Each year over 1,000 young athletes die unnecessarily from sudden cardiac death on the athletic field. Sudden cardiac death affects over 300,000 people per year in the US, 100,000 of these during physical activity. While most cardiac events occur in adults, sudden cardiac arrest can occur in children as well. Among young athletes, the incidence of sudden death is 1/100,000.
How It Happens
Sudden cardiac death implies an abrupt irregularity in heart rhythm that leads to a cessation of effective heart pumping, a lack of blood flow to the vital organs and ultimately death. Most cases of sudden cardiac arrest involve a rhythm called ventricular fibrillation, a useless quivering of the heart. This occurs most commonly in the setting of a heart attack. However, ventricular fibrillation can also occur in young patients with abnormally thickened hearts (hypertrophic cardiomyopathy), hearts weakened by processes other than heart attack damage, and genetic rhythm disorders (prolonged QT syndrome).
Commotio cordis, a blunt blow to the chest leading to ventricular fibrillation, is one of the less common causes of cardiac arrest, accounting for 6% of sudden cardiac deaths on the athletic field. However, victims have normal hearts at autopsy. They are completely healthy athletes – Commotio cordis can happen to anyone at any time. Roughly 20 cases of commotio cordis occur each year, most often in baseball, but also in hockey, lacrosse and martial arts.
CPR is only effective at keeping the organs alive until normal rhythm and effective heart pumping are restored. Once cardiac arrest occurs, survival drops 10% with every minute that passes, even with efficient CPR. Application of a controlled electric shock with a defibrillator is the only way to restore normal rhythm. Therefore, the sooner normal rhythm is restored the greater the chances of survival and neurologic recovery. Unfortunately, emergency medical services cannot always arrive at the scene and deliver therapy fast enough. Early defibrillation is still possible with public access to automatic external defibrillators (AEDs). An AED is a small, portable device that analyzes heart rhythms and delivers a defibrillation shock if indicated to reestablish a life sustaining heart rhythm.
Preventing Sudden Cardiac Death
When possible, prevention is of utmost importance. Pre-participation physicals try to identify those at risk for sudden cardiac death due to congenital or acquired cardiac disease using physical examination and medical history.
Concerning historical details include a history of passing out, lightheadedness with exertion, or family history of sudden cardiac death, arrhythmias, or heart muscle problems. Such factors may identify athletes who require medical therapy or need to avoid competitive athletics altogether. Random screening programs with electrocardiography and echocardiography remain controversial as scientific studies have not demonstrated a clear benefit of such programs. Such random screening is therefore not recommended by the American Heart Association or American College of Cardiology. Protective equipment may impart a false sense of security as current chest protector designs have been shown to be ineffective in preventing commotio cordis.
Chain of Survival for Cardiac Events on the Field
As attempts to prevent sudden cardiac death in athletes are imperfect at this time, response to events is of utmost importance. The chain of survival entails:
– Formulating an emergency response plan ahead of time
– Early recognition of cardiac arrest
– Prompt activation of the Emergency Medical Service (EMS)/911 system
– Prompt and effective CPR
– Early defibrillation – made possible by increasing public access to AEDs in the community
The risk of sudden cardiac death for young athletes is extremely rare, but is a horrific tragedy when it does occur. The risk of death can be diminished if coaches and athletic trainers are aware of the risk of sudden cardiac death on the athletic field, have an emergency response plan, are properly trained in administering CPR, and have access to AED’s for early defibrillation.