Implantable Cardioverter-Defibrillator (ICD)

Overview

An implantable cardioverter-defibrillator (ICD) continuously monitors the heart rhythm. If it detects a life-threatening fast rhythm, it can deliver pacing or an electric shock to restore a normal heartbeat. Some ICDs also work as a pacemaker.

Why it is done

• After surviving a cardiac arrest
• Dangerous fast heart rhythms such as ventricular tachycardia or ventricular fibrillation
• A high risk of these rhythms, for example because of a weak heart muscle

Before the procedure

Your cardiologist will explain the benefits and review tests such as an echocardiogram and heart rhythm monitoring. You may need to fast and adjust some medicines.

During the procedure

Like a pacemaker, the ICD is placed under the skin below the collarbone under local anaesthetic and sedation, with leads guided into the heart using X-ray imaging. The device may be tested before the procedure ends.

After the procedure

You will usually stay in hospital overnight and have regular device checks afterwards. Your doctor will explain what to do if the device delivers a shock, and any driving restrictions.

Risks

Risks include bleeding, infection, lead problems and, rarely, damage to the heart or lung. Some people receive a shock that was not needed; device settings can often be adjusted to reduce this.

At KIH

KIH's cardiac electrophysiology service offers implantation of pacemakers and cardioverter-defibrillators, including cardiac resynchronisation device therapy.