i ve had several episodes where my heart flutters then the top half and bottom half are beating hard, fast and not in sync. My heartbeat is all over yet my breathing is regular and I can talk. Lying down on the floor my body shakes with how hard my hearts pumping. I ve pushed my legs up into my chest several time and that has gotten it back in rhythm. After I feel like I ve run a marathon, wiped out. I ve worn a monitor and had an eco done. Nothing can be seen. The only thing my dr saw was that I had low Magnesium levels. I ve been taking Magnesium but it still happens. It feels as though the bottom half isn t pumping out blood and quivers where the top half is full and pumping too much, if that makes sense. It s very scary and I yell for someone to be with me in case I pass out or need 911. What the heck is this?