Implantable Cardioverter Defibrillator (ICD) and Cardiac Resynchronization Therapy (CRT)

Experience a consistent standard of
cardiovascular care.

At The Cardio Clinic, Dr. Tan Jian Jing, in cooperation with a cardiac electrophysiologist, provides these modern treatments to safeguard and improve the lives of patients with severe cardiac conditions.

Two different devices, two different jobs

An implantable cardioverter defibrillator monitors continuously for dangerous fast rhythms arising from the ventricles. If it detects one, it can deliver rapid pacing or a shock to restore a normal rhythm. Its purpose is to treat a life-threatening arrhythmia at the moment it occurs.

Cardiac resynchronisation therapy addresses a different problem. In some people with heart failure, the two ventricles no longer contract in a coordinated way, which makes an already weakened heart less efficient. CRT paces both ventricles to restore that coordination.

The two functions can be combined in a single device where both a coordination problem and a rhythm risk are present.

Who these devices are considered for

An ICD may be considered for people who have survived a dangerous ventricular arrhythmia, or who have not had one but whose heart function and clinical picture place them at raised risk. CRT is considered in heart failure where the pumping function is reduced and the electrical conduction pattern shows the delay that resynchronisation can address.

These are assessments made against established clinical criteria, using imaging and ECG findings alongside symptoms — not on symptoms alone.

Implantation and follow-up

Implantation is similar in approach to a pacemaker: the device sits under the skin below the collarbone with leads passed through a vein into the heart. CRT involves an additional lead to pace the left ventricle, which makes the procedure longer.

Devices are monitored regularly, often remotely, to check function, battery life and any rhythm events recorded. If an ICD delivers a shock, contact the clinic; if shocks are repeated, or you feel unwell afterwards, seek emergency care — in Singapore, call 995.