What is the most likely diagnosis for a 19-year-old footballer who collapsed on the pitch with no prior history of similar events and no current chest pain?

Hypertrophic Obstructive Cardiomyopathy (HOCM)

The most likely diagnosis is hypertrophic obstructive cardiomyopathy (HOCM), which is the leading cause of sudden cardiac arrest in young athletes under 35 years of age, accounting for approximately one-third of fatal events on the field. 1

Clinical Reasoning

Why HOCM is Most Likely

• Age and athletic context: In athletes younger than 35 years, hypertrophic cardiomyopathy is the single most frequent cause of sudden cardiac death during sports activity 1
• Presentation pattern: Any footballer who collapses without contact with another player or obstacle should be regarded as being in sudden cardiac arrest until proven otherwise 1
• Absence of chest pain: HOCM often remains clinically silent and can lack premonitory symptoms, making the absence of chest pain consistent with this diagnosis 1
• No prior history: Many athletes with HOCM have no previous symptoms before their first cardiac event 1

Why Other Options Are Less Likely

• Carotid stenosis (A): This is predominantly a disease of older adults with atherosclerotic risk factors, not a 19-year-old athlete 1
• Myocardial infarction (C): In athletes over 35 years, atherosclerotic coronary artery disease is the predominant cause, but in those under 35, congenital cardiac diseases like HOCM are far more common 1
• Rheumatic fever (D): Does not typically present as sudden collapse during athletic activity
• Thyrotoxicosis (E): Would not cause sudden collapse on the field without other preceding symptoms

Important Clinical Considerations

Immediate Management Priority

The guidelines emphasize that sudden cardiac arrest should be assumed in any collapsed and unresponsive athlete 1. The immediate focus must be on:

• Prompt recognition of cardiac arrest 1
• High-quality CPR with minimal interruptions 1
• Early defibrillation within 2 minutes of collapse 1

Common Pitfall to Avoid

Do not mistake seizure-like activity for a primary seizure disorder. Brief seizure-like activity or involuntary myoclonic movements occur in over 50% of athletes with sudden cardiac arrest and should not delay cardiac arrest management 1

Post-Recovery Evaluation

Even though this patient has recovered and denies chest pain, he should not return to play and requires comprehensive cardiac evaluation 1. The recovery does not rule out an underlying cardiac condition—athletes with HOCM may recover from near-arrest episodes but remain at high risk for future events.