Background Ventricular arrhythmias (VAs) originating from ventricular outflow tracts can possess a high similarity of QRS configuration resulting in an inaccurate localization, while the reminder of mapping or ablation in the lower right ventricular outflow tract (RVOT) commonly provide the preferred transformation strategy. Methods We retrospectively analyzed the total of 958 patients who were referred for radiofrequency (RF) ablation of VAs in our center. VAs with the sinus of valsalva (SoV) origins were enrolled. Results A total of 120 consecutive patients (mean age 45.0 ± 15.5 years) undergoing the ablation of VAs arising from the left-sided ventricular outflow tracts were included, with 55 (45.8%) female. All patients had a QRS morphology of the LBBB pattern and an inferior axis, with the mean earliest ventricular activation (EVA) of target site of 34.9 ± 8.8ms. 37 (30.8%), 60 (50.0%), and 23 (19.2%) patients obtained the successful RF ablation at the right sinus cusp (RCC), left sinus cusp (LCC), and the commissure of RCC and LCC (R-LCC), respectively. 62 (51.7%) target sites of SoV could record a high-frequency potential. Moreover, 25 (20.8%) patients were continuously recorded an early ventricular activation in the lower RVOT and achieved the elimination of VAs in SoV. Conclusions VAs originating from the SoV could show a low specificity of QRS morphology mimicking the RVOT-like ECG feature. An early ventricular activation mapped in the lower RVOT or RF ablation with poor response likely demonstrated the VAs originating from the SoV, especially the RCC.

Background: A common ostium of inferior pulmonary veins (COIPV) is a kind of unusual pulmonary veins variation. Limited data are available about the safety and efficacy using the second‐generation cryoballoon (CB) ablation in patients with atrial fibrillation with such an anatomical variation. Methods: A total of 10 (0.57%) patients with a common ostium of inferior pulmonary veins from a consecutive series of 1751 consecutive patients with atrial fibrillation (AF) were included. Pulmonary vein isolation was performed using the second‐generation CB. Results: PV isolation was successfully achieved in all PVs without the need of additional focal catheter procedures. CB could occlude and cryotherapy each inferior PV respectively. The mean number of freeze cycles of inferior PVs in each patient was 2.5±1.6, and 2.1±0.9, respectively. The mean time to isolation and nadir temperature were 54.3±22.1, 53.2±22.2 seconds and -39.7±3.4°C, -43.9±7.5°C, respectively. No procedure-related complications occurred in any of the 10 patients. 8 of 10 patients (80%) had no atrial arrhythmia recurrences without the use of antiarrhythmic drugs during a follow-up period of 24±13 months. Conclusion: The incidence of a common ostium of inferior pulmonary veins is 0.57% in present study. PV isolation with this unusual anatomic variation using the second‐generation 28‐mm CB is effective and safe.

BACKGROUND Several methods have been proposed to locate the conduction gap on the pulmonary vein isolation (PVI) ablation line. However, the value of the interval of far-field potential (FF potential) and pulmonary vein potential (PV potential) is unknown. METHODS: The state of PV potential and the location of that ablation sites were particularly recorded for analysis once LSPV was isolated in a development cohort of consecutive patients undergoing PVI ablation at a single center. These findings informed the development of a novel algorithm to discriminate the location of a conduction gap between upper portion and inferior portion of LSPV. The performance of this novel algorithm was prospectively tested in a validation cohort of consecutive re-do patients undergoing PVI ablation RESULTS: A total one hundred sixteen patients were recruited, of which 56 formed the validation cohort. Interval of FF potential and PV potential was associated with the location of the conduction gap, and the interval <5 ms predicted that there was a conduction gap in the upper portion of ostium with 92.9% sensitivity and 96.9% specificity. In the prospective evaluation, the interval was able to correctly predict the site of successful ablation in 89.6%. CONCLUSIONS: Interval of far-field potential and pulmonary vein potential is a novel and accurate marker to predict the location of a conduction gap.