Upper left back pain, went to er n had xray, ctscan with contrast, two ekgs, and blood work but all normal, pain persists, should i be concerned?

Go see a doctor: You should establish a relationship with a primary care physician and let them do a full history and physical exam. If they are not able to define the cause of this discomfort they will help to guide you to an appropriate source for further evaluation.

Muscle strain: What was your discharge diagnosis. Did you receive any prescriptions. If all your work up was negative then you are probably having a trapezius or rhomboid strain. You should consult your physician. Your symptoms are caused by a muscle spasm. Your physician can prescribe you some nonsteroidal anti-inflammatory medication and muscle relaxants and or physical therapy which will help

Mystery Back Pain: The most common causes of left upper back pain are muscle and ligament strain, shoulder injury, and muscle spasms. The majority of left upper back pain cases are from overuse. Due to the many factors that could contribute to back pain, a trained physician is required to diagnose the exact cause. It sounds like you had a thorough work up, but no cause was found. Hard to say w/o more details.