Beta-blockers are used often for performers as it keeps your sympathetic nervous system calm(keeps heart beat from raising). These alone, with alcohol, or any diazapam drug like valium, klonapin, clonazapam, lorazapam, can make you simply stop breathing. With the AAS working in a different way(not directly affecting nervous system) you shouldn't have problems. This is, however, not to be messed around with or taken lightly. Talk to your doctor about what your taking. They can't disclose any information and if they do you can sue them till you've taken their first born, so my advice is to talk to your doctor who works with you on your heart. The Bata-blocker in your case is just to keep the heart normal, but steroids affect more than your muscles, so ask a professional. Seriously, this is something I know a ton about, but don't know you or your problem, and without a professional opinion, I wouldn't mix the two just because there isn't a ton of literature about it.
Be aware, your doctor will scold you and tell you how horrible steroids are, but you're there to see if there is an interaction, so don't let them lecture you. Get your answer and feel safe.
Hope that helped and hope everything works out for you.
Best wishes,
Kirk