Cortisol and adrenaline can raise heart rate.  Maybe the zero carb is  
causing a little extra stress response.  How is your blood pressure?   If one's 
blood pressure drops, then the heart rate goes up as well --  otherwise 
you'd fall over.  My heart rate goes up when my bp drops.   This all assumes 
that the bp is normal.  Heart rate of 70 to 80 is still  within normal range.  
I'd bet the issue is increased cortisol and/or  adrenaline.
 
 
In a message dated 1/26/2012 2:39:30 P.M. Eastern Standard Time,  
[log in to unmask] writes:


Have  you, or any other zero-carbers on here, had any negative health 
effects  from zero carb?  I've been experimenting with it this year, and 
it's  making my heart run much faster than normal (70-80 bpm rather than  
50-60).