ECG cases is a monthly blog by Jesse McLaren (@ECGcases), a Toronto emergency physician with an interest in emergency cardiology quality improvement and education. Each post features a number of ECGs related to a particular theme or diagnosis (with a focus on acute coronary occlusion), so you can test your interpretation skills. We challenge you with missed or delayed diagnosis, those with false positive diagnosis, and those that had a rapid and correct diagnosis. Cases are followed by a quick summary of the literature that relates to the cases, and we bring it home with practice changing pearls that you can use on your next shift.