Well I see you are a Florida EMT. Good to start early, the recert deadline is December 1,2016. I used Centre Learn for my recert, it is a low cost organization through EMS world with good presentations. Any big questions you should call florida DOH and they can answer your questions.
Try this to understand it better, research the 2 drugs on google, then see how the bodies mediators figure in that would be cyclic AMP and Cyclic GMP as it relates to the respiratory system
sometimes you will st elevation in the lateral lead along with the inferior lead with deep st depression in v1-v4 if you see this simply put extra leads to the back known as v7 - v9, following it around until your v9 lead in just below the left scapula.