Implantable Cardioverter Defibrillator (ICD)

An implantable cardiac defibrillator (ICD) is a small, metal device which acts as a pacemaker, sending out electrical impulses to the heart to enable all 4 chambers to beat at the same time. It also delivers shock therapy to the heart to treat life-threatening heart rhythms that can be encountered in ventricular tachycardias or ventricular fibrillation.

The ICD is inserted under the skin, usually on the left side of the chest, under local anaesthetic, often with mild sedation. 2 or 3 leads from the pacemaker are then guided by xray through a vein under the collar bone to the heart. Moving the leads inside the heart is entirely painless.

A 1-2cm scar may be left following insertion of the ICD, and there may be a small bump where the devices lies.

Other risks of the procedure include:

  • A collapsed lung (1-2%) which normally does not require further treatment; occasionally, it is necessary to insert a chest drain to re-inflate the lung;

  • The leads becoming dislodged (5%). An xray and ECG are carried out following the procedure and the lead repositioned, if necessary, before discharge home; 

  • A collection of blood around the heart called a tamponade (0.1%), if the lead perforates the inner lining of the heart. Usually this requires no further treatment, but occasionally it may be necessary to insert a small drain;

  • Bruising over the pacemaker. This is usually of no significance, although if a collection of blood gathers at the site of the pacemaker that becomes too large, it may require drainage and

  • Infection (less than 1%). All patients are treated with antibiotics to minimise this risk.