Cardiac
ST-segment elevation myocardial infarction (STEMI)
Post-MI (ventricular aneurysm pattern)
Previous MI with recurrent ischemia in same area
Wellens' syndrome
Coronary artery vasospasm (eg, Prinzmetal's angina)
Coronary artery dissection
Pericarditis
Myocarditis
Aortic dissection in to coronary
Left ventricular aneurysm
Left ventricular pseudoaneurysm<unk> 
Left bundle branch block
Left ventricular hypertrophy (LVH)
Myocardial tumor
Myocardial trauma
RV pacing (appears as Left bundle branch block)
Brugada syndrome
Takotsubo cardiomyopathy
AVR ST elevation
Other thoracic
Pneumomediastinum
Pneumothorax
Pulmonary embolism
Metabolic
Drugs of abuse (eg, cocaine, crack, meth)
Cocaine chest pain
Hyperkalemia (only leads V1 and V2)
Hypothermia ("Osborn J waves")
Medications
Tricyclic (TCA) toxicity
Digoxin
ST-segment elevation myocardial infarction (STEMI)
Post-MI (ventricular aneurysm pattern)
Previous MI with recurrent ischemia in same area
Wellens' syndrome
Coronary artery vasospasm (eg, Prinzmetal's angina)
Coronary artery dissection
Pericarditis
Myocarditis
Aortic dissection in to coronary
Left ventricular aneurysm
Left ventricular pseudoaneurysm<unk> 
Left bundle branch block
Left ventricular hypertrophy (LVH)
Myocardial tumor
Myocardial trauma
RV pacing (appears as Left bundle branch block)
Brugada syndrome
Takotsubo cardiomyopathy
AVR ST elevation
Pneumomediastinum
Pneumothorax
Pulmonary embolism
Drugs of abuse (eg, cocaine, crack, meth)
Cocaine chest pain
Hyperkalemia (only leads V1 and V2)
Hypothermia ("Osborn J waves")
Cocaine chest pain
Tricyclic (TCA) toxicity
Digoxin
Early repolarization
Cardiac
Wide QRS
ST-segment elevation myocardial infarction 
T wave changes
Post-MI 
ST segment depression
Previous MI with recurrent ischemia in same area