Not always, but it depends on the underlying cause. If your child’s cardiac arrest was caused by a condition that creates ongoing risk of dangerous arrhythmias — such as Long QT Syndrome, HCM, CPVT, or Brugada Syndrome — an ICD is often recommended. If the arrest was caused by a fully reversible trigger with no ongoing risk, an ICD may not be necessary.
ICDs can be implanted in children and young people, including younger children, though the approach may differ from adult implantation. In smaller children a subcutaneous ICD (S-ICD), which sits under the skin without leads going into the heart, is sometimes preferred. The device and leads are also replaced as the child grows.
The decision will be made by a specialist paediatric cardiologist or electrophysiologist in discussion with you and, where age-appropriate, your child. It is reasonable to ask about the risks and benefits of implantation, the alternatives, and what monitoring would be needed if an ICD is not implanted.
If you have concerns about the recommendation, seeking a second opinion from another specialist centre is entirely reasonable and is something good clinical teams will support.