If the bottom chambers (ventricles) of your heart are prone to going into either a dangerously fast or a chaotic heart rhythm (called ventricular tachycardia and ventricular fibrillation respectively), or if you are thought to be at risk of your heart going into these dangerous rhythms, then an implantable cardioverter defibrillator (ICD) can help you.
An ICD is a small device that is about the size of a matchbox. It is implanted under the skin below the collar bone, usually on the left hand side. One or more wires run from the ICD to the heart. The ICD is able to monitor your heart rhythm at all times; if it notices that your heart is going into an abnormal rhythm, it returns it to normal in one of three ways:
1. Antitachycardia pacing (ATP) – fast, low-voltage impulses try to override an abnormally fast heart rhythm (usually ventricular tachycardia), momentarily taking over control of the heart, with the aim of restoring it back into a normal rhythm.
2. Cardioversion – small electric shocks return the heart to its normal rhythm.
3. Defibrillation – bigger electric shocks put the heart back into a normal rhythm.
When you have your ICD fitted, you will usually be sedated. This means that you will feel very relaxed and sleepy, and as a result people often remember nothing or very little of the procedure. You will also have a local anaesthetic so that you do not feel any pain where the ICD is inserted. Most people stay in hospital the night after their ICD is fitted. Before you leave, some tests will be performed to check that it is working as it should be.
ICD and Contact Sports
