Is Am Having Chest Pains In The Central Region That

is am having chest pains in the central region that is hurting straight through my back in the same area.i am a 45 year old male, light smoker and am a welder. I have been doing overhead welding lately that bothers my right shoulder, which i dont have full range in. My rotater cuff has a tear and the bone rubs in on it. It hurts to swallow and when i breathe it intensifies the pain. i had an EKG four months ago which came back normal, and was done because of a supposed heart murmer, it hurts mostly when i am laying down and particularly on my side (either).