Can SCA occur in apparently healthy athletes?
Registries from the United States of America estimate that SCD is the most common non-traumatic cause of death among college athletes. It is however important to reassure our readers and clarify that athletes are not at higher risk of sudden cardiac death when compared to non-athletes. In fact the estimated annual incidence of SCD among athletes versus non-athletes in the USA is respectively 0.44 per 100,000 and 12 per 100,000, indicating an overall protective effect of practicing sports activities.
In the particular subgroup of individuals who carry certain types of heart abnormalities, sudden cardiac death can occur during or shortly after sports activities. In fact, during physical exercise a number of normal changes occur in our body leading to an increased oxygen demand from the heart muscle, an activation of a nervous and hormonal stress response system in addition to significant changes in heart rate and blood pressure. In individuals with specific underlying heart abnormalities, those exercise-induced changes can serve as triggers for abnormal rapid heart rhythms (ventricular tachycardia or ventricular fibrillation) leading to sudden cardiac death.