I have been experiencing heart flutters that sometimes take my breath away. Also, sometimes my heart just starts racing out of no where. I experience chest tightness a lot along with feeling light headed. My dad has aphib and my grandfather died of heart attack at age 55. I am a 30yr old female. I have been to the dr. and have had an echocardiogram and holter monitor test which came back normal. I have read many stories about young women being misdiagnosed or not taken seriously especially when they are not overweight. I feel like there has to be a reason for this to keep happening. Is there additional tests I should be getting done??