RESUMEN

AIMS: Pulsed-field ablation (PFA) is a novel, myocardial-selective, non-thermal ablation modality used to target cardiac arrhythmias. Although prompt electrogram (EGM) signal disappearance is observed immediately after PFA application in the pulmonary veins, whether this finding results in adequate transmural lesions is unknown. The aim of this study is to check whether application repetition and catheter-tissue contact impact lesion formation during PFA. METHODS AND RESULTS: A circular loop PFA catheter was used to deliver repeated energy applications with various levels of contact force. A benchtop vegetal potato model and a beating heart ventricular myocardial model were utilized to evaluate the impact of application repetition, contact force, and catheter repositioning on contiguity and lesion depth. Lesion development occurred over 18 h in the vegetal model and over 6 h in the porcine model. Lesion formation was found to be dependent on application repetition and contact. In porcine ventricles, single and multiple stacked applications led to a lesion depth of 3.5 ± 0.7 and 4.4 ± 1.3 mm, respectively (P = 0.002). Furthermore, the greater the catheter-tissue contact, the more contiguous and deeper the lesions in the vegetal model (1.0 ± 0.9 mm with no contact vs. 5.4 ± 1.4 mm with 30 g of force; P = 0.0001). CONCLUSION: Pulsed-field ablation delivered via a circular catheter showed that both repetition and catheter contact led independently to deeper lesion formation. These findings indicate that endpoints for effective PFA are related more to PFA biophysics than to mere EGM attenuation.

Asunto(s)

RESUMEN

PURPOSE OF REVIEW: This article aims to empower the interventional pain physician to utilize RFA effectively by explaining the technical and electrophysiological features of monopolar, bipolar, and internally cooled RFA. Scientific data are used to provide advice on the effective, well tolerated, and rational application of these techniques. Moreover, physicians need to know how to analyze and generalize ex-vivo and in-vivo models to the clinical setting to optimize clinical outcomes. RECENT FINDINGS: Recent studies suggest that there are many ways to enhance the technical effectiveness of interventional pain medicine RFA through adjustments in the equipment selection and settings and the local tissue conditions specific to the targeted anatomical area. These modifications could assist in improving clinical and safety outcomes. SUMMARY: To optimize both the efficacy and safety of RFA, physicians must understand, conceptualize, interpret, and clinically translate the basic science of RFA. This knowledge is crucial for optimizing equipment selection and settings based on target location to enhance clinical outcomes and limit technical failures.

Asunto(s)

Asunto(s)

RESUMEN

BACKGROUND: During pulsed field ablation (PFA), relationships between ablation parameters (contact force [CF], number of burst pulses, impedance decrease, and electrode temperature) and lesion size in beating hearts have not been well validated. METHODS: A 7.5F-catheter with a 3.5-mm ablation electrode and CF sensor (ThermoCool SmartTouch SF-Dual-Energy, Biosense Webster, Inc, Irwindale, CA) was connected to a PFA system (TRUPULSE2, Biosense Webster, Inc). In 11 closed-chest swine, biphasic PFA current was delivered between the ablation electrode and the skin patch at 219 sites in left ventricle and right ventricle using 12, 18, and 24 burst pulses with 4 different levels of CF: (1) low (n=57; CF, 4-15g; median, 10g); (2) moderate (n=60; CF, 16-30g; median, 22.5g); (3) high (n=68; CF, 32-65g; median, 40g); and (4) no electrode contact (n=34), 2 mm away from the endocardium. Swine were euthanized 2 hours after ablation, and lesion size was measured using triphenyl tetrazolium chloride staining. RESULTS: All PFA lesions with electrode-myocardium contact were well demarcated with triphenyl tetrazolium chloride staining, demonstrating (1) pale central zone (contraction band necrosis with minimal coagulation necrosis), (2) dark brown zone (contraction band necrosis with hemorrhage), and (3) hyperstained red zone by triphenyl tetrazolium chloride (unaffected normal myocardium with preserved mitochondrial activity, consistent with reversible zone). Lesion depth increased significantly with increasing CF and the number of PFA burst pulses. An exponential/logarithmic formula combined with CF and the number of PFA burst pulses correlated lesion depth with high accuracy: R=0.809, P<0.0001, ±1.0-mm accuracy in 128 of 163 (79%) lesions, and ±1.5-mm accuracy in 153 of 163 (94%) lesions. Impedance decrease and electrode temperature were poor predictors of lesion size. There were no detectable lesions resulting from ablation without electrode contact. CONCLUSIONS: Acute PFA ventricular lesions demonstrate irreversible and reversible lesion boundaries. Electrode-tissue contact is required for effective lesion formation. Lesion depth increases significantly with increasing CF and PFA burst pulses. A new exponential/logarithmic formula combined with CF and the number of PFA burst pulses correlates lesion depth with high accuracy.

Asunto(s)

RESUMEN

OBJECTIVES: This study aimed at exploring how using different kinds of sheaths will affect the very first ablation procedure of apprentices. METHODS: 15 patients with paroxysmal atrial fibrillation were randomized to used fixed-curve, conventional steerable or visualized steerable sheath, and received complete isolation of pulmonary veins. All ablations were the very first procedure performed by 15 ablation apprentices. The use of fluoroscopy and catheter stability during the PVI were analyzed. RESULTS: Procedure duration was much longer in the fixed-curve group (116.8 ± 27 vs. 62.2 ± 17 vs. 60.4 ± 17, p < 0.001). X-ray exposure was lowest with visualized sheath (17.6 ± 5 vs. 18.6 ± 6 vs. 5.2 ± 6, p < 0.001). CF SD differed significantly, especially at the anterior aspect of LSPV (7.90 ± 2.90 vs. 5.04 ± 2.18 vs. 4.52 ± 2.40, p < 0.001) and posterior aspect of RSPV (6.84 ± 2.79 vs. 3.42 ± 2.04 vs. 3.50 ± 2.30, p < 0.001) in the fixed-curve group. Impedance drop was significantly smaller in the fixed-curve group at the anterior aspect of LSPV (8.74 ± 3.02 vs. 11.49 ± 5.48 vs. 12.57 ± 5.96, p = 0.005). CONCLUSION: Even for the very first ablation procedure of an ablation apprentice, the use of steerable sheaths will significantly reduce the procedure duration and improve the catheter stability, but only visualized steerable sheath can reduce fluoroscopic time.

Asunto(s)

RESUMEN

AIMS: Superior vena cava (SVC) isolation during atrial fibrillation catheter ablation is limited by the risk of collateral damage to the sinus node and/or the phrenic nerve. Due to its tissue-specificity, we hypothesized the feasibility and safety of pulsed-field ablation (PFA)-based SVC isolation. METHODS AND RESULTS: One hundred and five consecutive patients undergoing PFA-based AF catheter ablation were prospectively included. After pulmonary vein isolation (±posterior wall isolation and electrical cardioversion), SVC isolation was performed using a standardized workflow. Acute SVC isolation was achieved in 105/105 (100%) patients after 6 ± 1 applications. Transient phrenic nerve stunning occurred in 67/105 (64%) patients but without phrenic nerve palsy at the end of the procedure and at hospital discharge. Transient high-degree sinus node dysfunction occurred in 5/105 (4.7%) patients, with no recurrence at the end of the procedure and until discharge. At the 3-month follow-up visit, no complication occurred. CONCLUSION: SVC isolation using a pentaspline PFA catheter is feasible and safe.

Asunto(s)

Asunto(s)

RESUMEN

AIMS: Technological advancements have contributed to the enhanced precision and lesion flexibility in pulsed-field ablation (PFA) by integrating a three-dimensional mapping system combined with a point-by-point ablation strategy. Data regarding the feasibility of this technology remain limited to some clinical trials. This study aims to elucidate initial real-world data on catheter ablation utilizing a lattice-tip focal PFA/radiofrequency ablation (RFA) catheter in patients with persistent atrial fibrillation (AF). METHODS AND RESULTS: Consecutive patients who underwent catheter ablation for persistent AF via the lattice-tip PFA/RFA catheter were enrolled. We evaluated acute procedural data including periprocedural data as well as the clinical follow-up within a 90-day blanking period. In total, 28 patients with persistent AF underwent AF ablation either under general anaesthesia (n = 6) or deep sedation (n = 22). In all patients, pulmonary vein isolation was successfully achieved. Additional linear ablations were conducted in 21 patients (78%) with a combination of successful anterior line (n = 13, 46%) and roof line (n = 19, 68%). The median procedural and fluoroscopic times were 97 (interquartile range, IQR: 80-114) min and 8.5 (IQR: 7.2-9.5) min, respectively. A total of 27 patients (96%) were interviewed during the follow-up within the blanking period, and early recurrent AF was documented in four patients (15%) including one case of recurrent AF during the hospital stay. Neither major nor minor procedural complication occurred. CONCLUSION: In terms of real-world data, our data confirmed AF ablation feasibility utilizing the lattice-tip focal PFA/RFA catheter in patients with persistent AF.

Asunto(s)

RESUMEN

BACKGROUND: Radiofrequency thermorhizotomy (TRZ) is an established treatment for trigeminal neuralgia (TN). TRZ can result risky and painful in a consistent subset of patients, due to the need to perform multiple trajectories, before a successful foramen ovale cannulation. Moreover, intraoperative x-rays are required. METHOD: TRZ has been performed by using a neuronavigated stylet, before trajectory planning on a dedicated workstation. CONCLUSION: Navigated-TRZ (N-TRZ) meets the expectations of a safer and more tolerable procedure due to the use of a single trajectory, avoiding critical structures. Moreover, N-TRZ is x-ray free. Efficacy outcomes are similar to those reported in literature.

Asunto(s)

RESUMEN

BACKGROUND: Deep intramural ventricular tachycardia substrate targets are difficult to access, map, and ablate from endocardial and epicardial surfaces, resulting in high recurrence rates. OBJECTIVES: In this study, the authors introduce a novel approach called ventricular intramyocardial navigation for tachycardia ablation guided by electrograms (VINTAGE) to access and ablate anatomically challenging ventricular tachycardia from within the myocardium. METHODS: Guidewire/microcatheter combinations were navigated deep throughout the extravascular myocardium, accessed directly from the right ventricle cavity, in Yorkshire swine (6 naive, 1 infarcted). Devices were steered to various intramyocardial targets including the left ventricle summit, guided by fluoroscopy, unipolar electrograms, and/or electroanatomic mapping. Radiofrequency ablations were performed to characterize ablation parameters and reproducibility. Intramyocardial saline irrigation began 1 minute before ablation and continued throughout. Lesions were analyzed on cardiac magnetic resonance and necropsy. RESULTS: VINTAGE was feasible in all animals within naive and infarcted myocardium. Forty-three lesions were created, using various guidewires and power settings. Forty-one (95%) lesions were detected on cardiac magnetic resonance and 38 (88%) on necropsy; all undetected lesions resulted from intentionally subtherapeutic ablation energy (10 W). Larger-diameter guidewires yielded larger size lesions. Lesion volumes on necropsy were significantly larger at 20 W than 10 W (178 mm3 [Q1-Q3: 104-382 mm3] vs 49 mm3 [Q1-Q3: 35-93 mm3]; P = 0.02). Higher power (30 W) did not create larger lesions. Median impedance dropped with preablation irrigation by 12 Ω (Q1-Q3: 8-17 Ω), followed by a further 15-Ω (Q1-Q3: 11-19 Ω) drop during ablation. Intramyocardial navigation, ablation, and irrigation were not associated with any complications. CONCLUSIONS: VINTAGE was safe and effective at creating intramural ablation lesions in targets traditionally considered inaccessible from the endocardium and epicardium, both naive and infarcted. Intramyocardial guidewire irrigation and ablation at 20 W creates reproducibly large intramural lesions.

Asunto(s)

RESUMEN

AIMS: Contact force (CF)-sensing radiofrequency (RF) catheters with an ablation index have shown reproducible outcomes for the treatment of atrial fibrillation (AF) in large multicentre studies. A dual-energy (DE) focal CF catheter to deliver RF and unipolar/biphasic pulsed field ablation (PFA), integrated with a three-dimensional (3D) mapping system, can provide operators with additional flexibility. The SmartfIRE study assessed the safety and efficacy of this novel technology for the treatment of drug-refractory, symptomatic paroxysmal AF. Results at 3 months post-ablation are presented here. METHODS AND RESULTS: Pulmonary vein isolation (PVI) was performed using a DE focal, irrigated CF-sensing catheter with the recommendation of PFA at posterior/inferior and RF ablation at the anterior/ridge/carina segments. Irrespective of energy, a tag size of 3 mm; an inter-tag distance ≤6 mm; a target index of 550 for anterior, roof, ridge, and carina; and a target index of 400 for posterior and inferior were recommended. Cavotricuspid isthmus ablation was permitted in patients with documented typical atrial flutter. The primary effectiveness endpoint was acute procedural success. The primary safety endpoint was the rate of primary adverse events (PAEs) within 7 days of the procedure. A prespecified patient subset underwent oesophageal endoscopy (EE; 72 h post-procedure), neurological assessment (NA; pre-procedure and discharge), and cardiac computed tomography (CT)/magnetic resonance angiogram (MRA) imaging (pre-procedure and 3 months post-procedure) for additional safety evaluation, and a mandatory remapping procedure (Day 75 ± 15) for PVI durability assessment. Of 149 patients enrolled between February and June 2023, 140 had the study catheter inserted (safety analysis set) and 137 had ablation energy delivered (per-protocol analysis set). The median (Q1/Q3) total procedure and fluoroscopy times were 108.0 (91.0/126.0) and 4.2 (2.3/7.7) min (n = 137). The acute procedural success rate was 100%. First-pass isolation was achieved in 89.1% of patients and 96.8% of veins. Cavotricuspid isthmus ablations were successfully performed in 12 patients [pulsed field (PF) only: 6, RF only: 5, and RF/PF: 1]. The PAE rate was 4.4% [6/137 patients; 2 pulmonary vein (PV) stenoses, 2 cardiac tamponades/perforations, 1 stroke, and 1 pericarditis]. No coronary artery spasm was reported. No oesophageal lesion was seen in the EE subset (0/31, 0%). In the NA subset (n = 30), microemboli lesions were identified in 2 patients (2/30, 6.7%), both of which were resolved at follow-up; only 1 was symptomatic (silent cerebral lesion, 3.3%). In the CT/MRA subset (n = 30), severe PV narrowing (of >70%) was detected in 2 patients (2/30, 6.7%; vein level 2/128, 1.6%), of whom 1 underwent dilatation and stenting and 1 was asymptomatic; both were associated with high index values and a small inter-tag distance. In the PV durability subset (n = 30), 100/115 treated PVs (87%) were durably isolated and 18/30 patients (60.0%) had all PVs durably isolated. CONCLUSION: A DE focal CF catheter with 3D mapping integration showed a 100% acute success rate with an acceptable safety profile in the treatment of paroxysmal AF. Prespecified 3-month remapping showed notable PVI durability. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05752487.

Asunto(s)

RESUMEN

PURPOSE OF REVIEW: Percutaneous radiofrequency (RF) catheter ablation is an established strategy to prevent ventricular tachycardia (VT) recurrence and ICD shocks. Yet delivery of durable lesion sets by means of traditional unipolar radiofrequency ablation remains challenging, and left ventricular transmurality is rarely achieved. Failure to ablate and eliminate functionally relevant areas is particularly common in deep intramyocardial substrates, e.g. septal VT and cardiomyopathies. Here, we aim to give a practical-orientated overview of advanced and emerging RF ablation technologies to target these complex VT substrates. We summarize recent evidence in support of these technologies and share experiences from a tertiary VT centre to highlight important "hands-on" considerations for operators new to advanced RF ablation strategies. RECENT FINDINGS: A number of innovative and modified radiofrequency ablation approaches have been proposed to increase energy delivery to the myocardium and maximize RF lesion dimensions and depth. These include measures of impedance modulation, combinations of simultaneous unipolar ablations or true bipolar ablation, intramyocardial RF delivery via wires or extendable RF needles and investigational linear or spherical catheter designs. Recent new clinical evidence for the efficacy and safety of these investigational technologies and strategies merits a re-evaluation of their role and clinic application for percutaneous VT ablations. Complexity of substrates targeted with percutaneous VT ablation is increasing and requires detailed preprocedural imaging to characterize the substrate to inform the procedural approach and selection of ablation technology. Depending on local experience, options for additional and/or complementary interventional treatments should be considered upfront in challenging substrates to improve the success rates of index procedures. Advanced RF technologies available for clinical VT ablations include impedance modulation via hypotonic irrigation or additional dispersive patches and simultaneous unipolar as well as true bipolar ablation. Promising investigational RF technologies involve an extendable needle RF catheter, intramyocardial RF delivery over intentionally perforated wires as well as a variety of innovative ablation catheter designs including multipolar linear, spherical and partially insulated ablation catheters.

Asunto(s)

RESUMEN

BACKGROUND: Endocardial catheter-based pulsed field ablation (PFA) of the ventricular myocardium is promising. However, little is known about PFA's ability to target intracavitary structures, epicardium, and ways to achieve transmural lesions across thick ventricular tissue. METHODS: A lattice-tip catheter was used to deliver biphasic monopolar PFA to swine ventricles under general anesthesia, with electroanatomical mapping, fluoroscopy and intracardiac echocardiography guidance. We conducted experiments to assess the feasibility and safety of repetitive monopolar PFA applications to ablate (1) intracavitary papillary muscles and moderator bands, (2) epicardial targets, and (3) bipolar PFA for midmyocardial targets in the interventricular septum and left ventricular free wall. RESULTS: (1) Papillary muscles (n=13) were successfully ablated and then evaluated at 2, 7, and 21 days. Nine lesions with stable contact measured 18.3±2.4 mm long, 15.3±1.5 mm wide, and 5.8±1.0 mm deep at 2 days. Chronic lesions demonstrated preserved chordae without mitral regurgitation. Two targeted moderator bands were transmurally ablated without structural disruption. (2) Transatrial saline/carbon dioxide assisted epicardial access was obtained successfully and epicardial monopolar lesions had a mean length, width, and depth of 30.4±4.2, 23.5±4.1, and 9.1±1.9 mm, respectively. (3) Bipolar PFA lesions were delivered across the septum (n=11) and the left ventricular free wall (n=7). Twelve completed bipolar lesions had a mean length, width, and depth of 29.6±5.5, 21.0±7.3, and 14.3±4.7 mm, respectively. Chronically, these lesions demonstrated uniform fibrotic changes without tissue disruption. Bipolar lesions were significantly deeper than the monopolar epicardial lesions. CONCLUSIONS: This in vivo evaluation demonstrates that PFA can successfully ablate intracavitary structures and create deep epicardial lesions and transmural left ventricular lesions.

Asunto(s)

RESUMEN

BACKGROUND: Conventional focal radiofrequency catheters may be modified to enable multiple energy modalities (radiofrequency or pulsed field [PF]) with the benefit of contact force (CF) feedback, providing greater flexibility in the treatment of arrhythmias. Information on the impact of CF on lesion formation in PF ablations remains limited. METHODS: An in vivo study was performed with 8 swine using an investigational dual-energy CF focal catheter with local impedance. Experiment I: To evaluate atrial lesion formation, contiguity, and width, a point-by-point approach was used to create an intercaval line. The distance between the points was prespecified at 4±1 mm. Half of the line was created with radiofrequency energy, whereas the other half utilized PF (single 2.0 kV application with a proprietary waveform). Experiment II: To evaluate single application lesion dimensions with a proprietary waveform, discrete ventricular lesions were performed with PFA (single 2.0 kV application) with targeted levels of CF: low, 5 to 15 g; medium, 20 to 30 g; and high, 35 to 45 g. Following 1 week of survival, animals underwent endocardial/epicardial remapping, and euthanasia to enable histopathologic examination. RESULTS: Experiment I: Both energy modalities resulted in a complete intercaval line of transmural ablation. PF resulted in significantly wider lines than radiofrequency: minimum width, 14.9±2.3 versus 5.0±1.6 mm; maximum width, 21.8±3.4 versus 7.3±2.1 mm, respectively; P<0.01 for each. Histology confirmed transmural lesions with both modalities. Experiment II: With PF, lesion depth, width, and volume were larger with higher degrees of CF (depth: r=0.82, P<0.001; width: r=0.26, P=0.052; and volume: r=0.55, P<0.001), with depth increasing at a faster rate than width. The mean depths were as follows: low (n=17), 4.3±1.0 mm; medium (n=26), 6.4±1.2 mm; and high (n=14), 9.1±1.4 mm. CONCLUSIONS: Using the same focal point CF-sensing catheter, a novel PF ablation waveform with a single application resulted in transmural atrial lesions that were significantly wider than radiofrequency. Lesion depth showed a significant positive correlation with CF with depths of 6.4 mm at moderate CF.

Asunto(s)

RESUMEN

BACKGROUND: During pulsed field ablation (PFA), electrode-tissue proximity optimizes lesion quality. A novel "single-shot" map-and-ablate spherical multielectrode PFA array catheter that is able to verify electrode-tissue contact was recently studied in a first-in-human trial of atrial fibrillation (AF). OBJECTIVE: The aim of this study was to report lesion durability data, safety, and 12-month effectiveness outcomes. METHODS: The spherical PFA catheter, an all-in-one mapping and ablation system, was used to render anatomy and to deliver biphasic pulses (ungated 1.7 kV pulses; ∼40 seconds/application). Ablation sites included pulmonary veins (PVs) and, in selected patients, posterior wall and mitral isthmus. Follow-up was invasive remapping at ∼3 months, electrocardiograms, Holter monitoring at 6 and 12 months, and symptomatic and scheduled transtelephonic monitoring. The primary and secondary efficacy end points were acute PV isolation (PVI), PVI durability, and atrial arrhythmia recurrence. RESULTS: In the 48-patient AF cohort (paroxysmal, 48%; persistent, 52%), lesion sets included PVI (n = 48; 1.2 applications/PV), posterior wall (n = 20; 3.6 applications/posterior wall), and mitral isthmus (n = 11; 2.9 applications/mitral isthmus). Lesions were acutely successful for all 187 of 187 PVs (100%), 20 of 20 posterior walls (100%), and 10 of 11 mitral isthmuses (91%). Pulse delivery time, left atrial catheter dwell time, and procedure time were 61.5 ± 32.8 seconds, 53.9 ± 26.5 minutes, and 87.8 ± 29.8 minutes, respectively. Remapping (43/48 patients [89.5%]) revealed that 158 of 169 PVs (93.5%) were durably isolated. The only complication was a drug-responsive pericarditis. The 1-year Kaplan-Meier estimates of freedom from atrial arrhythmia were 84.2% (paroxysmal AF) and 80.0% (persistent AF). CONCLUSION: The single-shot spherical array PFA catheter can safely achieve durable lesions, translating into good clinical efficacy.

Asunto(s)

RESUMEN

AIMS: Pulsed field ablation (PFA) for the treatment of atrial fibrillation (AF) potentially offers improved safety and procedural efficiencies compared with thermal ablation. Opportunities remain to improve effective circumferential lesion delivery, safety, and workflow of first-generation PFA systems. In this study, we aim to evaluate the initial clinical experience with a balloon-in-basket, 3D integrated PFA system with a purpose-built form factor for pulmonary vein (PV) isolation. METHODS AND RESULTS: The VOLT CE Mark Study is a pre-market, prospective, multi-centre, single-arm study to evaluate the safety and effectiveness of the Volt™ PFA system for the treatment of paroxysmal (PAF) or persistent AF (PersAF). Feasibility sub-study subjects underwent phrenic nerve evaluation, endoscopy, chest computed tomography, and cerebral magnetic resonance imaging. Study endpoints were the rate of primary serious adverse event within 7 days and acute procedural effectiveness. A total of 32 subjects (age 61.6 ± 9.6 years, 65.6% male, 84.4% PAF) were enrolled and treated in the feasibility sub-study and completed a 30-day follow-up. Acute effectiveness was achieved in 99.2% (127/128) of treated PVs (96.9% of subjects, 31/32) with 23.8 ± 4.2 PFA applications/subject. Procedure, fluoroscopy, LA dwell, and transpired ablation times were 124.6 ± 28.1, 19.8 ± 8.9, 53.0 ± 21.0, and 48.0 ± 19.9 min, respectively. Systematic assessments of initial safety revealed no phrenic nerve injury, pulmonary vein stenosis, or oesophageal lesions causally related to the PFA system and three subjects with silent cerebral lesions (9.4%). There were no primary serious adverse events. CONCLUSION: The initial clinical use of the Volt PFA System demonstrates acute safety and effectiveness in the treatment of symptomatic, drug refractory AF.

Asunto(s)

RESUMEN

Radiofrequency (RF) ablation to perform pulmonary vein isolation (PVI) for the treatment of atrial fibrillation involves some risk to collateral structures, including the esophagus. Proactive esophageal cooling using a dedicated device has been granted marketing authorization by the Food and Drug Administration (FDA) to reduce the risk of ablation-related esophageal injury due to RF cardiac ablation procedures, and more recent data also suggest that esophageal cooling may contribute to improved long-term efficacy of treatment. A mechanistic underpinning explaining these findings exists through the quantification of lesion placement contiguity defined as the Continuity Index (CI). Kautzner et al. quantified the CI by the order of lesion placement, such that whenever a lesion is placed non-adjacent to the prior lesion, the CI is incremented by the number of segments the catheter tip has moved over. To facilitate real-time calculation of the CI and encourage further adoption of this instrument, we propose a modification in which the placement of non-adjacent lesions increments the CI by only one unit, avoiding the need to count potentially nebulous markers of atrial segmentation. The objective of this protocol is to describe the methods of calculating the CI both prospectively during real-time PVI cases and retrospectively using recorded case data. A comparison of the results obtained between cases that utilized proactive esophageal cooling and cases that used luminal esophageal temperature (LET) monitoring is then provided.

Asunto(s)

RESUMEN

AIMS: Pulsed field ablation (PFA) has significant advantages over conventional thermal ablation of atrial fibrillation (AF). This first-in-human, single-arm trial to treat paroxysmal AF (PAF) assessed the efficiency, safety, pulmonary vein isolation (PVI) durability and one-year clinical effectiveness of an 8 Fr, large-lattice, conformable single-shot PFA catheter together with a dedicated electroanatomical mapping system. METHODS AND RESULTS: After rendering the PV anatomy, the PFA catheter delivered monopolar, biphasic pulse trains (5-6 s per application; ∼4 applications per PV). Three waveforms were tested: PULSE1, PULSE2, and PULSE3. Follow-up included ECGs, Holters at 6 and 12 months, and symptomatic and scheduled transtelephonic monitoring. The primary and secondary efficacy endpoints were acute PVI and post-blanking atrial arrhythmia recurrence, respectively. Invasive remapping was conducted ∼75 days post-ablation. At three centres, PVI was performed by five operators in 85 patients using PULSE1 (n = 30), PULSE2 (n = 20), and PULSE3 (n = 35). Acute PVI was achieved in 100% of PVs using 3.9 ± 1.4 PFA applications per PV. Overall procedure, transpired ablation, PFA catheter dwell and fluoroscopy times were 56.5 ± 21.6, 10.0 ± 6.0, 19.1 ± 9.3, and 5.7 ± 3.9 min, respectively. No pre-defined primary safety events occurred. Upon remapping, PVI durability was 90% and 99% on a per-vein basis for the total and PULSE3 cohort, respectively. The Kaplan-Meier estimate of one-year freedom from atrial arrhythmias was 81.8% (95% CI 70.2-89.2%) for the total, and 100% (95% CI 80.6-100%) for the PULSE3 cohort. CONCLUSION: Pulmonary vein isolation (PVI) utilizing a conformable single-shot PFA catheter to treat PAF was efficient, safe, and effective, with durable lesions demonstrated upon remapping.

Asunto(s)

RESUMEN

AIMS: A three-dimensional electroanatomic mapping system-guided transseptal puncture (3D-TSP), without fluoroscopy or echocardiography, has been only minimally reported. Indications for 3D-TSP remain unclear. Against this background, this study aims to establish a precise technique and create a workflow for validating and selecting eligible patients for fluoroless 3D-TSP. METHODS AND RESULTS: We developed a new methodology for 3D-TSP based on a unipolar electrogram derived from a transseptal needle tip (UEGM tip) in 102 patients (the derivation cohort) with intracardiac echocardiography (ICE) from March 2018 to February 2019. The apparent current of injury (COI) was recorded at the muscular limbus of the foramen ovalis (FO) on the UEGM tip (sinus rhythm: 2.57 ± 0.95 mV, atrial fibrillation: 1.92 ± 0.77 mV), which then disappeared or significantly reduced at the central FO. Changes in the COI, serving as a major criterion to establish a 3D-TSP workflow, proved to be the most valuable indicator for identifying the FO in 99% (101/102) of patients compared with three previous techniques (three minor criteria) of reduction in atrial unipolar or bipolar potential and FO protrusion. A total of 99.9% (1042/1043) patients in the validation cohort underwent successful 3D-TSP through the workflow from March 2019 to July 2023. Intracardiac echocardiography guidance was required for 6.6% (69/1042) of patients. All four criteria were met in 740 patients, resulting in a 100% pure fluoroless 3D-TSP success rate. CONCLUSION: In most patients, fluoroless 3D-TSP was successfully achieved using changes in the COI on the UEGM tip. Patients who met all four criteria were considered suitable for 3D-TSP, while those who met none required ICE guidance.

Asunto(s)

RESUMEN

INTRODUCTION: In patients with paroxysmal atrial fibrillation, pulsed-field ablation has been developed as an alternative to thermal ablation. Three devices are currently available: Farawave by Boston, PulseSelect by Medtronic, and Varipulse by Johnson. In the present report, we studied the outcomes at 12 months of these three devices using indirect comparisons. METHODS: A standard PubMed search was conducted that identified all studies evaluating these devices in patients with paroxysmal atrial fibrillation. The endpoint was freedom from arrhythmia recurrence. Kaplan-Meier curves were subjected to the IPDfromKM method that generated reconstructed patients. Standard time-to-event statistical testss (including heterogeneity assessment) were performed. RESULTS: Our analysis included 9 studies (8 single-arm and 1 randomized trial based on Farawave for a total of 1916 patients). A significant heterogeneity was found across the trials using Farawave because the outcomes found in the single-arm trials were better than those found in the randomized trial. Farawave (according exclusively to the results of the randomized trial), PulseSelect, and Varipulse showed a similar time-course of their respective outcomes with no significant difference. The single-arm trials using Farawave showed better outcomes than the randomized trial using Farawave and the pivotal trials using PulseSelect and Varipulse. DISCUSSION: Our study provided an updated overview of all the studies that have so far used pulsed-fileld ablation in patients with paroxysmal atrial fibrillation.

Asunto(s)