What is cardiac arrest that killed Nana Patekar? Why can it affect healthy people?

When news broke on Thursday that veteran actor Nana Patekar had died at 75 in Goa, many people asked the same thing, how does a person go from being fine to gone in a matter of hours? Doctors at Manipal Hospital in Goa told ANI he was declared dead after being brought in following a cardiac arrest.Cardiac arrest is one of the most misunderstood terms in medicine. Most of us use it interchangeably with "heart attack." Cardiologists say that is a mistake, and an important one.WHAT EXACTLY IS CARDIAC ARREST?"Cardiac arrest is a condition where there is a sudden electrical disturbance in the heart and that can cause sudden stoppage of the heart and kill the patient instantaneously. This is called sudden cardiac death," says Dr Gajinder Kumar Goyal, Program Clinical Director, Cardiology, Marengo Asia Hospitals, Faridabad.Think of the heart as a pump that runs on electrical signals. In cardiac arrest, those signals go haywire. The American Heart Association describes it as an electrical malfunction that causes an irregular heartbeat, so the heart can no longer pump blood to the brain, lungs and other organs. CARDIAC ARREST IS NOT A HEART ATTACKThis is the point Dr Goyal stresses most: "Whenever there is a cardiac arrest, when a person dies suddenly, he is referred to as having died because of a heart attack, which is incorrect."The simplest way to remember the difference comes from the American Heart Association. A heart attack is a "circulation" problem, caused by a blocked artery. Cardiac arrest is an "electrical" problem. In a heart attack, the heart usually keeps beating while part of it is starved of blood. In cardiac arrest, it stops pumping effectively. The two are linked. Most heart attacks do not lead to cardiac arrest, but when cardiac arrest does occur, a heart attack is a common cause.heartDr Goyal also says that cardiac arrest "causes four times more death compared to what a heart attack causes."WHAT DOES IT LOOK LIKE?There is usually no slow build-up, which is why it feels so shocking. Dr Goyal explains: "The basic feature of cardiac arrest is a person suddenly collapses in front of you because since the heart stops, there is no circulation."Without blood reaching the brain, the person "becomes unconscious, collapses." He adds that some people may have "convulsive movements like seizures or epilepsy" if the arrest is prolonged.His rule for recognising it is simple: "You won't be able to wake him up when you call his name or try to wake him up by patting him on the shoulder or any other means. That is the hallmark of cardiac arrest." The American Heart Association lists the same two signs: the person is unresponsive and not breathing normally.heartWHY DOES IT HAPPEN TO PEOPLE WHO LOOK HEALTHY?This is the question that troubles families the most. Dr Goyal's answer is direct: "Cardiac arrest can take place in a perfectly normal heart also. It can take place in a person who is never known to have a heart disease."But he adds a caveat: "It is more commonly seen in people who already have heart disease, specially people who have experienced previous heart attacks or patients whose heart function has gone down significantly because of any other cause like valvular heart disease."The key phrase in all of this is "never known to have a heart disease." Looking healthy and being healthy are not the same thing. The US National Heart, Lung, and Blood Institute notes that most people who had a cardiac arrest outside a hospital had heart disease, although they may not have known it.nihHERE IS WHAT THE RESEARCH SAYS ABOUT THE HIDDEN CAUSES:Silent blockages. The most common culprit is coronary artery disease, where cholesterol plaque builds up and blocks the arteries that feed the heart. It can sit there for years without symptoms.Inherited conditions. Dr Goyal says some people, "because of their genetic make-up, because of congenital heart diseases, because of mutations in certain genes, are predisposed to have cardiac arrest." NHLBI says genetic disorders are the main cause of cardiac arrest in children and young adults.Heart muscle and valve problems. Conditions such as cardiomyopathy and heart valve disease also raise the risk.No cause found. Sometimes the cause of a cardiac arrest is simply not known.WHAT THE INDIAN DATA SHOWSA one-year study at AIIMS, New Delhi, published in the Indian Journal of Medical Research, looked at sudden deaths in people aged 18 to 45. Of the young adults who died suddenly, cardiovascular causes were the most common at about 43 per cent, and in most of those cases the cause was coronary artery disease. About one in five young deaths remained unexplained even after autopsy. The study found that more than half of the sudden deaths happened at home.It is a single-centre study, so it can't tell us the national picture, but it shows how often a "sudden" death has a quiet, long-standing cause.WHAT CAN TRIGGER AN ARREST?For someone who already has an underlying problem, a trigger can tip things over. NHLBI lists heavy alcohol use, intense physical exertion, drugs such as cocaine and amphetamines, too much caffeine, severe emotional stress, and a flu infection in the previous month as possible triggers. It adds that triggers are more common in people who already have heart conditions or other risk factors, and that regular physical activity lowers the overall risk.Dr Goyal does not soften this part: "Cardiac arrest is a very devastating phenomena and it leads to death almost certainly if not intervened." He says that only a few people recover on their own. "Rest of them die within a few minutes if no intervention is done."The numbers back him up. Only about 10 per cent of people who have a cardiac arrest outside a hospital survive, but CPR started right away can double or triple the chance of survival.If you ever see someone collapse and not respond, the American Heart Association's advice is: call emergency services, ask someone to bring an AED if there is one nearby, and begin chest compressions, pushing hard and fast in the centre of the chest. The AED will tell you if a shock is needed.HOW TO LOWER YOUR RISKDr Goyal's advice begins with knowing your own risk: "Preventions start knowing your risks."The most important question is about your family. "If anybody in your family has had an unexplained death, especially at a young age less than 50 years of age, all the family members should be aware that they may be at risk of having cardiac arrest. Hence at least once, they should get themselves evaluated by a doctor who can identify whether they are actually at risk of having a cardiac arrest or not."If you already have heart disease, he says you "should go to his doctor, cardiologist preferably, and find out whether he is at risk of having cardiac arrest at all."For people who are at risk, the key treatment is a device. "The most important line of treatment usually is implantation of a device called implantable cardioverter defibrillator, that is ICD. That is implanted like a pacemaker that keeps monitoring the heart rhythm and wherever cardiac arrest kind of situation happens, the machine itself gives an electrical shock to save life."For everyone else, the general advice holds. NHLBI says that never smoking, eating well and staying physically active throughout life can prevent coronary heart disease, the main risk factor for cardiac arrest in adults.Cardiac arrest is not a "bigger heart attack." It is an electrical failure, it can strike without warning, and it is not limited to people who know they have heart trouble. The best defences are knowing your family history, getting checked if you have risk factors, and having people around you who know how to do CPR.- Ends