FAQ

An ICD (Implantable Cardioverter Defibrillator) is a small device implanted under the skin, typically near the collarbone. It monitors your heart rhythm continuously and, if it detects a life-threatening arrhythmia, delivers a shock or pacing therapy to restore a normal rhythm. It works automatically — you do not need to do anything for it to act.

Not everyone with a heart condition needs an ICD. Whether one is appropriate depends on your specific diagnosis, your individual risk of a dangerous arrhythmia, and a detailed assessment by a specialist cardiologist.

ICDs are commonly considered for people who have already survived a cardiac arrest, and for some people assessed as being at high risk due to conditions including Hypertrophic Cardiomyopathy (HCM), Brugada Syndrome, CPVT, Long QT Syndrome, ARVC, and Dilated Cardiomyopathy. The decision is always individual — having one of these conditions does not automatically mean you need an ICD.

If you have been told you may need an ICD and want to understand the decision better, ask your specialist to walk through the reasons and what the alternatives are.

Category: Inherited Conditions

Having an inherited heart condition does not mean you will experience a cardiac arrest. It means you need the right specialist care, regular monitoring, and an informed conversation with your cardiologist about your personal risk profile.

Many people live long, full lives with conditions such as Hypertrophic Cardiomyopathy (HCM), Long QT Syndrome, Brugada Syndrome, CPVT, ARVC, and Dilated Cardiomyopathy — particularly when they are well managed. Understanding your specific triggers, adhering to any activity guidance, and taking prescribed medication consistently all make a significant difference.

Key steps if you have an inherited heart condition:

Know your triggers. Some conditions are provoked by exercise; others by sleep, sudden noise, or fever. Ask your cardiologist specifically what yours are.

Ask about treatment options. Medication, an ICD, catheter ablation, or a combination may all be relevant depending on your condition and risk.

Ensure your family is screened. Many inherited cardiac conditions can pass silently through families. First-degree relatives should be assessed even if they have no symptoms.

If you feel your condition is not being adequately monitored, ask your GP for a referral to an inherited cardiac conditions (ICC) clinic.

Category: Treatment

Life insurance is available after cardiac arrest and with an ICD, but it will typically be more expensive than standard rates and some providers may decline certain types of cover. The market varies considerably between insurers, so it is important to shop around and use a specialist broker where possible.

When applying for life insurance, you are required to disclose your medical history, including your cardiac arrest and any devices or conditions. Failing to disclose is likely to make any claim invalid. Insurers will usually ask for details of the event, the cause, your current medications, device type, and the results of your most recent cardiac review.

Some policies may be available at standard rates, particularly if the cardiac arrest occurred some years ago, the cause has been fully treated, you have a well-functioning ICD, and there are no other significant health conditions. Others will be offered at "loaded" (increased) premiums, or with exclusions for cardiac-related claims.

For those who cannot obtain standard life insurance, options include over-50s guaranteed acceptance plans (which do not require medical questions but typically pay a fixed sum) and specialist insurers who focus on people with pre-existing medical conditions.

The British Heart Foundation produces guidance on insurance for people with heart conditions. Specialist financial advisers experienced in this area can help identify the most suitable options.

A cardiac arrest does not mean life insurance is impossible — it means you need to look harder and possibly pay more.

Category: Implantable Devices

Moderate alcohol consumption is generally considered safe for most people with ICDs, but there are some important considerations.

Alcohol can affect heart rhythm. Even in healthy people, heavy alcohol consumption can trigger atrial fibrillation ("holiday heart") and, in people with certain underlying conditions, ventricular arrhythmias. For people with inherited arrhythmia conditions such as Brugada Syndrome, alcohol — particularly in large quantities — can be a recognised trigger for dangerous arrhythmias and should be avoided or very strictly limited.

For most ICD patients, the general advice is to drink sensibly and within the recommended UK guidelines (no more than 14 units per week, spread across three or more days, with alcohol-free days). Binge drinking should be avoided.

Alcohol can also interact with some cardiac medications. For example, certain antiarrhythmic drugs and blood-pressure medications are affected by alcohol. Ask your pharmacist or cardiac team about any specific interactions with your medications.

If you are unsure what is safe for your specific condition, discuss it with your cardiologist or device clinic. They can advise based on your diagnosis, your device settings, and the medications you take.

Category: Practical Issues

CPVT — Catecholaminergic Polymorphic Ventricular Tachycardia — is a rare inherited arrhythmia syndrome in which the heart is structurally normal but specific triggers, particularly physical exertion or emotional stress, can provoke dangerous ventricular arrhythmias. These can cause palpitations, blackouts, or sudden cardiac arrest.

CPVT is caused by mutations affecting calcium regulation within heart muscle cells, most commonly in the RYR2 gene. It typically presents in childhood or adolescence and can cause sudden cardiac arrest in young people who appear otherwise completely healthy. A standard resting ECG may be normal; an exercise stress test often reveals the characteristic bidirectional ventricular tachycardia.

Treatment includes beta-blockers to reduce the risk of arrhythmias triggered by adrenaline, strict avoidance of competitive and high-intensity exercise, and in many cases ICD implantation. Some patients are also treated with flecainide.

Because CPVT is inherited, family screening is essential following a diagnosis. First-degree relatives should be assessed with an exercise stress test as well as a resting ECG and echocardiogram, as the resting ECG may appear entirely normal even in affected individuals.

Category: Implantable Devices

Hypertrophic Cardiomyopathy (HCM) is the most common inherited heart muscle condition. In HCM, the walls of the heart — most often the left ventricle — become abnormally thickened (hypertrophied), which can obstruct blood flow, cause the heart to pump less efficiently, and create dangerous arrhythmias.

HCM affects approximately 1 in 500 people and is a leading cause of sudden cardiac death in young people, including young athletes. Many people with HCM have no symptoms at all; others experience breathlessness, chest pain, palpitations, or blackouts. In some cases, the first sign of HCM is a cardiac arrest.

HCM is caused by mutations in genes that encode the proteins of the heart muscle, most commonly MYH7 and MYBPC3. It is inherited in an autosomal dominant pattern, meaning each first-degree relative of someone with HCM has a 50% chance of carrying the same gene variant.

Treatment depends on symptoms and risk profile and may include medication (beta-blockers, calcium channel blockers), a procedure called septal reduction therapy (to reduce obstruction), and ICD implantation for those at high risk of sudden cardiac arrest.

Family screening — with ECG, echocardiogram, and genetic testing — is strongly recommended for all first-degree relatives.

Category: Implantable Devices

Brugada Syndrome is an inherited heart condition in which the heart’s electrical system malfunctions despite the heart having a normal structure. It is caused by mutations affecting sodium channels in heart cells — most commonly in the SCN5A gene — and produces a characteristic pattern on an ECG. People with Brugada Syndrome are at risk of dangerous ventricular arrhythmias (abnormal heart rhythms), which can cause sudden cardiac arrest, most often at rest or during sleep.

Brugada Syndrome is more common in men and in people of South-East Asian descent. It may be diagnosed after an unexplained cardiac arrest, after an abnormal ECG is found incidentally, or through family screening following a diagnosis in a relative.

The main treatment for those considered at high risk is an ICD (implantable cardioverter defibrillator), which can detect and terminate life-threatening arrhythmias. Certain medications and substances — including some antidepressants, sodium channel-blocking drugs, and large amounts of alcohol — can trigger arrhythmias in Brugada Syndrome and should be discussed with your cardiologist.

Because Brugada Syndrome is inherited, first-degree relatives (parents, siblings, and children) of anyone diagnosed should be offered cardiac screening.

Category: Cardiac Arrest

An implantable cardioverter-defibrillator (ICD) is a battery-powered device placed under the skin to monitor the heart rate. If an abnormal heart rhythm is detected (i.e., the heart is beating chaotically or too fast), the device will deliver a shock to restore a normal heartbeat. ICDs can prevent cardiac arrest in high-risk patients.

Category: Implantable Devices

For most people, the practical impact of an ICD on daily life is less significant than they expect going into implantation. The device works continuously in the background and does not require any action from you under normal circumstances.

Most activities are possible with an ICD, including work, driving (after any mandatory restriction period), travel, sport, and sexual activity. The restrictions that apply depend far more on your underlying cardiac condition than on the device itself. Your cardiologist will give you specific guidance based on your individual diagnosis and risk profile.

There are practical adjustments to get used to. You will carry a device ID card at all times. You will attend regular clinic appointments, typically every six to twelve months, and may have a remote monitoring base station at home. Some electromagnetic sources require a safe distance. The device may occasionally produce sounds or alerts that need to be reported to your clinic.

The psychological adjustment is often the more significant challenge, particularly in the first year. Anxiety about a possible shock, changes to body image, and the constant reminder of cardiac risk are all common experiences. These are worth discussing with your cardiac team, and peer support from others living with an ICD can make a real difference. SCA UK can connect you with people who have been through the same process.

Category: Implantable Devices

Patients who meet the criteria for an ICD are at higher risk of sudden cardiac arrest (SCA). An ICD is implanted to help protect against this risk. Without an ICD, a life-threatening arrhythmia such as ventricular fibrillation may not be treated in time for the person to survive. You should discuss the risks of not having an ICD with your cardiologist or electrophysiologist, who can explain the benefits in the context of your specific condition.

Category: Implantable Devices

Yes. A hearing aid worn in the ear will not interfere with an ICD. If the hearing aid has any wireless accessories, such as a Bluetooth streamer worn around the neck, keep the accessory at least 15cm (6 inches) away from your device.

Category: Implantable Devices

The effect of turning off a lead depends on which lead it is and what function it was providing. ICDs can have between one and three leads, each connected to a different chamber of the heart or serving a different purpose.

A lead may be turned off because it is no longer functioning correctly, because it is causing inappropriate sensing or therapy, or because a new lead has been added to replace its function. In some cases a lead is left in place but deactivated rather than removed, as lead extraction carries its own risks.

Whether the device can still deliver full therapy after a lead is turned off depends on the configuration. If the defibrillation lead is unaffected, the device can still deliver a shock when needed. If a pacing lead is turned off, the device may pace less effectively or not at all in certain situations. Your cardiologist will explain exactly what the change means for your individual device programming and what, if any, additional monitoring or precautions are needed.

If a lead has been turned off and you are unsure what that means for your protection, ask your ICD clinic directly. You are entitled to a clear explanation of how your device is currently configured and what it will and will not do.

Category: Implantable Devices

ICDs are programmed to meet a person’s needs. Typically, an ICD will be set to deliver 20-35 joules per shock. Talk to your doctor to discuss how your ICD is programmed.

Category: Implantable Devices

When your heart device is implanted, your doctor threads one end of the lead through a vein into your heart, attaching the lead tip to the heart wall. Your doctor then connects the other end of the lead to your heart device.

Category: Implantable Devices

Most ICDs today have both pacing therapies as well as defibrillation capabilities, so only one device is needed.

Category: Implantable Devices

Yes. Many people with ICDs and pacemakers choose to wear a medical ID bracelet or necklace alongside their device ID card. A medical ID can alert emergency responders to your device if you are unable to communicate. You can search online for suppliers of medical ID jewellery — several companies specialise in engraved medical alert products. Your local pharmacy may also stock basic options.

Category: Implantable Devices

ICD lead recalls and safety alerts do occasionally occur. In the UK, the Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for issuing medical device safety alerts, and manufacturers are required to notify affected patients and clinicians when a recall or field safety corrective action is issued.

If your leads are subject to a recall or safety alert, your ICD clinic should contact you directly with information about what has been found, what the risk level is, and what action if any is recommended. In many cases no immediate action is needed and increased monitoring is sufficient. In others, earlier replacement may be recommended. The decision is made on an individual basis taking into account the specific issue, your overall risk profile, and the risks of any procedure to address it.

If you have concerns about your leads and have not heard from your clinic, you can contact them directly and ask. You can also search the MHRA’s medical device alerts database at gov.uk/drug-device-alerts to see if any alerts have been issued for your device or lead model. You will find your device and lead model details on your device ID card or in your implant documentation.

Category: Implantable Devices

ICDs connect to the different chambers of your heart using 1 to 3 leads. Your doctor will determine the number of leads implanted based on your individual needs.

Category: Implantable Devices

Each patient describes an ICD shock differently. Some say it feels like a thump on the chest while others compare it to being kicked in the chest. It is normal to feel apprehensive, but also remember that a defibrillating shock from an ICD can be lifesaving. For most people, if there is pain, it quickly passes.

Category: Implantable Devices

Your ICD clinic or cardiac nurse should give you a written shock plan before you leave hospital after implantation. This sets out exactly what to do if your device delivers a therapy shock. If you have not received one, ask for it at your next clinic appointment.

In general, if you receive a single shock and feel well immediately afterwards, contact your ICD clinic the same day or the next working day so the episode can be reviewed by downloading your device data. If you receive two or more shocks in quick succession, feel unwell after a shock, or the shock does not resolve your symptoms, call 999 immediately.

If you are unsure what to do in any situation, contact your ICD clinic. Most clinics have a dedicated number for urgent queries during working hours, and you should be given a number to call out of hours.

Category: Implantable Devices

Each patient describes an ICD shock differently. Some say it feels like a thump on the chest while others compare it to being kicked in the chest. It is normal to feel apprehensive, but also remember that a defibrillating shock from an ICD can be lifesaving. For most people, if there is pain, it quickly passes.

Category: Implantable Devices

Most likely, you will not hear anything before a shock. If an ICD senses an event that requires a shock, it responds immediately, leaving no time for any warning signals.

Category: Implantable Devices

Your ICD is designed to deliver therapies that progress from the mildest form to be effective to an actual shock. If you receive a shock from your ICD, you will feel an obvious electrical jolt to your body, but each patient describes an ICD shock differently. Some say it feels like a thump on the chest, while others compare it to being kicked in the chest. It is normal to feel apprehensive, but also remember that a defibrillating shock from an ICD can be lifesaving. For most people, if there is pain, it quickly passes.

Category: Shock

Your partner will not be hurt by the shock. They may feel a tingle or brief sensation if they are in physical contact with you at the moment of the shock, but nothing more. This is the same whether you are in water or not.

If you receive a shock during intercourse, stop and contact your ICD clinic to have the episode reviewed, as you would for a shock at any other time.

Category: Implantable Devices

You will probably not need new leads. However, your doctor will test your existing leads before, during and after your surgery. If tests indicate that it’s time for new leads, they will be replaced along with your ICD.

Category: Implantable Devices

Typically, the leads are reused with the new heart device. If the existing leads cannot be reused, they will stay in the body and new leads will be implanted. In certain situations, the doctor may recommend a lead be removed and replaced with a new lead.  The lead removal procedure is usually performed by a doctor who specializes in lead extractions.

Category: Implantable Devices

If you receive a therapy shock, anyone touching you may feel the shock as a muscle spasm or a tingle, although it is unlikely. A therapy shock can be startling, but it will not hurt a person touching you.

Category: Implantable Devices

No. You will not receive a warning from your ICD before a shock. However, you may have symptoms that tell you a shock may be imminent.
Symptoms may include dizziness, lightheadedness, or a fluttering in the chest.

Category: Implantable Devices

No, your ICD will only shock you if it detects a heart rhythm that is too fast.

Category: Shock

No, your ICD is designed to deliver a shock to treat heart rhythms that are too fast.

Category: Implantable Devices

Your doctor will know if you recieve a shock as the ICD records and stores data when therapy like a shock is delivered.

Category: Implantable Devices

ICDs deliver shocks to save your life when pacing therapies don’t return your heart to a normal rhythm. After a successful shock, your normal heart rhythm will resume.

Category: Implantable Devices