Nothing at all to worry about, unless you already have serious heart problems. A sudden increase in heart rate is sometimes one of the effects of consuming to much and have a "whitie" or "greenie" or whatever you like to call it.

It's only happened to me once and I already had been smoking for quite some time so I didn't understand what was happening at first. I just sat down and it seemed to fade away slowly over about half an hour.

Don't smoke more just for the sake of it if you are already high. Next time you could faint and hit your head as you fall.

Take it easy :rasta: