I have had in the last year tests for sleep apnea, wore a heart monitor for 48 hours, had blood work, tests in the hospital Ekg and 6 hour enzyme tests, two days later, had a test on the treadmill, everything is fine? I seem to get these shock like feelings in my chest about twice a week and then they go away for a month or so and come back. They last no more than a second but it hits you so you would almost drop your coffee, it truly feels like a shock, my doctor has no answers, can you help?