I too suffer with missed heartbeats (please read my posting) it feels like my heart has stopped for a couple of second the BANG it fires up again. I went for an ECG last week and i felt it was happening all the time I was wired up to the machine..... the ECG said my heart was fine, if anything my pulse a little high.

I often get dizzy and lightheaded but i put that down to anxiety and adrenaline like a wave over my body, i also increase my breathing which i think contributes to the dizziness.

Anxiety can make our bodies do all types of strange things. Go to the Drs and be quite forceful (if need be) and ask for an ECG, i was always being fobbed off with its anxiety, but i needed reassurance.

Take care