What Is an ICD?

An Implantable Cardioverter Defibrillator (ICD) is a small battery-powered medical device placed inside the body. It continuously monitors the heart's rhythm. When it detects a dangerous heartbeat, it delivers an electric shock to restore a normal rhythm.

The heart works by sending electrical signals that control its pumping rhythm. Sometimes, these signals go wrong, causing the heart to beat too fast, too chaotically, or stop pumping properly. This is called a life-threatening arrhythmia. An ICD is designed to detect and correct this problem automatically - even without any warning.

Purpose and Where It Is Used

ICDs are used in children who are at high risk of a sudden life-threatening abnormal heart rhythm. This includes children who have already survived cardiac arrest or are at serious risk of one.

Common Conditions Where ICD Is Used in Children

Where Is It Implanted?

The ICD is most commonly placed under the skin near the collarbone area (left side of the chest). The leads (thin wires) run through a vein into the heart. In younger or smaller children, alternate placements may be used based on body size and anatomy.

Types of ICDs

There are several types of ICDs. The choice depends on the child's age, size, heart condition, and specific needs.

How an ICD Works

Understanding the basic function helps in knowing when and why the device activates.

Three Core Functions

• Monitoring: Continuously reads the heart's electrical activity through leads
• Anti-Tachycardia Pacing (ATP): Sends rapid small pulses to stop a fast abnormal rhythm without a shock
• Defibrillation Shock: Delivers a controlled electric shock if the rhythm becomes life-threatening and ATP fails

What a Shock Feels Like

A defibrillation shock is often described as a sudden strong jolt or a thump in the chest. It is usually very brief. Some children feel it clearly; others may not if they were unconscious. ATP therapy, on the other hand, is usually painless and unnoticed.

User Guide: Living with an ICD

The ICD works automatically. There is no button to press or setting to adjust during daily life. However, there are key practical steps to follow.

After Implantation - First Steps

1. The child stays in the hospital for monitoring after the procedure, usually 1-2 days. The wound site is checked before discharge.
2. Activity is restricted for several weeks after implant. No lifting arms above shoulder height on the side of implant until cleared by the care team.
3. The device is programmed by the cardiologist before discharge. Settings are customized to the child's specific heart condition.
4. A medical ID card is provided. This card contains ICD details and must be carried at all times.
5. An ICD identification bracelet is strongly recommended. This informs emergency responders about the device.

Routine Follow-Up

1. Regular check-ups with a pediatric cardiologist or electrophysiologist are required, typically every 3-6 months.
2. Remote monitoring may be available: a home transmitter sends device data to the cardiology team without a clinic visit.
3. The device stores all recorded heart events. The doctor reviews this data to assess device function and heart rhythm history.
4. Battery life is monitored at each visit. When the battery approaches end of life (usually after 5-10 years), a replacement procedure is scheduled.

What to Do When a Shock Occurs

1. Stay calm. A single shock that is followed by feeling well usually means the device worked correctly.
2. Sit or lie down until the feeling passes. Avoid driving or cycling immediately after a shock.
3. Contact the cardiology team to report the shock - even if feeling completely fine afterwards. All shocks should be reviewed.
4. Call emergency services immediately if: the child loses consciousness, multiple shocks occur in a short time, or the child feels very unwell after a shock.

Precautions and Things to Avoid

Electromagnetic Interference (EMI)

Strong magnetic or electrical fields can temporarily interfere with the ICD. This does not damage the device permanently, but may cause incorrect sensing or inappropriate shocks.

Physical Activity

Guidance on physical activity varies depending on the underlying heart condition, not just the ICD. The cardiologist provides specific exercise restrictions. In general:

• Competitive high-intensity sports may be restricted for some conditions
• Contact sports carry a risk of direct trauma to the device or leads
• Swimming is generally allowed but solo swimming in open water is not advised
• Regular moderate physical activity is often encouraged and is important for overall health

Dental and Medical Procedures

• Inform all medical professionals (dentists, surgeons, radiologists) about the ICD before any procedure
• Electrosurgery (diathermy) used during operations can interfere with the ICD - special precautions are taken by the surgical team
• Carry the ICD identification card to every medical appointment

School and Daily Life

• School staff (teachers, sports coaches, school nurse) should be informed about the ICD and the emergency plan
• The school should have a copy of the emergency action plan provided by the cardiology team
• Normal classroom activities including computers are safe
• Physical education participation should be guided by the cardiologist's specific recommendations

Keeping the ICD Safe

Wound and Device Site Care

• Keep the implant area clean and dry during healing (usually 4-6 weeks)
• Do not scratch, press hard, or rub the skin over the device
• Report any redness, swelling, warmth, or discharge from the wound site immediately
• Avoid tight clothing that puts constant pressure on the device

Device Monitoring

• Use the home remote monitoring transmitter as instructed - this allows the care team to check the device without a clinic visit
• Never miss scheduled follow-up appointments - they ensure the device is working correctly and the battery is adequate
• Know the make, model, and serial number of the ICD - this is on the ID card provided at discharge

Emergency Preparedness

• Ensure caregivers, school staff, and close contacts know basic CPR
• An external defibrillator (AED) can be used safely in a child with an ICD if needed during an emergency
• Keep emergency contact numbers for the cardiology team accessible at all times

Travel Tips

• Always carry the ICD identification card when travelling - it should be in the local language if possible
• Carry extra medication and a list of all current medicines
• Identify cardiac centres near the travel destination before leaving
• Inform the airline when booking - most are accommodating with security screening requests

Additional Important Considerations

Inappropriate Shocks

Sometimes the ICD may deliver a shock when it was not actually needed. This is called an inappropriate shock. It is more common in children than adults. Causes include: rapid heart rate from exercise, fever, anxiety, or a loose lead. Inappropriate shocks are painful and distressing but not dangerous. They should always be reported to the care team so device settings can be adjusted.

Psychological Impact

Living with an ICD can cause anxiety, fear of shocks, or restrictions in daily activities. This is common in both children and their families. Psychological support, counselling, or support groups can be very helpful. This aspect of care is as important as the physical side.

Growth and Device Changes

Children grow. As the child grows, leads may become too short and require replacement. The cardiologist monitors lead length and device function at each follow-up. Device upgrades or replacements may be planned as the child reaches adolescence or adulthood.

Transition to Adult Care

As children with ICDs grow into adults, care transitions from pediatric cardiology to adult electrophysiology teams. This transition should be planned carefully, usually starting around 16-18 years of age, depending on the centre.

Frequently Asked Questions (FAQs)