Pulsed Ablation Research Articles

Pulsed field ablation for atrial fibrillation in real-life settings: Efficacy, safety, and lesion durability in patients with recurrences

Pulsed field ablation for atrial fibrillation in real-life settings: Efficacy, safety, and lesion durability in patients with recurrences

A zero-exchange approach for left atrial access in pulmonary vein isolation with pulsed field ablation.

Pulsed field ablation (PFA) has emerged as an innovative technique for pulmonary vein isolation (PVI). Typically, a transeptal puncture (TSP) with a standard sheath precedes a switch to the larger diameter sheath in the left atrium. This study aimed to describe the safety and feasibility of direct TSP using the large diameter Faradrive sheath before performing PVI with PFA. We prospectively enrolled 166 consecutive patients with paroxysmal or persistent atrial fibrillation (AF) undergoing PVI with PFA at our institution. TSP was performed in all cases with transesophageal echocardiography guidance, using the Faradrive sheath and a 98 cm matched Brockenbrough needle. The primary endpoint was the occurrence of pericardial tamponade during or within the first 48 h after the procedure. The secondary endpoint was the occurrence of any major complication. All 166 patients were included into the final analysis (44% female): 64% of patients had paroxysmal AF and 36% persistent AF (68 ± 11 years old, median CHA2DS2Vasc Score 3, median left atrial volume index 31). The median duration of the procedure was 60 min, median time to TSP was 15 min, and the median fluoroscopy dose was 595 cGy × cm2. The primary endpoint occurred in one patient: a non-TSP related pericardial tamponade, which was managed with pericardial puncture. Direct TSP with skipping sheath exchange using the large diameter Faradrive sheath for PVI with PFA was safe, feasible, and reduced costs in all patients. Large scale studies and registries are needed to verify this workflow.

A pilot clinical assessment of biphasic asymmetric pulsed field ablation catheter for pulmonary vein isolation.

https://www.chictr.org.cn/, identifier, ChiCTR2100051894.

Cardiac Pulsed Field Ablation Lesion Durability Assessed by Polarization-Sensitive Optical Coherence Reflectometry.

Pulsed field ablation uses electrical fields to cause nonthermal cell death over several hours. Polarization-sensitive optical coherence reflectometry is an optical imaging technique that can detect changes in the tissue ultrastructure in real time, which occurs when muscular tissue is damaged. The objective of this study was to evaluate the ability of a polarization-sensitive optical coherence reflectometry system to predict the development of chronic lesions based on acute changes in tissue birefringence during pulsed field ablation. Superior vena cava isolation was performed in 30 swine using a biphasic, bipolar pulsed field ablation system delivered with a nonirrigated focal tip catheter. Acute changes in tissue birefringence and voltage abatement were analyzed for each individual lesion. A high-resolution electroanatomical map was performed at baseline and 4 to 12 weeks after ablation to locate electrical gaps in the ablated area. A total of 141 lesions were delivered and included in the analysis. Acute electrical isolation based on the electroanatomical map was achieved in 96% of the animals, but chronic isolation was only seen in 14 animals (46%). The mean voltage abatement of lesions that showed recovery was 82.8%±14.6% versus 84.4%±17.4% for those that showed fibrosis (P=0.7). The mean acute reduction in tissue birefringence in points demonstrating fibrosis was 63.8%±11.3% versus 9.1%±0.1% in the points that resulted in electrical gaps. A threshold of acute reduction of birefringence of ≥20% could predict chronic lesion formation with a sensitivity of 96% and a specificity of 83%. Acute tissue birefringence changes assessed with polarization-sensitive optical coherence reflectometry during pulsed field ablation can predict chronic lesion formation and guide the ablation procedure although limited by the tissue thickness.

Laser-Induced Plasmas of Plutonium Dioxide in a Double-Walled Cell.

Plutonium research has been stifled by the significant number of administrative controls and safety procedures, space and instrumentation limitations in radiological gloveboxes, and the potential for personnel and equipment contamination. To address the limited number of spectroscopic studies in Pu-bearing compounds in the current scientific literature, this work presents the use of double-walled cells (DWCs) in "clean" buildings/laboratories as an alternative to research in radiological gloveboxes. This study reports the first laser-induced breakdown spectroscopy (LIBS) experiments of a PuO2 pellet contained within a DWC, where the formation of elemental (atomic and ionic) species as well as the evolution from elemental to molecular products (PuxOy) was measured. Raman spectroscopy was also used to characterize the surface of the ablated pellet and the particulates deposited on the window of the inner cell. The full width half-maximum of the T2g band enabled us to obtain an estimate of the temperature at the pellet surface after the ablation pulse and the particulates based on the crystal lattice disorder. Particulates deposited on the window of the DWC during laser ablation were characterized using scanning electron microscopy, where molten irregular particulates and spheroids were observed. This exciting research conducted in a DWC describes our initial attempts to incorporate LIBS in the arsenal of spectroscopic tools for nuclear forensics applications.

A hybrid process technology of SiC die separation

ABSTRACT Silicon carbide (SiC) is ideal for making powerful, high-frequency chips for 5 G and electric vehicles due to its wide band gap and resistance to high voltage. However, its powerful chemical bond strength and extreme hardness make it difficult for die separation in the post-wafer process. A hybrid process technology is proposed, where die scribing is performed on SiC wafer using a femtosecond pulsed laser-assisted ablation. The extremely short energy pulses forced the ablation of traces of SiC at extreme speed, breaking chemical bonds and thereby reducing strength and hardness for easy high-speed cutting along the scribed lanes with a polycrystalline diamond wheel. The experiment showed that the average stage current dropped from 0.90 A to 0.45 A and kerf chipping ratio from 11.7 to 4.1 during die separation, proving that the process removed materials along the separation lanes using a wheel tool at low grinding force, creating separation lanes of outstanding straightness and minimal kerf chippings and SiC dies of high integrity. Furthermore, thanks to the on-line rotational machining and dressing of the wheel tool, the blunt diamond abrasive cutting edge could be redressed to expose chip pockets of appropriate depth and protruding grinding edges with a favorable negative rake angle. The established grinding regime utilizing a pressure-grinding force in cutting and material removal reduced cracking at the SiC surface. In this paper, the laser energy density, scanning speed, number of ablations, focus position, as well as the speed, feed-rate and grinding depth of the wheel tool are also discussed in detail.

Metal DiSulfide thin films synthesized by pulsed ion beam ablation: Self-assembled structures with improved mechanical properties in humid conditions

Thin films composed of transition metal dichalcogenides such as molybdenum disulfide (MoS2) or tungsten disulfide (WS2) are well known for their solid lubricating behavior in dry environments such as space, but deteriorate rapidly in environments where oxygen is present. There have been many attempts over recent decades to improve MoS2 lubricating performance in humid environments by addition of metals such as titanium to the film. The additions have come in the form of co-sputtering with the MoS2, or formation of nano multilayer coatings. We have previously reported on the synthesis of MoS2 films by high-power ion beam ablation [Prasad et al, Matls. Lett. 65 (2010) 4–6]. The resulting films are observed to contain spheres of pure Mo of 10–100 nm size evenly dispersed throughout the ~1 μm-thick film, a form of self-assembly not before seen in films produced by sputtering or by pulsed laser deposition (PLD). The remaining MoS matrix was observed to crystalize in situ under frictional contact into MoS2 with the basal planes orienting themselves in the direction of sliding underneath the wear surface. The present study concerns metal additions in the form of alternating layers with MoS2 deposited in between from an ablation target. The addition of Ti resulted in the extension of good tribological performance to humid air conditions, but the path to good performance appears to be relatively narrow. The same distributed Mo spheres were present in the new film, and similar self-assembled morphologies when V was substituted for the Ti, and when multilayers were formed of WS2 with Zr additions. It appears that addition of Ti resulted in improvements in mechanical film strength that contributed to the wear ability in humid conditions.

Cardiac blood vessels and irreversible electroporation: findings from pulsed field ablation.

The clinical use of irreversible electroporation in invasive cardiac laboratories, termed pulsed field ablation (PFA), is gaining early enthusiasm among electrophysiologists for the management of both atrial and ventricular arrhythmogenic substrates. Though electroporation is regularly employed in other branches of science and medicine, concerns regarding the acute and permanent vascular effects of PFA remain. This comprehensive review aims to summarize the preclinical and adult clinical data published to date on PFA's effects on pulmonary veins and coronary arteries. These data will be contrasted with the incidences of iatrogenic pulmonary vein stenosis and coronary artery injury secondary to thermal cardiac ablation modalities, namely radiofrequency energy, laser energy, and liquid nitrogen-based cryoablation.

Pulsed field versus cryoballoon ablation for atrial fibrillation: areal-world observational study on procedural outcomes and efficacy.

Atrial fibrillation often necessitates catheter ablation when antiarrhythmic drug therapy fails. Single-shot technologies using thermal energy, such as cryoballoon ablation, are commonly used, but pulsed field ablation (PFA), an innovative non-thermal ablation technique, is apotential alternative. This retrospective observational study aimed to compare the safety and efficacy of cryoballoon ablation and PFA in patients undergoing their first pulmonary vein isolation (PVI) procedure for atrial fibrillation treatment. We utilised real-world data from patients who underwent PVI using cryoballoon ablation or PFA. The primary outcome encompassed procedural complications, including phrenic nerve palsy, cardiac tamponade, thromboembolic complications, bleeding complications and mortality. Secondary outcomes were procedural characteristics including procedure duration, length of hospital admission, and re-do ablation rates within 6months. Atotal of 1714 procedures were analysed: 1241 in the cryoballoon group and 473 in the PFA group. Gender distribution (p = 0.03) and estimated glomerular filtration rate (p = 0.01) differed significantly. With regard to the primary outcome, the cryoballoon group demonstrated ahigher incidence of phrenic nerve palsy compared with the PFA group (15 vs0; p = 0.02). The procedure duration was shorter in the PFA group, even after adjusting for baseline characteristics (95.0 vs 74.0 min; p < 0.001). After adjustment for baseline characteristics, admission duration differed between the groups as well (p = 0.04). The study results supported the safety and efficacy of PFA over cryoballoon ablation for PVI, highlighting advantages such as shorter procedure duration and absence of phrenic nerve palsy.

A novel contact force sensing pulsed field ablation catheter in a porcine model.

Pulsed field ablation (PFA) has emerged as a novel non-thermal modality with highly myocardium-specific. However, the PFA catheter based on contact force (CF)-sensing has not been reported. The study aimed to evaluate the efficacy and safety of a novel CF-sensing PFA catheter. First, different CF (5, 15, 25, and 35 g) of the novel PFA catheter were evaluated on lesion dimensions during ablation on right and left ventricle in two pigs. Next, this catheter was further evaluated on four typical sites of superior vena cava (SVC), cavotricuspid isthmus (CTI), right superior pulmonary vein (RSPV), and right inferior pulmonary vein (RIPV) for atrial ablation in another six pigs. Electrical isolation was evaluated immediately after ablation and 30-day survival. Chronic lesions were assessed via histopathology after euthanasia. Acute and chronic safety outcomes were observed peri- and post-procedurally. In ventricular ablation, increased CF from 5 to 15 g produced significantly greater lesion depth but nonsignificant increases from 15 to 35 g. In atrial ablation, the novel CF-sensing PFA deliveries produced an acute attenuation of local electrograms and formation of a continuous line of block in all 6 pigs. The ablation line remained sustained blockage at the 30-day survival period. The CF of SVC, CTI, RSPV, and RIPV was 9.4 ± 1.5, 14.5 ± 3.2, 17.2 ± 2.6, and 13.4 ± 2.8 g, respectively. Moreover, no evidence of damage to esophagus or phrenic nerve was observed. The novel CF-sensing PFA catheter potentiated efficient, safe, and durable ablation, without causing damage to the esophagus or phrenic nerve.

Pulsed field ablation and cryoballoon ablation for pulmonary vein isolation: insights on efficacy, safety and cardiac function.

Pulmonary vein isolation (PVI) has become the cornerstone treatment of atrial fibrillation (AF). While in cryoablation cell damage is caused by thermal effects, lately, pulsed field ablation (PFA) has been established as a novel non-thermal tissue-specific ablation modality for PVI. However, data comparing outcomes of patients undergoing either PFA or cryoballoon ablation (CBA) for primary PVI are sparse. Consecutive patients with AF undergoing PVI by either CBA or PFA were included in the analysis. The primary outcome was the time to AF/AT recurrence. For secondary outcomes, clinical and periprocedural parameters were compared. In total, outcomes of 141 AF patients treated by PFA (94 patients) or CBA (47 patients) were compared. After 365 days, 70% of patients in the PFA group and 61% of patients in the CBA group were free from AF/AT (HR 1.35, 95% CI 0.60-3.00; p = 0.470). No deaths occurred. While symptoms alleviated in both groups, only after PFA, we observed significant improvement of left atrial volume index (PFA group baseline: 40 [31;62] ml/m2, PFA group follow-up: 35 [29;49] ml/m2; p = 0.015), NT-pro BNP levels (PFA group baseline: 1106 ± 2479 pg/ml, PFA group follow-up: 1033 ± 1742 pg/ml; p = 0.048), and left ventricular ejection fraction (LVEF) (PFA group baseline: 55 [48;60] %, PFA group follow-up: 58 [54;63] %; p = 0.006). PVI by PFA was the only independent predictor of LVEF improvement. In our study, we show that CBA and PFA for PVI are of similar efficacy when it comes to AF recurrence. However, our findings suggest that PFA rather than CBA might induce left atrial reverse remodeling thereby contributing to left ventricular systolic function.

Bipolar, high-voltage, long-duration pulsed radiofrequency ablation of the Gasserian ganglion for the treatment of trigeminal neuralgia in a patient with a cardiac implantable electronic device: illustrative case.

One of the common methods of treating trigeminal neuralgia (TN) nowadays is radiofrequency therapy. However, it has serious limitations in patients with a cardiac pacemaker because of electromagnetic interference. Therefore, it is crucial to select optimal radiofrequency ablation parameters to make this procedure safe with favorable outcomes for such patients. In this study, the authors present a case of a 70-year-old man with a history of cardiac pacemaker dependency and previous microvascular decompression with complaints of severe, constant facial pain. After reprogramming the cardiac implantable electronic device (CIED), the authors performed bipolar, high-voltage, long-duration pulsed radiofrequency therapy (PRFT) of the Gasserian ganglion under electrocardiography and pulse rate control in the pre-, intra-, and postoperative periods. There were no cardiovascular or neurological complications after PRFT. The patient reported relief of pain after the procedure, and at the 9-month follow-up, he was pain-free. This clinical case demonstrates that the use of bipolar, high-voltage PRFT for TN treatment in patients with a CIED can be safe and effective, provided that the rules and pacemaker instructions are followed. It is necessary to use ablative treatment with caution and to guide the patient in collaboration with a cardiac surgeon and an anesthesiologist resuscitator.

Focal Pulsed Field Ablation for Atrial Arrhythmias: Efficacy and Safety under Deep Sedation.

Focal pulsed field ablation (PFA) is a novel technique for treating cardiac arrhythmias. It has demonstrated positive results in initial studies and has a good safety profile. In recent studies, PFA was often utilized for first-time pulmonary vein isolation (PVI) and was performed under general anesthesia. In our study, we assessed the feasibility, safety, acute procedural efficacy, and efficiency of focal PFA under deep sedation in patients, 80% of whom had undergone at least one left atrial ablation previously. We treated 30 patients (71 ± 7, 46% male) using the CENTAURI system for various atrial arrhythmias, including atrial fibrillation, typical and atypical atrial flutter, and focal atrial tachycardia. The average procedure and fluoroscopy times were 122 ± 43 min and 9 ± 7 min, respectively. A total of 83.33% of patients received additional line ablations beyond PVI, specifically targeting the posterior box and anterior mitral line. All ablations were successfully performed in deep sedation with only one major and one minor complication observed. The major complication was a vasospasm of the right coronary artery during ablation of the cavotricuspid isthmus, which was treated successfully with intracoronary nitroglycerin. All patients could be discharged in sinus rhythm. Moreover, adenosine appears effective in identifying dormant conduction in some patients after focal PFA. In conclusion, focal PFA is an effective approach for complex left atrial ablations under deep sedation, offering both high efficacy and efficiency with a reliable safety profile. Studies on long-term outcomes are needed.

Outcomes of Focal Pulsed Field Ablation for Paroxysmal Supraventricular Tachycardia

BackgroundPulsed field ablation (PFA) is primarily used for treatment of atrial fibrillation as it provides better safety and efficacy. However, there are limited data available on the use of PFA for paroxysmal supraventricular tachycardia (PSVT). The study sought to describe the outcomes of PSVT ablation with a novel focal contact force (CF)-sensing PFA. MethodsIn this first-in-human pilot study, a focal CF-sensing PFA catheter was used for mapping and ablation navigated with an electroanatomic mapping system (EAMS). Pulsed field energy was delivered as biphasic/bipolar electrical pulse trains with 2000 V/delivery. CF was controlled from 2 g to 10 g during PFA. ResultsProcedural acute success was achieved without general anaesthesia or conscious sedation in all 10 patients, including 7 patients diagnosed with typical atrioventricular nodal re-entrant tachycardias and 3 patients with orthodromic reciprocating tachycardias. Successful target ablation time was 2.0 ± 0.5 seconds per patient, and the acute procedural success at the first single site was achieved in 5 patients. The mean skin-to-skin procedure time was 79.4 ± 15 minutes, PFA catheter dwell time was 50.1 ± 14 minutes, and fluoroscopy time was 6.2 ± 7 minutes. Maintenance of sinus rhythm was observed in all patients within 6-month follow-up. No serious adverse events occurred in any subjects during PFA or during the 6-month follow-up. ConclusionsA focal CF-sensing PFA catheter could effectively, rapidly, and safely ablate PSVT in conscious patients. Clinical Trial RegistrationNCT05770921

A novel platform allowing for pulsed field and radiofrequency ablation: First commercial atrial fibrillation ablation procedures worldwide with and without general anesthesia

A novel platform allowing for pulsed field and radiofrequency ablation: First commercial atrial fibrillation ablation procedures worldwide with and without general anesthesia

Comparative Safety of Pulsed Field Ablation and Cryoballoon Ablation Technologies for Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation: A Critical Literature Review and Indirect Treatment Comparison.

Cryoballoon ablation (CBA) is a standard catheter ablation technology with demonstrated clinical effectiveness for the treatment of paroxysmal atrial fibrillation (PAF); however, it can be associated with major adverse events, including phrenic nerve paralysis. Pulsed field ablation (PFA) is a novel, minimally thermal technology with comparable effectiveness and low safety risk. This study aimed to compare the safety profiles of PFA and CBA through critical analyses of the literature and indirect treatment comparisons. Studies were identified by searching the MEDLINE database and the Clinicaltrials.gov registry. Registered clinical trials and/or Food and Drug Administration Investigation Device Exemption (FDA IDE) studies evaluating PFA or CBA in adult patients with drug-refractory PAF between January 2008 and March 2023 were selected. Comparative safety between PFA and CBA was assessed for major and prespecified adverse events. Indirect comparisons were conducted using the proportion of patients experiencing adverse events and confirmed with single-arm meta-analyses and sensitivity analyses. Data were extracted from three PFA publications including a total of 497 patients and six CBA studies including a total of 1113 patients. The analysis revealed that PFA was associated with significantly lower risk of major adverse events {risk difference-4.3% [95% confidence interval (CI)-5.8,-2.8]; risk ratio 0.16 [95% CI 0.07, 0.45]} and prespecified adverse events [risk difference -2.5% (95% CI-4.4,-0.5); risk ratio 0.53 (95% CI 0.31, 0.96)]. Meta-analyses confirmed the lower rate of major adverse events for PFA [0.4% (95% CI 0.0, 1.3)] vs. CBA [5.6% (95% CI 2.6, 8.6)] and prespecified adverse events for PFA [2.7% (95% CI 1.2, 4.1)] vs. CBA [5.8% (95% CI 2.7, 9.0)]. Sensitivity analyses exploring heterogeneity across studies confirmed robustness of the main analyses. The findings of this study show that PFA has a more favorable safety profile than CBA, with significantly lower risks of major and prespecified adverse events. These indirect comparisons help contextualize the safety of PFA compared to CBA for the treatment of drug-refractory PAF in the absence of head-to-head studies.

Genetically engineered HEK cells as a valuable tool for studying electroporation in excitable cells

Electric pulses used in electroporation-based treatments have been shown to affect the excitability of muscle and neuronal cells. However, understanding the interplay between electroporation and electrophysiological response of excitable cells is complex, since both ion channel gating and electroporation depend on dynamic changes in the transmembrane voltage (TMV). In this study, a genetically engineered human embryonic kidney cells expressing NaV1.5 and Kir2.1, a minimal complementary channels required for excitability (named S-HEK), was characterized as a simple cell model used for studying the effects of electroporation in excitable cells. S-HEK cells and their non-excitable counterparts (NS-HEK) were exposed to 100 µs pulses of increasing electric field strength. Changes in TMV, plasma membrane permeability, and intracellular Ca2+ were monitored with fluorescence microscopy. We found that a very mild electroporation, undetectable with the classical propidium assay but associated with a transient increase in intracellular Ca2+, can already have a profound effect on excitability close to the electrostimulation threshold, as corroborated by multiscale computational modelling. These results are of great relevance for understanding the effects of pulse delivery on cell excitability observed in context of the rapidly developing cardiac pulsed field ablation as well as other electroporation-based treatments in excitable tissues.

A retrospective assessment of the effectiveness of pulsed radiofrequency ablation in the treatment of chronic pain caused by advanced knee osteoarthritis.

Patients suffering from severe chronic pain often have problems finding an appropriate combination of painkillers. We retrospectively evaluated the effectiveness and safety of pulsed radiofrequency ablation (pRFA) of the genicular nerves in 96 patients with knee osteoarthritis (KO). We hypothesized that age, sex, and body mass index (BMI) may influence the quality of the pRFA treatment. A diagnostic blockade with total volume of 9 ml of 1% lidocaine (WZF, Poland) combined with 4 mg of dexamethasone with subsequent pRFA with a radio frequency of 300-500 kHz under ultrasound guidance was used during the procedure. The study participants were assessed during regular monthly visits until 12 months. The nerves' ultrasound identification was successful in 90.62% of the cases. According to the numeric rating scale (NRS), pain was reduced by 50% or more in 64.06% of the cases. The average pain relief period lasted just over 7 and a half months. There were no pRFA-related complications or side effects of the drugs used. pRFA seems to be safe and effective for the treatment of chronic pain in KO. The outcome of the treatment may be related to the patient's age (block duration increased with patient age) and sex (in women, the therapeutic effect was more effectively prolonged) in our study group. There was also higher effectiveness of pRFA in high-BMI patients, which was close to statistical significance ( P = 0.053).

Pulsed Field Ablation in the Treatment of Cardiac Arrhythmias: A State-of-the-art Review

Abstract Pulsed-field ablation (PFA), specifically irreversible electroporation, induces cell membrane damage through the formation of irreversible pores, leading to apoptosis and necrosis, with applications in tumor treatment and myocardium ablation since 2007. This review is on PFA in the treatment of cardiac arrhythmias, including the basic principles, clinical applications, and hot issues of PFA. Presently, the pulsed electric field has demonstrated its effectiveness and safety in the treatment of atrial fibrillation, which is not inferior to that of traditional thermal energy. Research and application on pulsed electric ablation is rapidly advancing due to its advantages of rapidity and specificity in lesion creation. Moreover, pulsed electric ablation has reduced the difficulty of catheter manipulation in pulmonary vein isolation, making it an available treatment to benefit more patients.

Meta-analysis of Pulsed Field Ablation Versus Thermal Ablation for Pulmonary Vein Isolation in AF: A Broad Overview Focusing on Efficacy, Safety and Outcomes.

The recently established non-thermal, single-shot pulsed field ablation (PFA) is a potential tool for achieving rapid pulmonary vein isolation (PVI) to cause cell death by electroporation, yet data regarding this state-of-the-art technology remain sparse. In this meta-analysis, we included 3,857 patients from 20 studies. There was no significant difference in AF recurrence between the PFA and control groups. Subgroup analysis showed that additional ablation beyond PVI has a similar rate of AF recurrence to PVI alone (10% versus 13%, respectively). PVI durability was achieved in 83% (mean), 95% CI [65-99%] of the PFA group and in 79% (mean), 95% CI [60-98%] of the control group, with no significant difference in the rate of PVI durability between the two groups. The PFA group had considerably reduced procedure duration, but not fluoroscopy time. No statistically significant differences in periprocedural complications were observed. PFA is associated with shorter procedural time than thermal ablation. Cardiac complications were uncommon and mainly reversible in both the PFA and control groups.