12-lead electrocardiogram (ECG) showing antidromic atrioventricular reentrant tachycardia (AVRT)

The 12-lead ECG shows a wide complex tachycardia in a patient with Wolff-Parkinson-White syndrome and a left lateral accessory pathway. The QRS complexes are wide and have a morphology that is similar to that during sinus rhythm, confirming that this is an antidromic atrioventricular reentrant tachycardia.