Here is a great online STEMI test app. I found this over at EMS12Lead and one of the editors there Christopher Watford created an online STEMI test based on McCabe JM, et al. Physician Accuracy in Interpreting Potential ST-Segment Elevation Myocardial Infarction Electrocardiograms. J Am Heart Assoc. 2013; 2:e000268.
The test will tell you which ones you got right and which ones you got wrong. It will also compare your sensitivity and specificity against other health care disciplines.