Sudden unexpected deaths in children, adolescents, and young adults---other than those caused by accidents or drug abuse---are not commonly due to heart disease. In some, a disease may have been known to exist before the fatal event; in others, sudden death is the first indication that a problem had existed.
Among the overall population, sudden cardiac death is a huge problem, accounting for 300,000 deaths in the United States each year. The vast majority of these deaths are caused by cholesterol deposits in the arteries to the heart (coronary atherosclerosis), the disease that causes heart attacks in middle-aged and older people. However, this does not become an important cause until after the age of 30 years. In younger people, sudden death is most commonly caused by (1) diseases that cause abnormal thickening of the heart muscle (hypertrophic cardiomyopathy); (2) virus infections of the heart; (3) right ventricular dysplasia (RVD); and (4) an inherited electrical disorder of the heart called "long Q-T interval syndrome." There are still more causes, even less common. For many of these disorders, a simple electro-cardiogram (EKG) will provide a hint that something is wrong and lead to further studies. In the case of the disorder called Q-T interval syndrome, major progress in recent years has led to the ability to do genetic testing, which can both make the diagnoses, and find other family members who have inherited the disorder.
In the future, such testing may also guide therapy. There is reason to hope that other disorders which may be familial---such as RVD and hypertrophic cardiomyopathy---will also be amenable to testing soon. Hypertrophic cardiomyopathy is a particularly important cause of sudden death in young athletes.
Krissy Taylor suffered from right ventricular dysplasia. In this disease, the chamber of the heart that pumps blood back to the lungs (the right ventricle) is infiltrated by deposits of fat between the muscle bundles, and scar tissue develops. Establishing a cause of death for Krissy was complicated by the fact that she apparently also had changes in her lungs similar to abnormalities seen in patients with asthma. Based upon the absence of prior symptoms, the suddenness of her death, and her lack of a prior history with asthma, right ventricular dysplasia is indicated as a major contributor in Krissy's death; although clinically-inapparent asthma may have been a contributing factor.
Right ventricular dysplasia usually becomes apparent in adolescence or young adulthood. The first symptom may be fainting spells, sudden periods of fast beating of the heart, or even sudden death without warning. For reasons which are not yet understood, this abnormality causes rapid irregularities in heart rhythm, along with chaotic electrical disturbances which can prove fatal. The disease sometimes occurs in families and researchers are trying to find a genetic basis which will lead to the ability to screen individual members of affected families. At present, however, the majority of cases appear to be isolated.
Fortunately, sudden death in the young is very rare. However, when it occurs, the tragedy is amplified because of the youth and prior vitality of the victims. For children, adolescents, and young adults who, unlike Krissy, are fortunate enough to have warning signs---such as periods of rapid heart action, episodes of fainting or near fainting, or shortness-of-breath when they exert themselves---testing for these disorders may be lifesaving.
The CARE (Cardiac Arrhythmia Research and Education) Foundation, based in California, is a non-profit voluntary organization dedicated to fostering research and public and professional education in the area of life-threatening heart rhythm disturbances---particularly in children, adolescents and young adults. Its membership is comprised of physicians, scientists and interested citizens. The funds raised through its efforts support its stated goals and it provides grants through a peer-review mechanism to scientists working in the field.
CARE also functions as a clearinghouse for families affected with these disorders to share their experiences, disseminate new information and draw public attention to these tragic conditions.
The CARE offices can be reached at 800-404-9500 ( http://www.longqt.org/ ).
For more information about ARVD, browse to http://www.arvd.com/faq.html