Expecting failure yet obtaining success

Idiopathic ventricular arrhythmias originating from the aortic sinus of Valsalva often show preferential conduction to the right‐ventricular outflow tract, which may render radiofrequency ablation more difficult. We describe a patient with symptomatic premature ventricular contractions of left‐ventricular outflow tract origin presenting with a variation of QRS morphology during ablation. The correlation between the characteristics of local voltage potentials and the real origin site of the ventricular arrhythmia is discussed.