Wall Junction Research Articles

Domain wall and magnetic tunnel junction hybrid for on-chip learning in UNet architecture

We present a spintronic device based hardware implementation of UNet for segmentation tasks. Our approach involves designing hardware for convolution, deconvolution, rectified activation function (ReLU), and max pooling layers of the UNet architecture. We designed the convolution and deconvolution layers of the network using the synaptic behavior of the domain wall MTJ. We also construct the ReLU and max pooling functions of the network utilizing the spin hall driven orthogonal current injected MTJ. To incorporate the diverse physics of spin-transport, magnetization dynamics, and CMOS elements in our UNet design, we employ a hybrid simulation setup that couples micromagnetic simulation, non-equilibrium Green’s function, and SPICE simulation along with network implementation. We evaluate our UNet design on the CamVid dataset and achieve segmentation accuracies of 83.71% on test data, on par with the software implementation with 821 mJ of energy consumption for on-chip training over 150 epochs. We further demonstrate nearly one order of magnitude (10×) improvement in the energy requirement of the network using unstable ferromagnet (Δ = 4.58) over the stable ferromagnet (Δ = 45) based ReLU and max pooling functions while maintaining similar accuracy. The hybrid architecture comprising domain wall MTJ and unstable FM-based MTJ leads to an on-chip energy consumption of 85.79 mJ during training, with a testing energy cost of 1.55 µJ.

Optimization of high-power short-duration pulmonary vein isolation using QDOT catheter - the A-Q-RATE POWER trial

Abstract Background/Introduction The safety and efficacy of novel ablation catheter QDOT Micro, capable of delivering high-power short-duration (HPSD) radio-frequency (RF) applications, has already been demonstrated in clinical trials. It has been shown that lesions performed with 90 Watts/4 sec (vHPSD) are shallower but wider compared to HPSD (50 Watts/4 sec) or conventional ablation settings. Thus, it may be speculated that vHPSD applications may not achieve transmurality at thick (up to 4 mm) parts of anterior aspects of pulmonary vein (PV) - left atrial (LA) wall junction. Purpose To compare acute completeness of PV isolation (PVI) focused on anterior wall achieved using vHSPD versus HPSD in patients undergoing ablation for atrial fibrillation (AF). Methods Prospective, dual-center, randomized study was conducted over a 8-month period. Patients were randomized 1:1 to vHPSD versus HPSD delivered at anterior aspects of PV. Posterior parts of PV were ablated with vHPSD in both arms. The carina region between ipsilateral PVs was ablated using 35 W and ablation index of 380. Need for additional RF applications to achieve complete PVI was the primary outcome. Results 70 patients (mean age 63.5±11.2; 57.1% male) with paroxysmal (61.4%) or persistent AF (38.6%) were randomized to vHPSD (n=35) or HPSD (n=35). Additional RF touch-up applications at the anterior aspects of PV were significantly more frequently needed in the vHPSD group compared with the HPSD group (46% vs 19%, p<0.001) and in the right PVs (57% vs 20%, p=0.001) versus left PVs (34% vs 17%, p=0.1). Median procedure duration, LA dwell time and fluoroscopy time were similar in both groups [112 (IQR 90, 130) min vs 107 (IQR 90,125) min, p= 0.58; 95 (IQR 70,106) min vs 90 (IQR 71,100) min, p=0.55; and 28 (IQR 14,69) sec vs 46 (IQR 0,89) sec, p=0.97, respectively). In one patient in vHPSD we were not able to isolate right superior pulmonary vein (RSPV) despite additional RF touch-up applications. Conclusions vHPSD RF applications using the QDOT Micro catheter may not achieve transmurality in a significant proportion of anterior parts of PV. The proposed hybrid strategy consisting of HPSD delivery at anterior aspects of PV with vHPSD delivered at other parts of PV ostia is associated with significantly higher rate of first-pass PVI without extending procedural and fluoroscopy duration.

Incidence and prognosis of subclinical cardiac perforation after leadless pacemaker implantation

Abstract Introduction Subclinical cardiac perforation, a known complication of cardiac implantable electronic device leads, occurs in 6–20% of cases. While leadless pacemakers are advised to be placed in the septum to mitigate perforation risk, limited studies exist on lead positioning and perforation incidence. Objectives This retrospective observational study aimed to assess leadless pacemaker lead positions, determine the incidence of subclinical cardiac perforation, and evaluate associated prognoses through computed tomography (CT) in post-implantation patients. Methods Thirty-one patients underwent CT after leadless pacemaker implantation. Two cardiologists and a radiologist analyzed CT scans to categorize lead positions (septum, free wall, or septum-free wall junction) and identify subclinical perforation (defined as tine transversal beyond the outer myocardial contour without symptoms, hemodynamic instability, or pacemaker issues). Results Mean age at implantation was 70.5 ± 12.7 years; 35.5% were male, and 41.9% had atrial fibrillation. Twenty patients (64.5%) were on anticoagulants or antiplatelet agents. Twenty-four patients (77.4%) were positioned at the septum-free wall junction. Subclinical perforation occurred in 12 patients (38.7%), with a higher proportion in patients on non-vitamin K antagonist oral anticoagulants. Two patients had moderate amount of pericardial effusion; the remaining ten with subclinical perforation were stable during follow-up. Conclusions The most common leadless pacemaker implantation site was the septum-free wall junction with 38.7% of subclinical perforation.

Descripción y prevalencia de la disyunción del anillo mitral y el ventrículo: ¿variante de la normalidad o patológica?

Introduction and objectivesThe aim of this study was to investigate a new variation of the atrial wall-mitral annulus-ventricular wall junction along the mural mitral leaflet and commissures: the ventricular mitral annular disjunction (v-MAD). This new variant is characterized by spatial displacement of the mitral leaflet hinge line by more than 2mm toward the left ventricle. MethodsWe examined a cohort of autopsied human hearts (n=224, 21.9% females, 47.9±17.6 years) from patients without known cardiovascular disease to identify the presence of v-MAD. ResultsMore than half (57.1%) of the hearts showed no signs of MAD in the mural mitral leaflet or mitral commissures. However, v-MAD was found in 23.6% of cases, located within 20.1% of mural leaflets, 2.2% in superolateral commissures, and 1.3% in inferoseptal commissures. V-MAD was not uniformly distributed along the mitral annulus circumference, with the most frequent site being the P2 scallop (19.6% of hearts). The v-MAD height was significantly greater in mural leaflets than in commissures (4.4 mm±1.2 mm vs 2.1 mm±0.1 mm; P<.001). No specific variations in mitral valve morphology or anthropometrical features of donors were associated with the presence or distribution of v-MADs. Microscopic examinations revealed the overlap of the thin layer of atrial myocardium over ventricular myocardium in areas of v-MAD. ConclusionsOur study is the first to present a detailed definition and morphometric description of v-MAD. Further studies should focus on the clinical significance of v-MAD to elucidate whether it represents a benign anatomical variant or a significant clinical anomaly.

Description and prevalence of ventricular mitral annular disjunction: variation of normality or pathological variant?

Introduction and objectivesThe aim of this study was to investigate a new variation of the atrial wall-mitral annulus-ventricular wall junction along the mural mitral leaflet and commissures: the ventricular mitral annular disjunction (v-MAD). This new variant is characterized by spatial displacement of the mitral leaflet hinge line by more than 2mm toward the left ventricle. MethodsWe examined a cohort of autopsied human hearts (n=224, 21.9% females, 47.9±17.6 years) from patients without known cardiovascular disease to identify the presence of v-MAD. ResultsMore than half (57.1%) of the hearts showed no signs of MAD in the mural mitral leaflet or mitral commissures. However, v-MAD was found in 23.6% of cases, located within 20.1% of mural leaflets, 2.2% in superolateral commissures, and 1.3% in inferoseptal commissures. V-MAD was not uniformly distributed along the mitral annulus circumference, with the most frequent site being the P2 scallop (19.6% of hearts). The v-MAD height was significantly greater in mural leaflets than in commissures (4.4 mm±1.2 mm vs 2.1 mm±0.1 mm; P<.001). No specific variations in mitral valve morphology or anthropometrical features of donors were associated with the presence or distribution of v-MADs. Microscopic examinations revealed the overlap of the thin layer of atrial myocardium over ventricular myocardium in areas of v-MAD. ConclusionsOur study is the first to present a detailed definition and morphometric description of v-MAD. Further studies should focus on the clinical significance of v-MAD to elucidate whether it represents a benign anatomical variant or a significant clinical anomaly.

Remanufacturing waste steel sheet from end-of-life vehicles into electrical installation wall junction boxes: Quantitative sustainability assessment

The growing waste stream from the automotive industry is a mounting environmental burden, but also a potential source of valuable materials. This study evaluates a potential small business based on remanufacturing the metal sheets from end-of-life vehicles (ELVs) by applying inexpensive commercially available technology (such as cutting and welding) to produce wall junction boxes for electrical installations in construction applications. To evaluate this process as a sustainable alternative to recycling or landfilling metal sheets, the technical, economic, and environmental feasibilities of several case studies were analyzed. Single junction boxes can be purchased, manufactured using new steel, or remanufactured using waste sheet steel from ELVs. These boxes are assembled into multi-box modules with 2–5 boxes using backing plates made from new or ELV-derived steel. Twelve production alternatives based on the three main case studies were evaluated, giving profits of 49.4–90.0, 222.5–263.2, and 190.3–231.0 thousand USD/day in the case of purchased boxes/(re)manufactured backing plates, remanufactured boxes/(re)manufactured backing plates, and manufactured boxes/(re)manufactured backing plates, respectively. In a practical case study, remanufacturing of waste sheet steel to produce wall junction boxes for electrical installations was applied on an industrial scale using machinery currently available on the market to prove the technical feasibility of the proposed remanufacturing process. The calculated economic, environmental, and social feasibility values are shown to be sufficiently high for industrial application, with an overall remanufacturing sustainability index of 0.85 (which exceeds literature thresholds). The most appropriate technological alternatives were identified to guide the development of this business.

Morphology of the mural and commissural atrioventricular junction of the mitral valve

ObjectiveThis study investigates mitral annular disjunctions (MAD) in the atrial wall-mitral annulus-ventricular wall junction along the mural mitral leaflet and commissures.MethodsWe examined 224 adult human hearts (21.9% females, 47.9±17.6 years)...

An Experimental Investigation on Dike Stabilization against Floods

A flood protection dike blends seamlessly with natural surroundings. These dikes stand as vital shields, mitigating the catastrophic effects of floods and preserving both communities and ecosystems. Their design not only aids in controlling water flow but also ensures minimal disruption to the local environment and its biodiversity. The present study used a uniform cohesionless sand with d50 = 0.9 mm to investigate the local scour process near a single combined dike (permeable and impermeable), replicating a flooding scenario. The experiments revealed that the maximum scour depth is likely to occur at the upstream edge of the dike, resembling a local scour observed around a scaled-down emerged dike in an open channel. The scour hole downstream of the dike gets shallower as it gets smaller, as do the horseshoe vortices that surround it. Additionally, by combining different pile shapes, the flow surrounding the dike was changed to reduce horseshoe vortices, resulting in scour length and depth reductions of 48% at the nose and 45% and 65% at the upstream and downstream dike–wall junction, respectively. Contrarily, the deposition height downstream of the dike had a reciprocal effect on permeability, which can severely harm the riverbank defense system. The combined dike demonstrates their ability to mitigate scour by reducing the flow swirls formed around the dike. The suggested solutions can slow down the rapid deterioration and shield the dike and other river training infrastructure from scour-caused failures.

Flexural Behavior of Slabs with Different Anchorage Locations of Longitudinal Reinforcing Bars in a Composite Basement Wall Junction

Although the anchorage location of longitudinal reinforcing bars is a significant design element for flexural behavior, the conventional anchorage method of using longitudinal reinforcing bars has limited applications in new types of structures, such as composite structures. Therefore, this study examined the effect of the anchorage location of longitudinal reinforcing bars on the flexural behavior of slabs at the junctions of developed composite basement walls (SCBW) under monotonic loads at the top free end of the slab. The test results showed that the slab with longitudinal reinforcing bars anchored to the cast-in-place pile (CIP) in the composite basement wall exhibited ductile behavior accompanied by the yielding of the longitudinal reinforcing bars, a relatively wide area of vertical cracks propagating along the slab length, and a plastic plateau flow in the load–deflection relationships. In particular, the slab with longitudinal reinforcing bars anchored to the basement wall experienced severe crack concentration localized at the junction of the composite basement walls and concrete spalling in the basement walls, which resulted in no yielding of the longitudinal reinforcing bars and no cracks in the slab. Consequently, in a slab, it is recommended that longitudinal reinforcing bars be anchored into the CIP by penetrating the steel plate.

Activation of AcvR1-Mediated Signaling Results in Semilunar Valve Defects.

Calcific aortic valve disease (CAVD) is a common cardiac defect, particularly in the aging population. While several risk factors, such as bi-leaflet valve structure and old age, have been identified in CAVD pathogenesis, molecular mechanisms resulting in this condition are still under active investigation. Bone morphogenetic protein signaling via the activin type I receptor (AcvRI) plays an important role during physiological and pathological processes involving calcification, e.g., bone formation and heterotopic ossification. In addition, AcvRI is required for normal cardiac valve development, yet its role in aortic valve disease, if any, is currently unknown. Here, we induced the expression of constitutively active AcvRI in developing mouse embryos in the endocardium and in cells at the valve leaflet–wall junction that are not of endocardium origin using the Nfac1Cre transgene. The mutant mice were born alive, but showed thickened aortic and pulmonary valve leaflets during the early postnatal period. Adult mutant mice developed aortic stenosis with high frequency, sclerotic aortic valves, and displayed Alcian Blue-positive hypertrophic chondrocyte-like cells at the leaflet–wall junction. Calcification was only seen with low penetrance. In addition, we observed that the expression levels of gene sets associated with inflammation-related cytokine signaling, smooth muscle cell contraction, and cGMP signaling were altered in the mutants when compared with those of the controls. This work shows that, in a mouse model, such continuous AcvRI activity in the Nfatc1Cre recombination domain results in pathological changes in the aortic valve structure and function.

Disjunção do Anel Mitral: Modalidades Diagnósticas, Implicações Clínicas e Evolução Prognóstica

Mitral annulus disjunction (MAD) is an abnormal insertion of the flexion line of the mitral annulus into the atrial wall. The annulus presents a separation (disjunction) between the posterior leaflet–atrial wall junction and the left ventricular myocardial crest.1 MAD was first described more than 30 years ago in an autopsy study and is reportedly related to mitral valve prolapse (MVP) in 92% of cases.2 Since then, several studies have been conducted, and reports on the prevalence of MAD in patients with MVP have varied. Ultimately, it may or may not be associated with mitral regurgitation. Transthoracic echocardiography is part of initial MVP assessment, allowing its diagnosis and the assessment of related complications. As new diagnostic methods emerged, cardiac magnetic resonance imaging and transesophageal echocardiography improved the assessment of this pathology in terms of its diagnosis, extension, and location. However, the phenotypic characteristics of MVP that are more closely associated with MAD remain uncertain mainly due to the limited number of patients in classic studies on the subject. Patients with MAD may develop symptoms related to ventricular arrhythmias, configuring the MAD arrhythmic syndrome, which may progress to sudden death. The literature presents conflicting prognostic data among several studies on the subject from clear diagnostic criteria and best imaging method to be used to treatment and prognosis. This review describes MAD characteristics associated (or not) with valve prolapse to improve the diagnosis and management of this important pathology.

Primary reconstruction of extensive orbital fractures using two-piece patient-specific implants: the Helsinki protocol

PurposeWe present our experience of titanium-milled two-piece patient-specific implants (PSIs) for primary reconstructions of extensive orbital floor and medial wall fractures (EOFMFs) and evaluate their postoperative functional and aesthetic outcomes in relation to commercially available implants.MethodsWe included all patients with primary reconstructions (< 22 days from injury) of EOFMFs treated in our department between January 2011 and October 2020. Extensive orbital floor and medial wall fracture was defined as involvement of orbital floor, medial wall and maxilloethmoidal junction; a fracture defect 5 mm or more; defect size more than a third of both inferior and medial walls; and Jaquiéry classification III or more. Patient characteristics, details of fracture defects and surgeries, postoperative outcomes and implant positions were retrospectively evaluated and compared between study groups.ResultsNineteen patients were included: 5 with two-piece PSIs and 14 with commercial implants. Implant position was good in 4/5 patients with two-piece PSIs and 2/14 with commercial implants. Revision surgery, globe malposition (GMP) > 2 mm, significant diplopia and poor implant position were more frequent in patients with commercial implants than two-piece PSIs. None of the patients with a good overall implant position had any significant postoperative symptoms.ConclusionExtensive orbital fracture reconstructions are somewhat rare, and surgical treatment is associated with a high rate of complications and postoperative symptoms. Titanium-milled two-piece PSIs are well suited for primary reconstructions of EOFMFs, as they lead to more precise reconstructions and fewer postoperative symptoms than commercially available implants.

The spectrum of sonographic findings in enteric fever cases of paediatrics age group in Gurugram region of Haryana, India

There is always need for the earliest diagnosis of enteric fever to start the appropriate treatment for this life threatening illness. The diagnosis becomes difficult because of inherent limitation due to the long standing vague complaints. Some findings like acalculus cholecystitis, hepato-splenomegaly, enlarged mesenteric lymph nodes (MLN) and free fluid can easily be picked up by ultrasonography (USG). USG is easily available, without any ionizing radiation, non-invasive and economical. Hemoculture and Widal tests are time consuming and the cost is quite high. The study was conducted with 100 paediatric patients aged 1-year to 15-year. All were having enteric fever based on typhi dot-IgM presented to the paediatric department of the hospital. USG was conducted for the evaluation of the various relevant findings. Blood samples for CBC, LFT and blood culture were taken on the same day as that of USG evaluation. USG evaluation of confirmed enteric fever cases revealed that 25% had gall bladder findings, 23% had hepato-splenomegaly, 11% had hepatomegaly, 1% had enlarged mesenteric lymph nodes (MLN) and 3% had thickened caecum wall and ileocaecal junction. USG can diagnose many findings which are related to enteric fever and are helpful in starting the early management. Hemoculture and other investigations may delay the treatment which can lead to various complications.

Tomographic PIV investigation of vortex shedding topology for a cantilevered circular cylinder

The wake of a finite wall-mounted circular cylinder of diameter $D$ and height $H$ is investigated for aspect ratios $3\leq H/D \leq 7$ and boundary layer thickness of $\delta /D \approx 0.98$ using tomographic particle image velocimetry. The Reynolds number based on $D$ is $Re = 750$ . The mean wake topology is related to the evolution of the periodically shed vortices, educed from a low-order representation based on proper orthogonal decomposition of the three-dimensional velocity field. The main topological features are an arch vortex, defining the recirculating base region, and a quadrupole structure consisting of two pairs of opposite-sign vorticity concentrations extending downstream behind the obstacle-free end and wall junction. The quadrupole is the time-averaged signature of shed vortices. Vortex-tilting terms in the base region act to reorient flow-normal vorticity components streamwise, resulting in the reorientation of the ends of vortices initially shed parallel to the cylinder side walls. Through the action of the vortex-stretching terms, the bent ends connect successive vortices in a continuous chain. The influence of $H/D$ on the development of the quadrupole is characterized. The results demonstrate that the quadrupole in the mean field emerges as an imprint of the shed full-loop structures. This work reconciles mean and instantaneous interpretations satisfying the solenoidal condition on the vorticity field.

Numerical Analysis of the Structural Resistance and Stability of Masonry Walls with an AAC Thermal Break Layer

Since energy efficiency has become the main priority in the design of buildings, load-bearing walls in modern masonry constructions nowadays include thermal break elements at the floor–wall junction to mitigate thermal bridges. The structural stability of these bearing walls is consequently affected. In the present paper, a numerical study of the resistance and stability of such composite masonry walls, including AAC thermal break layers, is presented. A finite element mesoscopic model is successfully calibrated with respect to recent experimental results at small and medium scale, in terms of resistance and stiffness under vertical load with or without eccentricity. The model is then used to extend the numerical models to larger-scale masonry walls made of composite masonry, with the aim of investigating the consequences of thermal elements on global resistance and stability. The results confirm that the resistance of composite walls is governed by the masonry layer with the lowest resistance value, except for walls with very large slenderness and loaded eccentrically: composite walls with low slenderness or loaded by a vertical load with limited eccentricities are failing due to the crushing of the AAC layer, while the walls characterized by large slenderness ratios and loaded eccentrically tend to experience buckling failure in the main clay masonry layer.

Morphology of Mitral Annular Disjunction in Mitral Valve Prolapse

Mitral annular disjunction (MAD) is an abnormal insertion of the hinge line of the posterior mitral leaflet on the atrial wall: the mitral annulus shows a separation or "disjunction" between the leaflet-atrial wall junction and the crest of the left ventricle myocardium. This anomaly is often observed in patients with myxomatous mitral valve prolapse. The anatomical substrate of MAD remains unclear for the following reasons: (1) most studies are focused on the association between MAD and arrhythmias, rather than on pathomorphological aspects of MAD; and (2) the complex anatomic architecture of the posterior mitral annulus is often simply described as the posterior segment of a fibrous ring. The aims of this paper are to review the pertinent normal anatomy of the mitral valve and to propose new hypotheses on the morphological nature of MAD.

Topological confinement of vortices in two-flavor dense QCD

We find a novel confinement mechanism in the two-flavor dense quark matter proposed recently, that consists of the 2SC condensates and the P-wave diquark condensates of d-quarks. This quark matter exhibiting color superconductivity as well as superfluidity is classified into two phases; confined and deconfined phases of vortices. We establish that the criterion of the confinement is color neutrality of Aharonov-Bohm (AB) phases: vortices exhibiting color non-singlet AB phases are confined by the so-called AB defects to form color-singlet bound states. In the deconfined phase, the most stable vortices are non-Abelian Alice strings, which are superfluid vortices with fractional circulation and non-Abelian color magnetic fluxes therein, exhibiting color non-singlet AB phases. On the other hand, in the confined phase, these non-Abelian vortices are confined to either a baryonic or mesonic bound state in which constituent vortices are connected by AB defects. The baryonic bound state consists of three non-Abelian Alice strings with different color magnetic fluxes with the total flux canceled out connected by a domain wall junction, while the mesonic bound state consists of two non-Abelian Alice strings with the same color magnetic fluxes connected by a single domain wall. Interestingly, the latter contains a color magnetic flux in its core, but this can exist because of color neutrality of its AB phase.

Experimental Investigation of the Flow Characteristics and Noise Generation at the Wing–Wall Junction

AbstractThis paper is concerned with the flow characteristics and noise generation at the finite wing–wall junction. To characterize junction flow noise, acoustic measurements were taken in the aco...

Cardiac Sarcoidosis Mimicking Anterior Myocardial Infarction.

A 58-year-old asymptomatic man with electrocardiogram (ECG) abnormality was referred to our institution for cardiac exams. His ECG showed a bifascicular block, and the echocardiography demonstrated a wall motion abnormality in apex. Stress-rest myocardial perfusion imaging (MPI) showed a significant defect in anterior wall with partial redistribution at rest. He was suspected of having an anterior myocardial infarction (MI) and underwent cardiac catheterization. However, coronary angiography (CAG) revealed no significant coronary atherosclerosis. Cardiovascular magnetic resonance imaging (CMR) was performed to evaluate the extent of myocardial infarction. Late gadolinium enhancement (LGE) demonstrated a significant epicardial and midmyocardial LGE in the multiple site including anterior, anteroseptal, lateral, inferior wall, and basal right ventricle junction, which strongly indicated that the fibrosis was due to cardiac sarcoidosis (CS).A myocardial perfusion defect in anterior wall shown in the MPI revealed the fibrosis as an atypical finding mimicking anterior MI.

Catheter ablation of short-coupled variant of torsade de pointes

BackgroundThe short-coupled variant of torsade de pointes (sc-TdP) is a malignant arrhythmia that frequently presents with ventricular fibrillation (VF) electrical storm. Verapamil is considered the first-line therapy of sc-TdP while catheter ablation is not widely adopted. The aim of this study was to determine the origin of sc-TdP and to assess the outcome of catheter ablation using 3D-mapping.Methods and resultsWe retrospectively analyzed five patients with sc-TdP who underwent 3D-mapping and ablation of sc-TdP at five different institutions. Four patients initially presented with sudden cardiac arrest, one patient experienced recurrent syncope as the first manifestation. All patients demonstrated a monomorphic premature ventricular contraction (PVC) with late transition left bundle branch block pattern, superior axis, and a coupling interval of less than 300 ms. triggering recurrent TdP and VF. In four patients, the culprit PVC was mapped to the free wall insertion of the moderator band (MB) with a preceding Purkinje potential in two patients. Catheter ablation using 3D-mapping and intracardiac echocardiography eliminated sc-TdP in all patients, with no recurrence at mean 2.7 years (range 6 months to 8 years) of follow-up.Conclusion3D-mapping and intracardiac echocardiography demonstrate that sc-TdP predominantly originates from the MB free wall insertion and its Purkinje network. Catheter ablation of the culprit PVC at the MB free wall junction leads to excellent short- and long-term results and should be considered as first-line therapy in recurrent sc-TdP or electrical storm.Graphic abstract