This thread has become long and is diverging a bit.

1) I do not think B-vits give this feeling described here.

2) I have had this flopping in the chest flutter for years. Usually the heartbeat is not affected. But a year or so ago I had one episode where I would have
3-4 normal beats, then a skip. It happened once after a meal. We were on vacation, and I didn't want to drive over 100 miles in the boonies to a small ER...so I sat up (my spells always happen lying down) and the skipping stopped.

3) I have a severe hiatal hernia diagnosed along with my malrotation. So we thought this was the reason. The movement of the stomach/esophagus up thru the diaphram gives a peculiar feeling. and creates this need to cough as well.

4) So then I read a story in the paper about eating a heavy meal (it was after Thanksgiving) and how many people end up in the ER with "heart" symptoms.
The doctor in that article (and I will try to find another to put up here) said this can happen and is typically benign. It is something to do with irritation of the vagus nerve.

5) I have had the flutter for a while, then it goes away for months or even years only to return for a while and go away again. The "need to clear the throat or cough" seems to stop the sensation.

So I would recommend this original poster to evaluate for hiatal hernia, and watch for association of the symptom after a meal.

Edit--- here are some links I just found:
http://www.doctorslounge.com/cardiol...opic-6177.html
(about 1/2 way down the page)

and here is another forum where people discuss this same issue:
http://www.mvpsupport.com/ubb/Forum1/HTML/003916-2.html