Implantable Cardioverter Defibrillator (ICD) in London

Advanced protection against dangerous heart rhythms

At London Heart Group, our consultant cardiologists are experts in the implantation and management of implantable cardioverter defibrillators (ICDs) — small, life-saving devices that monitor your heart rhythm and deliver treatment if a dangerous rhythm is detected.

For people at risk of sudden cardiac arrest or serious rhythm disturbances, an ICD provides constant protection, peace of mind, and the chance to live life with confidence.

What Is an ICD?

An implantable cardioverter defibrillator (ICD) is a small device placed under the skin, usually below the collarbone, that continuously monitors your heartbeat.

If the ICD detects a dangerous heart rhythm — such as one that’s too fast (ventricular tachycardia) or chaotic (ventricular fibrillation) — it automatically delivers a precisely timed electrical pulse or shock to restore a normal rhythm.

Modern ICDs also act as pacemakers, ensuring your heart does not beat too slowly.

Why You Might Need an ICD

You may be advised to have an ICD if you have a high risk of life-threatening heart rhythms, either due to a previous cardiac event or an underlying heart condition.

Your cardiologist might recommend an ICD if you have:

  • Survived a cardiac arrest caused by ventricular arrhythmia

  • Experienced ventricular tachycardia (a dangerously fast heart rhythm)

  • Weakened heart muscle (heart failure or cardiomyopathy) that increases your risk of sudden arrhythmia

  • Certain inherited heart rhythm disorders, such as Long QT syndrome, Brugada syndrome, or arrhythmogenic right ventricular cardiomyopathy (ARVC)

  • Severe coronary artery disease with reduced heart pumping function

The goal of an ICD is to detect and treat abnormal rhythms instantly, preventing cardiac arrest and saving lives.

How the ICD Works

An ICD constantly monitors your heartbeat. If it detects a problem, it responds automatically:

  • For fast but organised rhythms, it can deliver painless pacing pulses to slow the heart down.

  • For chaotic or life-threatening rhythms, it gives a short electrical shock to restore a normal rhythm within seconds.

  • It stores detailed information about your heart activity, which your cardiologist reviews at each follow-up.

You won’t feel the device working most of the time — only if a shock is delivered, which may feel like a brief thump or jolt.

The ICD Implantation Procedure

ICD implantation is a routine, minimally invasive procedure, usually performed under local anaesthetic with sedation.

During the procedure:

  1. A small incision is made below the collarbone.

  2. One or more thin leads (wires) are guided through a vein into your heart.

  3. The ICD unit (containing the battery and circuitry) is connected to the leads and positioned under the skin.

  4. The system is tested to ensure it detects and treats rhythms correctly.

The procedure typically takes 1–2 hours, and most patients go home the next day.

How Safe Is an ICD?

ICD implantation is very safe, and serious complications are uncommon.
At London Heart Group procedures are performed by consultant electrophysiologists in a specialist cardiac catheter laboratory using advanced imaging, monitoring, and sterile techniques.

Minor side effects such as bruising or mild discomfort at the implant site are common but temporary.
The risk of major complications (such as infection or lead displacement) is low — typically under 1–2%.

Modern ICDs are reliable, long-lasting, and remotely monitored, ensuring your heart is protected around the clock.

Living with an ICD

After recovery, most people can return to their usual activities — including work, travel, and gentle exercise. You’ll have regular follow-up appointments to check your device’s performance and your heart rhythm data.

Your clinical team will also explain:

  • When to seek medical advice after a shock

  • How ICDs interact with electronic devices and airport security systems

  • What activities to avoid (usually temporary restrictions only)

Many patients find great reassurance in knowing their ICD is always ready to act if needed.

ICD and CRT-D: What’s the Difference?

Some patients with weakened heart muscle may benefit from a cardiac resynchronisation therapy defibrillator (CRT-D) — a special type of ICD that also helps coordinate the pumping action of the heart’s chambers. Your cardiologist will advise which device is best for your specific condition.

Book in with London Heart Group

If you have symptoms such as dizziness, fainting, or an unusually slow heartbeat — or if you’ve been advised you may need a pacemaker — we’re here to help.

Call us on 0208 226 5888 or email enquiries@londonheartgroup.co.uk


Safe, advanced, and personalised treatment for slow heart rhythms – helping your heart beat strong and steady.