If you enter a hospital, not feeling good, and you take all different types of tests while your there, the Dr. comes in and tell

I'm glad you found that you don't have cancer, and I am sorry that you had to go through the anguish of believing that you had little time left to live. That must have been very difficult.

The tort you are describing is "negligent infliction of emotional distress" and possibly some type of medical negligence. Whether or not you can recover for your anguish depends on whether the ER doctor was truly negligent in his diagnosis - just being mistaken isn't enough. It will depend on whether it was reasonable for doctors in the same situation to make the same diagnosis and handle it in the same manner that this doctor did. You should follow up with a personal injury / medical negligence attorney in your area or county.