My Resting Heart Rate Some Times Goes At 38 Bpm

my resting heart rate some times goes at 38 bpm I had a stent fitted 2 weeks ago and generally feel ok I take a low dose beta blocker + asparin+ bp tablet + platelet reducer + lipitor. heart rate never used to be much higher than 55bpm but I feel 38bpm is too slow doctor took me off beta but had what I think where palpitations or panic attack. doc put me back on beta blocker.