

Before you go home, the team at the hospital will check your device to ensure it is working as it should. They will also give you a card stating what type of device you have and the insertion date. Keep this with you at all times in case you have any problems.

After a month, you will have another check to see if the device is still working as it should. We then need to check your device every six months – 1 year.

Your local device clinic will give you a contact number should there be any problems. If you have a CRT-D and you think you’ve had a shock from the device, you should get in contact. They can check the device and, if necessary, take any action required.


How long will my CRT device last?

The battery of your CRT will last for around 7-10 years. After this time, you will need to have it replaced. It is a straightforward procedure. We attach a new battery to the existing leads, which don’t often need replacing. The leads can last longer and usually stay in for the rest of your life.


How long does a CRT battery last?0:17

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