for 2 years now my hushand has a pain that starts in his back under his left shoulder and go thru to his chest just like he is having a heart attack and sometimes down his arm. He has had his heart checked, no blockages and problems. As his heart doctor said he has had the million dollar check up and can't find anything wrong. Every possible part of his body has been checked. Can not determined what is causing the pain. The pain is very serve just like a heart attack and a nitro wil ease the pain for a short time. He eats nitro like candy. Can you help????