Much depends on what kinds of steroids you are talking about, how much, and for how long. Recreational steroids, so to speak, for
bulking up, are probably not good for heart health. You can google that, too.
Interestingly, though, one recent study of medical steroid use after ablation for atril fib indicates that such use may help to prevent recurrence:
http://www.theheart.org/article/1139047.