 Dr. Sandesh Dragu, cardiologist at Manipal Hospital, Whitefield, Bangalore. Recent demise of Raj Kaushal has shown not only the film industry, but youngsters across the country. Cardiac arrest is a silent killer. Cardiac arrest is a condition wherein the heart stops functioning all of a sudden and it is one of the most common cause of death worldwide. Most of the times, cardiac arrest is confused with heart attack. Heart attack happens because of blockage in the arteries which supply blood flow to the heart and restoration of the blood flow helps in recovery of the heart muscle. Cardiac arrest happens because of electrical disturbances in the heart. Heart attack can cause cardiac arrest, but cardiac arrest can happen in other conditions as well. It can happen in a structurally normal heart also, but most of the times it happens in a pre-existing heart problem where somebody had a previous heart attack, some previous valvular problem or baby birth defects. There are certain things we need to know about sudden cardiac arrest. One is that heart does not stop all of a sudden. Prior to stopping it beats abnormally rapidly and covertly for almost 3-5 minutes. This is called ventricular tachycardia or ventricular fibrillation. It gives a window of opportunity wherein if shock is delivered at this time, cardiac arrest can be prevented. There are certain things we need to know about sudden cardiac arrest. One is that heart does not stop just like that. In the 3-5 minutes before it stops, it usually beats very rapidly and covertly at a rate of almost 3-5 to 400 beats per minute and then it stops. So these 3-5 minutes gives us a window of opportunity to save the person. If you can deliver a shock in these 3-5 minutes, the person survives. Cardiac arrest can be prevented otherwise he dies. So this is important and a common problem. So if the best way to prevent cardiac arrest is by implanting a device called ICD, Implantable Cardioverter Defibrillator which is a small device which is implanted below the chest wall. It can automatically sense the abnormal heartbeat and give shock or appropriate therapy as required. So most important thing is how to recognize, identify these people who are at risk of sudden cardiac arrest. The risk factors usually what we look for are low pumping of the heart, abnormal heart rhythms called ventricular, tachycardia, ventricular fibrillation, recorded on a holed up monitor. If you can give a shock in those 3 minutes, he leaves if not he dies. So this is an important and common problem and it can be prevented by implanting a device called ICD, Implantable Cardioverter Defibrillator. It's a small device which is usually implanted below the chest wall and it automatically senses the abnormal rhythm and gives a shock or appropriate therapy as required. The most important thing is how to recognize these patients who are at risk of sudden cardiac death and who can be given a benefit of ICD. The risk factors are like low pumping of the heart, abnormal heart rhythms which is recorded on a holed up monitoring. And history of single, where in the person loses consciousness, collapses all of a sudden and regains complete consciousness. If these risk factors are there, they can be considered evaluated for ICD implantation. Suppose with these risk factors, so if a person with risk factor for sudden cardiac arrest is evaluated and implanted with an ICD, we actually can reduce the risk of sudden cardiac death by 49% when compared to an individual who is not implanted with ICD.