What should I be feeling right now.? Do I have a case for complaint against the hospital.? Read below..?

If the doc did the tests any other cardiologist would do...you have no case. The tests may well have all been negative. That is just how it works sometimes. Get a different cardiologist and sign a records release to have all your tests, etc sent to the new doc. He/she will know if everything reasonable was done. Unless there was gross negligence you are better off just thanking God you are alive. Imagine what the stress could do to you now... doctors rarely testify against one another