Prediction model of in-hospital cardiac arrest using machine learning in the early phase of hospitalization.

In hospitals, the deterioration of a patient's condition leading to death is often preceded by physiological abnormalities in the hours to days beforehand. Several risk-scoring systems have been developed to identify patients at risk of major adverse events; however, such systems often exhibit low sensitivity and specificity. To identify the risk factors associated with in-hospital cardiac arrest (IHCA), we conducted a retrospective cohort study at a tertiary medical center in Taiwan. Four machine learning algorithms were employed to identify the factors most predictive of IHCA. The support vector machine model was discovered to be the most effective at predicting IHCA. The ten most critical physiological parameters at 8 h prior to the event were pulse rate, age, white blood cell count, lymphocyte count, body temperature, body mass index, systolic and diastolic blood pressure, platelet count, and use of central nervous system-active medication. Using these parameters, we can enhance early warning and rapid response systems in our hospital, potentially reducing the incidence of IHCA in clinical practice.

The impact on users of an unfamiliar AED following a recent training experience: A randomized cross over simulation study.

Objective: This study examined the impact of prior familiarity with automated external defibrillator (AED) models on the time of defibrillation and the emotional experiences of laypersons. Methods: We conducted a randomized cross over simulation study with 123 participants to assess their reactions to both familiar and unfamiliar AED models. The time to first defibrillation was measured using three different AED training models, two of which were previously unknown to the participants. Additionally, semi-structured interviews were held with the participants to gather further insights. Results: Participants took longer to initiate defibrillation with unfamiliar (M = 34 s) AEDs compared to familiar (M = 27 s) ones. This delay was accompanied by feelings of confusion, nervousness, and anxiety. Factors such as the design of the AED covers, electrodes, and buttons were identified as sources of confusion. Nonetheless, clear instructions and similarities between devices helped facilitate their use. Conclusion: The findings suggest that AED design and familiarity with different AED designs may affect performance by laypersons. To improve user confidence, it would be useful to familiarize users with a variety of AED models as part of training initiatives. Understanding the impact of AED familiarity on rescuer's response can guide CPR training strategies and improve outcomes for OHCA. As more AED models become available to the public, the user-friendliness of AEDs may also be improved. It is beneficial for AED manufacturers to consider the results of research when developing new models.

Public access defibrillator locations and details in Forsyth County, North Carolina: Results of a telephone survey canvas of large businesses to facilitate out-of-hospital cardiac arrest treatment.

BACKGROUND: Limited data are available on locations of public access defibrillation programs across communities in the United States, despite their widespread presence. Our goal was to determine publicly available AED locations of large businesses in a mixed urban-rural county. We then compared our survey results to a NC state-mandated AED registry and the county's emergency medical dispatch center AED registry. METHODS: We conducted structured phone surveys of all large businesses (>19 employees) and select small businesses (healthcare, government, childcare, educational, and religious organizations with 1-19 employees) in Forsyth County, NC (n = 1702) to determine AED ownership and location. In addition, AED lists were elicited from multi-building organizations (e.g., health systems, universities, and local government), the NC Office of Emergency Medical Services (OEMS), and the Forsyth County emergency medical dispatch center. RESULTS: Our survey yielded a response rate of 79.1 % and identified 411 businesses with ≥ 1 AEDs. An additional 162 AED locations were contained in AED lists from multi-building organizations and registries. In total, our canvas identified 963 AEDs at 573 unique locations. The majority of AEDs (65.1 % [627/963]) were not previously registered in the NC OEMS AED registry. Few identified AEDs (11.8 % [114/963]) were listed in the county emergency medical dispatch center registry.

The factors associated with the provision of public access defibrillation in Japan - A nationwide cohort study.

AIM: The association between out-of-hospital cardiac arrest (OHCA) and the appropriate provision of public access defibrillation (PAD) remains unclear. This study aimed to evaluate the factors associated with whether or not PAD was provided. METHODS: This retrospective cohort study utilized the All-Japan Utstein and Emergency Transport Registries in 2021. We included OHCA patients who were applied to automated external defibrillators (AEDs) by bystanders and were deemed eligible for defibrillation by an AED. We defined PAD provided or no PAD provided based on bystander defibrillation. Multivariable logistic regression analysis with the Firth bias adjustment method was employed to estimate the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for the exploratory evaluation of factors associated with PAD provided. RESULTS: 1949 patients were eligible for analysis (PAD provided, n = 1696 [87.0%]; no PAD provided, n = 253 [13.0%]). Factors positively associated with PAD provided were male (AOR [95% CI], 1.61 [1.17-2.21]; vs. female), other public place incidence (AOR [95% CI], 10.65 [1.40-1367.54]; vs. public place), non-family member witnessed (AOR [95% CI], 2.51 [1.86-3.42]; vs. unwitnessed) and conventional cardiopulmonary resuscitation (CPR), (AOR [95% CI], 1.75 [1.17-2.67]; vs. hands-only CPR). Conversely, factors negatively associated with no PAD provided were over 65 years old (AOR [95% CI], 0.48 [0.28-0.80]; vs. 19-64 yr), night-time onset (AOR [95% CI], 0.61 [0.45-0.83]; vs. daytime), non-cardiogenic (AOR [95% CI], 0.43 [0.31-0.61]; vs. cardiogenic), home setting (AOR [95% CI], 0.33 [0.14-0.83]; vs. public place), healthcare facility setting (AOR [95% CI], 0.40 [0.23-0.66]; vs. public place), no bystander CPR (AOR [95% CI], 0.31 [0.14-0.71]; vs. hands-only CPR), and dispatcher-assistance (AOR [95% CI], 0.72 [0.53-0.97]; vs. no dispatcher-assistance). CONCLUSION: Male patients, other public place onset, witnessed by non-family and conventional CPR were associated with PAD provide. Therefore, training skilled first responders to use AEDs appropriately is necessary.

Prediction of the effect of electrical defibrillation by using spectral feature parameters.

This paper proposes a system for predicting the effect of electrical defibrillation using spectral feature parameters. The proposed method consists of two-stage prediction. The first stage involves predicting whether electrical defibrillation is "Successful" or "Ineffective." As the next stage, if the proposed prediction system determines "Ineffective," the proposed system discriminates between "VF recurrence" or "Failure" for electrical defibrillation. To develop the prediction system, feature parameters for the target electrocardiograms (ECGs) were first extracted by using the wavelet transform and spectral analysis. Next, effective feature parameters for prediction are selected through an analysis of variance. Moreover, in the preprocessing phase, the Synthetic Minority Oversampling Technique method and standardization are introduced. Finally, support vector machines with some kernel functions and the regularization method are utilized to predict the three states, i.e., "Successful," "Failure," and "VF recurrence," for electrical defibrillation in two phases. In this paper, we present our analysis method for ECGs and evaluate the effectiveness of the proposed prediction system.

Novel Recycling, Defibrillation, and Delignification Methods for Isolating α-Cellulose from Different Lignocellulosic Precursors for the Eco-Friendly Fiber Industry.

Alpha-cellulose, a unique, natural, and essential polymer for the fiber industry, was isolated in an ecofriendly manner using eleven novel systems comprising recycling, defibrillation, and delignification of prosenchyma cells (vessels and fibers) of ten lignocellulosic resources. Seven hardwood species were selected, namely Conocorpus erectus, Leucaena leucocephala, Simmondsia chinensis, Azadirachta indica, Moringa perigrina, Calotropis procera, and Ceiba pentandra. Moreover, three recycled cellulosic wastes were chosen due to their high levels of accumulation annually in the fibrous wastes of Saudi Arabia, namely recycled writing papers (RWPs), recycled newspapers (RNPs), and recycled cardboard (RC). Each of the parent samples and the resultant alpha-cellulose was characterized physically, chemically, and anatomically. The properties examined differed significantly among the ten resources studied, and their mean values lies within the cited ranges. Among the seven tree species, L. leucocephala was the best cellulosic precursor due to its higher fiber yield (55.46%) and holocellulose content (70.82%) with the lowest content of Klasson lignin (18.86%). Moreover, RWP was the best α-cellulose precursor, exhibiting the highest holocellulose (87%) and the lowest lignin (2%) content. Despite the high content of ash and other additives accompanied with the three lignocellulosic wastes that were added upon fabrication to enhance their quality (10%, 11%, and 14.52% for RWP, RNP, and RC, respectively), they can be considered as an inexhaustible treasure source for cellulose production due to the ease and efficiency of discarding their ash minerals using the novel CaCO3-elimination process along with the other innovative techniques. Besides its main role for adjusting the pH of the delignification process, citric acid serves as an effective and environmentally friendly additive enhancing lignin breakdown while preserving cellulose integrity. Comparing the thermal behavior of the ten cellulosic resources, C. procera and C. pentandra exhibited the highest moisture content and void volume as well as having the lowest specific gravity, crystallinity index, and holocellulose content and were found to yield the highest mass loss during their thermal degradation based on thermogravimetric and differential thermal analysis in an inert atmosphere. However, the other resources used were found to yield lower mass losses. The obtained results indicate that using the innovative procedures of recycling, defibrillation, and delignification did not alter or distort either the yield or structure of the isolated α-cellulose. This is a clear indicator of their high efficiency for isolating cellulose from lignocellulosic precursors.

A quality improvement project to enhance the knowledge, skills, and attitude of healthcare workers regarding the use of defibrillators.

Introduction: Defibrillation is a critical intervention in managing cardiac emergencies, yet healthcare workers (HCWs) preparation for utilizing defibrillators remains inadequate, particularly in low and middle-income countries. This quality improvement project aimed to assess and enhance HCWs' knowledge, skills, and attitudes toward defibrillator use in the emergency department (ED) through a 1-h defibrillator workshop. Methodology: An observational clinical audit was conducted within the ED of a tertiary care hospital. Pre- and post-workshop data were collected from the participants using structured questionnaires for demographics, knowledge assessment (20 multiple-choice questions), skills assessment (10-step checklist), and attitude evaluation (Likert-scale statements). The workshop included theoretical instruction and hands-on practice, with a post-workshop assessment conducted one week later. Data analysis employed descriptive statistics and paired t-tests, while ethical considerations ensured confidentiality and consent. Results: The study included 38 participants, demonstrating significant gaps in defibrillator knowledge, skills, and attitudes pre-workshop. Post-workshop assessments revealed a marked improvement in knowledge scores (P<0.05), attitudes (P<0.05), and practical skills (P<0.05). Participants' confidence and preparation for managing cardiac emergencies notably increased, indicating the workshop's efficacy in addressing the identified deficiencies. Conclusion: The 1-h defibrillator workshop effectively enhanced HCWs' competence and readiness to utilize ED defibrillators. The observed improvements underscore the importance of targeted educational interventions in bridging knowledge gaps and fostering proactive attitudes toward emergency management. Regular training sessions should be conducted to sustain these enhancements and improve patient outcomes in the ED.

Defibrillation strategies for patients with refractory ventricular fibrillation: A systematic review and meta-analysis.

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/.

Effect of posture on position of subcutaneous implantable cardioverter-defibrillator.

BACKGROUND: The PRAETORIAN score was developed as an alternative for defibrillation testing after subcutaneous implantable cardioverter-defibrillator implantation to assess 3 aspects of implant position on a bidirectional chest radiograph. The score is validated on a standard standing chest radiograph with arms elevated in the lateral view. OBJECTIVE: We aimed to evaluate the effect of different anatomic positions on the PRAETORIAN score. METHODS: Thirty patients with a subcutaneous implantable cardioverter-defibrillator underwent standard posterior-anterior and lateral chest radiography, including additional lateral views in 2 positions: standing with arms down and supine with arms alongside the body. PRAETORIAN score and weighted κ coefficient were calculated for each position. RESULTS: In 8 of 30 patients, the PRAETORIAN score was ≥90 in standard position. The agreement in PRAETORIAN score was substantial (κ = 0.677) for the position with the arms down and fair (κ = 0.399) for the supine position. With the arms down, the PRAETORIAN score decreased in 10 patients (33%), 4 of whom changed to a lower risk category. In supine position, the PRAETORIAN score decreased in 16 patients (53%), 7 of whom changed to a lower risk category, 1 from high to low risk. CONCLUSION: A supine or arms-down position during chest radiography can result in lower PRAETORIAN scores and underestimation of associated risk on defibrillation testing failure. This emphasizes the importance of correct anatomic positioning (arms up) during chest radiography when the PRAETORIAN score is used.

Combinations of First Responder and Drone Delivery to Achieve 5-Minute AED Deployment in OHCA.

Background: Defibrillation in the critical first minutes of out-of-hospital cardiac arrest (OHCA) can significantly improve survival. However, timely access to automated external defibrillators (AEDs) remains a barrier. Objectives: The authors estimated the impact of a statewide program for drone-delivered AEDs in North Carolina integrated into emergency medical service and first responder (FR) response for OHCA. Methods: Using Cardiac Arrest Registry to Enhance Survival registry data, we included 28,292 OHCA patients ≥18 years of age between 1 January 2013 and 31 December 2019 in 48 North Carolina counties. We estimated the improvement in response times (time from 9-1-1 call to AED arrival) achieved by 2 sequential interventions: 1) AEDs for all FRs; and 2) optimized placement of drones to maximize 5-minute AED arrival within each county. Interventions were evaluated with logistic regression models to estimate changes in initial shockable rhythm and survival. Results: Historical county-level median response times were 8.0 minutes (IQR: 7.0-9.0 minutes) with 16.5% of OHCAs having AED arrival times of <5 minutes (IQR: 11.2%-24.3%). Providing all FRs with AEDs improved median response to 7.0 minutes (IQR: 6.2-7.8 minutes) and increased OHCAs with <5-minute AED arrival to 22.3% (IQR: 16.4%-30.9%). Further incorporating optimized drone networks (326 drones across all 48 counties) improved median response to 4.8 minutes (IQR: 4.3-5.2 minutes) and OHCAs with <5-minute AED arrival to 56.3% (IQR: 46.9%-64.2%). Survival rates were estimated to increase by 34% for witnessed OHCAs with estimated drone arrival <5 minutes and ahead of FR and emergency medical service. Conclusions: Deployment of AEDs by FRs and optimized drone delivery can improve AED arrival times which may lead to improved clinical outcomes. Implementation studies are needed.

A manual synchronous low energy shock impedance as a predictor of successful defibrillation testing during subcutaneous ICD implantation.

BACKGROUND: Guidelines recommend defibrillation testing (DFT) during subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation. Implant position, patient characteristics and device factors, such as shock impedance, influence defibrillation success. To evaluate the shock impedance, a manual synchronous 10J shock (low energy synchronous shock [LESS]) can be delivered, without the need to induce ventricular fibrillation (VF). OBJECTIVE: To compare LESS and DFT impedance values and to evaluate the diagnostic accuracy of LESS impedance for predicting a successful DFT during S-ICD implantation. METHODS: Consecutive S-ICD implantations were included. Shock impedances were compared by paired t-tests. Univariate analysis was performed to investigate factors associated with successful DFT. A prediction model of successful DFT based on LESS impedance was assessed by logistic regression. Receiver operating characteristic (ROC) curve, area under the ROC curve and the Hosmer-Lemeshow tests were used to evaluate the accuracy of LESS impedance. RESULTS: Sixty patients were included (52 ± 14 years; 69% male). LESS and DFT impedance values were highly correlated (r2 = 0.97, p < .01). Patients with a failed first shock had higher body mass index (BMI) (30 ± 3 vs. 25.7 ± 4.3, p = .014), higher mean LESS (120 ± 35Ω vs. 86. ± 23Ω, p = .0013) and DFT impedance (122 ± 33Ω vs. 87 ± 24Ω, p = .0013). ROC analysis showed that LESS impedance had a good diagnostic performance in predicting a successful conversion test (AUC 84% [95% CI: 0.72-0.92]) with a cutoff value of <94Ω to identify a successful DFT (sensitivity 71%, specificity 73%). CONCLUSION: LESS impedance values without the need to induce VF can intraoperatively predict a successful DFT.

Bystander defibrillation for out-of-hospital cardiac arrest in Ireland.

Aims: To describe and explore predictors of bystander defibrillation in Ireland during the period 2012 to 2020. To examine the relationship between bystander defibrillation and health system developments. Methods: National level Out of Hospital Cardiac Arrest (OHCA) registry data were interrogated, focusing on patients who had defibrillation performed. Bystander defibrillation (as compared to EMS initiated defibrillation) was the key outcome of concern. Logistic regression models were built and refined by fitting predictors, performing stepwise variable selection and by adding pairwise interactions that improved fit. Results: The data included 5,751 cases of OHCA where defibrillation was performed. Increasing year over time (OR 1.17, 95% CI 1.13, 1.21) was associated with increased adjusted odds of bystander defibrillation. Non-cardiac aetiology was associated with reduced adjusted odds of bystander defibrillation (OR 0.30, 95% CI 0.21, 0.42), as were increasing age in years (OR 0.99, 95% CI 0.987, 0.996) and night-time occurrence of OHCA (OR 0.67, 95% CI 0.53, 0.83). Six further variables in the final model (sex, call response interval, incident location (home or other), who witnessed collapse (bystander or not witnessed), urban or rural location, and the COVID period) were involved in significant interactions. Bystander defibrillation was in general less likely in urban settings and at home locations. Whilst women were less likely to receive bystander defibrillation overall, in witnessed OHCAs, occurring outside the home, in urban areas and outside of the COVID-19 period women were more likely, to receive bystander defibrillation. Conclusions: Defibrillation by bystanders has increased incrementally over time in Ireland. Interventions to address sex and age-based disparities, alongside interventions to increase bystander defibrillation at night, in urban settings and at home locations are required.

Time difference between pad placement in single versus double external defibrillation: A live patient simulation model.

Background: Out-of-hospital cardiac arrest (OHCA) cause significant patient morbidity and mortality. Double sequential external defibrillation (DSED) represents an alternative treatment for OHCA patients, but the use is currently reserved for patients in refractory ventricular fibrillation. However, OHCA patients may achieve return of spontaneous circulation earlier with the use of DSED as initial treatment. This study compares the necessary times needed to establish pad placement in DSED compared to normal pad placement in a live patient simulation model. Methods: This study was an observational cohort study with ambulance personnel and live patient models. The procedure was performed on two patient categories, with BMI 20.9 (patient A) and BMI 32.8 (patient B). Two-member teams established two defibrillators ready for rhythm analysis. Time spent for standard and DSED procedure was registered in the same procedure. All team members performed the procedure on both patient categories. Results: In total, 108 procedures were performed on both patient categories. Mean time to standard pad placement was 24.6 ± 3.3 s for patient A, and 27.4 ± 3.7 s for patients B. Mean time to DSED pad placement was 38.3 ± 7.0 s for patient A, and 41.3 ± 7.4 s for patient B. Mean difference in time needed for DSED versus standard pad placement was 13.7 ± 4.8 s for patient A, and 13.9 ± 4.6 s for patient B. There was no significant difference in time spent between the two patient categories (p = 0.725). Conclusion: The necessary time to establish DSED versus standard defibrillation pad placement was short. This may support clinical studies on DSED as initial treatment for OHCA patients without risk of significant increase in time to first defibrillation.

Successful treatment of sepsis-induced cardiomyopathy with 36 hours refractory ventricular fibrillation: A case report.

Sepsis-induced cardiomyopathy (SIC) is generally characterized by decreased cardiac ejection fraction (EF) reversibility, less cardiac response to fluid resuscitation and catecholamine, and rarely complicated with refractory ventricular fibrillation (RVF). Once RVF is induced, the mortality rate of sepsis patients will be greatly increased. In this case, we reported a 26-year-old female patient who was diagnosed sepsis-induced cardiomyopathy (SIC), presented with RVF for 36 hours. The patient was maintained by the mechanical circulatory support (MCS) devices and experienced twice defibrillation. Finally, the patient was discharged without intracardial thrombosis and severe craniocerebral complications. This case suggested that early application of MCS and appropriate frequency of defibrillation may help the prognosis of SIC with RVF.

Chaos control in cardiac dynamics: terminating chaotic states with local minima pacing.

Current treatments of cardiac arrhythmias like ventricular fibrillation involve the application of a high-energy electric shock, that induces significant electrical currents in the myocardium and therefore involves severe side effects like possible tissue damage and post-traumatic stress. Using numerical simulations on four different models of 2D excitable media, this study demonstrates that low energy pulses applied shortly after local minima in the mean value of the transmembrane potential provide high success rates. We evaluate the performance of this approach for ten initial conditions of each model, ten spatially different stimuli, and different shock amplitudes. The investigated models of 2D excitable media cover a broad range of dominant frequencies and number of phase singularities, which demonstrates, that our findings are not limited to a specific kind of model or parameterization of it. Thus, we propose a method that incorporates the dynamics of the underlying system, even during pacing, and solely relies on a scalar observable, which is easily measurable in numerical simulations.

A His bundle pacing protocol for suppressing ventricular arrhythmia maintenance and improving defibrillation efficacy.

BACKGROUND: The excitable gap (EG), defined as the excitable tissue between two subsequent wavefronts of depolarization, is critical for maintaining reentry that underlies deadly ventricular arrhythmias. EG in the His-Purkinje Network (HPN) plays an important role in the maintenance of electrical wave reentry that underlies these arrhythmias. OBJECTIVE: To determine if rapid His bundle pacing (HBP) during reentry reduces the amount of EG in the HPN and ventricular myocardium to suppress reentry maintenance and/or improve defibrillation efficacy. METHODS: In a virtual human biventricular model, reentry was initiated with rapid line pacing followed by HBP delivered for 3, 6, or 9 s at pacing cycle lengths (PCLs) ranging from 10 to 300 ms (n=30). EG was calculated independently for the HPN and myocardium over each PCL. Defibrillation efficacy was assessed for each PCL by stimulating myocardial surface EG with delays ranging from 0.25 to 9 s (increments of 0.25 s, n=36) after the start of HBP. Defibrillation was successful if reentry terminated within 1 s after EG stimulation. This defibrillation protocol was repeated without HBP. To test the approach under different pathological conditions, all protocols were repeated in the model with right (RBBB) or left (LBBB) bundle branch block. RESULTS: Compared to without pacing, HBP for >3 seconds reduced average EG in the HPN and myocardium across a broad range of PCLs for the default, RBBB, and LBBB models. HBP >6 seconds terminated reentrant arrhythmia by converting HPN activation to a sinus rhythm behavior in the default (6/30 PCLs) and RBBB (7/30 PCLs) models. Myocardial EG stimulation during HBP increased the number of successful defibrillation attempts by 3%-19% for 30/30 PCLs in the default model, 3%-6% for 14/30 PCLs in the RBBB model, and 3%-11% for 27/30 PCLs in the LBBB model. CONCLUSION: HBP can reduce the amount of excitable gap and suppress reentry maintenance in the HPN and myocardium. HBP can also improve the efficacy of low-energy defibrillation approaches targeting excitable myocardium. HBP during reentrant arrhythmias is a promising anti-arrhythmic and defibrillation strategy.