This 53-year-old man was at a party when he suddenly experienced weakness, faintness and rapid palpitation. He had been well and normally active. He denies excessive alcohol intake:

• Wide QRS tachycardia (rate 163/min, QRS duration 144 msec) with monophasic right bundle branch block and right superior axis morphology
• Ventricular tachycardia likely originating from the left posterior fascicle (see next ECGs)

The patient undergoes DC cardioversion:

• Sinus rhythm
• Left axis deviation

Comment: The echocardiogram, a stress myocardial perfusion study, coronary and LV angiography were normal. The patient underwent EP studies and was found to have VT originating from the left posterior fascicle – this was successfully ablated without complication.