Is it possible to have a heart issue that is not seen by EKG or "bad blood"?

Yes it is possible - ask for a holter - its a portable EKG machine which monitors your heart and whenever you feel the heart acting weird you press the on and the technician determines whats wrong - ask for a 2 week Holter and it will be better for you! if it wasn't for the Holter doctors would not have know I have SVT !!!