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Cardioneuroablation aims to correct the imbalance between sympathetic and parasympathetic tone by targeting the cardiac postganglionic vagal fibers. Accurate localization of ganglionated plexi is crucial for the efficacy of the procedure. Omnipolar Technology Near Field is a novel mapping algorithm enabling real‐time, automatic spectral analysis with high spatial resolution and accuracy.

We prove that the classical line-tension approximation for dislocations in crystals, that is, the approximation that neglects interactions at a distance between dislocation segments and accords dislocations energy in proportion to their length, follows as the Γ -limit of regularized linear-elasticity as the lattice parameter becomes increasingly small or, equivalently, as the dislocation measure becomes increasingly dilute. We consider two regularizations of the theory of linear-elastic dislocations: a core-cutoff and a mollification of the dislocation measure. We show that both regularizations give the same energy in the limit, namely, an energy defined on matrix-valued divergence-free measures concentrated on lines. The corresponding self-energy per unit length ψ ( b , t ) , which depends on the local Burgers vector and orientation of the dislocation, does not, however, necessarily coincide with the self-energy per unit length ψ 0 ( b , t ) obtained from the classical theory of the prelogarithmic factor of linear-elastic straight dislocations. Indeed, microstructure can occur at small scales resulting in a further relaxation of the classical energy down to its H 1 -elliptic envelope.

Ablation of atypical atrial flutter may be challenging, particularly when a complex substrate is present. The persistence of left superior vena cava and severe coronary sinus dilatation carries an arrhythmogenic potential. In this case of atrial flutter, extensive substrate and activation mapping revealed the critical substrate within the coronary sinus.

Cardioneuroablation (CNA) has emerged as a promising therapeutic strategy for functional bradyarrhythmias, particularly in cases of cardioinhibitory neurocardiogenic syncope and certain forms of atrial fibrillation. Indeed, by targeting vagal innervation through endocardial radiofrequency catheter ablation, CNA can obviate the need for pacemaker (PM) implantation. This technique involves denervation of specific vagal nerve structures within the atria to modulate autonomic balance and prevent symptomatic bradycardia. The efficacy of this approach stems from the recognition that an imbalance between sympathetic and parasympathetic tones, often characterized by excessive vagal activity, underpins these arrhythmogenic conditions. Indeed, CNA may be more effective than a permanent PM implantation in some patients, as this method addresses the underlying etiology rather than merely treating symptoms. Specifically, modulating autonomic nervous system (ANS) signaling through procedures such as CNA holds considerable promise for preventing and treating a range of cardiac arrhythmias. This review aims to synthesize current knowledge regarding various CNA techniques, exploring the associated mechanisms, clinical applications, and outcomes across diverse patient populations.

We derive strain-gradient plasticity from a nonlocal phase-field model of dislocations in a plane. After scaling, from the nonlocal elastic interaction we derive a continuous energy with linear growth depending on a measure which characterizes the macroscopic dislocation density as well as a nonlocal effective energy representing the far-field interaction between dislocations. Relaxation and formation of microstructures at intermediate scales are automatically incorporated in the limiting procedure based on -convergence.

An explicit characterization of the quasiconvex envelope of the condensed energy in a model for finite elastoplasticity is presented, both in two and in three spatial dimensions. A variational formulation of plasticity, which is appropriate for the first time step in a time discrete formulation of the evolution problem, is used, and it is assumed that only one slip system is active. The model includes a nonlinear elastic energy, which is invariant under SO(n), and an effective plastic contribution which is quadratic in the slip parameter. The quasiconvex envelope arises via the formation of first-order laminates.

Crumpling a sheet of paper leads to the formation of complex folding patterns over several length scales. This can be understood on the basis of the interplay of a nonconvex elastic energy, which favors locally isometric deformations, and a small singular perturbation, which penalizes high curvature. Based on three-dimensional nonlinear elasticity and by using a combination of explicit constructions and general results from differential geometry, we prove that, in agreement with previous heuristic results in the physics literature, the total energy per unit thickness of such folding patterns scales at most as the thickness of the sheet to the power 5/3. For the case of a single fold we also obtain a corresponding lower bound.

Background Several novel technologies allowing catheter ablation (CA) with a favorable safety/efficacy profile have been recently developed, but not yet extensively clinically tested in the setting of ventricular tachycardia CA. Methods In this technical report, we overview technical aspects and preclinical/clinical information concerning the application of three novel CA technologies in the ventricular milieu: a pulsed field ablation (PFA) generator (CENTAURI™, Galaxy Medical) to be used with linear, contact force-sensing radiofrequency ablation catheters; a contact force-sensing radiofrequency ablation catheter equipped with six thermocouples and three microelectrodes (QDOT Micro™, Biosense-Webster), allowing high-resolution mapping and temperature-controlled CA; and a flexible and mesh-shaped irrigation tip, contact force-sensing radiofrequency ablation catheter (Tactiflex, Abbott). We also report three challenging VT cases in which CA was performed using these technologies. Results The CENTAURI system was used with the Tacticath™ (Abbott) ablation catheter to perform ventricular PFA in a patient with advanced heart failure, electrical storm, and a deep intramural septal substrate. Microelectrode mapping using QDOT Micro™ helped to refine substrate assessment in a VT patient with congenitally corrected transposition of the great arteries, and allowed the identification of the critical components of the VT circuit, which were successfully ablated. Tactiflex™ was used in two challenging CA cases (one endocardial and one epicardial), allowing acute and mid-term control of VT episodes without adverse events. Conclusion The ideation and development of novel technologies initially intended to treat atrial arrhythmias and successfully implemented in the ventricular milieu is contributing to the progressive improvement in the clinical benefits derived from VT CA, making this procedure key for successful management of increasingly complex patients. Graphical abstract

Martensitic transformations are diffusionless, solid-to-solid phase transitions, and have been observed in metals, alloys, ceramics and proteins 1 , 2 . They are characterized by a rapid change of crystal structure, accompanied by the development of a rich microstructure. Martensitic transformations can be irreversible, as seen in steels upon quenching 1 , or they can be reversible, such as those observed in shape-memory alloys 3 , 4 . In the latter case, the microstructures formed on cooling are easily manipulated by loads and disappear upon reheating. Here, using mathematical theory and numerical simulation, we explain these sharp differences in behaviour on the basis of the change in crystal symmetry during the transition. We find that a necessary condition for reversibility is that the symmetry groups of the parent and product phases be included in a common finite symmetry group. In these cases, the energy barrier to lattice-invariant shear is generically higher than that pertaining to the phase change and, consequently, transformations of this type can occur with virtually no plasticity. Irreversibility is inevitable in all other martensitic transformations, where the energy barrier to plastic deformation (via lattice-invariant shears, as in twinning or slip) is no higher than the barrier to the phase change itself. Various experimental observations confirm the importance of the symmetry of the stable states in determining the macroscopic reversibility of martensitic transformations.