Fig. 1

Ablation of PVCs with lead V1 presenting QS pattern with notching in descending limb. ECG showed frequent PVCs, in which the QRS complex showed a complete left bundle branch block (CLBBB) pattern with an inferior axis, r pattern in lead I, QS pattern with notching descending limb in lead V1-V2, R pattern in leads II, III, aVF and V4 ~ V6, QS pattern in leads aVR and aVL, the precordial transition zone between V3 and V4 (a). According to the characteristics of QRS complex in V1 ~ V2 combined with Yamada’s report, the PVCs was firstly considered arising from L-RCC. When activation mapping performed in ASCs, we mapped an relatively earlier ventricular potential preceding the spontaneous PVCs QRS complex onset by 21 ms (b) in RCC, and pacing this site showed a perfect pace match(c). X-ray image showed the ablation catheter in RCC(d). X-ray image showed another ablation catheter was located in RVOT and corresponding to the tip of ablation catheter in RCC(g). We then mapped a ventricular potential preceding the PVCs QRS onset by 35 ms in RVOT (e), pacing the potential result in a perfect QRS match to spontaneous PVCs(f). Current discharging on this site for approximately 3 s completely abolished PVCs. Note: RCC = right coronary cusp