Hi again, I might mention that over 100 is a pretty low BPM even for a half Hour. I mention this as there are people and I know of 2 of them Both are my daughters who have heart rates that normally are around 100. Like typically when your exercising your heart rate can be as high as 160-180. Most of these conditions are a particular way the heart beats thats where the names come from SVT ant VT are the lower parts of the heart and AFIB is in the upper area. When mine was getting to a dangerous area I'm talking like 200 or above while resting. So just wanted to let you know it more about other symptoms also. Like I mentioned the pulse missing. Or just feeling really weak, When I had an episode usually I had to lye down as I felt that weak. Once i actually lost my eyesight briefly. Hope that puts your mind at ease a bit. But always if you have things like chest pain or a feeling like you cant catch your breath please call for help. That was another sign for me. I felt like I was lacking oxygen, which I was due to the blood flow stopping.