I am a 39 year old female athlete. I run duathlons, play several sports, and lift weights. I am a little heavier than I should be and have been that way all me life, even as a collage athlete. I was diagnosed with a heart murmer years ago, but have never had any major issues. Within the last few months, when I am at rest, I get a quick flutter in my chest that makes me cough. It does not hurt, it just startles me. I ran three miles today, and about 4 hours later it happened. I had an EkG two months ago and everything was fine. Should I still be concerned?