The case of the Pu-powered pacemaker "Nuclear News provides a review of radioisotope-powered pacemakers in response to an article in The Wall Street Journal. The article, published earlier this week, looks at the issue of disposing of nuclear-powered pacemakers, although considering how few are still in use today, it seems like this is really much ado about nothing."
https://www.ans.org/news/article-3591/the-case-of-the-pupowered-pacemaker/