Wow! How did you figure this out? The answer I'm guessing must be a diet change, or to watch what we eat and see if any mixing of foods causes the acid reflux. The only problem is that I seem to get the irregular heartbeat about a week befofe my period, but so far that has been what I have recorded from the last 3 months. But this is different, it's tachycardia, which I never had before.
Did you have the exact same symptoms? Even burping?