Dad is going to Bali with us in a few weeks, his first time. He has a pacemaker and isn't allowed to go through the walkthrough x-rays that you have to go through in arrivals and departures. I'm sure there are others who have visited Bali with pacemakers, and intersted to hear about whether or not you have any problems explaining why you couldn't go through. He has a card that he has to show but not sure whether or not they would understand at Denpasar Airport.