Cardiac Arrest Tools and Resources Answers by Heart Patient Information Sheets What is an Automated External Defibrillator? (PDF) What is Arrhythmia? (PDF) See all Answers by Heart sheets Stories from the Heart – Cardiac Arrest Nurse was training for triathlon when her heart stopped mid-swim Teen's mall trip could have been her last, but CPR and an AED saved the day When hockey player's heart stopped on the ice, CPR and an AED saved him