Just so you know, I'm 26, and highly fit. I run 60 mi/week and I have the exact same thing your describing. Other symptoms I have are pain in my gallbladder, and excessive burping after eating. Because I can run so far, I seriously doubt it's a heart problem. Anyhow, I'm starting a parasite cleanse and will proceed with a Colon Cleanse and a liver cleanse. We see from there.
Matt
fishingking00 at comcast dot net.