The Safety and Feasibility of Pulsed-Field Ablation in Atrioventricular Nodal Re-Entrant Tachycardia: First-in-Human Pilot Trial.

BACKGROUND: The incidence of atrioventricular conduction system damage during the catheter ablation procedure has long been a safety concern in patients with atrioventricular nodal re-entrant tachycardia (AVNRT). Pulsed-field ablation (PFA) with high tissue selectivity is a promising technique to address this problem in patients with AVNRT. OBJECTIVES: This study aimed to evaluate the safety and feasibility of PFA in patients with AVNRT. METHODS: This was an investigator-initiated, single-center, single-arm, prospective study performed in West China Hospital, Sichuan University. Patients diagnosed with AVNRT by electrophysiological examination were included and treated using PFA. The primary outcome was the ability to achieve acute ablation success. The secondary outcomes were ablation success after 6 months and safety incidents reported. RESULTS: A total of 30 patients with AVNRT with a mean age of 47.9 ± 13.9 years were included and underwent PFA. Acute ablation success was achieved in all patients. The skin-to-skin procedure time was 109.1 ± 32.1 minutes, and fluoroscopy time was 4.1 ± 0.9 minutes. A median of 8 (range: 6.5 to 11.0) PFA applications were delivered. The average distance of the closest ablation site to the His bundle was 6.5 ± 2.5 mm, with a minimum distance of 2.0 mm. All patients maintained sinus rhythm after 6 months. No adverse events occurred in any patient during the ablation or the 6-month follow-up. CONCLUSIONS: PFA showed favorable feasibility and safety in patients with AVNRT in this pilot study. Further study with larger population and longer follow-up time is warranted to verify the results.

Development and Validation of a Modified QuEChERS Method for Simultaneous Analysis of 250 Flavor Constituents in Tobacco by Gas Chromatography Tandem Mass Spectrometry.

BACKGROUND: Flavor constituents play an important role in the flavor characteristics of tobacco leaves and cigarettes. Sensitive, selective, and high-throughput multi-analyte analytical methods are needed to satisfy the demand for analyzing trace-level flavor constituents in tobacco. However, trace analysis of multi-targets in a complex tobacco matrix is significantly challenging. OBJECTIVE: This study was undertaken to develop and validate a fast, selective, sensitive, and accurate GC-tandem mass spectrometry (GC-MS/MS) method for the simultaneous analysis of 250 flavor constituents in tobacco using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction procedure and backflushing technique. METHODS: The samples were extracted with a mixture of acetonitrile and phosphate buffer. GC-MS/MS served as a reliable tool to quantify the flavor constituents due to its high sensitivity, selectivity, and good repeatability. RESULTS: Our evaluation showed that 243 flavor constituents presented good linearity. Average recoveries of 216 target compounds in tobacco ranged from 70 to 120% with RSDs less than 20% at three fortification levels. The limits of quantitation of 225 and 25 compounds were in the range of 2-50 and 51-112 µg/kg, respectively. This method was then successfully applied to the analysis of 15 commercial cigarette samples with different style characteristics. CONCLUSION: The modified QuEChERS method worked very well for a wide range of flavor constituents that have not been reported by QuEChERS pretreatment previously, and the use of concurrent backflushing offered significant increase in system robustness and sample throughput. The method greatly improved the detection performance and the range of the flavor constituents, and proved to be more accurate, sensitive, selective, convenient, and practical than the reported method, and thus, can be applied in routine analysis. HIGHLIGHTS: A validated QuEChERS-based GC-MS/MS method for multiple flavor constituents analysis in tobacco was reported for the first time. The use of concurrent backflushing markedly improved the instrument robustness and sample throughput.

Pulsed Field Ablation of Superior Vena Cava: Feasibility and Safety of Pulsed Field Ablation.

Background: Studies have shown that pulsed field ablation (PFA) has excellent effectiveness and safety in pulmonary vein isolation (PVI). However, there are few reports about the application of PFA, especially the alternating current (AC) biphase PFA, in superior vena cava (SVC) isolation, and its effectiveness and safety are still unclear. Objective: To investigate the efficacy and safety of the AC biphase PFA for SVC isolation, and to provide evidence for the clinical use of PFA for SVC. Methods: Eight pigs and two dogs were included in the study. PFA was delivered to these pigs and dogs. Pacing threshold and electrogram data were recorded before and after PFA. Voltage mapping of SCV was obtained before, after, and 3 weeks after PFA. At the end, all animals were euthanatized for gross pathology analysis. Results: For eight pigs, the median pacing threshold was 1.5 (1.4, 2.75) mA before PFA, while > 6.0 mA after PFA for all animals. The average electrogram amplitude reduction was 61.33 ± 24.90% for ablations with the initial amplitude≥0.5 mv. For two dogs, pacing threshold change and electrogram amplitude reduction were also observed. No phrenic palsy or sinus node injury was observed during PFA in any animal. Furthermore, voltage mapping showed that the voltage amplitude was significantly decreased in all animals and this could be kept for more than 3 weeks. Moreover, transmural tissue damage with reserved vessel and nerve were shown, no SVC stenosis was found at 3 weeks after PFA. Conclusion: PFA can effectively isolate SVC. Transmural tissue damage of SVC can be achieved without phrenic palsy, sinus node injury nor SVC stenosis.