Assume any wide-complex tachycardia is<unk>  tachycardia until proven otherwise (it is safer to incorrectly assume a<unk>  dysrhythmia than supraventricular tachycardia with abberancy)
Regular
Monomorphic<unk>  tachycardia
PSVT with aberrant conduction:
PSVT with bundle branch block^
PSVT with accessory pathway
Atrial flutter with bundle branch block^
Sinus tachycardia with bundle branch block^
Accelerated idioventricular rhythm (consider if less than or ~120 bpm)
Metabolic
Hyperkalemia
Digoxin toxicity
Severe metabolic acidosis
Irregular
Atrial fibrillation/atrial flutter with variable AV conduction AND bundle branch block^
Atrial fibrillation/atrial flutter with variable AV conduction AND accessory pathway (e.g. WPW)
Atrial fibrillation + hyperkalemia
Polymorphic<unk>  tachycardia
Torsades de pointes<unk> 
Monomorphic<unk>  tachycardia
PSVT with aberrant conduction:
PSVT with bundle branch block^
PSVT with accessory pathway
Atrial flutter with bundle branch block^
Sinus tachycardia with bundle branch block^
Accelerated idioventricular rhythm (consider if less than or ~120 bpm)
Metabolic
Hyperkalemia
Digoxin toxicity
Severe metabolic acidosis
PSVT with bundle branch block^
PSVT with accessory pathway
Atrial flutter with bundle branch block^
Hyperkalemia
Digoxin toxicity
Severe metabolic acidosis
Atrial fibrillation/atrial flutter with variable AV conduction AND bundle branch block^
Atrial fibrillation/atrial flutter with variable AV conduction AND accessory pathway (e.g. WPW)
Atrial fibrillation + hyperkalemia
Polymorphic<unk>  tachycardia
Torsades de pointes<unk> 
Torsades de pointes<unk> 
^Fixed or rate-related
Nonsustained ventricular tachycardia
Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise 
Wide-complex tachycardia
Regular
Narrow-complex tachycardia
Monomorphic ventricular tachycardia
Accelerated idioventricular rhythm
PSVT with aberrant conduction: