Sudden Cardiac Arrest In Athletes

Sport is seen as a symbol of health in modern society. It is now undeniable that regular exercise reduces the risk of heart disease, diabetes, obesity, and premature death. Therefore, the sudden death of an athlete creates a great shock in society.

Sudden cardiac deaths in young athletes are often caused by previously unknown structural or electrical heart diseases . In most cases, the athlete has never experienced any symptoms.

The reason this situation is tragic is this:

• The person is young.

• They often possess superior physical capabilities.

• He is seen by those around him as the "healthiest" person.

• Death usually occurs during or shortly after training.

Scientific data shows that the vast majority of sudden deaths in young athletes occur during or immediately after exercise . This is because increased adrenaline levels during exercise can trigger lethal arrhythmias in underlying heart conditions.

There is a crucial distinction here. Exercise alone does not cause sudden death. Exercise can be a factor that reveals or triggers an existing heart condition.

Therefore, the issue is not whether sports are harmful or not, but which individuals are at risk and how to identify that risk.

WHAT IS SUDDEN CARDIAC DEATH?

Sudden cardiac death is death of cardiac origin that occurs unexpectedly and rapidly.

However, there are different definitions in the literature:

• American College of Cardiology (ACC) : Sudden cardiac death occurring within 6 hours in a previously healthy individual.

• World Health Organization (WHO) : Unexpected death occurring within one hour of symptom onset.

In the context of sports, a more specific definition is used:

• Sudden cardiac death occurring during or within one hour of non-traumatic, moderate to high-intensity exercise.

The important thing here is that it's non-traumatic. In other words, causes like traffic accidents or head injuries don't fall into this category.

HOW COMMON IS SUDDEN DEATH IN ATHLETES?

Sudden cardiac death is rare in young athletes.

According to US data, approximately one in every 200,000 to 300,000 young athletes experiences sudden death each year.

However, there is an important finding here. Young athletes with underlying heart disease have approximately 2.5 times higher risk of sudden death compared to similar individuals who do not exercise.

Moreover:

• The risk is approximately five times higher in male athletes than in females.

• Over 90% of deaths occur during or immediately after training or competition.

THE MOST COMMON CAUSES OF SUDDEN DEATH IN YOUNG ATHLETES

The sudden death of a young athlete is almost never "because of sports." The real problem is often a previously unknown heart condition. Sports are the triggering factor that makes this condition apparent or fatal.

STRUCTURAL HEART DISEASES

In athletes under 35, the most common cause of sudden cardiac death is structural diseases of the heart muscle . These diseases are often genetic and can progress for years without showing any symptoms .

A person might experience no problems in their normal life; they might even be a high-performing athlete. However, the situation changes when the heart is forced to work faster and harder during intense exercise.

For example, in cases where the heart muscle is thicker than normal ( such as in hypertrophic cardiomyopathy ) or where the muscle structure is damaged ( such as in arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy ), the electrical regulation within the heart becomes sensitive. This sensitivity, which does not cause problems in daily life, can turn into a fatal arrhythmia during exercise with increased adrenaline and elevated heart rate . The heart suddenly stops pumping regularly, and loss of consciousness develops within seconds. In most cases, this is the first symptom of the disease.

ELECTRICAL INFRASTRUCTURE PROBLEMS OF THE HEART

In some athletes, the problem lies more in the electrical infrastructure of the heart than in the structure of the heart muscle itself. In genetic rhythm disorders such as long QT syndrome or Brugada syndrome, the heart may appear completely normal externally. However, there is a microscopic abnormality in the electrical system. Stress hormones, which increase with exercise, destabilize this fragile system, and sudden arrhythmias can develop. The heart may appear normal at autopsy; this can lead to the cause remaining undiagnosed for a long time in some cases.

CARDIOVASCULAR PROBLEMS (CONGENITAL)

Another important cause is congenital coronary artery anomalies . When the vessels supplying the heart originate from an abnormal location, it often doesn't cause problems in daily life. However, during exercise, the heart's oxygen demand increases dramatically . If this vessel becomes constricted during exercise or fails to provide sufficient blood flow, the heart muscle can experience sudden oxygen deprivation . This can directly trigger arrhythmias.

MYOCARDITIS (HEART MUSCLE INFECTION)

Another particularly critical condition for young athletes is myocarditis. Inflammation of the heart muscle, developing after a simple viral infection, often presents with mild symptoms. The athlete can return to training early when they feel better. However, the heart tissue is still inflamed and fragile. Intense exercise during this period can trigger life-threatening arrhythmias .

All these different diseases have one thing in common: death is usually caused not by pump failure, but by a sudden, fatal arrhythmia . The heart doesn't stop beating; it begins to beat irregularly and chaotically. In this case, blood doesn't reach the brain, and loss of consciousness develops within seconds.

In summary, sudden death is rare in young athletes, but when it does occur, there is often an underlying, hidden heart condition. Sports do not cause this disease; however, under intense physiological stress, it can bring out the most dangerous aspects of the condition.

THE IMPORTANCE OF HEALTH CHECKS AND SCREENINGS IN ATHLETES

Sudden cardiac death is rare in young athletes. However, when it does occur, the question often arises in retrospect: "Couldn't we have foreseen this?"

A significant number of diseases that lead to sudden death can be detected before an athlete takes to the field through proper screening methods.

The basic logic here is this:

• Sports are not dangerous.

• Undiagnosed heart disease combined with intense exercise is risky.

• If we can identify at-risk individuals beforehand, death can be prevented.

  
  
  
  

WHY IS SCREENING NECESSARY?

Most sudden deaths in young athletes occur during or immediately after exercise. This clearly demonstrates the triggering role of exercise. The majority of serious heart diseases diagnosed in athletes do not present with prior symptoms . Therefore, the "no symptoms, no problem" approach is incorrect.

An athlete may never have fainted, may never have experienced chest pain, may perform exceptionally well, and yet still carry a genetic heart muscle disease.

Therefore, systematic screening aims to identify not only those with symptoms but also those who carry silent risks.

WHAT SHOULD SCREENING INCLUDE?

When screening is mentioned, many people immediately think of advanced tests. However, the most important step is to ask simple but accurate questions.

A good athlete evaluation should include the following:

• Do you experience fainting or dizziness on exertion?

• Is there a history of sudden deaths under the age of 50 in the family?

• Do you experience palpitations?

• Do you have unexplained shortness of breath?

Even these simple questions can reveal some at-risk individuals. This is supplemented by a physical examination and, in most countries, a 12-lead ECG. The ECG is particularly valuable in detecting certain heart muscle diseases and electrical syndromes .

DOES SCANNING PROVIDE 100% PROTECTION?

No.

No screening method can detect all cases. Some diseases are dynamic or have a late onset. Some electrical abnormalities are not always visible on an ECG. However, the risk can be significantly reduced.

Screening is not a one-time formality. Cardiovascular diseases can develop during adolescence and young adulthood, especially in young athletes. Therefore, regular check-ups are important, particularly for competitive athletes.

RISK REDUCTION

When a risky heart condition is detected in an athlete, the main question is no longer "Is there a disease?", but "How can this risk be managed?" .

Not every diagnosis means the end of an athlete's life. However, in some cases, competitive and high-intensity sports may be restricted. This is not because sports are harmful, but because most fatal arrhythmias occur during intense exertion.

In some diseases, drug treatment may be sufficient. Medications that reduce heart rate and the effect of adrenaline can lower the risk of arrhythmias. This approach is quite effective in electrical disorders or certain heart muscle problems.

Some athletes require more advanced solutions. In individuals considered to be at high risk of death, an ICD (implantable cardioverter defibrillator) device implanted in the heart can stop a sudden, life-threatening heart rhythm by delivering a shock within seconds. These devices are particularly life-saving in patients who meet specific risk criteria.

In some electrical disorders like WPW, catheter ablation can eliminate the problematic conduction pathway, allowing the athlete to safely resume their life.

For athletes who have suffered myocarditis, time is of the essence in treatment. Returning to intense sports is not recommended until the heart has fully healed. This process can sometimes take months.

The basic principle here is this:

The risk cannot be eliminated completely, but it can be significantly reduced. The decision must be made individually.

THE IMPORTANCE OF EMERGENCY INTERVENTION

Despite all screenings, some cases are unpredictable. Therefore, the second line of defense is emergency response preparedness.

In most cases of sudden cardiac death, the heart does not stop completely; it enters a lethal rhythm (ventricular fibrillation). This rhythm can be corrected with defibrillation. However, time is critical. If a shock is not applied within the first 3–5 minutes, the survival rate drops dramatically.

Because:

• Sports facilities should be equipped with automated external defibrillators (AEDs).

• Coaches and club staff should receive basic life support training.

• Intervention protocols should be in place.

MESSAGE TO SOCIETY AND ATHLETES

At this point, there are two extremely dangerous extremes:

1) Sports are dangerous.

2) Young people do not get heart disease.

Both are wrong.

Exercise generally protects heart health and reduces the risk of death in the long term. However, although rare, some individuals may have hidden heart conditions. These conditions often do not show any symptoms.

Because:

• If there is a history of sudden death at a young age in the family, it should be taken seriously.

• Fainting due to exertion should never be considered "insignificant".

• Palpitation attacks should be investigated.

• Intense exercise should be avoided during a feverish illness.

CONCLUSION

Sudden cardiac death is rare in young athletes. However, every case is dramatic. In most cases, there is an underlying genetic or structural heart disease .

Exercise does not cause this disease , but intense physiological stress can trigger a lethal rhythm.

Science tells us three clear things:

1. High-risk individuals often show no prior symptoms.

2. Some at-risk athletes can be identified through systematic screening.

3. Early defibrillation saves lives.

Therefore, the solution is not to stop exercising; it is scientific screening, conscious exercise, and preparedness for emergency intervention.

Exercise is health. But conscious and responsible exercise saves lives.

References:

• Halabchi F, Seif-Barghi T, Mazaheri R. Sudden cardiac death in young athletes; A literature review and special considerations in Asia. Asian J Sports Med. 2011 Mar;2(1):1-15. doi: 10.5812/asjsm.34818. PMID: 22375212; PMCID: PMC3289188.

• Basavarajaiah S, Shah A, Sharma S. Sudden cardiac death in young athletes. Heart. 2007 Mar;93(3):287-9. doi: 10.1136/hrt.2006.100107. PMID: 17322504; PMCID: PMC1861445.