I experience the same as you describe and have also come to the same conclusion. I've been carted off so many times in the ambulance because of the arrythmia. After years of being sent home after 6 hours in emergency having tests the doctor said he believed my problem was triggered off by reflux/hiatus hernia affecting the vagus nerve. I've also learned that if I lean over or squat down I must come back slowly, otherwise my heart will start fluttering. The worst time was when I was at the supermart; my trolley was facing forward but my body was leaning over to the side to get something from the shelf when someone's trolley bashed into the front of mine, jerking me. The reaction was immediate. That was the last time I went to hospital and they gave me the diagnosos I mentioned above. One last thing, sometimes when I'm in bed reading, sometimes I tense up and lean forward slightly, my heart will give a couple of bumps. I sit back again and it calms down.