fibrillation in WPW syndrome with accessory pathway conduction.
Left:Sinus rhythm with a typical preexcitation pattern.
Right:Accessory pathway conduction during
atrial fibrillation.The QRS has shifted to the left,and the ventricular
rhythm is now irregular at a rate in excess of 200 per minute.
Marriott, HM Rogers: Mimics of ventricular tachycardia associated with
the WPW syndrome. J ELECTRCARDIOL. 2,: 77,1969)