Having a device

Your heart is controlled by electrical impulses that co-ordinate the chambers of the heart as they pump blood through your heart to your body. You may have been advised to have a device implanted or know someone who has.

Some people will have medical devices to treat their cardiomyopathy. These are types of implanted technology to support the heart; either by monitoring the heart rate and treating any abnormal rhythms, or by taking over the control of the heart rate to keep a regular rhythm. 

What types of device are there?

There are different types of device, each with a slightly different function. They fall into three categories: ICDs, pacemakers (including CRT or cardiac resynchronisation therapy devices), and VADs
(ventricular assist devices). 

  • ICDs monitor and shock the heart when a dangerous arrhythmia occurs;
  • pacemakers set the pace of the heart;
  • CRTs synchronise both sides of the heart to beat together; and
  • VADs help to support the function of the heart if it is seriously impaired.

Implantable Cardioverter Defibrillators (ICDs)

  • ICDs monitor the heart rhythm and respond to abnormal heart rhythms. When dangerous abnormal rhythms are detected an ICD works to restore the normal rhythm of the heart.
  • ICDs are often implanted in someone who has experienced abnormal or dangerous heart rhythms (for example that have caused them to lose consciousness or led to a cardiac arrest). They are also used for people who are considered to be at risk of having abnormal or dangerous heart rhythms.
  • An ICD is implanted following a general anaesthetic, or while you are sedated with a local anaesthetic. You will usually be in hospital overnight following the implant in order to check on your recovery.


  • A pacemaker is a small device which is usually implanted if your heart is beating too slowly, either some or all of the time.
  • If the pacemaker senses that your heart has missed a beat or is beating too slowly, it sends a signal at a steady rate. If it senses that your heart is beating at a steady rate it doesn’t send any signals to the heart.
  • Pacemakers store information about your heart rhythm, which can then be analysed by a specialist. Sometimes this is sent via a home monitor to the specialist centre.

Cardiac Resynchronisation Therapy (CRT) Devices 

There are two types of devices:

  • Cardiac Resynchronisation Therapy Pacemaker (CRT-P) is similar to a pacemaker, sending an electrical signal to keep the heart beating at a steady rate. It also sends out a signal to the heart to help it pump more efficiently, increasing blood flow.
  • Cardiac Resynchronisation Therapy Defibrillator (CRT-D) is similar to an ICD, sending an electrical signal to keep the heart beating at a steady rate. It also senses abnormal heart rhythms and sends an electrical signal to restore the normal rhythm. 

Implantable Loop Recorders (IRL)

An implantable loop recorder (ILR) or Linq is a device which monitors and records the electrical activity of the heart.

  • You may need an ILR if you are experiencing symptoms that have not been detected by previous ECGs or a Holter monitor.
  • The ILR insertion is usually performed as a day case. It is inserted beneath the skin in the upper chest under local anaesthetic.
  • The ILR monitors and records any abnormal rhythms.