Pacemakers, CRT and defibrillators (ICDs)
Implantation and follow-up of pacemakers, cardiac resynchronisation therapy (CRT) devices and implantable cardioverter defibrillators (ICDs).
About heart rhythm devices
Your heart has its own electrical system that sets its rhythm. If that system becomes too slow or unreliable, if the two sides of the heart stop beating in step, or if you are at risk of a dangerous fast rhythm, a small device fitted under the skin of the chest can keep your heart beating safely.
- A pacemaker sends small electrical signals that stop the heart beating too slowly. A leadless pacemaker, placed inside the heart without wires, suits some people.
- A cardiac resynchronisation therapy (CRT) device is a pacemaker with an extra lead that makes the two sides of the heart pump together. It can include a defibrillator (CRT-D).
- An implantable cardioverter defibrillator (ICD) watches the heart rhythm and, if a dangerous fast rhythm starts, stops it with rapid pacing or a shock.
Is it right for me?
- A pacemaker is usually recommended when the heartbeat is too slow or pauses, for example because of heart block, where the electrical signal between the upper and lower chambers is delayed or blocked. A slow heartbeat can make you feel dizzy or faint, breathless or tired.
- CRT is used for some people with heart failure whose heart pumps weakly and whose lower chambers no longer beat in step. Bringing them back into step can help the heart pump more efficiently.
- An ICD is recommended if you have survived a cardiac arrest or a dangerous fast rhythm from the lower chambers, or if you are at high risk of one, for example because of an inherited heart condition or heart failure with weak pumping.
We will explain whether a device would help you, which type, and any alternatives.
What to expect
- Devices are fitted in hospital, usually under local anaesthetic, with sedation if needed.
- Fitting a pacemaker usually takes about an hour, longer for more complex devices. You may stay in hospital overnight.
- The device is checked before you go home and at regular follow-up appointments.
- Your chest will be sore for a few days. For 4 to 6 weeks, avoid lifting your elbow above shoulder height on the side of the device, carrying heavy objects and vigorous exercise.
Risks
Fitting a device is a common procedure and serious problems are unlikely. Infection is possible: contact us or NHS 111 if the wound becomes more swollen, tender or red, starts to leak, or if you develop a very high temperature.
Why choose Cambridge Cardiac
You will be under the care of Dr Claire Martin, an expert in pacemakers and implantable defibrillators.
Claire has been treating heart rhythm problems and fitting heart devices as a consultant at Royal Papworth Hospital since 2018, and holds a National Clinical Impact Award (2023) recognising her contribution to NHS patient care.
- She is part of international research to make device implantation safer, including a major trial of subcutaneous defibrillators (PRAETORIAN-DFT, published in Circulation in 2026) and a tool for predicting device infections.
- She advises device manufacturers, including Boston Scientific, Medtronic and Abbott, on developing new devices.
- She pioneers the use of new technologies, such as leadless pacing and extravascular ICDs, which have been shown to reduce the risk of long-term complications.
Next steps
- Contact us to arrange a consultation. If you have private health insurance, we will guide you through getting your insurer’s approval, and we can tell you about fees if you are paying for yourself.
- Consultations take place at Royal Papworth Hospital, Cambridge Heart Clinic and Nuffield Health Cambridge Hospital in Cambridge, and The Harley Street Clinic in London (see locations).
Further information
- NHS: Pacemaker implantation
- NHS: Heart rhythm problems (arrhythmia)
- NICE TA314: ICDs and CRT for arrhythmias and heart failure
This page is general information, not medical advice for your situation.