Cameron Crider had no symptoms despite years of football and basketball, but a mandatory ECG screening revealed a congenital heart defect needing surgery.
https://www.foxnews.com/health/healthy-athlete-had-no-symptoms-before-mandatory-heart-screening-revealed-hidden-defect
https://www.foxnews.com/health/healthy-athlete-had-no-symptoms-before-mandatory-heart-screening-revealed-hidden-defect