Yep. All kinds of meds, from the performance-enhancing taken by anyone who goes in for high-level competitive sports through to those taken by older folks thought to be at risk of a stroke or heart attack.
But there's also the plain ol' progression of the ticker through life. And personal events like getting fit, or vice versa. Useful bit of built-in obsolescence there ;) Some of us would insist on there being an override, like (say) the classic password on a post-it note.
 Of the kind that exercise the heart, so maybe not darts or snooker.