This happened to me this morning! I was in the shower, I have a little sinusitis, I was blowing my nose a little in the shower. Then when I got out I bent over to get something I dropped, when I stood up I almost passed out, my heart felt like it went out of rhythim, I was dizzy, lasted a few seconds, but I felt weird for a while after.
I work for a cardiologoy group so I asked one of the docs and she said VERY COMMON, it's a vagus nerver thing. I know that it happens often when I have tight pants on or am sitting in a weird hunched position for too long, I'll get the thud, but this was worse! Anyway, the docs always say, if no congenital defect and no underlying heart disease then arrthmias like these are harmless.
One thing that can aggrivate is lactose intolerance and high carb diet, as it bloats you and that puts pressure on the diaphram which irritates the vagus nerve.
I'm very petite, but I can feel every beat! Also, when I am bloated or gassey same thing happens and again I've been told it is vagal, not to worry. So that would explain the belching makes it feel better.
Yes I have been checked by many Dr's. I have been to the er, and my doctor has done many tests.
I am going to put myself on a diet called a raw diet. I am also going to remove coffee from my diet.
Thanks for the rely.
A quick response is I don't think you have a heart problem.
You mention over weight, and the thud occurring when you bend over. If you have a lot of extra weight on the stomach area (that's my problem area) that could put extra pressure on your internals when you bend over.
I think a effort that lowers weight, increases cardio strength (exercise) and a bland low fat diet is you best first try at a cure for the heart thud.
I am not saying you don't need to see a doctor, but from what I read I came to undersand that you have been checked out by one or more doctors.