This could be a symptom of gallstones.
"A main symptom of gallstones is commonly referred to as a gallstone "attack", also known as biliary colic, in which a person will experience intense pain in the upper abdominal region that steadily increases for approximately thirty minutes to several hours. A patient may also experience pain in the back, ordinarily between the shoulder blades, or pain under the right shoulder. In some cases, the pain develops in the lower region of the abdomen, nearer to the pelvis, but this is less common."
I've had gallstones and have now had my gallbladder removed. I had horrendous stabbing pain just under my breasts in the middle of my chest, it would then go away but rise up through my back. The pain lasted 15mins and I could time my watch by it. I would feel really cold and shaky after the attacks. I had about 4 attacks every few months. The last time I had it the pain lasted two hours (due to eating a lot of fatty food that weekend) and then I was rushed to hospital. Luckily the pain subsided and I was allowed home the next day and had an appointment for a few months later to have my gallbladder removed. I don't know how different symptoms are in other people, but cutting out fatty food may help if you do have gallstones. As I didn't have any problems after I made sure all my meals contained less than 5grams of saturated fat. It sounds extreme but I was so scared of having the pain back again. I also lost a stone in weight which was good! Also I was only 27 when I had my gallbladder removed and I was a UK size 12. The doctors criteria for gallstones is over 40 and overweight so I was not diagnosed for two years because of this! Hope this helps? x