Sudden Cardiac Death & Cardiac Conditions in Athletes / Pre-Participation Screening

Sudden cardiac death is the leading medical cause of death in sport, and in young athletes it usually reflects an underlying structural or electrical cardiac condition: hypertrophic cardiomyopathy, arrhythmogenic right-ventricular cardiomyopathy, dilated cardiomyopathy, congenital coronary artery anomalies, channelopathies such as long-QT syndrome, Brugada syndrome and catecholaminergic polymorphic VT, myocarditis, and commotio cordis, which is ventricular fibrillation from a blunt chest impact at a vulnerable point in the cardiac cycle. In older, master athletes, the leading cause is atherosclerotic coronary artery disease, so the differential is age-dependent. The 'grey zone' is the diagnostic overlap between the physiological cardiac adaptation of intense exercise - the athlete's heart, with mild balanced chamber enlargement and wall thickening and training-related ECG changes - and a genuine cardiomyopathy that could cause sudden death; the features overlap and are influenced by age, sex and ethnicity, so careful interpretation with a broad work-up, and sometimes ongoing surveillance especially in the young, is needed to avoid both missing disease and falsely disqualifying a healthy athlete. Pre-participation screening with a focused history and examination, and ECG in some protocols, aims to detect at-risk athletes, though the value and form of screening are debated. But the single factor that most determines survival of an on-field arrest is the emergency response: a rehearsed emergency action plan, prompt recognition, immediate CPR and, above all, early defibrillation with an accessible on-site automated external defibrillator - so venues and teams must have AEDs and trained responders.