A cardiac resynchronization therapy device is a medical device used to resynchronize the contractions of the heart's ventricles by sending tiny electrical impulses to the heart muscle.

Why do I need a cardiac resynchronization therapy device?

A cardiac resynchronization therapy (CRT) device may be suggested for patients with heart failure. A CRT can help your heart pump blood throughout the body more efficiently. When the heart chambers are weakened, the heart’s pumping ability is less than it should be. This weaker pumping action causes an increased strain on the heart which in turn can lead to symptoms such as breathlessness, fatigue, low blood pressure and fluid retention.

When medication options have been exhausted, a CRT device can help the heart pump stronger and improve your quality of life, overall lifespan and ability to exercise. 

What is a cardiac resynchronization therapy device?

A CRT device is a type of pacemaker that is inserted into your upper chest. It is usually placed just below the skin near your collarbone. A CRT device can be a pacemaker alone or a pacemaker with additional features of an implantable cardioverter defibrillator (ICD) device. The cardiac resynchronization therapy device is sometimes called a biventricular pacemaker.

What is an implantable cardioverter defibrillator and why would I need one?

An implantable cardioverter defibrillator device recognizes when the heart is beating dangerously fast. If your heart begins beating dangerously fast, the device will try to correct the rhythm by delivering rapid electrical signals to the heart which you will not be able to feel. If the rhythm does not respond to these signals the device will give a controlled electrical shock to correct the dangerous rhythm. You will feel this shock.

Implantable cardioverter defibrillators are usually very effective at being able to correct a dangerous rhythm and usually work within 10 seconds of detecting the problem. These devices do not prevent the dangerous rhythm from happening so you will also need to continue taking medication. One of these devices may be suggested because you are having dangerous fast heart rhythms or are at risk of having dangerous fast heart rhythms. These life-threatening rhythms can be corrected by an ICD device.

The CRT device and the ICD device have two parts:

  • The battery or generator
  • The pacing wires, called leads

The generator monitors your heart beat and rhythm. When needed, it sends an impulse to your heart. The leads go from the device to inside your heart. They are attached to the heart muscle. These devices can have one, two or three leads. There is always a high voltage lead if a CRT device with ICD features is implanted. The high voltage lead can both pace and provide a controlled electrical shock if needed.

How long does a CRT or ICD device last?

The battery life depends on the type of device. Usually, the battery lasts about six to 10 years. Most people have their battery checked every six to 12 months at a Cardiac Clinic or their heart specialist’s office. Your electrophysiologist may decide to use remote monitoring of your device. The leads can last many years and may never need to be replaced.

How can I prepare for my ICD implant?

Follow these preparation steps to prepare for your pacemaker procedure.

Contact your doctor or the implantable cardiac electrical devices coordinator at 1-855-529-7223 if you have any questions prior to your procedure.

What is done during an ICD implant?

In Fraser Health, your procedure could be done either at the Jim Pattison Outpatient Care and Surgery Centre or Royal Columbian Hospital depending on the type of procedure requested.

Learn more on our main implantable cardiac electrical devices page.

Resources