Hi Tracy
Yep I get these too from time to time. Mine tend to last from just a couple of minutes to about an hour! I get ectopic beats really often, usually no more than 10 or so a minute, but these episodes you describe are really scary and make me cough a lot. I just try to relax and calm down and eventually they go. I went to hospital once but they'd calmed down by the time I seen someone, so I don't bother any more. Wish I knew what caused them.
Take care and don't worry