Wow.. it was weird reading this post, the same happened to me on Wednesday.. driving home late off nights after attending a cardiac arrest, I had this weird feeling in my stomach, just like when you go over a hump in the road fast or when you're on a rollercoaster.. home to bed, woke up feeling the same and went back in for our second night shift.. on our first break I stuck myself on the Zoll in the vehicle and I was throwing up Ectopics too.. Did the same as Tom and attended the local A + E ( where they kindly put me in on the trolley next to the barking diabetic we'd taken in earlier). They did a 12 lead , noted the beats and said it was perfectly normal for ectopics now and again, gave me 2 Buscopan and sent me home.. It's all calmed down now, but I brought caffine free tea bags for work today.. just in case..! Shift Work = Bad for your Health..!