Hello there, I am trying to find out how to tell the difference between a pulled muscle in the chest or heart problems symptoms. I go to the Gym 3 times a week and NEVER get breathless when training or after I do both cardio and muscular at least 3 times a week, Chest pecturol machine I lift 60k 36 times 3 reps or 12, lat pull the same, 10 min run, 5 min cycle, 500m row, 55kg leg curls up and down. I have recently had my blood pressure and pulse rate taken in the gym and in the docs coming in at blood pressure 128 in the gym and 127 in the docs, pulse rate 66 in the gym and 70 in the docs. I just need to know If after all the information given that the NON severe niggle I would call it that I am getting under my left breast plate and sometime near my nipples left side. I am a 30 year old male from the UK, 6ft, 95kg in weight.