Subject: How does pure oxygen affect the heart and its conduction system?

I am doing research for a paper about the effects of pure oxygen 
inhalation on the heart and impulse conduction throught the heart.  I have 
searched the net for hours and can find very little about the effects of 
excess oxygen and nothing specifically about effects on the heart.  I have 
guessed that the heart rate would decrease as a response to 100% oxygen.  
Any resources that you could direct me to would be greatly appreciated.  
Thank you.

Re: How does pure oxygen affect the heart and its conduction system?