Thanks for all your replies...I had never heard of POTS until i came on this website,I will investigate this with the DRS here.As for 24/48 tapes i have had these but with sods law nothing ever showed except occasional ectopic beats.. pvc.....not sure if they have event moniters here but i will ask as the for the tilt test I read about this a long time ago in connection with pace makers..but all the tests I have had they never showed that I was in need of one.....but having read your replies I think when I have these attacks my blood pressure may drop causing me to awaken and then this will lead into a palpations and the heavy heart feeling.I have head an echogram which found nothing wrong with my mitral valve butI I believe 100% something is wrong as I said before I can handle the other symptoms of churning stomach,headaches,pins and needles,nausia ,shaking,sweating hands,lump in the throat the list goes on but these attack frighten me....thankyou for your replies.Its a bit lonely over here with knowone to dIscuss my problems....THIS WEBSITE IS A BLESSING brgds simon