I Had A Double Bypass Heart Surgery A Little More

I had a double bypass heart surgery a little more than one year ago. The surgeon did not prescribe any beta blocker. A month ago I went to a cardiologist( different from the surgeon) for an opinion on suspected PAH. He conducted TMT and told me that there is no PAH what so ever and added Concor tablets to what I was already taking. I was doing some breathing exercises too for some time. One day I did the same exercise a little briskly. I have been having uneasiness/tenderness/discomfort in the area of surgery for the last one month. Either Concor cor is causing it or my exercise has caused it. Can you please throw some light on this. Thank you