I was in the er today for left arm and chest pain. the ekg was fine. they said it was shoulder impingement. would you feel pain in your armpit as?

Not cardiac: What the ER did was determine that's it's not your heart. The shoulder impingement assessment is offered as their best educated guess. Understand: from your perspective, you want the ER to tell you precisely what's wrong. From the ER's view, they simply want to rule out life threatening problems.

Nerve impingement: can be caused by being sandwiched between two spinal bones, pressed by a bulging disc. It can cause muscle spasm and back pain. This condition must be professionally managed. See interventional pain management specialist for definitive diagnosis and management.