What causes a 10 second feeling of tightness and pressure at the top inside of left breast and sternum?pcp says not heart. fear cardiac problem!

Few other options: esophagus spasms can do this as can breast pathology. one simple way to tell if its ur heart is to press the chest area and if it hurts, its not you heart, except in one condition-pericarditis, which is inflammation of the lining capsule of the heart. But you have to press deeper, instead of a surface press. otherwise anxiety is another consideration as this causes adrenaline and cortisol rushes.