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Background: The initial rhythm is a known predictor of survival in extracorporeal cardiopulmonary resuscitation (ECPR) patients. However, the effect of the rhythm at hospital admission on outcomes in these patients is less clear., Methods: This observational, single-center study assessed the influence of the rhythm at hospital admission on 30-day survival and neurological outcomes at discharge in patients who underwent ECPR for out-of-hospital cardiac arrest (OHCA)., Results: Between January 2012 and December 2023, 1,219 OHCA patients were admitted, and 210 received ECPR. Of these, 196 patients were analyzed. The average age was 52.9 years (±13), with 80.6 % male. The median time to ECPR initiation was 61 min (IQR 54-72). Patients with ventricular fibrillation as both the initial and admission rhythm had the highest 30-day survival rate (52 %: 35/67), while those with asystole in both instances had the lowest (6 %: 1/17, log-rank p < 0.00001). After adjusting for age, sex, initial rhythm, resuscitation time, location, bystander, and witnessed status, asystole at admission was linked to higher 30-day mortality (OR 4.03, 95 % CI 1.49-12.38, p = 0.009) and worse neurological outcomes (Cerebral Performance Category 3-5) at discharge (OR 4.61, 95 % CI 1.49-17.62, p = 0.013)., Conclusions: The rhythm at hospital admission affects ECPR outcomes. Patients presenting with and maintaining ventricular fibrillation have a higher chance of favorable neurological survival, whereas those presenting with or converting to asystole have poor outcomes. The rhythm at hospital admission appears to be a valuable criterion for deciding on ECPR initiation., Competing Interests: Declaration of competing interest The corresponding author (JB) has received lecture honoraria from the Abiomed, Getinge, Xenios, Resuscitec, Novartis, Astra-Zeneca, Boegringer-Ingelheim.The remaining authors report no conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

Aim: The aim of this study was to summarize the existing evidence about the effectiveness of double defibrillation (DD) in comparison to standard defibrillation for patients with refractory ventricular fibrillation (RVF). DD encompasses double "sequential" external defibrillation (DSeq-D) and double "simultaneous" defibrillation (DSim-D), with the study also shedding light on the respective effects of DSeq-D and DSim-D., Methods: Investigators systematically searched PubMed, EMBASE and Cochrane Central databases for randomized controlled trials (RCTs) and cohort studies from their inception until June 06, 2024. The rate of survival to hospital discharge was the primary outcome, while the incidence of return of spontaneous circulation (ROSC), termination of ventricular fibrillation (VF), survival to hospital admission and good neurologic outcome were secondary outcomes. Relative ratios (RR) and 95% confidence intervals (CIs) were calculated for each outcome. Heterogeneity was assessed using I square value., Results: A total of 6 trials, comprising 1360 patients, were included. One was an RCT, and five were observational cohort studies. The RCT showed that, compared to standard defibrillation, DSeq-D was associated with higher incidences of survival to hospital discharge, termination of VF, ROSC and good neurologic outcome. However, the pooled results of cohort studies found no benefit of DD over standard defibrillation in survival to hospital discharge (RR, 0.91; 95% CI, 0.46-1.78), nor in secondary outcomes. Furthermore, subgroup analysis suggested DSim-D was linked with lower ROSC rate compared to standard defibrillation (RR, 0.65; 95% CI, 0.49-0.86), while there was no significance between DSeq-D and standard defibrillation (RR, 1.00; 95% CI, 0.70-1.42)., Conclusions: The benefit of DSeq-D in survival to hospital discharge for RVF patients was found in the RCT, but not in cohort studies. Additionally, DSim-D should be applied with greater caution for RVF patients. Further validation is needed through larger-scale and higher-quality trials., Trial Registry: INPLASY; Registration number: INPLASY202340015; URL: https://inplasy.com/., Competing Interests: Declaration of competing interest All authors have no conflicts to disclose., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Aims: During out-of-hospital cardiac arrest (OHCA), an automatic external defibrillator (AED) analyzes the cardiac rhythm every two minutes; however, 80% of refibrillations occur within the first minute post-shock. We have implemented an algorithm for Analyzing cardiac rhythm While performing chest Compression (AWC). When AWC detects a shockable rhythm, it shortens the time between analyses to one minute. We investigated the effect of AWC on cardiopulmonary resuscitation quality., Method: In this cross-sectional study, we compared patients treated in 2022 with AWC, to a historical cohort from 2017. Inclusion criteria were OHCA patients with a shockable rhythm at the first analysis. Primary endpoint was the chest compression fraction (CCF). Secondary endpoints were cardiac rhythm evolution and survival, including survival analysis of non-prespecified subgroups., Results: In 2017 and 2022, 355 and 377 OHCAs met the inclusion criteria, from which we analyzed the 285 first consecutive cases in each cohort. CCF increased in 2022 compared to 2017 (77% [72-80] vs 72% [67-76]; P < 0.001) and VF recurrences were shocked more promptly (53 s [32-69] vs 117 s [90-132]). Survival did not differ between 2017 and 2022 (adjusted hazard-ratio 0.96 [95% CI, 0.78-1.18]), but was higher in 2022 within the sub-group of OHCAs that occurred in a public place and within a short time from call to AED switch-on (adjusted hazard ratio 0.85[0.76-0.96])., Conclusions: OHCA patients treated with AWC had higher CCF, shorter time spent in ventricular fibrillation, but no survival difference, except for OHCA that occurred in public places with short intervention time., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: “Sarah Menetre reports a relationship with Schiller Medical France that includes: employment. Jean-Philippe Didon reports a relationship with Schiller Medical France that includes: employment. Xavier Jouven reports a relationship with Schiller Medical France that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.”, (Copyright © 2024. Published by Elsevier B.V.)

Background: Out-of-hospital cardiac arrest (OHCA) complicated by refractory ventricular fibrillation (VF) is associated with poor outcome. Beta-1-receptor selective blockade might overcome refractory VF and improve survival. This trial investigates the efficacy and safety of prehospital landiolol in OHCA and refractory VF., Methods: In this randomized, double-blind, placebo-controlled pilot trial, patients with OHCA and recurrent or refractory VF (at least 3 defibrillation attempts and last rhythm shockable), pretreated with epinephrine and amiodarone, were allocated to receive add-on treatment with landiolol or placebo. Landiolol was given as a 20 mg bolus infusion. The primary efficacy outcome was time from trial drug infusion to sustained return of spontaneous circulation (ROSC). Safety outcomes included the onset of bradycardia and asystole., Results: A total of 36 patients were enrolled, 19 were allocated to the landiolol group and 17 to the placebo group. Time from trial drug infusion to sustained ROSC was similar between treatment groups (39 min [landiolol] versus 41 min [placebo]). Sustained ROSC was numerically lower in the landiolol group compared with the placebo group (7 patients [36.8%] versus 11 patients [64.7%], respectively). Asystole within 15 min of trial drug infusion occurred significantly more often in the landiolol group than in the placebo group (7 patients [36.8%] and 0 patients [0.0%], respectively)., Conclusion: In patients with OHCA and refractory VF who are pretreated with epinephrine and amiodarone, add-on bolus infusion of landiolol 20 mg did not lead to a shorter time to sustained ROSC compared with placebo. Landiolol might be associated with bradycardia and asystole., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective: Optimal timing for subsequent defibrillation attempts for Out-of-hospital cardiac arrest (OHCA) patients with recurrent VF/pVT is uncertain. We investigated the relationship between VF/pVT duration and return of spontaneous circulation (ROSC) in OHCA patients with recurrent shockable rhythms., Methods: We analyzed data from the Salt Lake City Fire Department (SLCFD) spanning from 2012 to 2023. The implementation of rhythm-filtering technology since 2011 enabled real-time rhythm interpretation during CPR, with local protocols allowing early defibrillation for recurrent/refractory VF/pVT cases. We included patients experiencing four or five episodes of VF and pVT rhythms and employed generalized estimating equation (GEE) regression analysis to examine the association between VF/pVT durations preceding recurrent defibrillation and return of spontaneous circulation (ROSC)., Results: Analysis of 622 appropriate shocks showed that patients achieving ROSC had significantly shorter median VF/pVT duration than those who did not achieve ROSC (0.83 minutes vs. 1.2 minutes, p = 0.004). Adjusted analysis of those with 4 VF/pVT episodes (N = 142) revealed that longer VF/pVT durations were associated with lower odds of achieving ROSC (odds ratio: 0.81, 95% CI: 0.72-0.93, p = 0.005). Every one-minute delay in intra-arrest defibrillation is predicted to decrease the likelihood of achieving ROSC by 19%., Conclusion: Every one-minute increase in intra-arrest VF/pVT duration was associated with a statistically significant 19% decrease in the chance of achieving ROSC. This highlights the importance of reducing time to shock in managing recurrent VF/pVT. The findings suggest reevaluating the current recommendations of two minutes intervals for rhythm check and shock delivery., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier B.V.)

Brugada syndrome (BS) is characterized by ST segment elevation in right precordial leads (V1-V3), ventricular tachycardia (VT), ventricular fibrillation (VF), and sudden cardiac death (SCD) in individuals without structural heart disease. The aim of this study is to contribute to the controversial issue of finding the most valuable marker that can predict poor prognosis during follow-up in patients with a diagnosis of BS. A total of 68 patients diagnosed with BS or had Brugada-type ECG change between January 1997 and July 2012 at the Department of Cardiology of Başkent University Faculty of Medicine, Ankara, Turkey, were included in this cohort study. Patients were screened every 6 months for arrhythmia-related syncope, SCD, appropriate and inappropriate defibrillation (shock), AF development and death; collectively defined as "arrhythmic events" and were the primary endpoints. Patients with and without arrhythmic events were compared. The mean age was 34.9 ± 12.2 years (9-71 years), and 52 (76.5%) patients were male. Mean follow-up was 49.6 ± 37.6 months (4-188 months). Univariate analysis showed that male sex (P = .004), type 1 electrocardiographic pattern (P = .008), SCD (P = .036), VT/VF history (P = .046), requirement for electrophysiological studies (P = .034), implantable cardioverter-defibrillator placement (P = .014) were found to demonstrate significant differences in patients with and without arrhythmic events. In multivariable analyzes, spontaneous type 1 ECG presence (HR = 8.54, 95% CI: 0.38-26.37; P = .003) and VT/VF history (HR = 9.21, 95% CI: 0.004-1.88; P = .002) were found to be independently associated with arrhythmic events. We found the presence of spontaneous type 1 ECG and a history of VT/VF to be associated with increased likelihood of overall arrhythmic events in BS. Given the higher risk of poor prognosis, we recommend additional measures in patients with BS who have these features., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Annually 15,200 children suffer an in-hospital cardiac arrest (IHCA) in the US. Ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) is the initial rhythm in 10-15% of these arrests. We sought to evaluate the association of number of shocks and early dose escalation with survival for initial VF/pVT in pediatric IHCA., Methods: Using 2000-2020 data from the American Heart Association's (AHA) Get with the Guidelines®-Resuscitation (GWTG-R) registry, we identified children >48 hours of life and ≤18 years who had an IHCA from initial VF/pVT and received defibrillation., Results: There were 251 subjects (37.7%) who received a single shock and 415 subjects (62.3%) who received multiple shocks. Baseline and cardiac arrest characteristics did not differ between those who received a single shock versus multiple shocks except for duration of arrest and calendar year. The median first shock dose was consistent with AHA dosing recommendations and not different between those who received a single shock versus multiple shocks. Survival was improved for those who received a single shock compared to multiple shocks. However, no difference in survival was noted between those who received 2, 3, or ≥4 shocks. Of those receiving multiple shocks, no difference was observed with early dose escalation., Conclusions: In pediatric IHCA, most patients with initial VF/pVT require more than one shock. No distinctions in patient or pre-arrest characteristics were identified between those who received a single shock versus multiple shocks. Subjects who received a single shock were more likely to survive to hospital discharge even after adjusting for duration of resuscitation., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: ‘Tia Raymond reports she is a paid consultant of New England Research Institutes, Inc., as a member of the adjudication committee for the COMPASS Trial (Comparison of Methods for Pulmonary Blood Flow Augmentation in Neonates: Shunt versus Stent. Dianne Atkins reports she is a paid member of the Data Monitoring Safety Board for the Pediatric Heart Network, a multicenter study funded by NHLBI’., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Refractory ventricular fibrillation or pulseless ventricular tachycardia (rVF/pVT) during out-of-hospital cardiac arrest (OHCA) is associated with poor survival. Double sequential defibrillation (DSED) and vector change (VC) improved survival for rVF/pVT in the DOSE-VF RCT. However, the role of angiography and percutaneous coronary intervention (angiography/PCI) during the trial is unknown., Objectives: To determine the incidence of ST-elevation (STE) and no ST-elevation (NO-STE) on post-arrest ECG and the use of angiography/PCI in patients with rVF/pVT during the DOSE-VF RCT., Method: Adults (≥18-years) with rVF/pVT OHCA randomized in the DOSE-VF RCT who survived to hospital admission were included. The primary analysis compared the proportion of angiography in STE and NO-STE. We performed regression modelling to examine association between STE, the interaction with defibrillation strategy, and survival to discharge controlling for known covariates., Results: We included 151 patients, 74 (49%) with STE and 77 (51%) with NO-STE. The proportion of angiography was higher in the STE cohort than NO-STE (87.8% vs 44.2%, p < 0.001); similarly the proportion of PCI was also higher (75.7% vs 9.1%, p < 0.001). Survival to discharge was similar between STE and NO-STE (63.5% vs 51.9%, p = 0.15). Use of angiography/PCI did not differ between defibrillation strategies. Decreased age (OR 0.95, 95% CI 0.92-0.98; p = 0.001) and angiography (OR 9.33, 95% CI 3.60-26.94; p < 0.001) were predictors of survival; however, STE was not., Conclusion: We found high rates of angiography/PCI in patients with STE compared to NO-STE, however similar rates of survival. Angiography was an independent predictor of survival. Improved rates of survival employing DSED and VC were independent of angiography/PCI., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: The DOSE VF randomized controlled trial (RCT) employed a pragmatic definition of refractory ventricular fibrillation (VF after three successive shocks). However, it remains unclear whether the underlying rhythm during the first three shocks was shock-refractory or recurrent VF., Objective: To explore the relationship between alternate defibrillation strategies employed during the DOSE VF RCT and the type of VF, either shock-refractory VF or recurrent VF, on patient outcomes., Methods: We performed a secondary analysis of the DOSE VF RCT. We categorized cases as shock-refractory or recurrent VF based on pre-randomization shocks (shocks 1-3). We then analyzed all subsequent (post-randomization) shocks to assess the impact of standard, vector change (VC) or double sequential external defibrillation (DSED) shocks on clinical outcomes employing logistic regression adjusted for Utstein variables, antiarrhythmics, and epinephrine., Results: We included 345 patients; 60 (17%) shock-refractory VF, and 285 (83%) recurrent VF. Patients in recurrent VF had greater survival than shock-refractory VF (OR: 2.76 95% CI [1.04, 7.27]). DSED was superior to standard defibrillation for survival overall, and for patients with shock-refractory VF (28.6% vs 0%, p = 0.041) but not for those in recurrent VF. DSED was superior to standard defibrillation for return of spontaneous circulation (ROSC) and neurologic survival for shock-refractory and recurrent VF. VC defibrillation was not superior for survival or ROSC overall, for shock-refractory, or recurrent VF groups, but was superior for VF termination across all groups., Conclusion: DSED appears to be the superior defibrillation strategy in the DOSE VF trial, irrespective of whether the preceding VF is shock-refractory or recurrent., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective: We sought to evaluate the impact of a medical directive allowing nurses to use defibrillators in automated external defibrillator-mode (AED) on in-hospital cardiac arrest (IHCA) outcomes., Methods: We completed a health record review of consecutive IHCA for which resuscitation was attempted using a pragmatic multi-phase before-after cohort design. We report Utstein outcomes before (Jan.2012-Aug.2013;Control) the implementation of the AED medical directive following usual practice (Sept.2013-Aug.2016;Phase 1), and following the addition of a theory-based educational video (Sept.2016-Dec.2017;Phase 2)., Results: There were 753 IHCA with the following characteristics (Before n = 195; Phase 1n = 372; Phase 2n = 186): mean age 66, 60.0% male, 79.3% witnessed, 29.1% noncardiac-monitored medical ward, 23.9% cardiac cause, and initial ventricular fibrillation/tachycardia (VF/VT) 27.2%. Comparing the Before, Phase 1 and 2: an AED was used 0 time (0.0%), 21 times (5.7%), 15 times (8.1%); mean times to 1st analysis were 7 min, 3 min and 1 min (p < 0.0001); mean times to 1st shock were 12 min, 10 min and 8 min (p = 0.32); return of spontaneous circulation (ROSC) was 63.6%, 59.4% and 58.1% (p = 0.77); survival was 24.6%, 21.0% and 25.8% (p = 0.37). Among IHCA in VF/VT (n = 165), time to 1st analysis and 1st shock decreased by 5 min (p = 0.01) and 6 min (p = 0.23), and ROSC and survival increased by 3.0% (p = 0.80) and 15.6% (p = 0.31). There was no survival benefit overall (1.2%; p = 0.37) or within noncardiac-monitored areas (-7.2%; p = 0.24)., Conclusions: The implementation of a medical directive allowing for AED use by nurses successfully improved key outcomes for IHCA victims, particularly following the theory-based education video and among the VF/VT group., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Little has been reported on the predictors of 30-day survival after emergent percutaneous coronary intervention (PCI) following life-threatening ventricular tachyarrhythmias associated with acute myocardial infarction (AMI)., Methods: We analyzed 55 consecutive patients who underwent an emergent PCI after ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) complicating AMI between September 2014 and March 2023 in our hospital. These patients were categorized into two groups: survival group (S group) who survived >30 days after the emergent PCI and death group (D group) who died by 30 days after the emergent PCI. We compared the patient characteristics, coronary angiographic findings, and PCI procedures between the two groups., Results: S group consisted of 40 patients. In the univariate analysis, absence of diabetes mellitus, presence of immediate cardiopulmonary resuscitation (CPR), low arterial lactate, and single-vessel coronary artery disease (CAD) were associated with 30-day survival after the emergent PCI (P = 0.048, P < 0.001, P = 0.009, and P = 0.003, respectively). In the multivariate analysis, presence of immediate CPR and single-vessel CAD were independently associated with 30-day survival after the emergent PCI (P = 0.023 and P = 0.032, respectively)., Conclusions: Immediate CPR and single-vessel CAD were significant predictors of 30-day survival after the emergent PCI following VF or pulseless VT complicating AMI. Absence of diabetes mellitus and low arterial lactate were associated with 30-day survival in the univariate analysis., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare., (Copyright © 2024. Published by Elsevier B.V.)

Objective: To describe our early observations with sudden cardiac arrest (SCA) and sudden death (SD) in patients using vape products., Patients and Methods: A retrospective analysis of Mayo Clinic's Windland Smith Rice Genetic Heart Rhythm Clinic and Sudden Death Genomics Laboratory was performed on all SCA survivors and decedents who presented between January 1, 2007, and December 31, 2021, to identify patients/decedents with a history of vaping. Data abstraction included patient demographics, clinical characteristics, and documented use of vape products., Results: Among 144 SCA survivors and 360 SD victims, there were six individuals (1%; 3 females) with unexplained SCA (n=4) or SD (n=2) that was temporally associated with vaping use with a mean age at sentinel event of 23±5 years. The SCA survivors include a 19-year-old male who was resuscitated from documented ventricular fibrillation 40 minutes after vaping and a 19-year-old male who was resuscitated from ventricular fibrillation a few hours post vaping. The first SD victim was a 19-year-old female with exercise-induced asthma who died in her sleep after vaping that evening. Autopsy results showed eosinophilic infiltrates in the lung tissue and death was attributed to bronchial asthma. The second vaping-associated death involved a 26-year-old male whose autopsy attributed the death to acute respiratory distress syndrome., Conclusion: We have identified six young individuals with a history of vaping who experienced a near fatal episode or a tragic SD. Although larger cohort studies are needed to quantify the actual risk of SD, it seems prudent to sound an early warning about vaping's potential lethality., (Copyright © 2023 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

BACKGROUND Electrical storm is a rare but potentially life-threatening syndrome characterized by recurrent ventricular arrhythmias. Liver transplant recipients are at increased risk of developing electrical storms due to conditions that prolong QT intervals, such as cirrhotic cardiomyopathy. However, limited information exists on electrical storms in this specific population. This case report presents a patient who experienced 13 cardiac arrests during ventricular fibrillation following liver transplantation. CASE REPORT A 61-year-old woman with a medical history of diabetes, obesity, and cirrhosis due to non-alcoholic fatty liver disease underwent liver transplantation using a deceased donor's liver. Following the procedure, she developed a deterioration in her respiratory function, necessitating orotracheal intubation. Approximately 21 hours post-surgery, she experienced cardiac arrest during ventricular fibrillation, which was rapidly reversed with electrical defibrillation. However, the patient entered a state of electrical storm. Management involved antiarrhythmic medications and temporary transvenous cardiac pacing. She remained stable for 40 hours, but a dislodgment of the device triggered another episode of ventricular fibrillation, leading to her death. CONCLUSIONS This case report highlights the clinical presentation and challenges in managing electrical storms in liver transplant recipients. We hypothesize that cirrhotic cardiomyopathy could be the cause of her recurrent ventricular arrhythmias. Further studies are needed to better understand the underlying mechanisms and risk factors of this life-threatening syndrome in this population, which may enhance risk stratification and enable earlier intervention.

Although long-QT syndrome (LQTS) with a normal range QT interval at rest leads to fatal ventricular arrhythmias, it is difficult to diagnose. In this article, we present a rare case of a patient who suffered a cardiac arrest and was recently diagnosed with LQTS and coronary vasospasm. A 62-year-old man with no syncopal episodes had a cardiopulmonary arrest while running. During coronary angiography, vasospasm was induced and we prescribed coronary vasodilators, including calcium channel blockers. An exercise stress test was performed to evaluate the effect of medications and accidentally unveiled exercise-induced QT prolongation. He was diagnosed with LQTS based on diagnostic criteria. Pharmacotherapy and an implantable cardioverter defibrillator were used for his medical management. It is extremely rare for LQTS and coronary vasospasm to coexist. In cases of exercise-induced arrhythmic events, the exercise stress test might be helpful to diagnose underlying disease.

Objectives: Studies of out-of-hospital cardiac arrest generally document the presenting (pulseless electrical activity [PEA], ventricular fibrillation/tachycardia (VF/VT), asystole), and the final states (resuming stable spontaneous circulation [s-ROSC], being declared dead). Only a few studies described the transitions between clinical states during advanced life support (ALS). The aim of this study was to describe and analyze the dynamics of state transitions during ALS., Methods: A retrospective analysis of 464 OHCA events was conducted. Any observed state and its corresponding changing time were documented through continuous electrocardiographic and trans-thoracic impedance recording., Results: When achieved, most s-ROSCs were obtained by 30 min, regardless of the presenting state. After this time point, the persistence of any transient state was associated with a great probability of being declared dead. The most probable change for VF/VT or PEA at any time was the transition to asystole (36.4% and 34.4%, respectively); patients in asystole at any time had a 70% probability of death. Patients achieving s-ROSC mostly came from a VF/VT state.In most cases, the presenting rhythm tended to persist over time during ALS. Asystole was the most stable state; a higher degree of instability was observed when the presenting rhythms were VF/VT or PEA. Transient ROSC episodes occurred mainly as the first transition after the presenting state, especially for initial PEA., Conclusions: An understanding of the dynamic course of clinical state transitions during ALS may allow treatment strategies to be tailored in patients affected by OHCA.

Background: Animal studies suggest the efficacy of double sequential external defibrillation (DSED) may depend on the interval between the two shocks, or "DSED interval". No human studies have examined this concept., Objectives: To determine the relationship between DSED interval and termination of ventricular fibrillation (VFT), return of spontaneous circulation (ROSC), survival to hospital discharge, and favourable neurological status (MRS ≤ 2) for patients in refractory VF., Methods: We performed a retrospective review of adult (≥18 years) out-of-hospital cardiac arrest between January 2015 and May 2022 with refractory VF who received ≥1 DSED shock. DSED interval was divided into four pre-defined categories. We examined the association between DSED interval and patient outcomes using general estimated equation logistic regression or Fisher's exact test., Results: Among 106 included patients, 303 DSED shocks were delivered (median 2, IQR 1-3). DSED intervals of 75-125 ms (OR 0.39, 95% CI 0.16-0.98), 125-500 ms (OR 0.36, 95% CI 0.16-0.82), and >500 ms (OR 0.27, 95% CI 0.11-0.63) were associated with lower probability of VF termination compared to <75 ms interval. DSED interval of >75 ms was associated with lower probability of ROSC compared to <75 ms interval (OR 0.37, 95% CI 0.14-0.98). No association was noted between DSED interval and survival to hospital discharge or neurologic outcome., Conclusions: Among patients in refractory VF a DSED interval of less than 75 ms was associated with improved rates of VF termination and ROSC. No association was noted between DSED interval and survival to hospital discharge or neurologic outcome., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dr. Cheskes sits on the editorial board of the Journal Resuscitation., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: It remains unclear if percutaneous left ventricular assist device (pLVAD) reduces post-cardiac arrest myocardial dysfunction., Methods: This is a prespecified analysis of a subset of swine that achieved return of spontaneous circulation (ROSC) in a study comparing pLVAD, transient aortic occlusion (AO), or both during cardiopulmonary resuscitation (CPR). Devices were initiated after 24 minutes of ventricular fibrillation cardiac arrest (8 min no-flow and 16 min mechanical CPR). AO was discontinued post-ROSC, and pLVAD support or standard care were continued. Beginning 60 minutes post-ROSC, pLVAD support was weaned to < 1.0 L/min and subsequently removed at 240 minutes. The primary outcome was cardiac index (CI), stroke volume index (SVI), and left ventricular ejection fraction (LVEF) at 240 minutes post-ROSC. Data are shown as mean (standard error)., Results: Seventeen swine achieved ROSC without complication and were included in this analysis (pLVAD group, n = 11 and standard care group, n = 6). For the primary outcomes, the pLVAD group had significantly higher CI of 4.2(0.3) vs. 3.1(0.4) L/min/m 2 (p = 0.043) and LVEF 60(3) vs. 49(4) % (p = 0.029) at 240 minutes after ROSC when compared with the standard care group, while SVI was not statistically significantly different (32[3] vs. 23[4] mL/min/m 2 , p = 0.054). During the first 60 minutes post-ROSC, the pLVAD group had significantly higher coronary perfusion pressure, lower LV stroke work index, and total pulmonary resistance index., Conclusion: These results suggest that early pLVAD support after ROSC is associated with better recovery myocardial function compared to standard care after prolonged cardiac arrest., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Clinical features among patients with refractory out-of-hospital cardiac arrest (OHCA) and initial shockable rhythms of ventricular fibrillation/pulseless ventricular tachycardia are not well-characterized., Methods: We compared clinical characteristics and coronary angiographic findings between patients with refractory OHCA (incessant ventricular fibrillation/pulseless ventricular tachycardia after ≥3 direct-current shocks) and those without refractory OHCA., Results: Between 2014 and 2018, a total of 204 patients with ventricular fibrillation/pulseless ventricular tachycardia OHCA (median age 62; males 78%) were divided into groups with (36%, 74/204) and without refractory arrest (64%, 130/204). Refractory OHCA patients had longer cardiopulmonary resuscitation (23 versus 15 minutes), more frequently required ≥450 mg amiodarone (34% versus 3.8%), and had cardiogenic shock (80% versus 55%) necessitating higher adrenaline dose (4.0 versus 1.0 mg) and higher rates of mechanical ventilation (92% versus 74%; all P <0.01). Of 167 patients (82%) selected for coronary angiography, 33% (n=55) had refractory OHCA ( P =0.035). Significant coronary artery disease (≥1 major vessel with >70% stenosis) was present in >70% of patients. Refractory OHCA patients frequently had acute coronary occlusion (64% versus 47%), especially left circumflex (20% versus 6.4%) and graft vessel (7.3% versus 0.9%; all P <0.05) compared with those without refractory OHCA. Refractory OHCA group had higher in-hospital mortality (45% versus 30%, P =0.036) and greater new requirement for dialysis (18% versus 6.3%, P =0.011). After adjustment, refractory OHCA was associated with over 2-fold higher odds of in-hospital mortality (odds ratio, 2.28 [95% CI, 1.06-4.89]; P =0.034)., Conclusions: Refractory ventricular fibrillation/pulseless ventricular tachycardia OHCA was associated with more intensive resuscitation, higher rates of acute coronary occlusion, and poorer in-hospital outcomes, underscoring the need for future studies in this extreme-risk subgroup., Competing Interests: Disclosures None.

Background: Cardiac arrest can present with asystole, Pulseless Electrical Activity (PEA), or Ventricular Fibrillation/Tachycardia (VF/VT). We investigated the transition intensity of Return of spontaneous circulation (ROSC) from PEA and asystole during in-hospital resuscitation., Materials and Methods: We included 770 episodes of cardiac arrest. PEA was defined as ECG with >12 QRS complexes per min, asystole by an isoelectric signal >5 seconds. The observed times of PEA to ROSC transitions were fitted to five different parametric time-to-event models. At values ≤0.1, transition intensities roughly represent next-minute probabilities allowing for direct interpretation. Different entities of PEA and asystole, dependent on whether it was the primary or a secondary rhythm, were included as covariates., Results: The transition intensities to ROSC from primary PEA and PEA after asystole were unimodal with peaks of 0.12 at 3 min and 0.09 at 6 min, respectively. Transition intensities to ROSC from PEA after VF/VT, or following transient ROSC, exhibited high initial values of 0.32 and 0.26 at 3 minutes, respectively, but decreased. The transition intensity to ROSC from initial asystole and asystole after PEA were both about 0.01 and 0.02; while asystole after VF/VT had an intensity to ROSC of 0.15 initially which decreased. The transition intensity from asystole after temporary ROSC was constant at 0.08., Conclusion: The immediate probability of ROSC develops differently in PEA and asystole depending on the preceding rhythm and the duration of the resuscitation attempt. This knowledge may aid simple bedside prognostication and electronic resuscitation algorithms for monitors/defibrillators., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: One of the co-authors, Benjamin Abella, is a member of the journal’s Editorial Board. All authors declare that they have no interests, financial or otherwise, that could potentially influence or bias the research, results, or interpretation of the findings presented in this study., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Prompt defibrillation is key to successful resuscitation from ventricular fibrillation out-of-hospital cardiac arrest (VF-OHCA). Preliminary evidence suggests that the timing of shock relative to the amplitude of the VF ECG waveform may affect the likelihood of resuscitation. We investigated whether the VF waveform amplitude at the time of shock (instantaneous amplitude) predicts outcome independent of other validated waveform measures., Methods: We conducted a retrospective study of VF-OHCA patients ≥18 old. We evaluated three VF waveform measures for each shock: instantaneous amplitude at the time of shock, and maximum amplitude and amplitude spectrum area (AMSA) over a 3-s window preceding the shock. Linear mixed-effects modeling was used to determine whether instantaneous amplitude was associated with shock-specific return of organized rhythm (ROR) or return of spontaneous circulation (ROSC) independent of maximum amplitude or AMSA., Results: The 566 eligible patients received 1513 shocks, resulting in ROR of 62.0% (938/1513) and ROSC of 22.3% (337/1513). In unadjusted regression, an interquartile increase in instantaneous amplitude was associated with ROR (Odds ratio [OR] [95% confidence interval] = 1.27 [1.11-1.45]) and ROSC (OR = 1.27 [1.14-1.42]). However, instantaneous amplitude was not associated with ROR (OR = 1.13 [0.97-1.30]) after accounting for maximum amplitude, nor with ROR (OR = 1.00 [0.87-1.15]) or ROSC (OR = 1.05 [0.93-1.18]) after accounting for AMSA. By contrast, AMSA and maximum amplitude remained independently associated with ROR and ROSC., Conclusions: We did not observe an independent association between instantaneous amplitude and shock-specific outcomes. Efforts to time shock to the maximal amplitude of the VF waveform are unlikely to affect resuscitation outcome., Competing Interests: Declaration of Competing Interest Drs. Kwok and Rea have received research support from Philips Healthcare. The other authors have no conflicts to declare., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background and Objective: Double sequential external defibrillation (DSED) and vector-change defibrillation (VCD) have been suggested to enhance clinical outcomes for patients with ventricular fibrillation (VF) refractory of standard defibrillation (SD). Therefore, this network meta-analysis aims to evaluate the comparative efficacy of DSED, VCD, and SD for refractory VF., Methods: A systematic review and network meta-analysis synthesizing randomized controlled trials (RCTs) and comparative observational studies retrieved from PubMed, EMBASE, WOS, SCOPUS, and Cochrane through November 15th, 2022. R software netmeta and netrank package (R version 4.2.0) and meta-insight software were used to pool dichotomous outcomes using odds ratio (OR) presented with the corresponding confidence interval (CI). Our protocol was prospectively published in PROSPERO with ID: CRD42022378533., Results: We included seven studies with a total of 1632 participants. DSED was similar to SD in survival to hospital discharge (OR: 1.14 with 95% CI [0.55, 2.83]), favorable neurological outcome (modified Rankin scale ≤2 or cerebral performance category ≤2) (OR: 1.35 with 95% CI [0.46, 3.99]), and return of spontaneous circulation (ROSC) (OR: 0.81 with 95% CI [0.43; 1.5]). In addition, VCD was similar to SD in survival to hospital discharge (OR: 1.12 with 95% CI [0.27, 4.57]), favorable neurological outcome (OR: 1.01 with 95% CI [0.18, 5.75]), and ROSC (OR: 0.88 with 95% CI [0.24; 3.15])., Conclusion: Double sequential external defibrillation and VCD were not associated with enhanced outcomes in patients with refractory VF out-of-hospital cardiac arrest, compared to SD. However, the current evidence is still inconclusive, warranting further large-scale RCTs., (© 2023 The Authors. Annals of Noninvasive Electrocardiology published by Wiley Periodicals LLC.)

Background: Studies of outcome differences by sex in out-of-hospital cardiac arrest (OHCA) have produced mixed results that may depend on age, a potential surrogate for menopausal status., Objective: We used quantitative measures of ventricular fibrillation (VF) waveforms - indicators of the myocardium's physiology - to assess whether survival differences according to sex and age group may be mediated via a biologic mechanism., Methods: We conducted a cohort study of VF-OHCA in a metropolitan EMS system. We used multivariable logistic regression to assess the association of survival to hospital discharge with sex and age group (<55, ≥55 years). We determined the proportion of outcome difference mediated by VF waveform measures: VitalityScore and amplitude spectrum area (AMSA)., Results: Among 1526 VF-OHCA patients, the average age was 62 years, and 29% were female. Overall, younger women were more likely to survive than younger men (survival 67% vs 54%, p = 0.02), while survival among older women and older men did not differ (40% vs 44%, p = 0.3). Adjusting for Utstein characteristics, women <55 compared to men <55 had greater odds of survival to hospital discharge (OR = 1.93, 95% CI 1.23-3.09), an association not observed between the ≥55 groups. Waveform measures were more favorable among women and mediated some of the beneficial association between female sex and survival among those <55 years: 47% for VitalityScore and 25% for AMSA., Conclusions: Women <55 years were more likely to survive than men <55 years following VF-OHCA. The biologic mechanism represented by VF waveform mediated some, though not all, of the outcome difference., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: ‘TR and HK received modest support provided to the University of Washington by Philips, a major defibrillator manufacturer.’., (Copyright © 2023. Published by Elsevier B.V.)

Background We aim to compare the burden of cardiovascular disease risk factors and major adverse cardiac events and in-hospital outcomes among young Black patients (aged 18-44 years) hospitalized in 2007 and 2017 using data obtained from the National Inpatient Sample database. Method and Results Comparison of the sociodemographic characteristics, comorbidities, and inpatient outcomes, including major adverse cardiac events (all-cause mortality, acute myocardial infarction, cardiogenic shock, cardiac arrest, ventricular fibrillation/flutter, pulmonary embolism, and coronary intervention), between 2017 and 2007 was performed. Multivariable analyses were performed, controlling for potential covariates. A total of 2 922 743 (mean age, 31 years; 70.3% women) admissions among young Black individuals were studied (1 341 068 in 2007 and 1 581 675 in 2017). The 2017 cohort had a younger population (mean, 30 versus 31 years; P <0.001), more male patients (30.4% versus 28.8%; P <0.001), and patients with higher nonelective admissions (76.8% versus 75%; P <0.001), and showed an increasing burden of traditional cardiometabolic comorbidities, congestive heart failure, chronic pulmonary disease, coagulopathy, depression, along with notable reductions in alcohol abuse and drug abuse, compared with the 2007 cohort. The adjusted multivariable analysis showed worsening in-hospital outcomes, including major adverse cardiac events (adjusted odds ratio [aOR], 1.21), acute myocardial infarction (aOR, 1.34), cardiogenic shock (aOR, 3.12), atrial fibrillation/flutter (aOR, 1.34), ventricular fibrillation/flutter (aOR, 1.32), cardiac arrest (aOR, 2.55), pulmonary embolism (aOR, 1.89), and stroke (aOR, 1.53). The 2017 cohort showed a decreased rate of percutaneous coronary intervention/coronary artery bypass grafting and all-cause mortality versus the 2007 cohort ( P <0.001). Conclusions In conclusion, young Black patients have had an increasing burden of cardiovascular disease risk factors and worsened in-hospital outcomes, including major adverse cardiac events and stroke, in the past decade, although with improved survival odds.

Background: Out-of-hospital cardiac arrest due to shock-refractory ventricular fibrillation (VF) is associated with relatively poor survival. The ability to predict refractory VF (requiring ≥3 shocks) in advance of repeated shock failure could enable preemptive targeted interventions aimed at improving outcome, such as earlier administration of antiarrhythmics, reconsideration of epinephrine use or dosage, changes in shock delivery strategy, or expedited invasive treatments., Methods: We conducted a cohort study of VF out-of-hospital cardiac arrest to develop an ECG-based algorithm to predict patients with refractory VF. Patients with available defibrillator recordings were randomized 80%/20% into training/test groups. A random forest classifier applied to 3-s ECG segments immediately before and 1 minute after the initial shock during cardiopulmonary resuscitation was used to predict the need for ≥3 shocks based on singular value decompositions of ECG wavelet transforms. Performance was quantified by area under the receiver operating characteristic curve., Results: Of 1376 patients with VF out-of-hospital cardiac arrest, 311 (23%) were female, 864 (63%) experienced refractory VF, and 591 (43%) achieved functional neurological survival. Total shock count was associated with decreasing likelihood of functional neurological survival, with a relative risk of 0.95 (95% CI, 0.93-0.97) for each successive shock ( P <0.001). In the 275 test patients, the area under the receiver operating characteristic curve for predicting refractory VF was 0.85 (95% CI, 0.79-0.89), with specificity of 91%, sensitivity of 63%, and a positive likelihood ratio of 6.7., Conclusions: A machine learning algorithm using ECGs surrounding the initial shock predicts patients likely to experience refractory VF, and could enable rescuers to preemptively target interventions to potentially improve resuscitation outcome., Competing Interests: Disclosures Drs Rea and Kwok receive research support provided to the University of Washington by Philips, Bothell, WA. The other authors report no conflicts. None of the funding organizations had a role in the study design, generation of results, interpretation of results, writing of the article, or decision to submit for publication.

Several factors have been identified as contributing to medication administration errors, including look-alike, sound-alike (LASA) errors. LASA errors are important causes of serious adverse events arising from spinal injection of tranexamic acid, which can be confused with ampoules of local anaesthesia.We present a case of accidental injection of 250 mg of tranexamic acid rather than prilocaine during spinal anaesthesia. The patient developed lower extremities myoclonus, followed by generalised convulsions and ventricular fibrillation, that was reverted within 6 min. Severe cardiogenic shock requiring both inotropic and vasopressor therapy followed, along with a classic apical ballooning pattern on echocardiography and elevated myocardial injury markers, indicating Takotsubo cardiomyopathy. The patient's condition progressively improved to full recovery, and she was discharged from hospital after 1 month with no neurological deficit or cardiac dysfunction.To our knowledge, this is the 28th reported case of accidental spinal injection of tranexamic acid. We present a brief review of previously published cases., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

A 73-year-old woman with a history of aortitis syndrome was referred to our hospital presenting with congestive heart failure caused by acute severe mitral regurgitation due to posterior leaflet prolapse. Upon admission, the patient fell into shock state while undergoing an examination. Medical treatment including mechanical ventilation could not alleviate circulatory collapse, so emergency surgery was performed on the day of admission. Severe calcification of the ascending aorta and severe stenosis or occlusion of the aortic arch vessels resulted from the patient's aortitis syndrome precluded aortic cannulation and aortic clamp. Therefore, mitral valve repair was performed under ventricular fibrillation at moderate hypothermia. Surgery was successful, and the patient recovered well without any cerebral complications after the surgery.

Background: eCPR, the modality of extracorporeal membrane oxygenation (ECMO) applied in the setting of cardiac arrest, has emerged as a novel therapy which may improve outcomes in select patients with out-of-hospital cardiac arrest (OHCA). To date, implementation has been mainly limited to single academic centres. Our objective is to describe the feasibility and challenges with implementation of a regional protocol for eCPR., Methods: The Los Angeles County Emergency Medical Services (EMS) Agency implemented a regional eCPR protocol in July 2020, which included coordination across multiple EMS provider agencies and hospitals to route patients with refractory ventricular fibrillation (rVF) OHCA to eCPR-capable centres (ECCs). Data were entered on consecutive patients with rVF with suspected cardiac aetiology into a centralized database including time intervals, field and in-hospital care, survival and neurologic outcome., Results: From July 27, 2020 through July 31, 2022, 35 patients (median age 57 years, 6 (17%) female) were routed to ECCs, of whom 11 (31%) received eCPR and 3 (27%) treated with eCPR survived, all of whom had a full neurologic recovery. Challenges encountered during implementation included cost to EMS provider agencies for training, implementation, and purchase of automatic chest compression devices, maintenance of system awareness, hospital administrative support for staffing and equipment for the ECMO program, and interdepartmental coordination at ECCs., Conclusion: We describe the successful implementation of a regional eCPR program with ongoing patient enrolment and data collection. These preliminary findings can serve as a model for other EMS systems who seek to implement regional eCPR programs., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: American Heart Association Advanced Cardiac Life Support (ACLS) guidelines support the use of either amiodarone or lidocaine for cardiac arrest caused by ventricular tachycardia or ventricular fibrillation (VT/VF) based on studies of out-of-hospital cardiac arrest. Studies comparing amiodarone and lidocaine in adult populations with in-hospital VT/VF arrest are lacking., Research Question: Does treatment with amiodarone vs lidocaine therapy have differential associations with outcomes among adult patients with in-hospital cardiac arrest from VT/VF?, Study Design and Methods: This retrospective cohort study of adult patients receiving amiodarone or lidocaine for VT/VF in-hospital cardiac arrest refractory to CPR and defibrillation between January 1, 2000, and December 31, 2014, was conducted within American Heart Association Get With the Guidelines-Resuscitation (GWTG-R) participating hospitals. The primary outcome was return of spontaneous circulation (ROSC). Secondary outcomes were 24 h survival, survival to hospital discharge, and favorable neurologic outcome., Results: Among 14,630 patients with in-hospital VT/VF arrest, 68.7% (n = 10,058) were treated with amiodarone and 31.3% (n = 4,572) with lidocaine. When all covariates were statistically controlled, compared with amiodarone, lidocaine was associated with statistically significantly higher odds of the following: (1) ROSC (adjusted OR [AOR], 1.15, P = .01; average marginal effect [AME], 2.3; 95% CI, 0.5 to 4.2); (2) 24 h survival (AOR, 1.16; P = 004; AME, 3.0; 95% CI, 0.9 to 5.1); (3) survival to discharge (AOR, 1.19; P < .001; AME, 3.3; 95% CI, 1.5 to 5.2); and (4) favorable neurologic outcome at hospital discharge (AOR, 1.18; P < .001; AME, 3.1; 95% CI, 1.3 to 4.9). Results using propensity score methods were similar to those from multivariable logistic regression analyses., Interpretation: Compared with amiodarone, lidocaine therapy among adult patients with in-hospital cardiac arrest from VT/VF was associated with statistically significantly higher rates of ROSC, 24 h survival, survival to hospital discharge, and favorable neurologic outcome., (Copyright © 2022 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Cardiovascular mortality has declined significantly in recent years, however, sudden cardiac death remains the leading cause of death in a range of different mortality indicators, very often caused by cardiac arrhythmias. The electrophysiological causes of sudden cardiac death include ventricular tachycardia, ventricular fibrillation, asystole and pulseless electrical activity. In addition, other cardiac arrhythmias may also trigger sudden cardiac death, periarrest arrhytmias. The rapid and accurate recognition of the various arrhythmias and their appropriate management are major challenges at both prehospital and hospital care levels. In these conditions, prompt recognition of life-threatening conditions, rapid response and proper treatment are critical. This publication reviews the various device and drug treatment modalities for the management of periarrest arrythmic conditions in the light of the 2021 guidelines of the European Resuscitation Council. This article highlights the epidemiology and aetiology of periarrest arrythmic states, and outlines the state-of-the-art treatment options for various tachy- and bradyarrhythmias, providing guidance in the management of these conditions both in hospital and out-of-hospital settings. Orv Hetil. 2023; 164(13): 504-509.

Smaller electrodes allow more options for design of automated external defibrillator (AED) user interfaces. However, previous studies employing monophasic-waveform defibrillators found that smaller electrode sizes have lower defibrillation shock success rates. We hypothesize that, for impedance-compensated, biphasic truncated exponential (BTE) shocks, smaller electrodes increase transthoracic impedance (TTI) but do not adversely affect defibrillation success rates. METHODS AND RESULTS: In this prospective before-and-after clinical study, Amsterdam police and firefighters used AEDs with BTE waveforms: an AED with larger electrodes in 2016-2017 (113 cm 2 ), and an AED with smaller electrodes in 2017-2020 (65 cm 2 ). We analyzed 157 and 178 patient cases with an initial shockable rhythm where the larger and smaller electrodes were used, respectively. A single 200-J shock terminated ventricular fibrillation (VF) in 86% of patients treated with large electrodes and 89% of patients treated with smaller electrodes. Small electrodes had a non-inferior first shock defibrillation success rate compared to large electrodes, with a difference of 3% (95% CI: -3% -9%) with the lower confidence limit remaining above the defined non-inferiority threshold. TTI was significantly higher for the smaller electrodes (median: 100 Ω) compared to the larger electrodes (median: 88 Ω) (p < 0.001). CONCLUSIONS: For AEDs with impedance-compensating BTE waveforms, TTI was higher for smaller electrodes than the large electrode electrodes. Overall defibrillation shock success for AEDs with smaller electrodes was non-inferior to the AEDs with larger electrodes., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Implantable cardioverter-defibrillator (ICD) shocks are associated with higher rates of mortality and reduced quality of life. In this study we aimed to investigate the effectiveness of catheter ablation (CA) of ventricular tachycardia in patients with an ICD., Methods: An electronic literature search was conducted to identify randomized controlled trials that compared CA vs control. The primary outcomes were recurrence of ventricular arrhythmia (ventricular tachycardia or ventricular fibrillation) and mortality. Kaplan-Meier curves for these outcomes were digitized to obtain individual patient data, which were pooled in a 1-stage meta-analysis to determine hazard ratios (HRs) and 95% confidence intervals (CIs). Secondary outcomes included cardiac hospitalization, electrical storm, syncope, appropriate ICD therapies, appropriate ICD shocks, and inappropriate shocks. For these, study-level HRs or risk ratios were obtained and pooled in random effects meta-analyses. Subgroup analysis was performed for trials that investigated prophylactic CA (before or during ICD implantation)., Results: Data on 9 studies and 1103 patients were retrieved. CA significantly reduced ventricular tachycardia/ventricular fibrillation recurrence compared with control (shared frailty HR, 0.63; 95% CI, 0.49-0.81; P < 0.001) but not mortality (shared frailty HR, 0.84; 95% CI, 0.57-1.23; P = 0.361). CA was associated with significantly lower rates of cardiac hospitalization, electrical storm, appropriate ICD therapies and shocks, but not syncope or inappropriate shocks. Subgroup analysis showed similar results for prophylactic CA except that no significant difference was observed for cardiac hospitalizations., Conclusions: CA is associated with reduced ventricular arrhythmia recurrence, appropriate ICD therapies/shocks, electrical storm, and cardiac hospitalization, and might be effective in preventing future morbidity. Future trials are needed to support the continued benefit of these promising results, and to investigate the optimal timing of ablation., (Copyright © 2022 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Aims: Ventricular fibrillation (VF) occurring in the acute phase of ST-elevation myocardial infarction (STEMI) is the leading cause of sudden cardiac death worldwide. Several studies showed that reduced connexin 43 (Cx43) expression and reduced conduction velocity increase the risk of VF in acute myocardial infarction (MI). Furthermore, genetic background might predispose individuals to primary VF (PVF). The primary objective was to evaluate the presence of GJA1 variants in STEMI patients. The secondary objective was to evaluate the arrhythmogenic impact of GJA1 variants in STEMI patients with VF., Methods and Results: The MAP-IDM prospective cohort study included 966 STEMI patients and was designed to identify genetic predisposition to VF. A total of 483 (50.0%) STEMI patients with PVF were included. The presence of GJA1 variants increased the risk of VF in STEMI patients [from 49.1 to 70.8%, P = 0.0423; odds ratio (OR): 0.40; 95% confidence interval: 0.16-0.97; P = 0.04]. The risk of PVF decreased with beta-blocker intake (from 53.5 to 44.8%, P = 0.0085), atrial fibrillation (from 50.7 to 26.4%, P = 0.0022), and with left ventricular ejection fraction >50% (from 60.2 to 41.4%, P < 0.0001). Among 16 GJA1 variants, three novel heterozygous missense variants were identified in three patients: V236I, H248R, and I327M. In vitro studies of these variants showed altered Cx43 localization and decreased cellular communication, mainly during acidosis., Conclusion: Connexin 43 variants are associated with increased VF susceptibility in STEMI patients. Restoring Cx43 function may be a potential therapeutic target to prevent PVF in patients with acute MI., Clinical Trial Registration: Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT00859300., Competing Interests: Conflict of interest: None declared., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background Heart failure (HF) has been increasing in prevalence, and a need exists for biomarkers with improved predictive and prognostic ability. GDF-15 (growth differentiation factor-15) is a novel biomarker associated with HF mortality, but no serial studies of GDF-15 have been conducted. This study aimed to investigate the association between GDF-15 levels over time and the occurrence of ventricular arrhythmias, HF hospitalizations, and all-cause mortality. Methods and Results We used a retrospective case-control design to analyze 148 patients with ischemic and nonischemic cardiomyopathies and primary prevention implantable cardioverter-defibrillator (ICD) from the PROSe-ICD (Prospective Observational Study of the ICD in Sudden Cardiac Death Prevention) cohort. Patients had blood drawn every 6 months and after each appropriate ICD therapy and were followed for a median follow-up of 4.6 years, between 2005 to 2019. We compared serum GDF-15 levels within ±90 days of an event among those with a ventricular tachycardia/fibrillation event requiring ICD therapies and those hospitalized for decompensated HF. A comparator/control group comprised patients with GDF-15 levels available during 2-year follow-up periods without events. Median follow-up was 4.6 years in the 148 patients studied (mean age 58±12, 27% women). The HF cohort had greater median GDF-15 values within 90 days (1797 pg/mL) and 30 days (2039 pg/mL) compared with the control group (1062 pg/mL, both P <0.0001). No difference was found between the ventricular tachycardia/fibrillation subgroup within 90 days (1173 pg/mL, P =0.60) or 30 days (1173 pg/mL, P =0.78) and the control group. GDF-15 was also significantly predictive of mortality (hazard ratio, 3.17 [95% CI, 2.33-4.30]). Conclusions GDF-15 levels are associated with HF hospitalization and mortality but not ventricular arrhythmic events.

Background: Refractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) cardiac arrest describes a subset of patients who do not respond to standard Advanced Cardiac Life Support (ACLS) interventions and are associated with poor outcomes. Esmolol administration and vector change defibrillation have shown promise in improving outcomes in these patients, however evidence is limited., Objectives: This study compares clinical outcomes between patients with prehospital refractory VF/pVT who received an Emergency Medical Service (EMS) bundle, comprised of esmolol administration, vector change defibrillation, and dose-capped epinephrine at 3 mg, to patients who received standard ACLS interventions., Methods: This multicenter, retrospective, cohort study evaluated medical records between October 18, 2017 and March 15, 2022. Patients were enrolled if they experienced a prehospital cardiac arrest with the rhythm VF or pVT, had received at least three standard defibrillations, at least 3 mg of epinephrine, and 300 mg of amiodarone. Patients who received the EMS bundle after its implementation were compared to patients who received standard ACLS interventions prior to its implementation. The primary outcome was sustained return of spontaneous circulation (ROSC), defined as ROSC lasting 20 min without recurrence of cardiac arrest. Secondary outcomes included the incidence of any ROSC, survival to hospital arrival, survival at hospital discharge, and neurologically intact survival at hospital discharge., Results: Eighty-three patients were included in the study. Thirty-six were included in the pre-EMS bundle group and 47 patients were included in the post-EMS bundle group. Patients in the pre-EMS bundle group achieved significantly higher rates of sustained ROSC (58.3% vs 17%, p < 0.001), any ROSC (66.7% vs 19.1%, p < 0.001), and survival to hospital arrival (55.6% vs 17%, p < 0.001). The rates of survival to hospital discharge (16.7% vs 6.4%, p = 0.17) and neurologically intact survival at hospital discharge (5.9% vs 4.3%, p = 1.00) were not significantly different between groups., Conclusions: Patients who received the EMS bundle achieved sustained ROSC significantly less often and were less likely to have pulses at hospital arrival. The incidence of neurologically intact survival was low and similar between groups., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Understanding health care resource utilisation and its associated costs are important for identifying areas of improvement regarding resource allocations. However, there is limited research exploring this issue in the setting of Brugada syndrome (BrS).This was a retrospective territory-wide study of BrS patients from Hong Kong. Healthcare resource utilisation for accident and emergency (A&E), inpatient and specialist outpatient attendances were analyzed over a 19-year period, with their associated costs presented in US dollars. A total of 507 BrS patients with a mean presentation age of 49.9 ± 16.3 years old were included. Of these, 384 patients displayed spontaneous type 1 electrocardiographic (ECG) Brugada pattern and 77 patients had presented with ventricular tachycardia/ventricular fibrillation (VT/VF). At the individual patient level, the median annualized costs were $110 (52-224) at the (A&E) setting, $6812 (1982-32414) at the inpatient setting and $557 (326-1001) for specialist outpatient attendances. Patients with initial VT/VF presentation had overall greater costs in inpatient ($20161 [9147-189215] vs $5290 [1613-24937],P < 0.0001) and specialist outpatient setting ($776 [438-1076] vs $542 [293-972],P = 0.015) compared to those who did not present VT. In addition, patients without Type 1 ECG pattern had greater median costs in the specialist outpatient setting ($7036 [3136-14378] vs $4895 [2409-10554],p=0.019). There is a greater health care demand in the inpatient and specialist outpatient settings for BrS patients. The most expensive attendance type was inpatient setting stay at $6812 per year. The total median annualized cost of BrS patients without VT/VF presentation was 78% lower compared to patients with VT/VF presentation., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: High-risk patients with coronary heart disease who develop acute myocardial infarction (AMI) have severe coronary lesions. If severe complications occur, such as malignant ventricular arrhythmia, cardiogenic shock, and cardiac arrest, implementation of emergency percutaneous coronary intervention (PCI) may be hindered, leading to a higher perioperative mortality rate. Extracorporeal membrane oxygenation (ECMO) can pave the way for rapid myocardial reperfusion therapy. When cardiac arrest occurs, hemodynamic support with ECMO can facilitate revascularization with PCI, which can increase the time available for further salvage and treatment and reduce intraoperative risk during PCI., Case Presentation: Herein, we report a case of a 61-year-old man with AMI who suffered electrical storm of sustained malignant ventricular fibrillation, cardiogenic shock, and cardiac arrest and was successfully treated with PCI with ECMO support. During PCI, repeated aspiration and removal of the right coronary artery thrombus were performed, and blood flow was restored after right coronary artery balloon dilation. One episode of defibrillation was delivered to restore sinus rhythm. Then, stents were implanted in the distal and proximal right coronary artery lesions to achieve revascularization. After PCI with ECMO support, irreversible malignant arrhythmia returned to sinus rhythm through coronary perfusion, which prevented death following unsuccessful cardiopulmonary resuscitation. After applying active treatments, including anti-shock, mechanical ventilation, anti-inflammation, and organ support, the patient was discharged after his condition and vital signs stabilized. The patient was followed up once a week after hospital discharge, and his cardiopulmonary function recovered well., Conclusions: With ECMO support, PCI should be performed immediately in patients with inferior wall AMI complicated by electrical storm of sustained ventricular fibrillation, cardiogenic shock, and cardiac arrest to facilitate stent placement, achieve complete revascularization, restore coronary perfusion, and avoid death., (© 2023. The Author(s).)

Background: Brugada syndrome (BrS), which is characterized by J-point elevation in right precordial leads of a 12-lead electrocardiogram, is associated with the occurrence of ventricular fibrillation (VF). However, risk stratification of VF in patients with BrS remains challenging., Objective: The aim of this study was to identify a risk predictor of VF in patients with BrS using pharmacological tests., Methods: Twenty-one consecutive patients with BrS and a history of documented spontaneous VF (n = 16) or syncope presumed to be caused by lethal ventricular arrhythmia (n = 5) were enrolled. J-wave changes in response to intravenous verapamil, propranolol, and pilsicainide were separately assessed., Results: During the median follow-up period of 86.0 months, 8 patients had VF recurrence (recurrence group) and 13 patients did not have VF recurrence (non-recurrence group). Intravenous propranolol injection induced significant J-wave augmentation (i.e., increase in amplitude >0.1 mV) in the inferior and/or lateral leads in the recurrence group compared to the non-recurrence group (p = .048 and p = .015, respectively). Kaplan-Meier analysis revealed that VF recurrence is significantly higher in patients with BrS and J-wave augmentation due to intravenous propranolol than in patients without J-wave augmentation (p = .014)., Conclusion: The study results show that propranolol-induced J-wave augmentation is involved in the risk of VF in patients with BrS. The results suggest that early repolarization patterns in response to pharmacological tests may be useful for risk stratification of VF in patients with symptomatic BrS., (© 2022 Wiley Periodicals LLC.)

Introduction: Perfusion pressure and chest compression quality are generally considered key determinants of brain oxygenation during cardiopulmonary resuscitation (CPR) and the impact of oxygen administration is less clear. We compared ventilation with 100% and 50% oxygen during ineffective manual chest compressions and hypothesized that 100% oxygen would improve brain oxygenation., Methods: Ventricular fibrillation (VF) was induced electrically in anaesthetized pigs and left untreated for 5 minutes, followed by randomization to ineffective manual CPR with ventilation of 50% or 100% oxygen. The first defibrillation was performed 10 minutes after induction of VF, and CPR continued with mechanical chest compressions (LUCAS2™) and defibrillation every 2 minutes until 36 minutes or return of spontaneous circulation (ROSC). Brain oxygenation was measured with near-infrared spectroscopy (rSO 2 ) and invasive brain tissue oxygen (PbtO 2 ) with a probe (NEUROVENT-PTO, RAUMEDIC) inserted into frontal brain tissue. Cerebral oxygenation was compared between groups with Mann-Whitney U tests and linear mixed models., Results: Twenty-eight pigs were included in the study: 14 subjects in each group. During ineffective chest compressions relative PbtO 2 was higher in the group ventilated with 100% compared to 50% oxygen (5.2 mmHg [1.4-20.5] vs 2.2 [0.8-6.8], p = 0.001), but there was no difference in rSO 2 (22% [16-28] vs 18 [15-25], p = 0.090). The use of 50% or 100% oxygen showed no difference in relative PbtO 2 (p = 1.00) and rSO 2 (p = 0.206) during mechanical CPR., Conclusions: The use of 100% compared to 50% oxygen during ineffective manual CPR improved brain oxygenation measured invasively in brain tissue, but there was no difference in rSO 2 ., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

BACKGROUND Prevention of lethal arrhythmias in congenital long QT syndrome type 1 (LQT1) requires avoidance of sympathoexcitation, drugs that prolong QT, and electrolyte abnormalities. However, it is often difficult to avoid all these risks in the perioperative period of open heart surgery. Herein, we report hypokalemia-induced cardiac arrest in a postoperative cardiac patient with LQT1 on catecholamine. CASE REPORT A 79-year-old woman underwent surgical aortic valve replacement for severe aortic stenosis. Although the initial plan was not to use catecholamine, catecholamine was used in the Postoperative Intensive Care Unit with attention to QT interval and electrolytes due to heart failure caused by postoperative bleeding. Serum potassium levels were controlled above 4.5 mEq/L, and no arrhythmic events occurred. On postoperative day 4, the patient was started on insulin owing to hyperglycemia. Cardiac arrest occurred after the first insulin dose; the implantable cardioverter defibrillator was activated, and the patient's own heartbeat resumed. Subsequent examination revealed that a marked decrease in serum potassium level had occurred after insulin administration. The electrocardiogram showed obvious QT prolongation and ventricular fibrillation following R on T. Thereafter, under strict potassium management, there was no recurrence of cardiac arrest events. CONCLUSIONS A patient with LQT1 who underwent open heart surgery developed ventricular fibrillation after Torsades de Pointes, probably due to hypokalemia after insulin administration in addition to catecholamine. It is important to check serum potassium levels to avoid the onset of Torsades de Pointes in patients with long QT syndrome. In addition, the impact of insulin administration was reaffirmed.

Background: Out-of-hospital cardiac arrest (OHCA) with shockable rhythms, including ventricular fibrillation and pulseless ventricular tachycardia, is associated with better prognosis and neurological outcome than OHCA due to other rhythms. Antiarrhythmic drugs, including lidocaine and amiodarone, are often used for defibrillation. This study aimed to compare the effects of lidocaine and amiodarone on the prognosis and neurological outcome of patients with OHCA due to shockable rhythms in a real-world setting., Methods: We conducted a retrospective observational study using a multicenter OHCA registry of 91 participating hospitals in Japan. We included adult patients with shockable rhythms, such as ventricular fibrillation and pulseless ventricular tachycardia, who were administered either lidocaine or amiodarone. The primary outcome was 30-day survival, and the secondary outcome was a good neurological outcome at 30 days. We compared the effects of lidocaine and amiodarone for patients with OHCA due to shockable rhythms for these outcomes using logistic regression analysis after propensity score matching (PSM)., Results: Of the 51,199 patients registered in the OHCA registry, 1970 patients were analyzed. In total, 105 patients (5.3%) were administered lidocaine, and 1865 (94.7%) were administered amiodarone. After performing PSM with amiodarone used as the reference, the odds ratios and 95% confidence intervals of lidocaine use for 30-day survival and 30-day good neurological outcome were 1.44 (0.58-3.61) and 1.77 (0.59-5.29), respectively., Conclusion: The use of lidocaine and amiodarone for patients with OHCA due to shockable rhythms within a real-world setting showed no significant differences in short-term mortality or neurological outcome. There is no evidence that either amiodarone or lidocaine is superior in treatment; thus, either or both drugs could be administered., (© 2022. The Author(s).)

Background: Ventricular fibrillation (VF) waveform measures reflect myocardial physiologic status. Continuous assessment of VF prognosis using such measures could guide resuscitation, but has not been possible due to CPR artifact in the ECG. A recently-validated VF measure (termed VitalityScore), which estimates the probability (0-100%) of return-of-rhythm (ROR) after shock, can assess VF during CPR, suggesting potential for continuous application during resuscitation., Objective: We evaluated VF using VitalityScore to characterize VF prognostic status continuously during resuscitation., Methods: We characterized VF using VitalityScore during 60 seconds of CPR and 10 seconds of subsequent pre-shock CPR interruption in patients with out-of-hospital VF arrest. VitalityScore utility was quantified using area under the receiver operating characteristic curve (AUC). VitalityScore trends over time were estimated using mixed-effects models, and associations between trends and ROR were evaluated using logistic models. A sensitivity analysis characterized VF during protracted (100-second) periods of CPR., Results: We evaluated 724 VF episodes among 434 patients. After an initial decline from 0-8 seconds following VF onset, VitalityScore increased slightly during CPR from 8-60 seconds (slope: 0.18%/min). During the first 10 seconds of subsequent pre-shock CPR interruption, VitalityScore declined (slope: -14%/min). VitalityScore predicted ROR throughout CPR with AUCs 0.73-0.75. Individual VitalityScore trends during 8-60 seconds of CPR were marginally associated with subsequent ROR (adjusted odds ratio for interquartile slope change (OR) = 1.10, p = 0.21), and became significant with protracted (100 seconds) CPR duration (OR = 1.28, p = 0.006)., Conclusion: VF prognostic status can be continuously evaluated during resuscitation, a development that could translate to patient-specific resuscitation strategies., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: The study aimed to explore the characteristics, predictors, and chronological trends of outcomes for adult out-of-hospital cardiac arrests (OHCAs) with shockable rhythms., Methods: A 7-year, community-wide observational study using an Utstein-style registry was conducted. Patients who were not transported, those who experienced trauma and those who lacked electronic electrocardiography data were excluded; those with initial shockable rhythms of ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) were included. Outcomes were survival of discharge (SOD) and favorable neurological status (CPC 1-2). The outcome predictors, chronological trends, and their relationship with system interventions were analyzed., Results: Of the 1544 shockable OHCAs (incidence 12.6%) included, 97.6% had VF and 2.4% had pVT. VF showed better outcomes than pVT. Predictors for both outcomes (SOD; CPC 1-2) were chronological change (adjusted odds ratio [aOR]: 1.133; 1.176), younger age (aOR: 0.973; 0.967), shorter response time (aOR: 0.998; 0.999), shorter scene time (aOR: 0.999; 0.999), witnessed collapse (aOR: 1.668; 1.670), and bystander cardiopulmonary resuscitation (BCPR) (aOR: 1.448; 1.576). Predictors for only SOD were public location (aOR: 1.450) and successful prehospital defibrillation (aOR: 3.374). The use of the supraglottic airway was associated with adverse outcomes. Chronologically with system interventions, BCPR rate, the proportion of shockable OHCA, and improved neurological outcomes increased over time., Conclusion: The incidence of shockable OHCA remained low in Asian community. VF showed better outcomes than pVT. Over time, the incidence of shockable rhythm, BCPR rate and patient outcomes did improve with health system interventions. The number of prehospital defibrillations did not predict outcomes., Competing Interests: Declaration of competing interest The authors have no conflicts of interest relevant to this article., (Copyright © 2022. Published by Elsevier B.V.)

Background: The subcutaneous implantable cardioverter defibrillator (S-ICD) was developed as an alternative to the transvenous ICD, to prevent lead-related complications associated with the latter. The absence of intravascular or intracardiac components offers potential advantages to pediatric patients., Aims: The aim of the study is to present an overview of our experience with S-ICDs in the pediatric center that, currently, has performed the largest number of implantations in children in Poland., Methods: Retrospective analysis of data from medical history, qualification, implantation procedure, and S-ICD post-implantation observations in 11 pediatric patients were performed., Results: S-ICDs were implanted in 11 patients, 8 boys and 3 girls, aged 12-17 years. The S-ICD was implanted for primary prevention in seven patients: four with hypertrophic cardiomyopathy (HCM), two with dilated cardiomyopathy (DCM), and one with arrhythmogenic right ventricular cardiomyopathy (ARVC). It was implanted for secondary prevention in four patients: two with sudden cardiac arrest (SCA) in the course of idiopathic ventricular fibrillation (IVF), one with long QT syndrome (LQTS) after probable SCA, and one with Brugada syndrome after SCA. In all patients, the device was implanted intramuscularly. One patient did not have a defibrillation test performed due to the presence of an intracardiac thrombus. In one patient, during screening, it was decided to implant an electrode on the right side of the sternum. There were no early or late complications with any of the procedures. So far, no inadequate discharges have been observed., Conclusions: Our results prove the efficacy of the S-ICD treatment option along with technically simple surgery, which supports its further and more widespread application in children.

Children, adolescents, and young adults with conditions such as cardiomyopathies and channelopathies are at higher risk of sudden cardiac death caused by lethal arrhythmias, especially ventricular fibrillation. Timely defibrillation saves lives. Patients thought to be at significantly high risk of sudden death typically undergo placement of an implantable cardioverter-defibrillator. Patients thought to be at lower risk are typically followed medically but do not undergo implantable cardioverter-defibrillator placement. However, low risk does not equal no risk. Compared with the general population, many of these patients are at significantly higher risk for lethal arrhythmias. We make the case that such individuals and families will benefit from having an at-home automatic external defibrillator. Used in conjunction with conventional measures such as training on cardiopulmonary resuscitation, an at-home automatic external defibrillator could lead to significantly shortened time to defibrillation with better overall and neurological survival. We recommend that the cost of such home automatic external defibrillators should be covered by medical insurance., Competing Interests: Funding Support and Author Disclosures Dr Balaji has a grant from Medtronic to study sudden cardiac death in hypertrophic cardiomyopathy; and is a consultant for Milestone and Janssen pharmaceuticals. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)