Wide Complex Tachycardia

Wide-complex tachycardias (WCTs) should always alert the emergency physician to a potentially immediate or rapidly developing, life-threatening scenario. The approach to these patients should follow general emergency medicine principles. The review covers the pathophysiology, stabilization and assessment, diagnosis and treatment, and disposition and outcomes of WCT. Figures show a basic electrocardiogram (ECG) tracing, an ambulatory monitoring strip of a patient with recurrent presyncope showing repetitive monomorphic ventricular tachycardia, a 12-lead ECG of a rapid wide QRS tachycardia due to an antidromic atrioventricular reciprocating tachycardia in a patient with Wolff-Parkinson-White (WPW) syndrome, an example of pacemaker-mediated tachycardia, ventricular tachycardia occurring in the context of QT prolongation consistent with torsades de pointes, a 12-lead ECG in a patient with WPW syndrome showing a rapid, irregular ventricular rate and wide QRS complexes of atrial fibrillation with a short refractory period, an ECG representative of tricyclic antidepressant overdose, and an algorithm for identifying patients with systolic heart failure and left ventricular ejection fractio