I had horrible palpitations today after I woke up. I woke with a start at 5.15 (!) and I had a new bout of tinnitus in my right ear (a lower tone than usual), and when I tried to turn over to sleep again, my heart started racing really fast and hard.
It lasted about 15 minutes and felt horrible. I've had palpitations from anxiety before, but this was much worse, as though my heart was really thumping and racing. It scared me a bit, and only subsided after I did that method of calming down by holding my nose, and closing my mouth then blowing out.
I will keep an eye on it, but i know it's horrid hormones. I have been feeling dizzy standing up randomly too, but I guesd that's all part of the joys of perimenopause!