Sudden cardiac death of athletes
The prevalence of any single, associated condition is low, probably less than 0.3% of the population in the athletes' age group,[citation needed] and the sensitivity and specificity of common screening tests leave much to be desired.
[2] The victims include many well-known names, especially in professional association football, and close relatives are often at risk for similar cardiac problems.
The sudden cardiac deaths of 387 young American athletes (under age 35) were analyzed in a 2003 medical review:[3] While most causes of sudden cardiac death relate to congenital or acquired cardiovascular disease, an exception is commotio cordis, in which the heart is structurally normal but a potentially fatal loss of rhythm occurs because of the accident of timing of a blow to the chest.
In individuals without a family history, the most common cause of the disease is a "de novo" mutation of the gene that produces the β-myosin heavy chain.
[citation needed] Sudden cardiac death can usually be attributed to cardiovascular disease or commotio cordis, but about 20% of cases show no obvious cause and remain undiagnosed after autopsy.
These electrolyte channels are pores regulating the movement of sodium, potassium and calcium ions into cardiac cells, collectively responsible for creating and controlling the electrical signals that govern the heart's rhythm.
Consequently, autopsy-negative sudden cardiac deaths (no physical abnormalities identified) may comprise a larger part of the channelopathies than previously anticipated.
[15] After a disease-causing mutation has been identified in an index case (which is not always accomplished conclusively), the main task is genetic identification of carriers within a pedigree, a sequential process known as "cascade testing".
It should be stressed that this was a single pilot program, but it was indicative of the problems associated with large-scale screening, and consistent with experience in other locations with low prevalence of sudden death in athletes.
[20] However, a population as large as the United States will experience the sudden cardiac death of a competitive athlete at the average rate of one every three days, often with significant local media coverage heightening public attention.
