Try taking extra magnesium and potassium. I would wager it goes away, especially if the Doc didn't find anything else wrong with you.
Try 300mg of magnesium citrate twice daily. 90 percent of the population is magnesium deficient.
Try adding 1000-1500mg daily of extra potassium in divided doses. Buy the capsules and open them up and put them in a water bottle.
http://www.ctds.info/5_13_magnesium.html
there are lots of links online, but i just finished two books on Magnesium . . .
Also . . . sometimes just being inside too much with airconditioning can cause odd breathing patterns.
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