I do not have a pacemaker but work with them frequently. I would talk to your cardiologist before you set out on the trip. As you know there are so many different reasons for people to have pacemakers so the advice would be specific to each individual. What I would recommend you do is have a copy of the pacemaker details with you, the settings, the make and model, is it a simple pacemaker or an ICD/pacemaker, single lead or dual lead etc. and then make sure you have a copy in a pocket, no just in your backpack so that if there were problems those trying to help have the information they need quickly. A medic alert bracelet might be a good thing to invest in.