Fig. 2

a The final target in the right cusp (RC) (white point). Ventricular activation on the unipolar electrocardiogram has a sharp QS morphology. b Angiogram of the final target via the reversed U curve method. The black curve shows the bottom of the RC. c Local bipolar potential at the final target. There is a blunt far-field activation followed by a sharp near-field potential during sinus rhythm (the first black arrow). The relationship between the two signals is reversed during ventricular parasystoles (VPs) (the second black arrow). d After 7 s of ablation (30 W, 43 °C), VPs are terminated. e Local bipolar potential at the final target. After catheter ablation, the sharp potential is eliminated (the blank arrow)