Pulsed field ablation prevents chronic atrial fibrotic changes and restrictive mechanics after catheter ablation for atrial fibrillation.

Aims: Pulsed field ablation (PFA), a non-thermal ablative modality, may show different effects on the myocardial tissue compared to thermal ablation. Thus, this study aimed to compare the left atrial (LA) structural and mechanical characteristics after PFA vs. thermal ablation.

Pulsed field ablation selectively spares the oesophagus during pulmonary vein isolation for atrial fibrillation.

Aims: Extra-atrial injury can cause complications after catheter ablation for atrial fibrillation (AF). Pulsed field ablation (PFA) has generated preclinical data suggesting that it selectively targets the myocardium. We sought to characterize extra-atrial injuries after pulmonary vein isolation (PVI) between PFA and thermal ablation methods.

Emerging Technologies for Pulmonary Vein Isolation.

Atrial fibrillation is the most common sustained cardiac arrhythmia and is associated with considerable morbidity and mortality. Electrically isolating the pulmonary veins from the left atrium by catheter ablation is superior to antiarrhythmic drug therapy for maintaining sinus rhythm, but its success varies depending on multiple factors, including arrhythmic burden. Although procedural outcomes have improved over the years, further gains are limited by a seemingly zero-sum relationship between effectiveness and safety, which is largely a product of the available technologies.

Pulsed Field Ablation Versus Radiofrequency Ablation: Esophageal Injury in a Novel Porcine Model.

Background: Pulsed field ablation (PFA) can be myocardium selective, potentially sparing the esophagus during left atrial ablation. In an in vivo porcine esophageal injury model, we compared the effects of newer biphasic PFA with radiofrequency ablation (RFA).

Methods: In 10 animals, under general anesthesia, the lower esophagus was deflected toward the inferior vena cava using an esophageal deviation balloon, and ablation was performed from within the inferior vena cava at areas of esophageal contact.

Endocardial ventricular pulsed field ablation: a proof-of-concept preclinical evaluation.

Aims: Pulsed field ablation (PFA) is a novel, non-thermal modality that selectively ablates myocardium with ultra-short electrical impulses while sparing collateral tissues. In a proof-of-concept study, the safety and feasibility of ventricular PFA were assessed using a prototype steerable, endocardial catheter.

Methods And Results: Under general anaesthesia, the left and right ventricles of four healthy swine were ablated using the 12-Fr deflectable PFA catheter and a deflectable sheath guided by electroanatomic mapping.

Preclinical Evaluation of Pulsed Field Ablation: Electrophysiological and Histological Assessment of Thoracic Vein Isolation.

Background: Pulsed field ablation (PFA) is a uniquely tissue-selective, nonthermal cardiac ablation modality. Delivery parameters such as the electrical waveform composition and device design are critical to PFA's efficacy and safety, particularly tissue specificity. In a series of preclinical studies, we sought to examine the electrophysiological and histological effects of PFA and compare the safety and feasibility of durable pulmonary vein and superior vena cava (SVC) isolation between radiofrequency ablation and PFA waveforms.

Earth before life.

Background: A recent study argued, based on data on functional genome size of major phyla, that there is evidence life may have originated significantly prior to the formation of the Earth.

Results: Here a more refined regression analysis is performed in which 1) measurement error is systematically taken into account, and 2) interval estimates (e.g.

Intraparenchymal drug delivery via positive-pressure infusion: experimental and modeling studies of poroelasticity in brain phantom gels.

We have used agarose gel to develop a robust model of the intraparenchymal brain tissues for the purpose of simulating positive-pressure infusion of therapeutic agents directly into the brain. In parallel with that effort, we have synthesized a mathematical description of the infusion process on the basis of a poroelastic theory for the swelling of the tissues under the influence of the infusate's penetration into the interstitial space. Infusion line pressure measurements and video microscopy determinations of infusate volume of distribution within the gel demonstrate a good match between theory and experiment over a wide range of flow rates (0.