What are common causes of sudden cardiac arrest in athletes and how should you respond?

• A. Dehydration and heat illness.
• B. Underlying conditions such as hypertrophic cardiomyopathy, coronary anomalies, myocarditis; respond with immediate CPR and early AED use, call EMS, and follow local protocols.
• C. Minor sprains.
• D. Vitamin deficiencies.

Answer: (B)

SCA in athletes is usually caused by hidden heart problems that can spark a life-threatening rhythm during exercise. Hypertrophic cardiomyopathy, where the heart muscle is abnormally thick, can disrupt the heart’s electrical signals and trigger dangerous arrhythmias during exertion. Coronary anomalies, meaning abnormal origins or paths of the coronary arteries, can lead to reduced blood flow to the heart during intense activity and provoke ischemia and arrhythmias. Myocarditis, an inflammatory disease of the heart muscle often following infection, can also set up abnormal rhythms and sudden collapse in athletes.

The most important response is immediate CPR with early use of an automated external defibrillator (AED), because delivering chest compressions and a shock promptly greatly improves survival. Call EMS and follow local protocols as you begin care, then continue CPR and use the AED as soon as it’s available, circulating between compressions and defibrillation per device prompts. In the meantime, ensure the environment is safe and evacuate the athlete to a safe location if needed, but do not delay CPR or AED use for other actions.

Other causes like dehydration, heat illness, minor sprains, or vitamin deficiencies can cause dizziness or collapse, but they do not account for the typical heart-rhythm–related collapse seen with SCA in athletes, so they’re not the primary focus of the response.