I know swagg and mexican based sativas do me the same way. I already suffer from panick attacks and elevated heart rate due to the great operation Iraqi freedom.
You have to remember that smoking naturally raises the heart rate. As long as you are not having any pain its fine. Some weed does it more than others and some people react differently than others. So its all in how you toke. I would just take one hit at a time! It gives you the high but at a weaker strength.