Heart disease is the second leading cause of death in Singapore. It increases the risk of death from sudden cardiac arrest (SCA). The initial rhythm of SCA is most commonly a malignant ventricular arrhythmia, either ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT), the occurrence of which inhibits the activity of the natural pacemakers of the heart, causing cardiac standstill. The key treatment for VF and pVT is defibrillation, supported by good cardiopulmonary resuscitation (CPR). Therefore, defibrillation and CPR remains the cornerstone of both basic and advanced cardiac life support. When delivered early, they confer significant survival benefits. A device that sends an electric shock or pulse to the heart in order to restore a normal heartbeat is called as Defibrillators. They are used to prevent or correct an arrhythmia, a heartbeat that is uneven or that is too slow or too fast. Defibrillators can also restore the heart’s beating if the heart suddenly stops.

Other defibrillators can prevent sudden death among people who have a high risk of a life-threatening arrhythmia. They include implantable cardioverter defibrillators (ICDs), which are surgically placed inside your body, and wearable cardioverter defibrillators (WCDs), which rest on the body. It can take time and effort to get used to living with a defibrillator, and it is important to be aware of possible risks and complications.

Explore this Health Topic to learn more about defibrillators, our role in research and clinical trials to improve health, and where to find more information.

WCDs, ICDs and AEDs are the three types of defibrillators. Each type works by checking for arrhythmias, or irregular heart rhythms. Once detected, each defibrillator will send a shock to restore a normal rhythm.

An AED is easy to carry anywhere. This device is battery-operated and lightweight. It sends a shock to the heart after checking its rhythm in order to restore a normal rhythm. The device is used to help people having sudden cardiac arrest.

Defibrillators can be used in children, teens, and adults. For the treatment of impulsive heart attacks AEDs are used. Your doctor may recommend an ICD or WCD to treat an arrhythmia and prevent new or repeat sudden cardiac arrests.

AEDs may be used in an emergency to help someone who is experiencing sudden cardiac arrest.

If your doctor recommends an ICD to treat an arrhythmia, your healthcare team will help you prepare for surgery.

After sudden cardiac arrest, surgery to implant an ICD, or a fitting for a WCD, you will need regular visits with your doctor to check your condition, the device, or any medicines you are taking. You can get an ID card with information about your device to keep with you. It can be helpful in an emergency, to show airport security, or for medical personnel who need to know more about your device. If you have an ICD, be aware of the signs of complications with your device.

The NHLBI is part of the U.S. Department of Health and Human Services’ National Institutes of Health (NIH)—the Nation’s biomedical research agency that makes important scientific discovery to improve health and save lives. We are committed to advancing science and translating discoveries into clinical practice to promote the prevention and treatment of heart, lung, blood, and sleep disorders, including defibrillators.