Why do i only feel a tingling sensation in the left ring and little fingers every time i have chest pain? why the pain doesn't spread to other fingers?

Perhaps ulnar nerve: The anatomy suggests a problem affecting the left ulnar nerve, and the chest pain could represent a site of compression over lateral pectorals minor muscle, or even a problem in lower brachial plexus such as thoracic outlet syndrome. An EMG test might confirm. Reassured that your docs are looking at heart issues, as this is another possibility.