London Heart

Cardiac Resynchronization Therapy

What is CRT?

Cardiac Resynchronisation Therapy (CRT) also known as bi-ventricular pacing is a special. type of pacemaker device. It is buried under the skin with leads that are passed 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, which allows the heart to beat more efficiently. In some people, there is also an additional function which monitors your hearts rhythm for dangerous fast rhythms and, if it detects one, can deliver a small electrical shock to shock your heart back into normal rhythm. This is known as a cardiac resynchronisation defibrillator or CRT-D for short.

Why do I need a CRT?

A CRT device is used in patients who have heart failure. This means that your heart is not pumping blood out as efficiently as it should. There are various reasons for this, such as muscle damage from heart attacks or heart muscle disease (cardiomyopathies). If your heart is working normally, both ventricles beat at the same time which means blood can be pumped 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. This may lead to you feeling more short of breath than you once did or that you develop fluid building up in your legs. Initially, your Cardiologist will try to control these symptoms with medications to take the pressure off the heart but, if these aren’t working optimally, CRT may be considered.

Why do I need a defibrillator?

If your heart isn’t beating as well as it should you may be an increase risk of dangerous fast heart rhythms. These could make you feel faint and dizzy, lose consciousness and, in very severe case, could be fatal. Therefore, in some cases, your CRT device can monitor your heart rhythm for these dangerous rhythms and, if it detects one, can pace your heart rapidly or deliver a small electric shock to put your heart back into normal rhythm.

Your Cardiologist will discuss the specific types of CRT and, with you, decide which one is the best for you.

How is a CRT inserted?

A CRT is usually inserted whilst you are still awake. You will be given some sedation (medication to make you sleepy) and local anaesthetic (medication injected under the skin to make the area numb). A cut is then made in your chest, just below the collar bone, and usually on the left side. From the veins in your chest, leads are passed down to the heart the heart. Usually, there are 3 leads but sometimes there are only 2, depending on your individual case. A pocket is then made under the skin for the battery, or generator. Once the leads and the battery are connected, the wound is closed with sutures (stitches). After your CRT is inserted, you will usually stay in hospital overnight for monitoring and to make sure everything is ok.

Depending on which type of sutures your Cardiologist uses, you may need to have the sutures removed in 7-10 days by your GPs practice nurse. The hospital staff will tell you if and when you need to do this.

What are the risks from 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 and the risk of the leads moving. Almost all the complications can be treated 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 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, it is important to keep the wound clean and dry. This is important to minimise the chances of the wound getting infected.

It is also important that, for the first 6 weeks, you don’t lift your left arm (or right arm if the device is on the right side) above your shoulder. This is because 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 move. This means that it wont be able to work effectively and you may 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 period of time after the device is implanted and inform the DVLA that you have had the device implanted. The time that you are restricted from driving depends on the type of device and the reasons why it was implanted.

What is the follow-up?

Before you go home, the team at the hospital will probably check your device to make sure that it is working as it should. They will also give you a card stating what type of device you have and when it was inserted. It is important to keep this with you at all times, just in case you have any problems.

Then, after a month, you wil have another check to make sure that the device is still working efficiently as it should. Thereafter, your device is checked every 6 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 that you’ve had a shock from the device, you should get in contact and 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. This is a straightforward procedure but your Cardiologist can attach a new battery to the existing leads, which do not normally need to be replaced. The leads can last longer and usually, stay in for the rest of your life.