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A key method to investigate magma dynamics is the analysis of the crystal cargoes carried by erupted magmas. These cargoes may comprise crystals that crystallize in different parts of the magmatic system (throughout the crust) and/or at different times. While an individual eruption likely provides a partial view of the subvolcanic plumbing system, compiling data from multiple eruptions can build a picture of a whole magmatic system. In this study, we use machine learning techniques to analyze a large (>2,000) compilation of mineral compositions from a highly active arc volcano: Villarrica, Chile. Villarrica's postglacial eruptive activity (14 ka–present) displays large variation in eruptive style (mafic ignimbrites to Hawaiian style effusive eruptions), yet its eruptive products have a near constant basalt‐basaltic andesite bulk‐rock composition. What therefore, is driving explosive eruptions at Villarrica and can differences in storage dynamics be related to eruptive style? Here, we use a hierarchical cluster analysis to detect previously unseen structure in the composition of olivine, plagioclase and clinopyroxene crystals erupted at Villarrica, revealing the presence of compositionally distinct clusters within each crystal population. Using rhyolite‐MELTS thermodynamic modeling, we related these clusters to intensive magmatic variables: temperature, pressure, water content, and oxygen fugacity. Our results provide evidence for the existence of multiple discrete (spatial and temporal) magma reservoirs beneath Villarrica where melts differentiate and mix with incoming more primitive magma. The compositional diversity within an erupted crystal cargo strongly correlates with eruptive intensity, and we postulate that mixing between primitive and differentiated magma drives explosive activity at Villarrica. Plain Language Summary Studies of volcanoes often focus on a single eruption. However, the magmatic systems beneath volcanoes are complex: magmas crystallize throughout the crust and the minerals erupted at the surface can be formed just prior to eruption, or thousands of years earlier. Here, we use machine‐learning methods to group mineral compositions from many eruptions of an active Chilean volcano (Villarrica) to build a picture of the magmatic system. By using the appropriate mathematical treatment, we find that there are distinct groups of mineral compositions that were not identified by past studies. These different compositions are used to demonstrate that different batches of magma have mixed throughout Villarrica's postglacial history. This suggests that mixing of different magmas drives explosive eruptions at Villarrica volcano. Key Points Unsupervised machine learning reveals previously undetected compositional clusters in Villarrica's crystal cargoes Thermodynamic models demonstrate magma storage occurs in a vertically extensive system containing variably evolved mushy reservoirs Temporal trends in crystal cargo contents and mineral zoning suggest magma mixing triggers unusual large mafic ignimbrites

Pulsed-field ablation (PFA) has emerged as a promising nonthermal ablation alternative for treating atrial fibrillation (AF). By delivering ultra-rapid high-energy electrical pulses, PFA induces irreversible electroporation, selectively targeting myocardial tissue while sparing adjacent structures from thermal or other damage. This article provides a comprehensive review of multiple pre-clinical studies, clinical studies, and clinical trials evaluating the safety, efficacy, and long-term outcomes of PFA in various settings and patient populations. Overall, the reviewed evidence highlights PFA’s potential as a revolutionary ablation strategy for AF treatment. Offering comparable procedural efficacy to conventional ablation methods, PFA distinguishes itself with shorter procedure times and reduced risks of complications such as phrenic nerve palsy and potential esophageal injury. While further research is warranted to establish long-term efficacy, PFA’s distinct advantages and evolving clinical evidence suggest a promising future for this novel nonthermal ablation approach. As PFA continues to advance, it has the potential to transform AF ablation procedures, providing a safer alternative for patients with atrial fibrillation.

Atrial fibrillation (AF) is a prevalent arrhythmia, while pulmonary vein isolation (PVI) has become a cornerstone in its treatment. The creation of durable lesions is crucial for successful and long-lasting PVI, as inconsistent lesions lead to reconnections and recurrence after ablation. Various approaches have been developed to assess lesion quality and transmurality in vivo, acting as surrogates for improved lesion creation and long-term outcomes utilizing radiofrequency (RF) energy. This review manuscript examines the biophysics of lesion creation and different lesion assessment techniques that can be used daily in the electrophysiology laboratory when utilizing RF energy. These methods provide valuable insights into lesion effectiveness, facilitating optimized ablation procedures and reducing atrial arrhythmia recurrences. However, each approach has its limitations, and a combination of techniques is recommended for comprehensive lesion assessment during AF catheter ablation. Future advancements in imaging techniques, such as magnetic Resonance Imaging (MRI), optical coherence tomography, and photoacoustic imaging, hold promise in further enhancing lesion evaluation and guiding treatment strategies.

Alkaline mafic magmas forming intra-plate oceanic islands are believed to be strongly enriched in CO 2 due to low-degree partial melting of enriched mantle sources. However, until now, such CO 2 enhancement has not been verified by measuring CO 2 degassing during a subaerial eruption. Here, we provide evidence of highly CO 2 -rich gas emissions during the 86-day 2021 Tajogaite eruption of Cumbre Vieja volcano on La Palma Island, in the Canary archipelago. Our results reveal sustained high plume CO 2 /SO 2 ratios, which, when combined with SO 2 fluxes, melt inclusion volatile contents and magma production rates at explosive and effusive vents, imply a magmatic CO 2 content of 4.5 ± 1.5 wt%. The amount of CO 2 released during the 2021 eruptive activity was 28 ± 14 Mt CO 2 . Extrapolating to the volume of alkaline mafic magmas forming La Palma alone (estimated as 4000 km 3 erupted over 11 Ma), we infer a maximum CO 2 emission into the ocean and atmosphere of 10 16 moles of CO 2 , equivalent to 20% of the eruptive CO 2 emissions from a large igneous province eruption, suggesting that the formation of the Canary volcanic archipelago produced a CO 2 emission of similar magnitude as a large igneous province.

Long-lasting eruptions of some subduction zone volcanoes may be regulated by their magma sources in the mantle. This suggests that direct connections between the mantle and surface are possible through a relatively thick crust.

Cardiac resynchronisation therapy (CRT) reduces the risk of heart failure-related hospitalisations and all-cause mortality, as well as improving quality of life and functional status in patients with persistent heart failure symptoms despite optimal medical treatment and left bundle branch block. CRT has traditionally been delivered by implanting a lead through the coronary sinus to capture the left ventricular epicardium; however, this approach is associated with significant drawbacks, including a high rate of procedural failure, phrenic nerve stimulation, high pacing thresholds and lead dislodgement. Moreover, a significant proportion of patients fail to derive any significant benefit. Left bundle branch area pacing (LBBAP) has recently emerged as a suitable alternative to traditional CRT. By stimulating the cardiac conduction system physiologically, LBBAP can result in a more homogeneous left ventricular contraction and relaxation, thus having the potential to improve outcomes compared with conventional CRT strategies. In this article, the evidence supporting the use of LBBAP in patients with heart failure is reviewed.

Left atrial appendage occlusion (LAAO) is a suitable alternative to oral anticoagulant therapy to prevent stroke in patients with AF. Most procedures are performed under transoesophageal echocardiography (TOE) guidance, which facilitates transseptal puncture, reduces the risk of procedure-related complications and provides an additional method for device selection and real-time monitoring during device deployment. However, TOE has significant shortcomings, including the need for general anaesthesia/deep sedation as well as a significant risk of procedure-related adverse events. More recently, intracardiac echocardiography has been proposed as an alternative to TOE guidance during LAAO procedures. In this review, we summarise the available evidence as well as providing a step-by-step approach for intracardiac echocardiography-guided LAAO.

Cardiac implantable electronic device (CIED) infections represent one of the most threatening complications associated with device implantation, due to an increase in morbidity and mortality rates, as well as healthcare costs. Besides, it is important to highlight that when compared to the initial implantation of a device, the risks associated with procedures like generator changes, lead and pocket revisions, or device upgrades double. Consequently, to address this issue, various scoring systems, like the PADIT (Prior Procedures, Age, Depressed Renal Function, Immunocompromised Status, Type of Procedure), the RI-AIAC (Ricerca Sulle Infezioni Associate a ImpiAnto o Sostituzione di CIED), and the Shariff score, along with predictive models, have been developed to identify patients at a greater risk of infection. Moreover, several interventions have been assessed to evaluate their role in infection prevention ranging from improving skin preparation and surgical techniques to considering alternative strategies such as the subcutaneous Implantable Cardioverter-Defibrillator (ICD). Methods like antimicrobial prophylaxis, pocket irrigation, chlorhexidine gluconate pocket lavage, capsulectomy, and the use of antibacterial envelopes have been also explored as preventive measures. In this review, we provide a comprehensive assessment of CIED infections in patients undergoing repeat procedures and the strategies designed to reduce the risk of these infections.

Catheter ablation has become a cornerstone in atrial fibrillation (AF) therapy, improving freedom from all-atrial arrhythmias, as well as outperforming antiarrhythmic drugs in alleviating AF-related symptoms, reducing hospitalizations, and enhancing quality of life. Nevertheless, the success rate of traditional radiofrequency ablation (RFA) methods remains less than ideal. To address these issues, refinement in RFA strategies has been developed to improve efficacy and laboratory efficiency during pulmonary vein isolation (PVI). High-power short-duration (HPSD) RFA has emerged as a safe strategy to reduce the time required to produce durable lesions. This article reviews critical aspects of HPSD ablation in the management of both paroxysmal and persistent AF, covering aspects such as effectiveness, safety, procedural intricacies, and the underlying biophysics.

Beyond the catastrophic environmental effects of large (>1 km 3 ) volcanic landslides, their impact on underlying magmatic systems remains unclear. Chemical variations in post-collapse volcanic products, alongside dramatic eruptive behaviour transitions reported from several volcanoes, imply that surface unloading directly influences subsurface magmatic processes. By combining petrologic data with magma ascent models, we track the post-collapse (<7 ka) magmatic system evolution of Antuco volcano (Chile). During the pre-collapse period, low-explosivity eruptions were sourced from a hotter and deeper storage region. However, the landslide-induced unloading and decompression reactivated a pre-existing, shallower, silicic magma reservoir, favouring more explosive activity. The pre-collapse conditions were restored after edifice regeneration over a few thousand years. Since shallow magma reservoirs are common beneath volcanoes (e.g. in Etna, Villarrica, or Fuji), similar responses could follow future lateral collapses. These findings are relevant when assessing volcanic hazards at gravitationally unstable or collapsed volcanoes on a hundred- to thousand-year timescale.