Pressure-Volume Analysis Demonstrates Short- and Long-Term Hemodynamic Effects of Atrioventricular Interval Modulation Therapy in Hypertension.

Background: Prior studies show that atrioventricular interval modulation (AVIM) therapy provides immediate, substantial, and sustained clinically meaningful reductions in ambulatory and office systolic blood pressures (SBPs) in hypertensive patients with pacemakers.

Objectives: The goal of this study was to assess the acute and chronic mechanisms by which AVIM therapy reduces blood pressure and assess the impact of lead location on these mechanisms.

Methods: Acute hemodynamic effects were assessed by invasive pressure-volume (PV) analysis in hypertensive subjects (N = 16) with intact atrioventricular (AV) conduction.

Safety and efficacy of a lattice-tip catheter for ventricular arrhythmia ablation: the Affera Ventricular Arrhythmia Ablation (AVAAR) Registry.

Background: The feasibility and safety of the lattice-tip catheter for ventricular arrhythmia (VA) ablation in humans remain largely unknown. This study aimed to assess feasibility, safety profile as well as patient outcomes after VA ablation with a lattice-tip catheter in a multicenter European registry.

Methods: All 18 European centers using the AFFERA system on September 2024 agreed to participate.

Is the esophagus spared during pulsed field ablation? Early histopathology and in vivo esophageal retraction.

Background: Preclinical studies of pulsed field ablation (PFA) have demonstrated an absence of esophageal lesions. However, esophageal assessments are typically performed weeks after PFA, precluding an understanding of acute effects.

Objective: This study aimed to characterize the mechanism of esophageal safety with PFA, using preclinical and clinical assessments.

Catheters and Tools with Pulsed Field Ablation-Pulmonary Vein Isolation and Nanosecond Pulse Field Ablation.

Pulse field ablation (PFA) has gained attention in the field of atrial fibrillation catheter treatment recently. All currently used or developed technologies use ultrashort pulses (on the order of microseconds). The Emerging CellFX System (Pulse Biosciences, Inc, Inc) utilizes nanosecond PFA (nsPFA) and is thus several orders of magnitude shorter than the initial PFA systems.

One-year outcomes of a conformable single-shot pulsed-field ablation catheter for the treatment of paroxysmal atrial fibrillation.

Background: Most single-shot pulsed-field ablation (PFA) catheters require extensive repositioning for pulmonary vein isolation (PVI), posing a challenge for obtaining contiguous, durable lesions.

Objective: To determine 1-year outcomes of a single-shot, all-in-one mapping and ablation PFA catheter for treating paroxysmal atrial fibrillation (PAF).

Methods: After PVI with the large-lattice catheter with expandable tip (Sphere-360), follow-up included Holter monitoring at 180 and 365 days and scheduled/symptomatic trans-telephonic monitoring (TTM) or modeled insertable loop recorder (ILR) data.

Acute Procedural Results of Pulsed Field Cryoablation for Persistent Atrial Fibrillation: Multicenter First-in-Human PARALELL Trial.

Introduction: Pulsed Field Cryoablation (PFCA) is a dual-energy cardiac ablation modality consisting of short-duration ultra-low temperature cryoablation (ULTC) followed immediately by pulsed field ablation (PFA) delivered from the same catheter. It is hypothesized that PFCA may improve contact stability during PFA, while maintaining lesion depth and effectiveness of ULTC.

Methods: PARALELL is a first-in-human multicenter study evaluating safety and effectiveness of a novel PFCA catheter and system in patients with persistent atrial fibrillation (PsAF) using the combination of pulmonary vein (PVI) and posterior wall (PWI) isolation.

Repeat procedures after pulsed field ablation for atrial fibrillation: MANIFEST-REDO study.

Aims: Initial clinical studies of pulsed field ablation (PFA) to treat atrial fibrillation (AF) indicated a >90% durability rate of pulmonary vein isolation (PVI). However, these studies were largely conducted in single centres and involved a limited number of operators. We aimed to describe the electrophysiological findings and outcomes in patients undergoing repeat ablation after an initial PF ablation for AF.

First human safety and effectiveness study of defibrillation with a novel patch wearable cardioverter-defibrillator.

Aims: Wearable cardioverter-defibrillators (WCDs) are indicated in patients at risk of sudden cardiac arrest who are not immediate candidates for implantable defibrillator therapy. Limitations of existing WCDs include poor compliance and high false alarm rates. The Jewel is a novel patch-WCD (P-WCD) that addresses these limitations with an adhesive-based design for near-continuous wear and a machine learning algorithm designed to minimize inappropriate detections.

Safety and Effectiveness of Pulsed Field Ablation for Atrial Fibrillation in Patients with Heart Failure: A MANIFEST-PF Sub-analysis.

Background: Atrial fibrillation (AF) and heart failure (HF) coexist, increasing morbidity and mortality. Studies have demonstrated improved outcomes following AF ablation in HF patients with reduced ejection fraction (EF).

Objective: To assess the outcomes of pulsed-field ablation (PFA) in HF.

Safety and Effectiveness of Pulsed Field Ablation for Atrial Fibrillation in Patients With Heart Failure.

Background: Atrial fibrillation (AF) and heart failure (HF) coexist, increasing morbidity and mortality. Studies have demonstrated improved outcomes following AF ablation in HF patients with reduced ejection fraction (EF).

Objective: This study sought to assess the outcomes of pulsed field ablation (PFA) in HF.

A Randomized Trial of Electrographic Flow-Guided Redo Ablation for Nonparoxysmal Atrial Fibrillation (FLOW-AF).

Background: Electrographic flow (EGF) mapping enables full spatiotemporal reconstruction of organized wavefront propagation to identify extrapulmonary vein sources of atrial fibrillation (AF).

Objectives: FLOW-AF (A Randomized Controlled Study to Evaluate the Reliability of the Ablacon Electrographic FLOW [EGF] Algorithm Technology [Ablamap Software] to Identify AF Sources and Guide Ablation Therapy in Patients With Persistent Atrial Fibrillation) was multicenter, randomized controlled study of EGF mapping to: 1) stratify a nonparoxysmal AF population undergoing redo ablation; 2) guide ablation of these extrapulmonary vein AF sources; and 3) improve AF recurrence outcomes.

Methods: FLOW-AF enrolled persistent atrial fibrillation (PerAF)/long-standing PerAF patients undergoing redo ablation at 4 centers.

AF ablation using a novel "single-shot" map-and-ablate spherical array pulsed field ablation catheter: 1-Year outcomes of the first-in-human PULSE-EU trial.

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.

Nitroglycerin to Ameliorate Coronary Artery Spasm During Focal Pulsed-Field Ablation for Atrial Fibrillation.

Background: In treating atrial fibrillation, pulsed-field ablation (PFA) has comparable efficacy to conventional thermal ablation, but with important safety advantages: no esophageal injury or pulmonary vein stenosis, and rare phrenic nerve injury. However, when PFA is delivered in proximity to coronary arteries using a pentaspline catheter, which generates a broad electrical field, severe vasospasm can be provoked.

Objectives: The authors sought to study the vasospastic potential of a focal PFA catheter with a narrower electrical field and develop a preventive strategy with nitroglycerin.

Coronary Artery Spasm During Pulsed Field vs Radiofrequency Catheter Ablation of the Mitral Isthmus.

Importance: In treating atrial fibrillation, pulsed field ablation (PFA) is a novel energy modality with comparable efficacy to conventional thermal ablation, such as radiofrequency ablation (RFA), but with the benefit of some preferentiality to myocardial tissue ablation. Studies have demonstrated important safety advantages, including the absence of esophageal injury or pulmonary vein stenosis and only rare phrenic nerve injury. However, there is emerging evidence of coronary artery vasospasm provoked by PFA.

Electrographic flow mapping of persistent atrial fibrillation: intra- and inter-procedure reproducibility in the absence of 'ground truth'.

Aims: Validating mapping systems that identify atrial fibrillation (AF) sources (focal/rotational activity) is confounded by the absence of ground truth. A key concern of prior mapping technologies is spatiotemporal instability, manifesting as poor map reproducibility. Electrographic flow (EGF) employs a novel algorithm that visualizes atrial electrical wavefront propagation to identify putative AF sources.

Clinical Outcomes by Sex After Pulsed Field Ablation of Atrial Fibrillation.

Importance: Previous studies evaluating the association of patient sex with clinical outcomes using conventional thermal ablative modalities for atrial fibrillation (AF) such as radiofrequency or cryoablation are controversial due to mixed results. Pulsed field ablation (PFA) is a novel AF ablation energy modality that has demonstrated preferential myocardial tissue ablation with a unique safety profile.

Objective: To compare sex differences in patients undergoing PFA for AF in the Multinational Survey on the Methods, Efficacy, and Safety on the Postapproval Clinical Use of Pulsed Field Ablation (MANIFEST-PF) registry.

Reversible Pulsed Electrical Fields as an In Vivo Tool to Study Cardiac Electrophysiology: The Advent of Pulsed Field Mapping.

Background: During electrophysiological mapping of tachycardias, putative target sites are often only truly confirmed to be vital after observing the effect of ablation. This lack of mapping specificity potentiates inadvertent ablation of innocent cardiac tissue not relevant to the arrhythmia. But if myocardial excitability could be transiently suppressed at critical regions, their suitability as targets could be conclusively determined before delivering tissue-destructive ablation lesions.