Sudden Cardiac Death

by on May 2, 2012

in Monthly

I have a son who is almost ten years old. He is very athletic. His paternal grandfather died of heart disease before age 50. I am concerned that the grandparent’s death was unexplained. What is my son’s risk of having similar problems?

Sudden cardiac arrest (SCA) is an event where the heart loses its function abruptly and unexpectedly. It can be a devastating event not only to a family, but also to a community or a sports team of a school. Often there is no previous warning—making the sudden and unexpected demise of a young life that harder to process.

However there are some conditions which put a patient at higher risk.

These are diagnoses such as structural heart abnormalities which may put a child at higher risk for SCA (Structural abnormalities such as coronary artery defects; an enlarged heart due to an oversized muscle known as cardiomyopathy; myocarditis, post operative congenital heart disease, Marfans Syndrome and mitral valve prolapse)

Electrical or conduction abnormalities such as Wolf Parkinson White Syndrome, short QT Syndrome or a Long QT interval may also predispose a child to SCA.

Medications such as ephedra, ketaconazole, carbamazapine or erythromycin may also predispose a child to SCA according to a recent report and position statement in Pediatrics (April 2012)

Most patients with the above conditions end up being seen by a cardiologist, but it is important that anyone with a family history of unexpected and sudden death be assessed for their risk of having SCA themselves.

Symptoms and signs which may be warning features of being at a higher risk for SCA are: dizzy spells, chest pains when exercising, fainting, palpitations, shortness of breath, unexplained wheezing not responding to appropriate medications  and a baby born deaf ( the latter patient is at a higher risk of conduction abnormalities of the heart)

The incidence of SCA is not exactly known because at this time there is no central registry. Some data suggest that it may occur in 1-6 patients per 100, 000 people per year. An Italian study showed that in athletes it may happen in 1 per 25,000 people. Some cardiologists have determined that the incidence of SCA is increasing but there is no agreement as to why.

One of the key goals is to pick up early those children who are at risk for developing SCA. In many cases a family history of early cardiac death or any of the above heart conditions may alert a doctor to screen patients. And yet there are no perfect screening tools available at this time.

In a recent position paper published in Pediatrics (April 2012), the authors pointed out that both a screening electrocardiogram (EKG) and a pre-participation physical exam (PPE) of athletes do not help to pick up those who are at risk for SCA. However in Japan and Italy the use of an EKG has become standard of care.(In Japan since 1973) In North America there is a concern that using EKG’s as a screening tool may not be cost effective.

The quality of a PPE was thought to be a determining factor in identifying athletes who are at higher risks for collapsing and dying due to SCA. However a UK study showed that even with more questions in the PPE and if done by well trained experts, there was no improvement in predicting which athletes are at risk for SCA.

Genetic testing has become more sophisticated but according to the Pediatrics Position Paper, the ability to rely on genetic testing in picking up those who are most at risk for SCA is not yet well developed. It has yet to become standard of care.

The bottom line is that a history of unexplained fainting and a family history of unexpected and premature cardiac death are two key tip offs to doctors to look deeper into structural or electrical abnormalities of the heart.

The immediate response in the event of a SCA is to administer CPR. Yet data shows that a majority of bystanders were reluctant or uneducated when it came to administering CPR. Mouth to mouth breathing was said to make many reluctant to perform CPR on a stranger.

Recently cardiologist demonstrated that in adults rapid chest compressions (100 times per minute) without mouth to mouth breathing may be beneficial. Data on the role of rapid compressions only as a CPR approach, is lacking in pediatric patients.

More and more schools and athletic arenas have defibrillators (Automated external defibrillators or AEDs) These devices have saved many lives and are relatively easy to use. The ideal goal is for all schools or places where athletes work out to provide these devices.

For more detailed information on the causes and screening for SCA see the abstract in PEDIATRICS Volume 129, Number 4, April 2012


Dr Peter Nieman is a community pediatrician and the President of the Alberta Chapter of the American Academy of Pediatrics. He is also a member of the Canadian Pediatric Society and the co-founder of the Calgary Pediatric Weight Clinic which was established in 2004.

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