<prompt> A 55-year-old woman with non-ischemic cardiomyo- pathy presents with this wide complex tachycardia. ECG shows?Ventricular tachycardiaBidirectional tachycardiaTorsades de pointesPSVT  <response>: Ans. a Ventricular tachycardia. This tracing reveals a wide complex tachycardia at a rate of approximately 150 beats min. Most of the ventricular beats have identical morphologies; hence, this is a monomorphic wide complex tachycardia in contrast to a polymorphic ventricular tachycardia where the majority of the QRS complexes have a varying morphology. The differential diagnosis of a monomorphic wide complex tachycardia includes ventricular tachycardia or supraven -tricular tachycardia conducted with aberrancy. Several clues in this tracing suggest the diagnosis of ventricular tachycardia. When ventricular tachycardia occurs, ventricular depolarization does not conduct through the normal His-Purkinje system but rather conducts slowly directly through ventricular myocardium. During some ventricular tachycardias, sinus node depolarization continues unabated, and most of the sinus impulses meet a refractory ventricle due to the dominant ectopic ventricular activity preventing conduction. 