Radiofrequency catheter ablation of ventricular arrhythmias arising from the region above pulmonary valve

Fig. 1. Radiofrequency catheter ablation of PVCs rising from MSPA 16 mm above PLC. a ECG of the PVCs. The PVCs exhibited a left bundle branch block (LBBB) morphology and inferior axis deviation, r morphology in lead I, QS morphology in both aVL and aVR with QSaVR>QS aVL, rS pattern in lead V1-V2, R morphology in lead II, III, aVF and V4-V6 with an ascending notch, precordial transition zone between lead V2-V3. High R wave was recorded in inferior leads with an average amplitude more than 3.0 mV. b Activation mapping of the PVCs. Activation mapping in MSPA above PLC showed a local ventricular activation with initial discrete potential preceding the QRS onset by 32 ms. c Pace mapping of the target site. Pacing mapping performed on the site with earliest ventricular activation showed an excellent pace match between paced QRS and clinical PVCs. d PVCs disappeared after energy application on target site for 6 s. e, f Left anterior oblique projection of the target site (the tip of the catheter). g Right anterior oblique projection of the target site (the tip of the catheter)

Fig. 2. Radiofrequency catheter ablation of PVCs rising from PAC. a Activation mapping of PVCs in the PAC. The PVCs exhibited a left bundle branch block (LBBB) morphology and inferior axis deviation, rs morphology in lead I, QS morphology in both aVL and aVR with QSaVL>QS aVR, rS pattern in lead V1-V2, R morphology in lead II, III and aVF and V4-V6, precordial transition zone between lead V2-V3. Activation mapping showed local ventricular activation with initial discrete peak potential preceding the QRS onset by 37 ms. b Pace mapping showed a 11-lead match between paced QRS and clinical PVCs. c Angiograph of pulmonary artery prior to ablation showed the tip of ablation catheter located in anterior PSCs. Energy application in PAC led to instant elimination of PVCs. The PVCs could not be induced by further isoproterenol administration combined with programmed electrical stimulation. No recurrence was reported during the follow-up of 2 years

Fig. 3. PLC-LMSPA, PAC-AMSPA and PRC-RMSPA anatomy. Pulmonary arteriography, three-dimension mapping and RVOT anatomy revealed that the PLC-LMSPA is situated at the lowest level above the posterior septum of the RVOT, the PAC-AMSPA situated relatively superior above the anterior septum of RVOT and PRC-RMSPA situated at the most rightward above the free wall of RVOT