Sudden Cardiac Death: What you should Know

Knowing the difference between sudden cardiac arrest and heart attack can help you spot warning signs

By Dr K. Javeed Nayeem

The sudden passing away of the apparently ‘fit as a fiddle’ film actor, Puneeth Raajkumar, has shocked most people. This is so not only because of the suddenness of the event but because everyone naturally felt that it was not even the time for a young, active and healthy person to die. Another reason for the shock perhaps stems from the fact that most lay people believe that deaths like these are extremely rare. But contrary to this belief, Sudden Cardiac Death (SCD) is a very well-known medical entity and a whopping three hundred and fifty thousand SCDs occur worldwide each year. Sadly, it is a problem which, despite all the advancements in medical science, has a very dismal survival rate with or without medical help, unlike most other medical problems.

SCDs can be fairly effectively prevented, rather than be treated. It is just that many miss the early warning signs. Most who die due to SCD go within ten minutes, if medical help is not available immediately. And more often than not, it takes more than ten minutes for the people around to realise something. It is something more serious than another case of fainting due to exhaustion or an epileptic fit. Another sad fact is that any resuscitation after about five minutes may not be a very fruitful achievement because it takes less time than that for the cells of an oxygen-starved brain to die permanently, leaving the affected person completely brain dead and in a permanent vegetative state.

Early signs

Studies show that many persons who succumb to SCD are the ones who missed the early warning signs and thus could have saved their lives by preventing the fatal event. A medical study conducted at a leading heart hospital in New York has shown that at least fifty percent of the people who had a sudden cardiac arrest had some warning signs or symptoms up to a week before, which were missed by them and sometimes by their doctors too. And, while nearly eighty percent of them had such symptoms a day before, ninety percent of them had them an hour before the event.

But unfortunately, it was found that only twelve percent of the people sought the medical help which could have saved their lives. The events that usually herald a SCD are chest pain or chest discomfort in 46 percent of the cases with shortness of breath in 18 percent and nausea, abdominal pain or heart burn in 20 percent.

While most people think that heart attacks are the reason why SCDs occur, they are only partly correct. Medical experts know that while heart attacks too can kill suddenly, it is the electrical disturbances in the heart which can cause it to stop working suddenly and helplessly.

How is SCD different

I feel that it will be worthwhile to enlighten you in a nutshell, about the difference between these two killer events. A heart attack is a circulatory problem. The heart is a pumping organ with two circulatory systems in it. The larger one keeps the blood flowing through all parts of the body and the lungs. The smaller one keeps the blood flowing through its own muscle to keep it nourished and beating.

Interestingly, it is the much smaller system that is the potential killer. It has three very narrow blood vessels, called the coronary arteries which are highly prone to getting blocked gradually due to fatty and calcific deposits. Or it can happen suddenly due to a wandering blood clot that can prevent blood flow to the heart muscle, leading to its death. And, a death of a sufficiently large portion of the heart muscle naturally translates into the death of its owner. But while heart attacks too can kill suddenly, most heart attacks give enough time for most patients to access medical help. But SCD is often due to an electrical malfunction within the heart where the heart just stops beating which kills the patient much faster.

In addition to having a tiny circulatory system of its own, the heart also has an electrical conducting system which stimulates its muscle to keep beating steadily life-long. Any malfunction of this electrical system can cause the heart to lose its rhythm and start beating too slowly or too rapidly. This loss of rhythm is more fatal than a heart attack.

(The writer is a practicing physician at Mysuru. Email: kjnmysore@rediffmail.com)