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Background: Pulmonary vein isolation (PVI) alone is less effective in patients with persistent atrial fibrillation (AF) compared with those with paroxysmal AF. We investigate whether additional linear ablation from the superior vena cava to the right atrial septum and cavotricuspid isthmus ablation improves the rhythm outcome of patients with persistent AF undergoing cryoballoon PVI (Cryo-PVI)., Methods: In this investigator-initiated, multicenter, randomized clinical trial, 289 patients with persistent AF refractory to antiarrhythmic drug therapy were randomized 1:1 to either Cryo-PVI with additional right atrium (RA) linear ablation or Cryo-PVI alone. The primary end point was any documented atrial arrhythmia lasting ≥30 seconds after a 3-month blanking period after ablation. The secondary end points were atrial arrhythmia recurrence or antiarrhythmic drug use after a 3-month blanking period, complications, and total procedure time., Results: During the median follow-up of 24 months (median age, 63 years; 23.9% women), the atrial arrhythmia recurrence was less frequent in the additional RA ablation group (n=50, 37.5%) than in the Cryo-PVI alone group (n=69, 53.1%; absolute difference, -15.6% [95% CI, -27.9% to -3.4%]; hazard ratio, 0.66 [95% CI, 0.46-0.94]). Antiarrhythmic drugs were prescribed after the 3-month period to 72 (49.3%) patients in the additional RA ablation group and 79 (55.2%) patients in the Cryo-PVI alone group. No difference was found in complication rate between the 2 groups. Total procedure time was longer in the additional RA ablation group (median, 88 versus 72 minutes; P <0.001)., Conclusions: Additional RA linear ablation beyond Cryo-PVI improved the ablation outcome compared with that of PVI alone in persistent AF patients., Competing Interests: None.

Background: The effectiveness of cryoballoon ablation (CBA) of the left atrial (LA) roof in addition to pulmonary vein isolation (PVI) using a novel cryoballoon catheter, POLARx, remains unclear., Methods: This study compared the efficacy of LA roof line ablation and PVI using POLARx (Boston Scientific) or AFA-Pro (Medtronic) in 100 patients with persistent atrial fibrillation. The right superior pulmonary vein (PV) anchoring and raise-up techniques were consistently used for LA roof line ablation, and rapid right ventricular pacing was applied if the cryoballoon temperature did not reach -40°C., Results: Complete conduction block at the LA roof could be obtained in all patients with POLARx and in 98.0% of patients with AFA-Pro. Rapid right ventricular pacing was needed in 64.0% of patients with AFA-Pro and in no patients with POLARx. During LA roof line ablation, the nadir cryoballoon temperature was significantly lower with POLARx than with AFA-Pro (right: -54.2°C ± 4.4°C vs. -46.0°C ± 5.4°C; central: -56.8°C ± 4.4°C vs. -45.7°C ± 4.8°C; left: -56.1°C ± 4.3°C vs. -46.1°C ± 5.7°C), and the cryoballoon temperature reached -40°C earlier with POLARx than with AFA-Pro (right: 30.8 ± 7.4 s vs. 74.1 ± 37.7 s; central: 28.2 ± 5.2 s vs. 62.9 ± 30.9 s; left: 29.8 ± 5.8 s vs. 69.6 ± 40.7 s)., Conclusion: The nadir cryoballoon temperature with POLARx was approximately 10°C lower than with AFA-Pro, consistently dropping below -40°C during LA roof line CBA. Thus, a complete conduction block of the LA roof line can be easily accomplished using right superior PV anchoring and the raise-up techniques without the need for rapid right ventricular pacing with POLARx., (© 2024 Wiley Periodicals LLC.)

Surface ablation temperature and linear ablation rate are two crucial indicators for ceramic coatings under ultrahigh temperatures service, yet the results collection of such two indicators in the process is difficult due to the long‐period material preparation and the high‐cost test. In this work, four kinds of machine learning models are applied to predict the above two indicators. The Random Forest (RF) model exhibits a high accuracy of 87% in predicting surface ablation temperature, while a low accuracy of 60% in linear ablation rate. To optimize the model, the novel features are constructed based on the original features by the sum of the importance weights in the model. Thereafter, the importance of the newly constructed features increases significantly, and the accuracy of the optimized RF model is improved by 11%, exceeding 70% in accuracy. By validation with available data and experiments, the optimized model demonstrates precise predictions of the target variables. [ABSTRACT FROM AUTHOR]

C/C–HfC–SiC composites were prepared by reactive melt infiltration using Hf–Si alloy (Hf, more than 95 wt%) with a density of 3.86 g/cm3 and an open porosity of 8.34%. The microstructure, mechanical properties, and ablation behavior at high temperatures were studied in detail. SiC played a crucial role in alleviating the thermal mismatch between HfC and PyC, which formed at the interface between the carbon matrix and the HfC matrix. The flexural strength and modulus of C/C–HfC–SiC composites were 237 MPa and 37.6 GPa, respectively. The C/C–HfC–SiC composites exhibited excellent ablation resistance with a linear ablation rate of 8.9 × 10−3 mm/s and maintained a surface temperature above 2925°C during ablation. During this process, HfO₂ remained in a molten state with high viscosity and served as a thermal barrier, while the volatilization of SiO₂ effectively removed heat, protecting the composites from further ablation. [ABSTRACT FROM AUTHOR]

The mechanical, thermophysical, and ablation properties of 2.5D C/HfC–SiC composites with various SiC/HfC ratios are studied. The S7‐C/HfC–SiC composite with a high SiC/HfC volume ratio of 30.4/15.2 has the highest flexural strength of 203.4 ± 26.8 MPa and fracture toughness of 10.0 ±.5 MPa·m1/2. All C/HfC–SiC composites have a similar low thermal conductivity of ∼2 W·m−1·K−1 and their CTEs are in the range of.45–4.0 × 10−6/K from 30°C to 1400°C. S5‐C/HfC–SiC with medium SiC/HfC ratio possesses the lowest mass ablation rate of.29 ±.02 mg·cm−2·s−1 and linear ablation rate of.003 ±.0002 mm/s. The C/HfC–SiC composites are endowed with a pitting corrosion feature according to the morphology and composition evolution of the ablated surface, which results from both high temperature and stagnation pressure gradients in the radial direction of the oxyacetylene torch. [ABSTRACT FROM AUTHOR]

In this contribution, we propose a new approach to enhance the ablation properties of carbon/carbon (C/C) composites. 2.5D CFMP/C composites were obtained by mesophase pitch-based carbon fiber (CFMP) as the reinforcing carbon fibers, which facilitates the high aerodynamic heat flow near the stagnation to be rapidly guided to the low heat flow region at the rear of the structure. The results show that the surface temperature of 2.5D CFMP/C composites is 100 °C lower than that of 2.5D CFPAN/C composites prepared by traditional PAN-based carbon fiber (CFPAN), and the mass ablation rate and linear ablation rate of 2.5D CFMP/C composites decreased from 3.307 mg/s to 1.412 mg/s and from 3.067 µm/s to 0.501 µm/s, respectively. In addition, the mechanical properties of the 2.5D CFMP/C composites are outstanding, which will lay the foundation for their stability in ablative environments. Our work will bring new blessings for the further development of C/C composites in the aerospace field. [ABSTRACT FROM AUTHOR]

In this contribution, we propose a new approach to enhance the ablation properties of carbon/carbon (C/C) composites. 2.5D CFMP/C composites were obtained by mesophase pitch-based carbon fiber (CFMP) as the reinforcing carbon fibers, which facilitates the high aerodynamic heat flow near the stagnation to be rapidly guided to the low heat flow region at the rear of the structure. The results show that the surface temperature of 2.5D CFMP/C composites is 100 °C lower than that of 2.5D CFPAN/C composites prepared by traditional PAN-based carbon fiber (CFPAN), and the mass ablation rate and linear ablation rate of 2.5D CFMP/C composites decreased from 3.307 mg/s to 1.412 mg/s and from 3.067 µm/s to 0.501 µm/s, respectively. In addition, the mechanical properties of the 2.5D CFMP/C composites are outstanding, which will lay the foundation for their stability in ablative environments. Our work will bring new blessings for the further development of C/C composites in the aerospace field. [ABSTRACT FROM AUTHOR]

Atrial flutter (AFL), defined as macro-re-entrant atrial tachycardia, is associated with debilitating symptoms, stroke, heart failure, and increased mortality. AFL is classified into typical, or cavotricuspid isthmus (CTI)-dependent, and atypical, or non-CTI-dependent. Atypical AFL is a heterogenous group of re-entrant atrial tachycardias that most commonly occur in patients with prior heart surgery or catheter ablation. The ECG pattern is poorly predictive of circuit anatomy but may still provide mechanistic insight. AFL is difficult to manage medically and catheter ablation is the preferred treatment for most patients. Recent progress in technology and clinical electrophysiology has led to detailed characterization of re-entry circuits and effective ablation strategies. Combined activation and entrainment mapping are key to identifying the re-entry circuit. The presence of a slow-conducting isthmus, localized re-entry, dual-loop re-entry or bystander loops may lead to misleading activation maps but can be identified by electrogram examination and entrainment mapping. In the occasional patient without inducible AFL, substrate mapping in sinus rhythm may be a viable strategy. Long-term ablation success requires the creation of a transmural continuous lesion across a critical component of the re-entry circuit. Procedural endpoints include bidirectional conduction block across linear lesions and non-inducibility of atrial tachycardia. The present review discusses the epidemiology, mechanisms, ECG characteristics, electrophysiological characterization, and catheter ablation of atypical AFL., (© 2025 Wiley Periodicals LLC.)

Compared with the traditional C/C composites modified by ultra-high-temperature ceramics (C/C-UHTCs), those modified by metal/medium-entropy ceramics have excellent mechanical properties, thermophysical properties, and long-term ablation resistance. These composites have great potential towards improving the high-temperature resistance and service life of thermal protection systems for spacecraft. In this study, a new type of (Hf 0.5 Zr 0.3 Ti 0.2)C–W–Cu cermet-modified C/C composites (C/C-(Hf 0.5 Zr 0.3 Ti 0.2)C–W–Cu) was prepared at 1500 °C. Compared with C/C-UHTCs, the bending strength and fracture toughness of C/C-(Hf 0.5 Zr 0.3 Ti 0.2)C–W–Cu increased by 70 % and 110 % to 364.25 MPa and 14.64 MPa m1/2, respectively. Due to the high thermal conductivity of Cu and W, the thermal conductivity of this new composite was 106 % higher than that of C/C-(Hf 0.5 Zr 0.3 Ti 0.2)C (44.26 versus 21.53 W/m·K). Under a high heat flow of 4.18 MW/m2, this material exhibited very low mass and linear ablation rates (−0.163 mg/s and −0.193 μm/s, respectively). Active and passive protection occur during ablation due to the evaporative cooling of Cu, CuO, and WO 3 as well as a dense outer oxide layer that inhibits oxygen diffusion. The internal oxide layer forms a Hf-Zr-Ti-C-O framework mingled with Ti-rich Ti-Hf-Zr-C-O and an unoxidised W–Cu structure, effectively reducing the osmotic oxygen content. This work provides a new direction for developing thermal protection materials capable of long-term service in ultra-high-temperature environments. [ABSTRACT FROM AUTHOR]

• Phenolic resin without free phenols (H-BPM) built integrated crosslinking networks. • The cured H-BPM exhibited ultra-high thermal decomposition temperature and char yield. • CF/H-BPM composites shown superior interlaminar shear strength and ablation resistance. • Resin matrix with good processability was obtained for spacecraft thermal protection. Phenolic resins (PRs) are one of the most important matrix resins for advanced aerospace thermal protection composites. However, improving the thermal stability and char yield of PRs while maintaining the good processability always remain a challenge. Herein, a resole-type PR (H-BPM), which contained no free phenol and exhibited good processability was synthesized from p, p' -dihydroxy diphenylmethane. The hydroxymethyl content of H-BPM was tuned to obtain resin networks with varied crosslinking density. The total number of crosslinking bridges, methylene bridges and dimethyl ether bridges were proposed to evaluate the different crosslinking bonding content in cured H-BPM, offering a quantitative description of the crosslinked structure. The cured resin with optimized crosslinked structure exhibited excellent thermal stability with a high thermal decomposition temperature of 376°C and a char yield (800°C, nitrogen) of 66%. Additionally, the carbon fabric composites based on optimized resin possesses high interlaminar shear strength of 37 MPa and superior ablative resistance with a linear ablation rate of 0.0195 mm/s and a mass ablation rate of 0.0460 g/s. This study provides new solutions to develop high char yield PRs matrix for ablative resistant composites without introducing any inorganic compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

Using transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) to investigate the occurrence and related causes of iatrogenic atrial septal defect (iASD) after catheter ablation combined with left atrial appendage closure (LAAC) for atrial fibrillation (AF) and its impact on the right heart system. We retrospectively analyzed 330 patients that underwent combined procedure of catheter ablation for AF and LAAC at General Hospital of Northern Theater Command from January 2018 to March 2022. These patients were divided into iASD group and non-iASD group according to whether there was persistent iASD shown on TEE at 3 months after procedure. There were 96 (29.1%) patients with iASD and 234 patients without in the TEE follow up at 3 months post-operation. Patients with iASD had larger left atrial volumes (76.5 ± 35.2 ml vs. 61.1 ± 21.9 ml, p = 0.036) as well as higher occurrence of mitral regurgitation (MR) (32.3% vs. 12.8%, p = 0.018) and tricuspid regurgitation (TR) (27.1% vs. 7.3%, p = 0.002). Procedural features showed that patients with persistent iASD had longer procedure time (92.1 ± 36.3 vs. 69.1 ± 17.8 min, p = 0.003) and larger sheath sizes (4.1 ± 1.2 mm vs. 3.3 ± 1.2 mm, p = 0.022). The preoperative and postoperative right heart parameters of patients in the persistent iASD group were compared, and there were no significant differences on right atrial/ventricular diameter, right heart systolic/diastolic function and pulmonary artery pressure (P > 0.05). The occurrence of iASD 3 months after combined atrial fibrillation ablation and LAAC was 29.1%. The size of left atrium, the pressure of left atrium, the manipulation time within left atrium, the size of sheath, and the use of ICE during operation was related to the closure of iASD. [ABSTRACT FROM AUTHOR]

Background: The prognosis of acute decompensated heart failure (ADHF) and heart failure (HF) with atrial fibrillation (AF) has been dismal. This study was performed to investigate the clinical outcomes of catheter ablation (CA) performed in patients with concurrent ADHF and AF. Methods: We retrospectively analyzed ADHF patients with AF who were admitted to our institution from 2007 to 2017. Results: In total, 472 patients were included in this study, with a mean follow-up duration of 32.8 ± 32.9 months. The 5-year event-free rate (cardiovascular death and HF hospitalization) was 61.4%, and the 10-year event-free rate was 42.7%. A comparative analysis of the event group and control group revealed that patients in the event group were older (event group vs. control group: 72.1 ± 11.0 vs. 68.8 ± 13.4 years, p = 0.008) and had a higher proportion of Clinical Scenario 3 classifications (event group vs. control group: 24% vs. 12%, p = 0.001). Notably, patients in the event group had a lower sinus rhythm maintenance rate (event group vs. control group: 17% vs. 31%, p < 0.001) and CA rate (event group vs. control group: 9% vs. 21%, p = 0.003). The CA group had a higher event-free rate than the non-CA group, and this trend persisted even after matching the patients' backgrounds (log-rank test: p < 0.001). Conclusions: Patients presenting with AF at the onset of ADHF showed a poor prognosis, whereas CA demonstrated potential for improving the prognosis for some of these patients. [ABSTRACT FROM AUTHOR]

Background: Atrial tachycardias (AT) occurring in patients after previous atrial fibrillation (AF) ablation are increasingly observed in clinical practice. Catheter ablation is the treatment of choice but an optimal workflow to improve patient outcome has not been defined. The purpose of this study was to assess procedural and clinical outcome depending on baseline rhythm at the beginning of AT ablation. Methods: A total of 380 patients (69 (61–75) years, 56.6% male) who underwent catheter ablation for consecutive AT after previous AF ablation were studied. Results: At the beginning of the procedure, 140 patients (36.8%) presented in sinus rhythm (SR), 208 (54.7%) with AT and 32 (8.4%) with AF. Patients in SR or with AT underwent shorter procedures (173 (132–213) minutes vs. 161 (120–203) minutes vs. 226 (154–249) minutes; p = 0.002) with more frequent termination to SR (87.9% vs. 81.3% vs. 56.3%; p < 0.001) than patients with AF. Acute procedural success did not differ between patients in SR or with AT but was higher compared to those with AF (96.4% vs. 97.1% vs. 87.5%; p = 0.033). During a follow-up of 290 (181–680) days, patients in baseline SR experienced arrhythmia recurrences less often (36.4% vs. 49.5% vs. 68.8%; p = 0.002) than patients with AT or AF. Conclusion: Baseline rhythm during AT ablation predicts procedural and clinical outcome. Whereas acute procedural success does not differ between patients in SR or with AT, patients presenting in SR have a more favorable mid-term success rate. [ABSTRACT FROM AUTHOR]

The global incidence of atrial fibrillation is on the rise. Atrial fibrillation, a complex disease, heightens the likelihood of heart failure, stroke, and mortality, necessitating careful attention. Controlling heart rate and rhythm, addressing risk factors, and preventing strokes are fundamental in treating atrial fibrillation. Catheter ablation stands out as the primary approach for atrial fibrillation rhythm control. Nevertheless, the limited success rates pose a significant challenge to catheter ablation, particularly for persistent atrial fibrillation. Various adjunctive ablation techniques are currently under investigation to enhance the effectiveness of catheter ablation. This review provides an overview of the current state of the art and the latest optimized treatments for persistent atrial fibrillation in the areas of rhythm control, heart rate control, and risk factor management. [ABSTRACT FROM AUTHOR]

Purpose of Review: Ventricular arrhythmias in non-ischemic cardiomyopathies can be uniquely challenging to manage with a higher rate of unsuccessful procedures and recurrent arrhythmia. This review focuses on ventricular tachycardia (VT) mapping and the utility of bipolar and unipolar substrate mapping to guide successful ablation. Recent Findings: Bipolar voltage mapping can be used to identify potential channels of healthy tissue surrounded by myocardial scar and provide a target for ablation along isthmuses within scar or border zones. However, bipolar voltage is limited in field of view and unipolar electrograms can provide greater insight into the deeper myocardial tissue in both ischemic and non-ischemic cardiomyopathies. Endocardial unipolar voltage mapping may detect scar beyond the endocardium in regions of normal bipolar voltage, which could be critical for VT circuits. Thus, it may provide a better understanding of intramyocardial or epicardial components of VT circuits. In our experience, we have observed a series of patients with critical components of the VT circuit located in unipolar scar border zones in regions with normal bipolar endocardial voltage, suggesting that unipolar mapping with modern high density mapping catheters may be beneficial in identifying targets for VT ablation in those with mid-myocardial or epicardial scar. Summary: Unipolar voltage mapping with modern high density mapping catheters can identify mid-myocardial or epicardial substrate that might not otherwise be recognized using bipolar endocardial mapping alone. The use of current high density mapping catheters to create unipolar voltage maps and identify critical VT circuits may be beneficial to improve VT ablation outcomes in patients with mid-myocardial or epicardial scar. Trial Registration: Not applicable. [ABSTRACT FROM AUTHOR]

To improve the high-temperature ablation resistance properties of Ta(W) refractory alloys, a novel ultra-high-temperature ceramic (UHTC) composite coating was prepared by combining the technological advantages of high-speed laser cladding (HSLC) and pack cementation (PC). First, the HSLC process was employed to fabricate a (Hf,Ta)C–Ta(W) UHTC–refractory metal composite coating that had metallurgical bonding with the Ta(W) substrate. Then, the PC process was utilized to transform the refractory metal phase in the coating into the corresponding refractory silicide (RMSi2) phase. Consequently, the (Hf,Ta)C–TaSi2 UHTC composite coating was successfully prepared. This new coating was ablated at a heat flux density of 8.0 MW/m2 for 300 s at a surface temperature of 2300 °C, and the structural integrity of the coating was retained. The linear ablation rate of the coating is −0.67 µm/s. The ablated coating exhibits three distinct oxide layers: a loose HfO2 top layer, a dense HfO2 middle layer, and a slightly oxidized (Hf,Ta)CxOy–Hf–Ta–O glassy layer. The synergistic effect of HfO2 and Hf–Ta–O glassy oxide film endows the coating with excellent anti-ablation resistance. This innovative design of the UHTC–RMSi2 composite coating provides robust protection to the Ta(W) substrate from ultra-high temperature ablation and mechanical scouring.

Renal Denervation (RDN) has emerged over the last decade as a third pillar in the treatment of arterial hypertension, alongside pharmacotherapy and lifestyle modifications. Mechanistically, it reduces central sympathetic overactivation, a process also relevant to heart failure. In this mini-review, we summarize the development of RDN for heart failure, discuss the current evidence supporting its effects, and provide an outlook on future developments., Competing Interests: Declarations. Conflict of interest: Dr. Rommel consults for Gradient Denervation Technologies and reports speaker fees from ReCor Medical. Dr. Lurz reports speaker fees and institutional research funds from Medtronic and ReCor Medical. Dr. Fengler received institutional grants as well as institutional consultancy and speaker fees from Medtronic and ReCor Medical., (© 2025. The Author(s).)

Background: Slow activation areas, characterized by decreased conduction velocities in the left atrium, are commonly observed in patients with persistent atrial fibrillation (PeAF). However, it remains unclear whether the ablation of slow activation areas combined with pulmonary vein isolation (PVI) improves clinical outcomes in these patients., Methods: This single-center retrospective study included patients who underwent catheter ablation for PeAF. A total of 78 consecutive patients were included in the PVI + SAA group, while another 78 patients who underwent PVI with/without the roof line, matched 1:1 by propensity score, served as the control group. Slow activation area was defined as ≥ 4 10 ms-step isochrones within 10 mm distance. The endpoint was AF recurrence, atrial flutter, or atrial tachycardia (AT) lasting > 30 s after the blanking period., Results: The mean mapping time was 10 ± 3 min in the PVI + SAA group. Slow activation areas were identified in 37 of the 78 patients, predominantly located in the anterior wall and often overlapping with the low-voltage areas. The proportion of atrial arrhythmia-free patients was significantly higher in the PVI + SAA group compared to the PVI group (Log-rank P = 0.024; hazard ratio [HR]: 0.40; 95% confidence interval [CI]: 0.19-0.85). Subgroup analysis showed no significant difference in AT/AF recurrence rates between patients who underwent additional ablation of slow activation area and those without identified slow activation areas in the PVI + SAA group (Log-rank P = 0.73; HR: 1.20; 95% CI: 0.42-3.42)., Conclusions: Slow activation areas can be efficiently identified using isochronal mapping. Targeted ablation of slow activation areas helps reduce AT/AF recurrence in patients with PeAF., Competing Interests: Declarations. Conflict of interest: The authors declare no conflict of interest., (© 2025. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: An indicator of successful cryoballoon (CB)-assisted pulmonary vein (PV) isolation is complete PV occlusion. However, CBs may exhibit a weaker freezing effect on the equatorial plane. This study investigates the predictors of failed left superior PV (LSPV) isolation despite complete occlusion with novel CBs., Methods: This retrospective analysis enrolled 300 consecutive patients who underwent first-time ablation with POLARx or POLARxFIT between November 2021 and October 2023. Of the total, complete occlusion of the LSPV was achieved in 200 patients. Patients in whom LSPV isolation was achieved with additional nonocclusive freezing of the LSPV roof due to nonisolation of LSPV despite complete occlusion (Group A) were compared with those in whom isolation was achieved with complete PV occlusion alone (Group B)., Results: Group A had a larger LSPV diameter (21.5 ± 4.6 mm vs. 18.8 ± 3.3 mm, p = 0.052), larger left atrial volume on CT (142.3 ± 47.8 cc vs. 117.8 ± 39.0 cc, p = 0.028), higher nadir temperature (-54.1 ± 5.1°C vs. -60.2 ± 4.4°C, p < 0.001), and smaller northern latitude of the balloon contact site on the LSPV roof side (20.9° ± 3.8° vs. 38.9° ± 6.7°, p < 0.001) compared with Group B. A 27.5° north latitude was observed in most of Group A (sensitivity, 100%; specificity, 96%)., Conclusions: Adequate contact positioning of the northern hemisphere to the LSPV is critical for effective isolation, particularly when isolation is challenging despite complete occlusion. In such cases, nonocclusive cryoablation against the LSPV roof might be effective., (© 2025 Wiley Periodicals LLC.)

Background: Ethanol infusion into the vein of Marshall (EI-VOM) is an adjunctive therapy to pulmonary vein isolation (PVI), which improves the efficacy of persistent atrial fibrillation (AF) ablation procedures. It is unknown how EI-VOM scar formation impacts left atrium (LA) structure and function., Objective: To characterize scar formation after EI-VOM, and its impact on LA function, by cardiac magnetic resonance (CMR)., Methods: Consecutive patients referred for persistent AF ablation, or any repeat procedure, were included. Ablation strategy included PVI, EI-VOM and linear lesions when deemed necessary. LA was assessed by late gadolinium enhancement (LGE) CMR at baseline and 3-month follow-up. CMR was post-processed off-line with dedicated software. The LA was regionalized into 17 segments, and global and regional scarring were calculated. Strain parameters were analyzed-including LA reservoir, conduit, and booster strain; LA ejection fraction; and LA passive and active emptying function. Follow-up LGE-CMR reconstruction was coregistered with the voltage map, ablation RF points, and fluoroscopy to compare the scar location with the VOM trajectory., Results: This study included 21 patients (65 ± 8 years; 76% men; 57% ablation of persistent AF). After EI-VOM, 95% of patients presented new low-voltage areas, all of whom exhibited new LGE-CMR scarring at follow-up. Voltage map and LGE-CMR coregistration showed comparable scar areas (p = 0.287). LGE-CMR scarring frequently involved the whole VOM trajectory, predominantly affecting the LA ridge, mitral isthmus, and left posterior wall. LA volume was significantly reduced after ablation, without significant changes in LA functional parameters., Conclusion: EI-VOM causes permanent scarring at 3-month follow-up, with no adverse impact on CMR LA functional parameters., (© 2024 Wiley Periodicals LLC.)

A 58-year-old woman was referred for atrial flutter ablation after atrial fibrillation ablation. Linear and reinforcement mitral isthmus ablation failed to terminate the perimitral flutter. During vein of Marshall ethanol infusion (VOMEI), the flutter was terminated and followed by left atrial appendage (LAA) isolation. Voltage mapping showed that a large low voltage area was created in the superior and anterior wall of left atrium. During the waiting time, the LAA activation recovered. It would be necessary to keep in mind that VOMEI would lead to uncontrolled lesion of left atrium., (© 2024 Wiley Periodicals LLC.)