I am 76 and have had some heart problems. Yesterday I shot my .223 (TAC) and some 9mm/45 (Bullseye) with wind blowing in my face. An hour later I went to Cardiac rehab and my heart rate was double my normal with some A-fib. Five hours later everything was back to normal. Could inhaling the un-burnt gun powder or smoke have caused this? I have never checked my heart rate after shooting before. Sorry if this is not the right place for this question, but this is an active forum and I thought this might be of interest.