Cardiac risk factors for teens including obesity, high blood pressure, smoking and tobacco, high cholesterol, exercise and nutrition are discussed in other chapters. Substance abuse such as cocaine, amphetamines and anabolic steroids, that may have cardiac effects are also reviewed in other sections. Chest pain, which might be a serious concern in teens and their families has also been considered elsewhere. This chapter reviews sudden death in adolescents due to heart disease.
Sudden death is very rare between the ages of one to twenty-one years with an overall incidence in the United States of approximately six hundred deaths annually. No more than half of the patients with sudden death every had any previous symptoms that may include fainting, palpitations, shortness of breath on exertion or chest pain. Not all sudden death in adolescents is due to heart disease. Sickle cell disease, diabetes, epilepsy and asthma may also be causes of sudden death.
However a cardiac cause is probably the most common cause of sudden death in teens. In a study performed in Allegheny County, Pennsylvania, of individuals who died suddenly between ages one and twenty-one years, forty-two percent had a previous history of heart disease. The likelihood that a healthy teen will die suddenly from a cardiac cause is exceedingly remote.
About ten to twenty-five sports related sudden cardiac deaths in young athletes occur annually in the United States. This compares with 1,500 drownings and the loss of 14,700 adolescents in motor vehicle accidents. Researchers estimate that five out of one hundred thousand young athletes have a condition that may predispose them to sudden death. Further studies suggest that ten percent of these are at risk for dying suddenly. This computes to one out of two hundred thousand youthful athletes being at risk for sudden death.
It is especially hard to understand when sudden death occurs in a physically fit athlete. It is thought that athletes dying suddenly have a fatal heart rhythm called ventricular fibrillation. Most of these deaths are associated with underlying heart disease including hypertrophic cardiomyopathy and congenital coronary artery anomalies. Other causes include prolonged QT syndrome and Wolff-Parkinson-White syndromes.
Hypertrophic cardiomyopathy is probably the most common cause of sudden cardiac death peaking between ages fifteen and thirty-five years. In this disease portions of the left ventricle of the heart may enlarge and lead to obstruction of blood flow from the ventricle especially during heavy exertion. When blood flow obstruction occurs, the teen may develop shortness of breath on exertion, chest pain, palpitations and fainting. A fatal heart rhythm could ensue. Up to fifty percent of patients with hypertrophic cardiomyopathy have a close relative who is also affected to some degree with the problem.
Abnormalities of the coronary arteries, the vessels that feed blood to the ventricles of the heart, may also cause sudden death in teens. In these cases, the coronary arteries may not have the normal anatomic path and this may lead to deficient blood flow to the heart muscle. For example, a coronary artery could pass abnormally between the aorta and the outflow tract of the right ventricle. Under certain conditions such as physical exertion, the coronary artery could be squeezed by the aorta and pulmonary artery causing a restriction of blood flow to the ventricle. As a result, the heart muscle may not receive enough blood and ischemia may occur. This could then lead to a fatal heart rhythm.
Prolonged QT and Wolff-Parkinson-White syndromes refer to heart electrical patterns detected on an electrocardiogram. These electrical abnormalities have been linked to some sudden deaths in adolescent athletes.
In very rare instances, an adolescent who sustained a blunt blow to the chest during sports may have a cardiac arrest and die. More often than not, there is no history of heart disease. In most cases, a baseball or hockey pock inflicts a blow to the adolescent athlete’s chest. The impact of the projectile induces a fatal heart rhythm that leads to cardiac arrest. The precise mechanisms on how this happens have not been determined with certainty.
With the very rare chance that an adolescent athlete will have heart disease that predisposes him or her to sudden death, what should be done in an evaluation? The American Heart Association concluded that screening for cardiovascular disease in athletes might be best performed by a complete history and physical examination including a good family history. The adolescent’s primary care clinician may do this. It is recommended that adolescent athletes have an annual visit with their primary care clinician for a relevant examination. During this visit, a family history of sudden death or heart rhythm disturbances should be assessed. Teens who have a history of heart disease, shortness of breath on exertion, loss of consciousness or fainting on exertion and chest pain should be carefully evaluated. In addition, heart murmurs and heart rhythm problems may need an evaluation by a cardiologist.
An electrocardiogram is an inexpensive test that is very useful in making the diagnosis of prolonged QT and Wolff-Parkinson White syndromes. The primary care clinician or a cardiologist can perform further testing. Echocardiography is a painless test that is useful in delineating the anatomy of the heart. This type of examination could diagnose hypertrophic cardiomyopathy. Holter monitor testing records the heart rhythm over a period of time, typically twenty-four hours, and is useful in documenting unusual rhythms. Exercise stress testing may be able to detect heart problems under closely monitored physically stressful conditions. Under the supervision of a cardiologist, further testing may be performed. This may include tilt table testing, cardiac catheterization and electrophysiology studies.
There are treatments available for these conditions. Hypertrophic cardiomyopathy may be treated by medication or surgery to relieve obstruction. Coronary artery abnormalities may be amenable to surgery. Prolonged QT and Wolff-Parkinson-White may also be treated. In all of these conditions, a cardiologist experienced with adolescents should be consulted to discuss all options. In some cases, the teen may be restricted from certain sports activities.
Why shouldn’t all athletes, or even all adolescents have testing to determine if they have underlying heart disease that could lead to sudden death? The expense would be enormous to look for a fortunately exceedingly rare event. In addition, this type of screening would lead to a large amount of false positive tests. This could lead to even further expense, emotional stress and unwarranted exclusion of healthy adolescents from sports.
Related topics:
Arrhythmias, chest pain, cholesterol and triglycerides, cocaine and crack, deaths, exercise, fainting, high blood pressure, inhalants, obesity, physical examinations, rheumatic fever, sickle cell anemia, sports, steroids, substance abuse
