This sounds like something I had first thing in the morning a month or so ago - I thought I was having a heart attack or something, it frightened me so much! I had it a few times over the course of three days, and must admit that the prospect of it happening again does scare me...

I'd be interested to know what yours felt like, if you had any other symptoms, how long it lasted, etc. Also how often it happens

Hope you're having a good day today

Bram.