Periop Pacemaker is a smartphone app that assists medical professionals who take care of surgical patients that have implantable defibrillators or pacemakers. The decision algorithm is endorsed by the Heart Rhythm Society and is based on the American Society of Anesthesiologists Perioperative Cardiac Implantable Electronic Device Management Aid. As device technology evolves, an expert committee of anesthesiologists, cardiologists, and device representatives will meet annually to keep information up-to-date. The app is subscription-based.