Can the palpitations caused by pots cause any damage to the heart or lead to any serious cardiac events? its normal when laying down only goes up when standing. no bp drop. echo is normal and all cardiac test came back normal. any long term risks?

Normally, heart rate goes up when changing position for preventing a drop in blood pressure but the increase is normally less than 10 beats/minute. In your case the change is more significant, most of the time more than 20 beats/min and you feel palpitation due to a sudden change. This change rarely causes any long term risk. However, it should be treated if you are bothered too much by the sx.