Truly, there are no doctors on this site. The fact you didn't pass out means it was probably not heat stroke, as you'd have likely ended up in the hospital when some passerby found you lying face down. The continued feeling of skipped beats could be skipped beats or just feeling like you're having skipped beats. But only a doctor's exam will tell you if something happened. I'm guessing this wasn't serious because, again, when it's more than just your body telling you that you didn't hydrate enough or you pushed yourself beyond your endurance capability on that day, you'd usually find yourself in the company of strangers. I've seen it happen in road races. Again, though, no docs on here.