A:Answer No sir, it doesn't affect your AICD/defibrillator. The fit bit takes you radial pulse. Your AICD/defibrillator will know if your heart goes out of rhythm into a shockable arrhythmia, you might catch it too in your Fit bit. The advantage of the Fit bit is that it will guide you through a healthy exercise routine - steps, calories, and other features. Definitely a cool gadget and I love it.