Additional Study Information: We are doing this study to gather information on participants returning at time of Cardiovascular Implantable Electronic Device (CIED) change-out or revision who underwent a device implantation with either a CanGaroo envelope, Tyrx envelope, or no envelope. A CIED is a device implantable inside the body, able to conduct pacing of the heart and therefore capable of correcting most life-threatening abnormal heart rhythms. People who have had surgery to implant a medical device that helps their heart, may have had their surgery done in slightly different ways. In this study, the investigators are looking for people to participate who need to undergo another surgical procedure to change or revise their implanted heart device. The study will look at several pieces of information that may help provide a better understanding of how your body has healed and also to see if there is any difference between people who had their surgery done in slightly different ways.