It's just when I stretch or laugh or get up too fast my hr slows down and I sometimes feel it beat. But no other symptoms
My HR jumps around when I move, shift, etc. and like you I absolutely feel it. Just the other day, I was in the cardio's office laying on his table and when the nurse lifted my arm up my HR jumped up & the dr didn't think it was worrisome. He said as long as it didn't get dangerously high or dangerously low or stay high or low that I shouldn't worry too much about it. Don't you just love those responses...all I do is worry about it and can't help it. He went on to say that some of us are just more sensitive to our HR and we feel palpitations that others don't but that most people experience a shift in HR when they move. HTH.
Are you sure you it's not your BP and not your HR. You dont really discribe the feeling that you feel. that might make it easier to help you understand what might be happening.
If you really think your HR is slowing down maybe you could purchase a HR monitor to see if that's what really is happening.
My BP drops suddenly when I change position. I some time I do feel palpiation after shifting postions suddenly as well. The ECG dont show any thing irregular except tachycardia after changing potion which i did not even suspect untill I got my self a HR montior.