Hi, I was wondering if there was a difference between vagus nerve ectopics and adrenaline induced ectopics.  I read that adrenaline causes them via calcium ionz.  The adrenaline's effect on the heart causes calcium to build on the mucsle causing a pvc.  Is this accurate?  It also stated that large quantities of adrenaline can be harmful(calcium overload).  Please explain how ectopics from adrenaline whether it be from exercise or anxiety are caused.  I understand that the vagus nerve is the sole cause in benign ectopics, but texts state that adrenaline causes them to via calcium ionz overload.