Implantable Cardioverter Defibrillator

Heart rhythm is mainly controlled by the conduction system of the heart. Any abnormality in the conduction system may result in abnormal heart rhythm (arrhythmia). Life-threatening arrhythmias such as ventricular tachycardia (VT) and ventricular fibrillation (VF) cause not only palpitations, dizziness and syncope but also sudden death.

Implantable Cardioverter Defibrillator (ICD) is an implantable device used for treatment of VT and VF. It is essentially an implantable cardiac pacemaker which consists of a battery-powered generator and leads that connect the generator to the patient’s heart. The lead placed in the right heart has defibrillation function. As soon as a VT or VF is detected, the ICD will automatically try to correct it by anti-tachycardia pacing, cardioversion or defibrillation. It has been proven in various clinical trials that ICD is better than the best anti-arrhythmic drugs in prolonging survival among patients with a high risk of sudden cardiac death due to VT or VF.

The Procedure:
  • This invasive procedure is usually performed under local anesthesia in a Cardiac Catheterization & Intervention Laboratory (CCIL). You are alert during the procedure, but we may give you sedation to calm you down.
  • Electrodes are adhered to the chest to monitor the heart rate and rhythm. Blood oxygen monitor through your fingertip will be set up. Measurement of blood pressure from your arm will be taken during the examination.
  • Skin disinfection will be performed and a small skin incision (about 3-5 cm long) will be made under your left (sometimes right) clavicle.
  • Contrast may be injected intravenously to visualize the veins in your arm and needle puncture under the clavicle may be required to obtain access to your vein.
  • 1 to 2 leads will be advanced to your heart chambers through your vein under X-ray guidance.
  • The generator will be connected with the lead(s) and implanted in a pocket created under the skin or muscle.
  • VF will be induced under sedation for testing the proper functioning of the ICD.
  • The wound will be closed with suturing material and covered with pressure dressing.
  • The procedure usually takes around 2 to 3 hours.
Post-Procedure Follow-up

  • You may be discharged from hospital a few days after the ICD implantation.
  • The wound should be covered with light dressing. Please keep the wound site clean and avoid making the dressing wet during shower. Always change dressing if wet.
  • You may need to come back to the clinic for suture removal 1 week after the procedure if any.
  • You may remove the dressing 2-3 days after suture removal.
  • Please avoid lifting the affected arm for 1 month and avoid vigorous arm movement in the first week after the procedure.
  • You will be arranged to attend regular ICD analysis, re-programming and battery power assessment.
  • Please carry your ICD identity card at all times.
  • Follow your doctor’s instructions or refer to the information booklet from the ICD company to minimize the risk of pacemaker malfunction due to electromagnetic interference. In general, strong electro-magnetic field or radiofrequency signal will interfere your ICD. Please keep a distance of >15 cm (6 inches) from an active mobile phone. Household electrical or electronic appliance usually does not affect ICD.
  • You should report to your doctor or nearby Accident and Emergency Department if you suffer from syncope or electric shocks delivered by the ICD.
  • ICD generator will need to be replaced in 3-6 years’ time when the battery is depleted.