12-lead ECG sustained monomorphic VT

The electrocardiogram (ECG) hallmark for the diagnosis of sustained monomorphic ventricular tachycardia (SMVT) is a wide complex tachycardia with the obvious presence of atrioventricular (AV) dissociation. AV dissociation is suggested by the presence of fusion complexes (which reflect a supraventricular impulse coming from above the AV node fusing with an impulse generated in the ventricle) or captured complexes (which reflect an impulse coming from above the AV node that depolarizes the ventricles when they are no longer refractory but before the next ventricle-generated complex). Beats 12, 17, and 22 on this ECG likely represent capture beats.