Thunderstorm Research Articles

Efficacy of early use of Percutaneous Stellate Ganglion Block for electrical storms.

Electrical Storm (ES) is a life-threatening condition requiring a rapid management. Percutaneous Stellate Ganglion Block (PSGB) proved to be safe and effective on top of standard therapy, but no data are available about its early use. We considered all patients enrolled from 1st July 2017 to 30th April 2024 in the STAR registry (STellate ganglion block for Arrhythmic stoRm), a multicentre, international, observational, prospective registry. We aimed to assess the effectiveness of the first PSGB only. Patients were divided into two groups depending on whether they received PSGB before (Early-PSGB, often due to AAD contraindication) or after (Delayed-PSGB) intravenous antiarrhythmic drugs (AADs other than beta-blockers). We considered 180 PSGB (26 Early-PSGB and 154 AAD-first). In the early-PSGB group we observed a statistically significant reduction of treated arrhythmic events in the hour after PSGB compared to the hour before: 0 (0-0) vs 4.5 (1-10), p<0.001 and the extent of the reduction was similar in the Early-PSGB and delayed-PSGB group [-4.5 (-7 to -2) vs. -2.5 (-3.5 to -1.5), p=ns]. The percentage of patients free from arrhythmias was similar in the two groups up to 12 hours after PSGB (81%vs 84%, p=0.6 after one hour; 77% vs 79%, p=0.8 at three hours and 65% vs 69%, p= 0.7 after 12 hours). PSGB proved to be effective also when used early in the treatment of ES. Due to its rapidity of action, our results may suggest its early use to reduce the number of defibrillations and possibly to reduce the likelihood of a refractory ES.

Optimizing Numerical Weather Prediction Utility of the Maryland Mesonet with Observing System Simulation Experiments

Abstract The Maryland Mesonet Project will construct a network of 75 surface observing stations with aims that include mitigating the statewide impact of severe convective storms and improving analyses of record. The spatial configuration of mesonet stations is expected to affect the utility newly provided observations will have via data assimilation, making it desirable to study the effects of mesonet configuration. Furthermore, the impact associated with any observing system configuration is constrained by errors inherent to the prediction systems used to generate forecasts, which may change with future advances in data assimilation methodology, physical parameterization schemes, and resource availability. To address such possibilities, we perform sets of observing system simulation experiments using a high-resolution regional modeling system to assess the expected impact of four candidate mesonet configurations. Experiments cover seven 18-hour case-study events featuring moist convective regimes associated with severe weather over the state of Maryland and are performed using two versions of our experimental modeling system: a ’standard-uncertainty’ configuration tuned to be representative of existing convective-allowing prediction systems, and a ’constrained-uncertainty’ configuration with reduced boundary condition and model error that reflects a possible trajectory for future prediction systems. We find that the assimilation of mesonet data produces definitive improvements to analysis fields below 1000 m that are mediated by modeling system uncertainty. Conversely, mesonet impact on forecast verification is inconclusive and strongly variable across verification metrics. The impact of mesonet configuration appears limited by a saturation effect that caps local analysis improvements past a minimal density of observing stations.

Catheter ablation vs advanced therapy for patients with severe heart failure and ventricular electrical storm

BackgroundCurrent data on outcomes of an initial strategy of catheter ablation vs advanced therapy in patients with severe heart failure (HF) and electric storm (ES) are limited. ObjectiveThe purpose of this study was to evaluate the outcomes of ventricular tachycardia (VT) ablation vs left ventricular assist device (LVAD) or heart transplantation (HT) in patients with severe HF and ventricular ES. MethodsPatients with severe HF and ES who underwent VT ablation, LVAD, or HT between 2012 and 2022 at our medical center were reviewed. Severe HF was defined as ejection fraction ≤ 35% or presence of severe restrictive, valvular, or genetic cardiomyopathy. We assessed in-hospital adverse events and 1-year outcomes between the 2 groups. ResultsOf the 73 patients, 43 underwent VT ablation and 30 received advanced therapy (21 HT and 9 LVAD). One-year survival was similar (76.7% vs 86.7%; log-rank, P = .308). However, 10 patients (23.3%) in the ablation group underwent HT during follow-up. After multivariable analysis, United Network for Organ Sharing status 1 or 2 by VT criteria (hazard ratio 5.52; 95% confidence interval 1.27–24.12; P = .023) and early VT recurrence (hazard ratio 5.67; 95% confidence interval 1.68–19.09; P = .005) were associated with HT or mortality in patients who underwent VT ablation. ConclusionPatients with severe HF and ES who underwent VT ablation had similar overall survival to patients who directly proceeded with advanced therapy, although rates of HT were high during follow-up. Predictors of HT or mortality after catheter ablation include United Network for Organ Sharing status 1 or 2 by VT criteria and early VT recurrence.

Automatic Identification of Three-Body Scatter Spike Based on Jensen–Shannon Divergence and Support Vector Machine

Abstract The three-body scatter spike (TBSS), an echo artifact in radar imagery, manifests as a weak, linear echo extending radially from a core of high reflectivity. Adequately, though not indispensably, indicating the presence of large hail in convective storms, the automatic identification of the TBSS proves advantageous in significantly improving the effectiveness of hailstorm detection. This study introduces an algorithm that synergizes Jensen–Shannon divergence (JSD) and support vector machine (SVM) for rapid TBSS detection in two decades’ worth of single-polarization radar data across China. The algorithm, tested on data from 50 S-band China Next Generation Weather Radar (CINRAD) in central and eastern China, utilized reflectivity factor images for sample extraction. An application in Chenzhou, China, demonstrates the algorithm’s efficacy in improving hailstorm detection resolution. Significance Statement In recent years, China’s hail recordkeeping, primarily based on manual observations at national surface meteorological stations, has suffered from limited spatial and temporal detail. However, the advent of the China Next Generation Weather Radar (CINRAD) network offers a new avenue for hailstorm detection. TBSS, a secondary but significant indicator for large hail in S-band radar, presents an opportunity for enhanced hail warning capabilities. By automating TBSS detection in radar archives spanning two decades, this research significantly enhances the resolution of hailstorm climatology, contributing to more effective hail disaster mitigation and management.

Analysis of infrasound array data from tornadic storms in the southeastern United States

Data recorded by several infrasound sensor arrays deployed in the southeastern United States during the spring of 2018 have been analyzed during a period when a storm front passed through and spawned several tornado touchdowns. The tornadoes ranged from EF-0 to EF-2. Accurate bearings have been obtained, corresponding to tornadoes at ranges up to more than 100 km. Earlier in the day, a convective storm cell passed and triggered a tornado warning but no verified tornado touchdowns. During this earlier passage, a weaker signal was detected with bearings that tracked this convective storm cell. The analyses reveal that on the systems deployed, the dominant band of coherent infrasound measured from the tornadic storms was between 2 and 6 Hz. Atmospheric conditions are known to have a significant influence on signal detection because of propagation effects and local wind noise conditions. Propagation modeling and wind noise analysis were undertaken and are observed to be consistent with signal detection from the tornadoes. Because of the static sources, as well as the multiple strong cells that were in the region simultaneously, it was necessary to use array signal processing methods that are capable of resolving multiple sources.

What happens to patients awaiting urgent transplantation for refractory electrical storm when they are not transplanted?

What happens to patients awaiting urgent transplantation for refractory electrical storm when they are not transplanted?

AN ANALYSIS OF WIND SPEED VARIATIONS INSIDE AND OUTSIDE OF THE ATMOSPHERIC BOUNDARY LAYER DURING CONVECTIVE STORMS USING SODAR AND RADIOSONDE DATA

This paper analyzes the mean wind speed variations inside the atmospheric boundary layer and in the free troposphere based on data from vertical sounding of the atmosphere using SODAR and radiosonde data. The variation of the mean wind speed inside and outside of the atmospheric boundary layer were analyzed using data collected during warnings of convective storms, but also 12 hours before and after the alerts. The resulting data are important in understanding the way the wind behaves in the atmospheric boundary layer and the free troposphere before, during and after convective events.

Stellate ganglion block & ventricular arrhythmias.

An electrical or ventricular storm is a life-threatening condition that must be treated as soon as possible. Here we have successfully saved a 32-year-old male patient with ventricular storm by going beyond the conventional treatment of ACLS. The ultrasound-guided stellate ganglion block terminates sympathetic over discharge thus terminates electrical storm. The emergency physicians need to be aware of the right timing, indication & ultrasound-guided nerve block technique as it is time a sensitive & final rescue technique to save the patient. Lack of expertise can lead to treatment failure or delay which can lead to poor resuscitation outcomes.

Characteristics and Outcome of Patients with or without Previous Implantable Cardioverter Defibrillator Interventions Undergoing Ablation for Ventricular Tachycardia.

Background: Catheter ablation (CA) is a well-established treatment in patients with ventricular tachycardia and appropriate implantable cardioverter defibrillator (ICD) therapies. Methods: We enrolled 57 consecutive carriers of ICD undergoing CA for electrical storm (ES). Our aim was to investigate differences in clinical, device-related, and electroanatomic features among patients who had history of appropriate ICD interventions before the ES compared to those who had not. The primary endpoint was a composite of death from any cause and recurrences of sustained VT, ventricular fibrillation, appropriate ICD therapy, or ES. Results: During a median follow up of 39 months, 28 patients (49%) met the primary endpoint. Those with previous ICD interventions had a higher prevalence of late potentials and a greater unipolar low-voltage area at electroanatomic mapping. Patients who met the primary endpoint had a higher prevalence of ATP/shock episodes preceding the ES event. At Cox regression analysis, non-ischemic dilated cardiomyopathy (NIDCM), QRS duration, and previous ATP and/or shock before the ES were associated with arrhythmic recurrences and/or death. At multivariate analysis, NIDCM and previous shock were associated with arrhythmic recurrences and/or death. Conclusions: A history of recurrent ICD therapies predicts worse outcomes when CA is needed because of ES. Although more studies are needed to definitively address this question, our data speak in support of an early referral for CA of ES.

How Electrical Storms Recur Over Time in Patients With Implantable Cardioverter Defibrillators - Subanalysis of the Nippon Storm Study.

Electrical storms (E-storms), defined as multiple fatal ventricular arrhythmias over a short period, negatively affect the prognosis of patients receiving an implantable cardioverter defibrillator or cardiac resynchronization therapy with a defibrillator (ICD/CRT-D). However, the prognostic impact of recurrent E-storms has not been well elucidated. We analyzed the association between E-storm recurrences and mortality using data from 1,274 participants in the Nippon Storm Study, a prospective observational study conducted at 48 ICD/CRT-D centers in Japan. Differences in E-storm recurrences by patient characteristics were evaluated using the mean cumulative function (MCF), which is the cumulative number of E-storm episodes per patient as a function of time. Patients with multiple E-storms had a 3.39-fold higher mortality risk than those without E-storms (95% confidence interval 1.82-6.28; P<0.01). However, there was no significant difference in mortality risk between patients with a single E-storm and those without E-storms. The MCF curve exhibited a slower ascent in patients who received primary prevention ICD/CRT-D than in those who received secondary prevention ICD/CRT-D. However, when analyzing only patients with E-storms, the MCF curves demonstrated comparable trajectories in both groups. E-storm recurrences may have a negative impact on prognosis. Once patients with primary prevention experience an E-storm episode, they face a similar risk of subsequent recurrent E-storms as patients with secondary prevention.

Increasing frequency and precipitation intensity of convective storms in the Peruvian Central Andes: Projections from convection‐permitting regional climate simulations

Increasing frequency and precipitation intensity of convective storms in the Peruvian Central Andes: Projections from convection‐permitting regional climate simulations

Green Flashes Observed in Optical and Infrared during an Extreme Electric Storm

Green Flashes Observed in Optical and Infrared during an Extreme Electric Storm

Impella-assisted ventricular tachycardia ablation in a patient with dilated cardiomyopathy and electrical storm.

Impella-assisted ventricular tachycardia ablation in a patient with dilated cardiomyopathy and electrical storm.

Sensitivity of Coastal Squall-Line Evolution to Numerical Sea-Breeze Initialization Method

Abstract This study employs 3D idealized numerical experiments to investigate the physical processes associated with coastal convection initiation (CI) as an offshore-moving squall line traverses a mountainous coastal region. A squall line can propagate discretely as convection initiates over the lee slope downstream of the primary storm as the cold pool collides with a sea breeze. Intensity of the initiating convection, thus the downstream squall line, is sensitive to the sea-breeze numerical initialization method, since it influences sea-breeze and cold pool characteristics, instability and vertical wind shear in the sea-breeze environment, and ultimately the vertical acceleration of air parcels during CI. Here, sea breezes are generated through four commonly used numerical methods: a cold-block marine atmospheric boundary layer (MABL), a prescribed surface sensible heat flux function, a prescribed surface sensible plus latent heat flux functions, and radiation plus surface-layer parameterization schemes. For MABL-initialized sea breezes, shallow weak sea-breeze flow in a relatively low instability environment results in weak CI. For the remainder, deeper stronger sea-breeze flow in an environment of enhanced instability supports more robust CI. In a subset of experiments, however, the vertical trajectory of air parcels is suppressed leading to weaker convection. Downward acceleration forms due to the horizontal rotation of the sea-breeze flow. Accurate simulations of coastal convective storms rely on an accurate representation of sea breezes. For idealized experiments such as the present simulations, a combination of initialization methods likely produces a more realistic representation of sea breeze and the associated physical processes.

Development of Multiscale EnKF within GSI and Its Applications to Multiple Convective Storm Cases with Radar Reflectivity Data Assimilation Using the FV3 Limited-Area Model

Abstract To improve the representation of all relevant scales in initial conditions for large-domain convection-allowing models, a new multiscale ensemble Kalman filter (MEnKF) algorithm is developed and implemented within the Gridpoint Statistical Interpolation analysis system (GSI) data assimilation framework coupled with the Finite-Volume Cubed-Sphere Dynamical Core (FV3) limited-area model. The algorithm utilizes ensemble background error covariances filtered to match the observations assimilated. This is realized in a sequential manner. 1) When assimilating coarse-resolution observations such as radiosondes, ensemble background perturbations are filtered to remove scales smaller than those the observations can represent, along with relatively large horizontal localization radii to ensure low-noise and balanced analysis increments. 2) The resulting ensemble analyses from the first step then serve as the background to assimilate denser observations such as radar data with smaller localization radii. Several passes can be taken to assimilate all observations. In this paper, vertically increasing horizontal filter scales are used when assimilating rawinsonde and surface observations together, while radar data are assimilated in the second step. The algorithm is evaluated through six convective storm cases during May 2021, with cycled assimilation of either conventional data only or with additional radar reflectivity followed by 24-h ensemble forecasts. Overall, positive impacts of the MEnKF on forecasts are obtained regardless of reflectivity data; its advantage over the single-scale EnKF is most significant in surface humidity and temperature forecasts up to at least 12 h. More accurate hourly precipitation forecasts with MEnKF can last up to 24 h for light rain. Furthermore, MEnKF forecasts higher ensemble probabilities for the observed hazardous events.

Seismic signature of an extreme hydro-meteorological event in Italy

Flash floods are a major threat for Mediterranean countries and their frequency is expected to increase in the next years due to the climatic change. Civil protection agencies are called to deal with increasing hydrological risk, but existing hydro-meteorological monitoring networks might not be enough for detecting, tracking, and characterizing rapidly evolving floods produced by severe convective storms. Nowadays, hydro-meteorological information in several watersheds particularly in small and mid-size in orographically complex regions or in third-world countries, is still not available or insufficient. To improve our observational capability of these events, we propose to exploit the seismic recordings, which act as opportunistic signals and can complement well-established procedures to early detect the occurrence of flash floods at regional scale. Here, we investigate the hydro-meteorological event that hit central Italy in September 2022 and resulted in a devastating flash flood. We compare seismic data from a national monitoring network with raingauges and hydrometer data. Our evidence suggests that the main stages of the hydro-meteorological events can be tracked by the spatio-temporal evolution of the seismic noise confirming the capability of this multi-sensor approach in detecting and characterizing such kind of events.

Spatial and temporal characteristics of warm season convective storms over the southeastern coast of China

Utilizing observational data from the Xiamen radar station during the warm season of 2015–2018 (May to September), this study employs a convective storm identification algorithm to statistically analyze the spatiotemporal distribution, diurnal propagation, and seasonal variability of convective storms over the southeastern coast of China. Key findings include: (1) Significant monthly variations in convective storm frequency, with peaks in August over land areas of Zhangzhou and Xiamen's northwest, and offshore southeast of Xiamen. Seasonal circulation patterns, particularly the subtropical high and northern high-level troughs, drive these variations. (2) Large-scale convective storms are most frequent, while small-scale ones are less common. Mid-deep convective storms dominate, particularly in southern Zhangzhou and southwestern mountainous Quanzhou, whereas shallow convective storms are rare and scattered. High-frequency areas correlate with higher terrain, underscoring the influence of topography on storm occurrence and development. (3) Hovmöller plots reveal a bimodal diurnal pattern in propagation of storms for July and August, with peaks in the daytime and late night. Daytime storms propagate from coastal to higher terrain areas, while nighttime storms maybe driven by enhanced vertical wind shear. These findings enhance the understanding of convective storms in the region and highlight the crucial role of the circulation background, terrain, and prevailing wind directions in the spatiotemporal characteristics of warm season convective storms in southeastern China.

Management of Ventricular Arrhythmias in Heart Failure: Can Less Be More?

Ventricular arrhythmias (VAs) affect many patients with heart failure and underlying structural heart disease and are associated with significant morbidity and mortality. Antiarrhythmic drugs are often the initial treatment, but medication alone often fails to sufficiently suppress VAs. While catheter ablation (CA) remains the gold standard for treatment of VAs, CA is an invasive procedure and can be associated with periprocedural complications including acute clinical decompensation. Thus, there is an important need for alternative therapies. Recent advances in risk stratification and the development of new ablation technologies may reduce some of the periprocedural complications and limitations of CA. In addition, less invasive therapies for VAs may provide an alternative treatment strategy for patients in both the acute and chronic setting. For patients acutely admitted with ventricular tachycardia electrical storm (VT-ES) or recurrent VT and cardiogenic shock, risk stratification tools have been developed to identify patients at high risk of acute hemodynamic decompensation during CA. These patients require a multidisciplinary approach and might need mechanical circulatory support (MCS) if CA is selected as the treatment strategy. Alternatively, less invasive therapies targeting the autonomic nervous system may be reasonable. In the chronic setting, developments in medical therapy have reduced the risk of sudden cardiac death in heart failure patients and stereotactic whole-body radiation (SBRT) has evolved as a potential, non-invasive therapy. Further research is needed to personalize VA therapy for individual patients.

Beta-Blockers as an Immunologic and Autonomic Manipulator in Critically Ill Patients: A Review of the Recent Literature.

The autonomic nervous system plays a key role in maintaining body hemostasis through both the sympathetic and parasympathetic nervous systems. Sympathetic overstimulation as a reflex to multiple pathologies, such as septic shock, brain injury, cardiogenic shock, and cardiac arrest, could be harmful and lead to autonomic and immunologic dysfunction. The continuous stimulation of the beta receptors on immune cells has an inhibitory effect on these cells and may lead to immunologic dysfunction through enhancing the production of anti-inflammatory cytokines, such as interleukin-10 (IL-10), and inhibiting the production of pro-inflammatory factors, such as interleukin-1B IL-1B and tissue necrotizing factor-alpha (TNF-alpha). Sympathetic overstimulation-induced autonomic dysfunction may also happen due to adrenergic receptor insensitivity or downregulation. Administering anti-adrenergic medication, such as beta-blockers, is a promising treatment to compensate against the undesired effects of adrenergic surge. Despite many misconceptions about beta-blockers, beta-blockers have shown a promising effect in decreasing mortality in patients with critical illness. In this review, we summarize the recently published articles that have discussed using beta-blockers as a promising treatment to decrease mortality in critically ill patients, such as patients with septic shock, traumatic brain injury, cardiogenic shock, acute decompensated heart failure, and electrical storm. We also discuss the potential pathophysiology of beta-blockers in various types of critical illness. More clinical trials are encouraged to evaluate the safety and effectiveness of beta-blockers in improving mortality among critically ill patients.

Exploring suitability to electrical storm ablation in patients in waiting list for heart transplantation: A single center experience.

Electrical storm (ES) is among the most fearsome events in patients in waiting list for heart transplantation (HT) and catheter ablation (CA) demonstrated to be effective in reduce the arrhythmic burden. However, selection criteria for CA suitability in this specific population have never been addressed before. We retrospectively enrolled 36 patients (mean age 51±8 years; 83% men) waiting HT referred to our department for ES resistant to antiarrhythmic drugs and percutaneous stellate ganglion blockade. Twenty patients were judged suitable for VT ablation according to specific criteria including absence of increased arrhythmic burden secondary to volume overload and hemodynamic decompensation; expected CA outcome favorable due to etiology of the cardiomyopathy, no need for coronary revascularization and technical feasibility of the procedure. The pre-emptive use of mechanical circulatory supports (MCS) were discussed integrating the PAINESD score with additional clinical and hemodynamic parameters. Acute procedural success was accounted in 85% of cases with only two major complications. The CA group reported lower length of in-hospital stay after CA suitability evaluation (56±17vs. 131±64 days, p=.004). Furthermore, at a mean follow-up of 703±145 days, this group showed reduction of ventricular arrhythmia (VA) recurrence leading to implantable cardioverter defibrillator shock (4vs. 8, p=.051) and underwent HT with a lower level of urgency (0vs. 6 patients needed for UNOS1 status upgrade). Respectively, one patient of the CA group and two patients of the conservative group died (p=.839). At the end of follow-up, eight patients underwent heart transplantation (p=.964) while four patients underwent Left Ventricular Assist device (LVAD) implantation (p=.440). This pilot study should be a proof for further studies exploring CA of VAs as a possible bridge therapy to HT.