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.