Sudden Cardiac Deaths in Athletes

Context: Instances of sudden cardiac death (SCD) in athletes, while rare, remain a significant concern that requires careful attention and preventive measures.

Relevance of the Topic: Key facts about Sudden Cardiac Death & Cardiovascular diseases (CVDs). 

What is Sudden Cardiac Death (SCD)?

• The most common cause of SCD is sudden cardiac arrest (SCA), characterised by an unexpected circulatory arrest (a condition where blood circulation suddenly stops) typically due to cardiac arrhythmia, occurring within an hour of symptom onset.
  • Sudden cardiac arrest (SCA) is the sudden loss of all heart activity due to an irregular heart rhythm.
  • Breathing stops, the person becomes unconscious. Without immediate treatment, sudden cardiac arrest can lead to death.
• It is concerning as it causes sudden death in a structurally normal heart with no other explanation and a history consistent with cardiac-related death.

Risk Factors:

• The risk factors for SCA and SCD include: 
  • Coronary artery disease - Narrowing or blockage of coronary arteries (due to plaque/cholesterol buildup in these arteries), which supply oxygen-rich blood to the heart.
  • Hypertrophic cardiomyopathy- A disease in which the heart muscle becomes thickened, also called hypertrophied. The thickened heart muscle can make it harder for the heart to pump blood.
  • Arrhythmias - An irregular heartbeat.
  • A genetic predisposition
  • Pre-existing heart conditions
  • Weight issues
  • High-intensity exercise without proper training
  • History of smoking 
  • Increased ambient temperature.

Exercise and Cardiovascular Health: 

• Exercise is a vital tool for promoting health and well-being. It improves cardiovascular risk factors like lipid levels, hypertension, insulin sensitivity, and weight.
• Multiple studies have established a positive correlation between moderate aerobic exercise and reduced risk of coronary artery disease.

Guidelines to Prevent Sudden Cardiac Death (SCD) in Athletes: 

• According to International Olympic Committee recommendations, pre-participation screening and periodic health evaluation are the only ways to reduce the incidence of cardiovascular accidents and other injuries in athletes.
• The World Athletics Health and Science Department, based on IOC guidelines, recommends a pre-participation medical evaluation (PPME) at the start of the season for athletes in competitive sports. 
• A study conducted on the benefits of pre-participation screening and periodic health evaluation demonstrated a drop in the incidence of SCD by 90% in young athletes.

Challenges: 

• Concerns with Athletes: During vigorous physical activity by athletes, there is a substantial increase in sympathetic nervous system activity. This surge can trigger arrhythmias and potentially lead to sudden cardiac arrest.
• Pre-participation screening and periodic health evaluation may not be possible in mass endurance events where the majority of participants are recreational athletes. Despite screening, sudden cardiac arrest may be challenging to predict. 

Way Forward

• Prompt and appropriate resuscitation - Evidence points to excellent survival rates after arrest when appropriate resuscitation is started promptly (for every minute delay, there is a 7% decreased chance of survival.) Personnel trained in CPR and access to defibrillators on the route and at sports venues are crucial in reducing the incidence of sudden cardiac death.
• Periodic health evaluations - As athletes, competitive or recreational, it is important to have periodic health evaluations. The ECG needs to be read by a trained physician who is aware of the physiological and structural adaptations in the heart of an athlete.
• Correct medical information should be provided honestly by the athletes during their screening.
• Workouts under trained coach - The risk of sudden cardiac death is higher in those with pre-existing conditions, and hence it is important that exercise be carried out under supervision or with the help of a trained coach.