Journal articles: 'Defibrillation'

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Ul Haq, Ehtesham, and Bassam Omar. "Traumatic Tension Pneumothorax as a Cause of ICD Failure: A Case Report and Review of the Literature." Case Reports in Cardiology 2014 (2014): 1–4. http://dx.doi.org/10.1155/2014/261705.

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Background. Tension pneumothorax can infrequently cause ventricular arrhythmias and increase the threshold of defibrillation. It should be suspected whenever there is difficulty in defibrillation for a ventricular arrhythmia.Purpose. To report a case of traumatic tension pneumothorax leading to ventricular tachycardia and causing defibrillator failure.Case. A 65-year-old African-American female was brought in to our emergency department complaining of dyspnea after being forced down by cops. She had history of mitral valve replacement for severe mitral regurgitation and biventricular implantable cardioverter defibrillator inserted for nonischemic cardiomyopathy. Shortly after arrival, she developed sustained ventricular tachycardia, causing repetitive unsuccessful ICD shocks. She was intubated and ventricular tachycardia resolved with amiodarone. Chest radiograph revealed large left sided tension pneumothorax which was promptly drained. The patient was treated for congestive heart failure; she was extubated on the third day of admission, and the chest tube was removed.Conclusion. Prompt recognition of tension pneumothorax is essential, by maintaining a high index of suspicion in patients with an increased defibrillation threshold causing ineffective defibrillations.

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Curnis, Antonio, Claudio Muneretto, Gianluigi Bisleri, Manuel Cerini, Lorenza Inama, Francesca Salghetti, Raffaella De Vito, et al. "Thoracoscopic Implantation of An Array Electrode in the Pericardium Transverse Sinus to Reduce Defibrillation Threshold." Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery 12, no. 4 (July 2017): e6-e9. http://dx.doi.org/10.1097/imi.0000000000000384.

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Among the implantable cardioverter defibrillator recipients, there is still a subgroup of patients in whom the defibrillation threshold is too high and the maximal shock output of the implantable cardioverter defibrillator can fail to terminate a ventricular arrhythmia. We report a new thoracoscopic minimally invasive approach to place a standard array electrode in the transverse pericardial sinus of a patient implanted with a cardiac resynchronization and defibrillation therapy device with persistent high defibrillation threshold. This approach was developed to achieve very low shock impedance with a consequent increase in the current flow and reduction of defibrillation threshold.

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Skyschally, Andreas, Georgios Amanakis, Markus Neuhäuser, Petra Kleinbongard, and Gerd Heusch. "Impact of electrical defibrillation on infarct size and no-reflow in pigs subjected to myocardial ischemia-reperfusion without and with ischemic conditioning." American Journal of Physiology-Heart and Circulatory Physiology 313, no. 5 (November 1, 2017): H871—H878. http://dx.doi.org/10.1152/ajpheart.00293.2017.

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Ventricular fibrillation (VF) occurs frequently during myocardial ischemia-reperfusion (I/R) and must then be terminated by electrical defibrillation. We have investigated the impact of VF/defibrillation on infarct size (IS) or area of no reflow (NR) without and with ischemic conditioning interventions. Anesthetized pigs were subjected to 60/180 min of coronary occlusion/reperfusion. VF, as identified from the ECG, was terminated by intrathoracic defibrillation. The area at risk (AAR), IS, and NR were determined by staining techniques (patent blue, triphenyltetrazolium chloride, and thioflavin-S). Four experimental protocols were analyzed: I/R ( n = 49), I/R with ischemic preconditioning (IPC; n = 22), I/R with ischemic postconditioning (POCO; n = 22), or I/R with remote IPC (RIPC; n = 34). The incidence of VF was not different between I/R (44%), IPC (45%), POCO (50%), and RIPC (33%). IS was reduced by IPC (23 ± 12% of AAR), POCO (31 ± 16%), and RIPC (22 ± 13%, all P < 0.05 vs. I/R: 41 ± 12%). NR was not different between protocols (I/R: 17 ± 15% of AAR, IPC: 15 ± 18%, POCO: 25 ± 16%, and RIPC: 18 ± 17%). In pigs with defibrillation, IS was 50% larger than in pigs without defibrillation but independent of the number of defibrillations. Analysis of covariance confirmed the established determinants of IS, i.e., AAR, residual blood flow during ischemia (RMBFi), and a conditioning protocol, and revealed VF/defibrillation as a novel covariate. VF/defibrillation in turn was associated with larger AAR and lower RMBFi. Lack of dose-response relation between IS and the number of defibrillations excluded direct electrical injury as the cause of increased IS. Obviously, AAR size and RMBFi account for both IS and the incidence of VF. IS and NR are mechanistically distinct phenomena. NEW & NOTEWORTHY Ventricular fibrillation/defibrillation is associated with increased infarct size. Electrical injury is unlikely the cause of such association, since there is no dose-response relation between infarct size and number of defibrillations. Ventricular fibrillation, in turn, is associated with a larger area at risk and lower residual blood flow.

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Ross, Linda, Brett Williams, and Malcolm Boyle. "Defibrillation safety: an examination of paramedic perceptions using eye-tracking technology." BMJ Simulation and Technology Enhanced Learning 1, no. 2 (September 3, 2015): 62–66. http://dx.doi.org/10.1136/bmjstel-2015-000033.

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ObjectiveThe importance of access to early defibrillation for patients in cardiac arrest has been emphasised as a critical part of the chain of survival by resuscitation bodies internationally; as such defibrillation has become a key procedure for many out-of-hospital emergency healthcare providers. However, little research has been undertaken specifically addressing students’ safety during defibrillation procedures. The objective of this study was to examine visual and verbal safety checks prior to defibrillation utilising eye-tracking technology.MethodsThis was an observational study of student safety during cardiac rhythm analysis, defibrillator charging and immediately prior to defibrillation during a resuscitation attempt using a medium fidelity mannequin. The participants completed two 10 min simulations each requiring three defibrillation attempts. The κ statistic was used to determine the agreement by the student of their perceived safety performance and that viewed in the video.ResultsIn both scenarios the student's level of agreement for their perceived defibrillation safety performance and what was observed in the video decreased from defibrillation one to three in both scenarios. However, there was agreement in their overall defibrillation safety performance for both scenarios.ConclusionsStudent perceptions of their actions during defibrillation are not always an accurate representation of their actual actions.

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Qu, Fujian, Fidel Zarubin, Brian Wollenzier, Vladimir P. Nikolski, and Igor R. Efimov. "The Gurvich waveform has lower defibrillation threshold than the rectilinear waveform and the truncated exponential waveform in the rabbit heart." Canadian Journal of Physiology and Pharmacology 83, no. 2 (February 1, 2005): 152–60. http://dx.doi.org/10.1139/y04-131.

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Implantable cardioverter defibrillator studies have established the superiority of biphasic waveforms over monophasic waveforms. However, external defibrillator studies of biphasic waveforms are not as widespread. Our objective was to compare the defibrillation efficacy of clinically used biphasic waveforms, i.e., truncated exponential, rectilinear, and quasi-sinusoidal (Gurvich) waveforms in a fibrillating heart model. Langendorff-perfused rabbit hearts (n = 10) were stained with a voltage-sensitive fluorescent dye, Di-4-ANEPPS. Transmembrane action potentials were optically mapped from the anterior epicardium. We found that the Gurvich waveform was significantly superior (p < 0.05) to the rectilinear and truncated exponential waveforms. The defibrillation thresholds (mean ± SE) were as follows: Gurvich, 0.25 ± 0.01 J; rectilinear-1, 0.34 ± 0.01 J; rectilinear-2, 0.33 ± 0.01 J; and truncated exponential, 0.32 ± 0.02 J. Using optically recorded transmembrane responses, we determined the shock-response transfer function, which allowed us to predict the cellular response to waveforms at high accuracy. The passive parallel resistor-capacitor model (RC-model) predicted polarization superiority of the Gurvich waveform in the myocardium with a membrane time constant (τm) of less than 2 ms. The finding of a lower defibrillation threshold with the Gurvich waveform in an in vitro model of external defibrillation suggests that the Gurvich waveform may be important for future external defibrillator designs.Key words: defibrillation, optical mapping, biphasic waveform, Gurvich waveform.

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Bänsch, Dietmar. "Defibrillation Testing During Defibrillator Implantation." Arrhythmia & Electrophysiology Review 1 (2012): 51. http://dx.doi.org/10.15420/aer.2012.1.51.

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Implantable cardioverter defibrillators (ICDs) terminate ventricular tachycardia (VT) and ventricular fibrillation (VF) with high efficacy. ICDs improve mortality in patients after survived sudden cardiac death (SCD) and in patients at high risk of dying suddenly. All trials which show a benefit of ICD therapy, have performed some kind of defibrillation testing in order to prove correct system function, sensing of VF and effective defibrillation. Current devices show a shock efficacy of 80–90 % for singular shocks and devices provide up to seven rescue shocks. The probability that a device does not terminate an episode of VT or VF should therefore be very low. However, it is difficult to abandon defibrillation testing because prospective data is lacking that demonstrate non-inferiority, if ICDs are implanted without some kind of test. Two prospective trials are on the way and will be finish by 2013/14: the SIMPLE and NORDIC trial, which will answer the question if defibrillation testing can be abandoned without any effect on the benefit of ICD therapy or if testing may even be harmful.

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Peters, W., S. Solingen, Y. Kobayashi, R. Scharf, W. J. Mandel, and E. S. Gang. "Transmyocardial impedance during single and multiple internal ventricular defibrillation shocks." American Journal of Physiology-Heart and Circulatory Physiology 267, no. 2 (August 1, 1994): H684—H693. http://dx.doi.org/10.1152/ajpheart.1994.267.2.h684.

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Little is known about the transmyocardial impedance during internal ventricular defibrillation. In a canine model, using high rate on-line digitization, random shock delivery, and titanium electrodes, we determined the relationship among voltage, current, and impedance, delivered energy, and defibrillation success within the individual and within successive defibrillation shocks. Impedance decreased with repeated defibrillation in 10 of 11 dogs. Impedance always increased during trapezoidal discharges, whereas voltage decreased. Impedance was lower with high energy-voltage shocks in all dogs. Visually, voltage and current waveform did not show a phase shift. There was no difference in the total energy delivered and the energy converted into heat by the resistive part of the impedance. With a formula valid only for resistive loads, the capacitance of the defibrillator was calculated to be within the measurement accuracy and tolerance of the factory-provided value of 132 microF. Polarization voltage was consistently observed. Thus the transmyocardial impedance during defibrillation is primarily resistive, nonlinear voltage dependent, and declines with successive shocks. Defibrillation success was not influenced by these phenomena.

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Prokopenko, A. V., and E. A. Ivanitskiy. "Experience of using the of subcutaneous cardioverter-defibrillators in the world practice: review." Journal of Arrhythmology 29, no. 4 (December 8, 2022): 42–46. http://dx.doi.org/10.35336/va-2022-4-06.

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The article provides a review of international clinical studies on the use of a subcutaneous implantable cardioverter-defibrillator (ICD) in comparison with classical intravenous defibrillation systems. Subcutaneous ICDs have shown themselves to be a worthy alternative to intravenous defibrillating systems for the primary prevention of sudden cardiac death, when the patient is not indicated for anti-tachy stimulation and anti-brady stimulation. World experience on the use of subcutaneous ICDs proves the safety and effectiveness of the functioning of the subcutaneous ICD system, excluding from the patient’s life the formidable risks associated with the implantation procedure and further functioning of the classical intravenous ICD system.

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Goodloe, J. M., L. D. Vinson, M. L. Cox, and B. D. Burns. "P059: Paramedic compliance with a novel defibrillation strategy in a large, urban EMS system in the United States." CJEM 19, S1 (May 2017): S98. http://dx.doi.org/10.1017/cem.2017.261.

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Introduction: Emergency Medical Services (EMS) care confers distinct impact upon survivability from sudden cardiac arrest. Many studies have been conducted regarding EMS interventions for cardiac arrest, though fewer studies have been published detailing specific analysis of paramedic compliance with standing orders, particularly those involving a novel energy strategy in defibrillation. Methods: Adults in sudden cardiac arrest with resuscitation initiated, including at least one defibrillation, between July 1, 2016 and December 1, 2016 were enrolled. Education on a novel defibrillation strategy, involving weight-based joule settings and double sequential external defibrillation (DSED) was delivered in classroom and internet-accessed settings. Paramedics then performed hands-on practice in DSED. All resuscitations were reviewed from electronic medical records (EMRs) completed by treating paramedics, alongside telemetry and defibrillation events recorded, transmitted, and analyzed in proprietary software (CODE-STAT™, Physio-Control Corporation, Redmond, WA). All ECGs and defibrillation events were reviewed by an emergency physician to determine energy settings used by paramedics for determining the accuracy of compliance with protocol-based standing orders. Results: During the 5 month study period, the paramedics involved treated 133 adults in sudden cardiac arrest involving perceived ventricular fibrillation that was treated with at least one defibrillation. 76/90 (84.4%) with estimated weight <100 kg were treated with correct joule settings, though only 7/43 (16.3%) with estimated weight ≥100kg received all defibrillations at 360J as protocol-specified. 26/44 (59.1%) in refractory ventricular fibrillation, defined as requiring a fourth defibrillation, received DSED as protocol-specified. Conclusion: Paramedics, when specifically trained on a novel defibrillation strategy, involving both weight-based joule settings and use of DSED for refractory ventricular fibrillation, are inconsistently able to quickly and successfully incorporate that strategy in EMS resuscitation care. Further educational endeavours are warranted to achieve higher defibrillation strategy protocol compliance.

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Chiladakis, John, Fani Zagkli, and Dimitrios Alexopoulos. "External defibrillation on an implantable defibrillator." Journal of Anesthesia 28, no. 2 (October 6, 2013): 312. http://dx.doi.org/10.1007/s00540-013-1710-9.

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Cheskes, S., P. Dorian, M. Feldman, S. McLeod, D. Scales, R. Pinto, L. Turner, L. Morrison, I. Drennan, and P. Verbeek. "PL02: Double Sequential External Defibrillation for Refractory Ventricular Fibrillation: the DOSE VF pilot randomized controlled trial." CJEM 22, S1 (May 2020): S5. http://dx.doi.org/10.1017/cem.2020.54.

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Introduction: Despite recent advances in resuscitation, some patients remain in ventricular fibrillation (VF) after multiple defibrillation attempts during out-of-hospital cardiac arrest (OHCA). Vector change defibrillation (VC) and double sequential external defibrillation (DSED) have been proposed as alternate therapeutic strategies for OHCA patients with refractory VF. The primary objective was to determine the feasibility, safety and sample size required for a future cluster randomized controlled trial (RCT) with crossover comparing VC or DSED to standard defibrillation for patients experiencing refractory VF. Secondary objectives were to evaluate the intervention effect on VF termination and return of spontaneous circulation (ROSC). Methods: We conducted a pilot cluster RCT with crossover in four Canadian paramedic services and included all treated adult OHCA patients who presented in VF and received a minimum of three defibrillation attempts. In addition to standard cardiac arrest care, each EMS service was randomly assigned to provide continued standard defibrillation (control), VC or DSED. Services crossed over to an alternate defibrillation strategy after six months. Prior to the launch of the trial, 2,500 paramedics received in-person training for VC and DSED defibrillation using a combination of didactic, video and simulated scenarios. Results: Between March 2018 and September 2019, 152 patients were enrolled. Monthly enrollment varied from 1.4 to 6.1 cases per service. With respect to feasibility, 89.5% of cases received the defibrillation strategy they were randomly allocated to, and 93.1% of cases received a VC or DSED shock prior to the sixth defibrillation attempt. There were no reported cases of defibrillator malfunction, skin burns, difficulty with pad placement or concerns expressed by paramedics, patients, families, or ED staff about the trial. In the standard defibrillation group, 66.6% of cases resulted in VF termination, compared to 82.0% in VC and 76.3% of cases in the DSED group. ROSC was achieved in 25.0%, 39.3% and 40.0% of standard, VC and DSED groups, respectively. Conclusion: Findings from our pilot RCT suggest the DOSE VF protocol is feasible and safe. VF termination and ROSC were higher with VC and DSED compared to standard defibrillation. The results of this pilot trial will allow us to inform a multicenter cluster RCT with crossover to determine if alternate defibrillation strategies for refractory VF may impact patient-centered, clinical outcomes

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Rattes, M. F., A. D. Sharma, G. J. Klein, T. Szabo, and D. L. Jones. "Adrenergic effects on internal cardiac defibrillation threshold." American Journal of Physiology-Heart and Circulatory Physiology 253, no. 3 (September 1, 1987): H500—H506. http://dx.doi.org/10.1152/ajpheart.1987.253.3.h500.

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Autonomic neural tone modulates arrhythmias and could affect the efficacy of an implantable defibrillator if defibrillation threshold is also altered by changes in neural activity. We determined the effects of alpha- and beta-adrenoceptor agonists and antagonists on the energy requirement for defibrillation using a sequential-pulse technique in anesthetized pigs. The doses for each drug were selected based on the results of dose-response curves. The mean defibrillation threshold was 10.2 +/- 0.65 J (mean +/- SE) in control and 10.0 +/- 0.84, 9.4 +/- 0.87 and 8.9 +/- 0.89 J during phenylephrine infusions of 0.7, 1.35, and 2.0-4.0 micrograms X kg-1 X min-1 [n = 8, P = not significant (NS)]. Phenylephrine at all infusion rates increased the ventricular fibrillation threshold, indicating that effects on the ventricular fibrillation threshold may occur independent of changes in defibrillation threshold. No significant change was observed in the defibrillation threshold before and after administration of isoproterenol (6.5 +/- 0.72 and 6.7 +/- 0.93 J, n = 8, P = NS). Similarly, no change in defibrillation thresholds was observed after 1.5-2.0 mg/kg phentolamine (8.5 +/- 0.85 and 7.9 +/- 0.93 J, n = 8, P = NS) or 3.0-6.0 mg/kg atenolol (10.0 +/- 1.7 and 10.3 +/- 2.6 J, n = 8, P = NS). However, when defibrillation threshold was determined using a single-pulse method, isoproterenol infusion produced a significant decrease (17.3 +/- 1.5 vs. 14.6 +/- 1.9 J, n = 7, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

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Peters, W., S. Solingen, Y. Kobayashi, R. Scharf, W. J. Mandel, and E. S. Gang. "Transmyocardial impedance during single and multiple internal ventricular defibrillation shocks." American Journal of Physiology-Heart and Circulatory Physiology 268, no. 1 (January 1, 1995): 1. http://dx.doi.org/10.1152/ajpheart.1995.268.1.1-a.

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Pages H664–H693: W. Peters, S. Solingen, Y. Kobayashi, R. Scharf, W. J. Mandel, and E. S. Gang. “Transmyocardial impedance during single and multiple internal ventricular defibrillation shocks.” The following corrections should be noted. Page H684, methods section, first paragraph: The analysis presented here is based on measurements during infusion with saline or lactated Ringer solution in the same dogs later treated with propafenone or lactated Ringer solution as described elsewhere (24). Page H685, methods section, fourth paragraph: In dog 4, the same defibrillator-electrode combination was used to deliver 20 shocks of a damped half sine waveform as clinically used in external defibrillation (here C = 32 μF, inductance = 40 mH). Page H686, Figure 2 legend: Typical graph of delivered voltage [V(t)] and transmyocardial impedance [Z(t)] during defibrillation with truncated trapezoidal pulse waveform [stored energy (Esto) = 20 J]. Pol, polarization. Page H689, Table 6 title: Calculated defibrillator C according to Eq. 5 and relative difference in Edel and energy converted into heat (Eres by resistive part of transmyocardial impedance.

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Rothmier, Justin D., and Jonathan A. Drezner. "The Role of Automated External Defibrillators in Athletics." Sports Health: A Multidisciplinary Approach 1, no. 1 (January 2009): 16–20. http://dx.doi.org/10.1177/1941738108326979.

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Context: Sudden cardiac arrest is the leading cause of death in young athletes. The purpose of this review is to summarize the role of automated external defibrillators and emergency planning for sudden cardiac arrest in the athletic setting. Evidence Acquisition: Relevant studies on automated external defibrillators, early defibrillation, and public-access defibrillation programs were reviewed. Recommendations from consensus guidelines and position statements applicable to automated external defibrillators in athletics were also considered. Results: Early defibrillation programs involving access to automated external defibrillators by targeted local responders have demonstrated a survival benefit for sudden cardiac arrest in many public and athletic settings. Conclusion: Schools and organizations sponsoring athletic programs should implement automated external defibrillators as part of a comprehensive emergency action plan for sudden cardiac arrest. In a collapsed and unresponsive athlete, sudden cardiac arrest should be suspected and an automated external defibrillator applied as soon as possible, as decreasing the time interval to defibrillation is the most important priority to improve survival in sudden cardiac arrest.

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Strickberger, S. Adam, and George J. Klein. "Is defibrillation testing required for defibrillator implantation?" Journal of the American College of Cardiology 44, no. 1 (July 2004): 88–91. http://dx.doi.org/10.1016/j.jacc.2003.11.068.

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Strickberger, S. A., and G. J. Klein. "Is defibrillation testing required for defibrillator implantation?" ACC Current Journal Review 13, no. 9 (September 2004): 38. http://dx.doi.org/10.1016/j.accreview.2004.08.026.

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Troup, Paul J., Peter D. Chapman, Gordon N. Olinger, and Leonard H. Kleinman. "The implanted defibrillator: relation of defibrillating lead configuration and clinical variables to defibrillation threshold." Journal of the American College of Cardiology 6, no. 6 (December 1985): 1315–21. http://dx.doi.org/10.1016/s0735-1097(85)80219-9.

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Quarta, Giovanni, Paola Ferrari, Andrea Giammarresi, Giovanni Malanchini, Cristina Leidi, Michele Senni, and Paolo De Filippo. "Azygos Vein ICD Lead Implantation Lowers Defibrillation Threshold in a Patient with Hypertrophic Cardiomyopathy." Cardiogenetics 11, no. 4 (October 7, 2021): 185–90. http://dx.doi.org/10.3390/cardiogenetics11040019.

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A 14-year-old boy with hypertrophic cardiomyopathy (HCM) diagnosed at the age of 1 year and with massive left ventricular hypertrophy suffered an episode of ventricular fibrillation during mild effort. He underwent a dual-chamber implantable cardioverter defibrillator (ICD) implantation. The defibrillation threshold testing (DFT) was ineffective. Subcutaneous multi-coli arrays tunneled into the left postero-lateral position and connected to the superior vena cava (SVC) port of the dual-chamber ICD were added to increase the myocardial mass involved in the defibrillation shock pathway. A new DFT was unsuccessful. The patient was transferred to our hospital for myectomy. An epicardial defibrillation patch was placed on the left ventricular lateral wall, but again, DFT testing was ineffective using the right ventricular (RV) coil to lateral patch as shock pathway. Another epicardial defibrillation patch was then placed on the inferior wall. In this case, DFT testing was effective with a defibrillation pathway between the two patches and the can. In November 2015, a high shock impedance alarm was recorded through remote monitoring, thus compromising the safety of the ICD shock pathway. The patient underwent the implant of a new trans-venous defibrillation coil lead in the azygos vein. After few months, the patient developed symptomatic severe aortic regurgitation and underwent an aortic valve replacement. During the operation, DFT testing was performed and was successful. Our case illustrates that azygous vein ICD lead implantation is efficacious in HCM with massive hypertrophy and high DFT, and prompts further studies to systematically investigate its efficacy in this particular subgroup of the HCM population.

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Lee, Dong Keon, Seung Min Park, Yu Jin Kim, Choung Ah Lee, Won Jung Jeong, Gi Woon Kim, Dong Hyuk Shin, and Young Hwan Lee. "CPR Guidance by an Emergency Physician via Video Call: A Simulation Study." Emergency Medicine International 2018 (November 29, 2018): 1–6. http://dx.doi.org/10.1155/2018/1480726.

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Background. In South Korea, the prehospital treatment of cardiac arrest is generally led by an emergency medical technician-paramedic (EMT-P), and defibrillation is delivered by the automatic external defibrillator (AED). This study aimed at examining the effects of direct medical guidance by an emergency physician through a video call that enabled prompt manual defibrillation. Methods. Two-hundred eighty-eight paramedics based in Gyeonggi Province were studied for four months, from July to November 2015. The participants were divided into 96 teams, and the teams were randomly divided into either a conventional group that was to use the AED or a video call guidance group which was to use the manual defibrillators, with 48 teams in each group. The time to first defibrillation, total hands-off time, and hands-off ratio were compared between the two groups. Results. The median value of the time to the first defibrillation was significantly shorter in the video call guidance group (56 s) than in the conventional group (73 s) (p<0.001). The median value of the total hands-off time was also significantly shorter (228 vs. 285.5 s) (p<0.001), and the hands-off ratio, defined as the proportion of hands-off time out of the total CPR time, was significantly shorter in the video call guidance group (0.32 vs. 0.41) (p<0.001). Conclusion. Physician-guided CPR with a video call enabled prompt manual defibrillation and significantly shortened the time required for first defibrillation, hands-off time, and hands-off ratio in simulated cases of prehospital cardiac arrest.

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Jurcevic, Ruzica, Lazar Angelkov, Dejan Vukajlovic, Velibor Ristic, Milosav Tomovic, and Bosko Djukanovic. "Implantable cardioverter-defibrillator oversensing due to electric shock." Srpski arhiv za celokupno lekarstvo 138, no. 3-4 (2010): 236–39. http://dx.doi.org/10.2298/sarh1004236j.

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Introduction. We described the first case of oversensing due to electric shock in Serbia, in a 54-year-old man who had implantable cardioverter-defibrillator (ICD). Case Outline. In July 2002, the patient had acute anteroseptal myocardial infarction and ventricular fibrillation (VF) which was terminated with six defibrillation shocks of 360 J. Coronary angiography revealed 30% stenosis of circumflex artery, the left anterior descending coronary artery was recanalized and the right coronary artery was without stenosis. Left ventricular ejection fraction was 20%. In December 2003, an electrophysiology study was performed and ventricular tachycardia (VT) was induced and terminated with 200 J defibrillation shock. Single chamber ICD Medtronic Gem III VR was implanted in January 2004 and defibrillation threshold was 12 J. The patient was followed up during three years every three months and there were no VT/VF episodes and VT/VF therapies. In December 2007, the patient experienced electric shock through the fork while he was making barbecue on the electric grill. ICD recognized this event in VF zone (oversensing) and delivered defibrillation shock of 18 J. The electrogram of the episode showed ventricular sensing - intrinsic sinus rhythm with electric shock potentials which were misidentified as VF. After charge time of 3.16 seconds, ICD delivered defibrillation shock and sinus rhythm was still present. Conclusion. Oversensing of ICD has different aetiology and the most common cause is supraventricular tachyarrhythmia.

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Davis, M., A. Schappert, K. Van Aarsen, J. Loosley, S. McLeod, and S. Cheskes. "P029: A descriptive analysis of defibrillation vector change for prehospital refractory ventricular fibrillation." CJEM 20, S1 (May 2018): S67. http://dx.doi.org/10.1017/cem.2018.227.

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Introduction: Patients in ventricular fibrillation (VF) who do not respond to standard Advanced Cardiac Life Support treatments are deemed to be in refractory VF (rVF). The ideal prehospital treatment for patients with rVF remains unknown. Double sequential external defibrillation (DSED) has been proposed as a viable option for patients in rVF. Although the mechanism by which DSED terminates rVF remains unknown, one theory is that the change in defibrillation vector that occurs may contribute. The objective of this study was to describe clinical outcomes for patients presenting in rVF during out-of-hospital cardiac arrest (OOHCA) for those who underwent vector change defibrillation, compared to those who received standard treatment. Methods: This was a retrospective chart review of adult (18 years) patients presenting in rVF during OOHCA over 15 months beginning in March 2016. Patients who underwent vector change defibrillation had a change in pad position (anterior-anterior to anterior-posterior) after 3 or more consecutive shocks. Termination of rVF was defined as the absence of VF after a vector change or standard shock during the next rhythm analysis. Results: There were 372 OOHCA, with 25 (6.7%) patients meeting our definition of rVF. Of these, 16 (64.0%) patients (median age 62 years, 81.3% male) had vector change after a median (IQR) of 3 (3.0-4.0) paramedic defibrillation attempts. Median (IQR) time to vector change defibrillation was 8.8 (7.1-11.1) minutes. Eight (50%) patients had termination of rVF after the first vector change shock, 6 (37.5%) had prehospital return of spontaneous circulation (ROSC) and 5 (31.3%) patients survived to hospital discharge. Of the 9 rVF patients who did not have vector change, median age was 63 years and 88.9% were male. The median (IQR) number of defibrillations within this group was 5 (4.5-7.0). No patients converted after the 4th defibrillation. Prehospital ROSC was achieved in 3 (33.3%) patients and 5 (55.5%) patients were transported while in rVF . Three patients (33.3%) survived to hospital discharge. Conclusion: This is preliminary evidence that vector change defibrillation in patients with rVF may result in VF termination. A randomized controlled trial is warranted to test whether or not vector change has a role in the termination of rVF.

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Podoliak, O. O., V. A. Ovchinnikova, S. N. Selyahov, T. G. Kormin, and A. V. Korejatov. "Optimization methods of assembly processes of defibrillation equipment." Ural Radio Engineering Journal 5, no. 4 (2021): 410–31. http://dx.doi.org/10.15826/urej.2021.5.4.005.

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The electronic medical equipment developing process includes the problems and tasks of medical devices’ technical characteristics improvement, using alternative physical methods of recording medical information. Medical electronic equipment includes defibrillation equipment of various classes, the modernization of which is inextricably connected with scientific and technical research in the field of physics, circuit engineering, design, technology, modeling, characteristics’ measurement, as well as medicine. One of the interdisciplinary research areas at the cardiology and engineering issue is the development of new and modernisation of existing defibrillation devices, improving their functional and operational characteristics, as well as their application efficiency, which is necessary for the provision of extended resuscitation measures. This research is devoted to the research and modeling of defibrillator performance characteristics taking into account components reliability and the operational failure rate determination. The paper also contains study of the production process optimizing methods, in particular assembly operations of high-tech defibrillation products, where the search of optimization solutions was carried out using simulation modeling.

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Hassan, A., and R. Sajjad. "ID: 16: INAPPROPRIATE DEFIBRILLATION DUE TO ELCTRO-MAGNETIC INTERFERENCE FROM NEARBY ALTERNATING CURRENT." Journal of Investigative Medicine 64, no. 4 (March 22, 2016): 925.1–925. http://dx.doi.org/10.1136/jim-2016-000120.30.

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IntroductionImplantable cardioverter-defibrillator (ICD) to monitor and promptly treat life-threatening arrhythmia has been a very successful approach. However, inappropriate defibrillation could increase morbidity and mortality. Most common causes of inappropriate defibrillation are: supra-ventricular arrhythmia and device malfunctions.Case DescriptionA 31-year-old female with arrythmogenic right ventricular cardiomyopathy (ARVC) status post dual chamber ICD presented after her ICD had fired. Patient was sitting near a public swimming pool and suddenly felt a jolt, “getting hit at the back of the head”. On further ICD Interrogation revealed a high frequency artifact on the intra-cardiac electrogram which was sensed by the device as ventricular fibrillation, and subsequently it was defibrillated. Other parameters including sensing and pacing thresholds, lead impedances were all within normal limits.DiscussionAlternating current from a nearby electric generator created Electro-magnetic interference (EMI) which led to inappropriate defibrillation. High frequency oscillating artifact is the hallmark of EMI from alternating current. We should be aware of all possible causes that can interfere with cardiac devices. .

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Mancini, ME, and W. Kaye. "In-hospital first-responder automated external defibrillation: what critical care practitioners need to know." American Journal of Critical Care 7, no. 4 (July 1, 1998): 314–19. http://dx.doi.org/10.4037/ajcc1998.7.4.314.

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Despite the development and widespread implementation of Basic Life Support and Advanced Cardiac Life Support, the percentage of patients who survive in-hospital cardiac arrest has remained stable at approximately 15%. Although survival rates may approach 90% in coronary care units, survival rates plummet outside of these units. The lower survival rates for cardiac arrest that occur outside of the coronary care unit may relate to the time elapsed between the onset of ventricular fibrillation and first defibrillation. The advent of automated external defibrillators has made it possible to decrease the time elapsed before first defibrillation in non-critical care areas of the hospital. First responders need only recognize that the patient is unresponsive, apneic, and pulseless before attaching and activating the automated external defibrillator. Our research shows that, as part of Basic Life Support training, non-critical care nurses can learn to use the device and can retain the knowledge and skill over time. Establishing an in-hospital automated external defibrillator program requires commitment from administration, physicians, and nursing personnel. Critical care practitioners should be aware of this technology and the literature that supports its safety and effectiveness when used by non-critical care first responders. Critical care nurses are in a unique position to effect changes that will decrease the time between the onset of cardiac arrest and first defibrillation.

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Thompson, Dennis F., Marsha A. Raebel, Patrick L. McCollam, and Jean M. Nappi. "Concomitant Amiodarone and the Implantable Cardioverter-Defibrillator: Is There a Place?" Annals of Pharmacotherapy 27, no. 6 (June 1993): 736–41. http://dx.doi.org/10.1177/106002809302700614.

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OBJECTIVE: To discuss the controversy surrounding concomitant therapy with amiodarone and the implantable cardioverter-defibrillator (ICD). DATA SOURCES: A MEDLINE search identified English-language literature sources, including nonhuman studies. STUDY SELECTION: Studies included those that specifically addressed the use of amiodarone plus the ICD as well as reviews of the ICD. DATA EXTRACTION: Studies were evaluated for design, type of defibrillation electrode or defibrillator, method of defibrillation, amiodarone loading and maintenance dosages, duration of amiodarone therapy, and study endpoints. DATA SYNTHESIS: Because the ICD functions by delivering energy to depolarize a mass of myocardium, concomitant use of antiarrhythmic agents that elevate the defibrillation threshold (DFT) beyond an ICD's energy capability may adversely effect patient outcome. Amiodarone has been shown to both increase and decrease the DFT. Trials examining the use of amiodarone plus the ICD have not provided strong evidence that amiodarone will decrease the number of ICD discharges or favorably affect the mortality rate. Amiodarone is also expensive and toxic. Although the cost of the ICD is relatively high, continuing improvements in battery life will decrease long-term costs. CONCLUSIONS: Controlled trials are required to substantiate the improved survival rate with the ICD and to determine the role of antiarrhythmic agents in conjunction with the device. At present, there are no data to support the combination of amiodarone and an ICD in terms of improved quality or duration of life.

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Bun, Sok-Sithikun, Fabien Squara, Didier Scarlatti, Guillaume Theodore, Decebal Gabriel Latcu, Karim Hasni, Fatima Benaich, Emna Allouche, Nadir Saoudi, and Emile Ferrari. "Technological advances in cardiac pacing and defibrillation." Heart, Vessels and Transplantation 3, Issue 3 (May 5, 2019): 95. http://dx.doi.org/10.24969/hvt.2019.129.

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Since more than a half century, cardiac pacing and defibrillation represent a field in constant evolution, and they have shown some great technological advances from its conception to its methods of insertion. In this review, the recent developments about the accesses for pacemakers and ICD will be described: the axillary and the femoral vein. The His bundle pacing and the advantages of the entirely subcutaneous defibrillator will also be presented.

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Miller, Marc A., Chandrasekar Palaniswamy, Srinivas R. Dukkipati, Sujata Balulad, Jeffrey Smietana, Aaron Vigdor, Jacob S. Koruth, Subbarao Choudry, William Whang, and Vivek Y. Reddy. "Subcutaneous Implantable Cardioverter-Defibrillator Implantation Without Defibrillation Testing." Journal of the American College of Cardiology 69, no. 25 (June 2017): 3118–19. http://dx.doi.org/10.1016/j.jacc.2017.04.037.

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Lim, Gregory B. "Defibrillation testing unnecessary during routine cardioverter–defibrillator implantation." Nature Reviews Cardiology 12, no. 9 (July 14, 2015): 501. http://dx.doi.org/10.1038/nrcardio.2015.111.

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Kim, Hee Eun, Kui Ja Lee, You Hwan Jo, Jae Hyuk Lee, Yu Jin Kim, Joong Hee Kim, Dong Keon Lee, Dong Won Kim, Seung Min Park, and Young Taeck Oh. "Refractory Ventricular Fibrillation Treated with Double Simultaneous Defibrillation: Pilot Study." Emergency Medicine International 2020 (May 27, 2020): 1–6. http://dx.doi.org/10.1155/2020/5470912.

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Introduction. Refractory shockable rhythm has a high mortality rate and poor neurological outcome. Treatments for refractory shockable rhythm presenting after defibrillation and medical treatment are not definite. We conducted research on the application of double simultaneous defibrillation (DSiD) for refractory shockable rhythms. Methods. This is a retrospective pilot study performed using medical records from 1 January 2016 to 31 December 2017. The prephase was from January to December 2016. The post-phase was from January to December 2017. During the prephase, we conducted conventional defibrillation with one defibrillator, and during the post-phase, we conducted DSiD using two defibrillators. Primary outcome was survival to hospital discharge. Secondary outcomes included survival to hospital admission and good neurological outcome at 12 months. Statistical analysis was conducted using Fisher’s exact test. Data were regarded statistically significant when p<0.05. Result. A total of 38 patients were included. Twenty-one patients underwent conventional defibrillation, and 17 underwent DSiD. The DSiD group had a higher survival to admission rate (14/17 (82.4%) vs. 6/21 (28.6%), p=0.001) and showed a trend for higher survival to discharge (7/17 (41.2%) vs. 3/21 (14.3%), p=0.078). Good neurological outcome at 12 months of the DSiD group was higher than that of the conventional defibrillation group, but the difference was not statistically significant (5/17 (29.4%) vs 2/21 (9.5%), p=0.207). Conclusion. In patients with refractory shockable rhythms, DSiD has increased survival to hospital admission and a trend of increased survival to hospital discharge. However, DSiD did not improve neurological outcome at 12 months.

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Jones, J. L., and K. B. Milne. "Dysfunction and safety factor strength-duration curves for biphasic defibrillator waveforms." American Journal of Physiology-Heart and Circulatory Physiology 266, no. 1 (January 1, 1994): H263—H271. http://dx.doi.org/10.1152/ajpheart.1994.266.1.h263.

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Newly developed biphasic waveforms significantly lower defibrillation threshold in animal and clinical models. However, underlying mechanisms and optimum waveform shape are unknown. Defibrillation shocks produce dysfunction; safety factor, the ratio of shock intensity inducing dysfunction to that producing stimulation of partially refractory cells, is an important parameter for defibrillator waveforms. We determined dysfunction and safety factor strength-duration curves for symmetric and asymmetric (50% undershoot) monophasic and biphasic rectangular (0%-tilt) waveforms. Dysfunction threshold, defined as the voltage producing a 4-s postshock contractile arrest, was determined for waveforms with total durations from 1 to 40 ms. For all waveforms, dysfunction threshold decreased with waveform duration. At all durations, dysfunction threshold was similar for symmetric monophasic and biphasic waveforms with the same total duration. In contrast, asymmetric biphasic waveforms increased dysfunction threshold 14 +/- 3% (P < 0.005) compared with monophasic control waveforms. Because long-duration, low-tilt, biphasic waveforms improve excitation threshold for refractory cells, they should improve defibrillation threshold. Asymmetric waveforms have the additional advantage of improving safety factor by reducing postshock dysfunction.

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Marchlinski, Francis E., Belinda Flores, John M. Miller, Charles D. Gottlieb, and W. Clark Hargrove. "Relation of the intraoperative defibrillation threshold to successful postoperative defibrillation with an automatic implantable cardioverter defibrillator." American Journal of Cardiology 62, no. 7 (September 1988): 393–98. http://dx.doi.org/10.1016/0002-9149(88)90965-4.

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Cummins, Richard O. "Defibrillation." Emergency Medicine Clinics of North America 6, no. 2 (May 1988): 217–40. http://dx.doi.org/10.1016/s0733-8627(20)30557-5.

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Kelly, Lyn. "Defibrillation." Nursing Standard 23, no. 3 (September 25, 2008): 59–60. http://dx.doi.org/10.7748/ns.23.3.59.s53.

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Thomas, Stephen. "Defibrillation." Nursing Standard 5, no. 32 (May 7, 1991): 52–53. http://dx.doi.org/10.7748/ns.5.32.52.s61.

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Cheney, Ruth. "Defibrillation." Critical Care Nursing Quarterly 10, no. 4 (March 1988): 9–16. http://dx.doi.org/10.1097/00002727-198803000-00003.

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Peberdy, Mary Anne. "Defibrillation." Cardiology Clinics 20, no. 1 (February 2002): 13–21. http://dx.doi.org/10.1016/s0733-8651(03)00062-6.

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37

Trayanova, Natalia, and Wanda Krassowska. "Defibrillation." Annals of Biomedical Engineering 25, no. 1 (January 1997): S—60. http://dx.doi.org/10.1007/bf02647375.

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38

Buenger, Richard E. "Defibrillation." JAMA: The Journal of the American Medical Association 271, no. 4 (January 26, 1994): 252B. http://dx.doi.org/10.1001/jama.1994.03510280008002.

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Choi, Hyo Jeong, and Hyun Noh. "Successful defibrillation using double sequence defibrillation." Medicine 100, no. 10 (March 12, 2021): e24992. http://dx.doi.org/10.1097/md.0000000000024992.

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40

Atkins, Dianne L., Leo L. Bossaert, Mary Fran Hazinski, Richard E. Kerber, Mary Beth Mancini, Joseph P. Ornato, Mary Ann Peberdy, et al. "Automated external defibrillation/public access defibrillation." Annals of Emergency Medicine 37, no. 4 (April 2001): S60—S67. http://dx.doi.org/10.1067/mem.2001.114124.

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Brown, Samuel, Jason L. Mool, William E. Young, Kourtney M. Hollensteiner, Ashley Cyr, Fia Yi, and Andrew J. Gausepohl. "A Case Report of External Cardiac Pads Used for Internal Cardiac Defibrillation During Resuscitative Thoracotomy." Military Medicine 187, no. 1-2 (October 22, 2021): 259–61. http://dx.doi.org/10.1093/milmed/usab433.

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ABSTRACT This is a case report regarding the use of non-conventional methods to perform internal cardiac defibrillation on a trauma patient in an austere environment. The patient was a polytrauma causality of an improvised explosive device who arrived to a far forward resuscitative surgical team during a recent armed conflict. After arrival, the patient lost pulses. An emergency resuscitative thoracotomy was performed, and the patient was noted to have ventricular fibrillation on direct cardiac visualization. In the absence of standard surgical defibrillation paddles, the team applied external defibrillator stickers directly to the patient’s myocardium to deliver an electrical shock. The procedure successfully led to the return of spontaneous circulation. This report highlights a novel approach to resuscitation in resource-limited environments by a military surgical team.

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Shiner, Stephen L., and Martin I. Gold. "DC Defibrillators: The Difference Between Selected and Delivered Energy." Journal of the World Association for Emergency and Disaster Medicine 3, no. 1 (1987): 1–6. http://dx.doi.org/10.1017/s1049023x00028582.

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AbstractThere is controversy over the “ideal” electrical energy needed for defibrillation. Furthermore, too massive an electrical shock decreases the possibility of survival by direct damage to an already ailing myocardium and too little energy results in further deterioration of myocardial physiology and metabolism. Therefore, delivery of an erroneous amount of electrical energy decreases the likelihood of successful defibrillation and survival. All 190 defibrillators within 3 medical school hospitals were investigated. Each defibrillator was analyzed at four selected settings ranging from 100-400 Joules (J). Only 29 of 190 defibrillators delivered 100% of the energy selected, while 161 of the 190 (85%) delivered an average of 74% of the energy selected. This discrepancy between selected and delivered energy should be corrected by regulations and standards for manufacturers.

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Żuratyński, Przemysław, Daniel Ślęzak, Sebastian Dąbrowski, Kamil Krzyżanowski, Wioletta Mędrzycka-Dąbrowska, and Przemysław Rutkowski. "Use of Public Automated External Defibrillators in Out-of-Hospital Cardiac Arrest in Poland." Medicina 57, no. 3 (March 22, 2021): 298. http://dx.doi.org/10.3390/medicina57030298.

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Background and objectives: National medical records indicate that approximately 350,000–700,000 people die each year from sudden cardiac arrest. The guidelines of the European Resuscitation Council (ERC) and the International Liaison Committee on Resuscitation (ILCOR) indicate that in addition to resuscitation, it is important—in the case of so-called defibrillation rhythms—to perform defibrillation as quickly as possible. The aim of this study was to assess the use of public automated external defibrillators in out of hospital cardiac arrest in Poland between 2008 and 2018. Materials and Methods: One hundred and twenty cases of use of an automated external defibrillator placed in a public space between 2008 and 2018 were analyzed. The study material consisted of data on cases of use of an automated external defibrillator in adults (over 18 years of age). Only cases of automated external defibrillators (AED) use in a public place other than a medical facility were analysed, additionally excluding emergency services, i.e., the State Fire Service and the Volunteer Fire Service, which have an AED as part of their emergency equipment. The survey questionnaire was sent electronically to 1165 sites with AEDs and AED manufacturers. A total of 298 relevant feedback responses were received. Results: The analysis yielded data on 120 cases of AED use in a public place. Conclusions: Since 2016, there has been a noticeable increase in the frequency of use of AEDs located in public spaces. This is most likely related to the spread of public access to defibrillation and increased public awareness.

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Tovar, Oscar H., David E. Snyder, and Janice L. Jones. "Immediate defibrillation predicts probability of defibrillation curve width for external defibrillation waveforms." Journal of the American College of Cardiology 41, no. 6 (March 2003): 351. http://dx.doi.org/10.1016/s0735-1097(03)82090-9.

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Jones, Douglas L., and Njanoor Narayanan. "Defibrillation depresses heart sarcoplasmic reticulum calcium pump: a mechanism of postshock dysfunction." American Journal of Physiology-Heart and Circulatory Physiology 274, no. 1 (January 1, 1998): H98—H105. http://dx.doi.org/10.1152/ajpheart.1998.274.1.h98.

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Presently, the only therapy for ventricular fibrillation is delivery of high-voltage shocks. Despite “successful defibrillation,” patients may have poor cardiac contractility, the mechanisms of which are unknown. Intracellular Ca2+ handling by the sarcoplasmic reticulum (SR) plays a major role in contractility. We tested the hypothesis that defibrillation shocks interfere with Ca2+ transport function of cardiac SR. Rats anesthetized with pentobarbital sodium had bilateral electrodes implanted subcutaneously for transthoracic shocks. A series of 10 shocks, 10 s apart, at 0–250 V was delivered from a trapezoidal defibrillator. The hearts were rapidly removed, SR-enriched membrane vesicles were isolated, and ATP-dependent Ca2+ uptake and Ca2+-stimulated ATP hydrolysis were determined. There was a marked, shock-related decline in Ca2+ uptake, whereas adenosinetriphosphatase activity remained unaltered. The polypeptide compositions were similar in control and shocked SR. In Langendorff hearts, shocks also decreased contractility and slowed relaxation. These data indicate that shocks with current densities similar to defibrillation depress Ca2+-pumping function of cardiac SR because of uncoupling of ATP hydrolysis and Ca2+ transport. Shock-induced impairment of Ca2+ pump function may underlie postshock myocardial dysfunction.

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Strickberger, S. Adam, Emile G. Daoud, Theresa Davidson, Raul Weiss, Frank Bogun, Bradley P. Knight, Marwan Bahu, Rajiva Goyal, K. Ching Man, and Fred Morady. "Probability of Successful Defibrillation at Multiples of the Defibrillation Energy Requirement in Patients With an Implantable Defibrillator." Circulation 96, no. 4 (August 19, 1997): 1217–23. http://dx.doi.org/10.1161/01.cir.96.4.1217.

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Mistry, Amar, Vivetha Pooranachandran, Harshil Dhutia, Rajesh Chelliah, and Ravi K. Pathmanathan. "Intermuscular Subcutaneous Implantable Cardioverter-Defibrillator Implantation Without Defibrillation Testing." JACC: Clinical Electrophysiology 7, no. 1 (January 2021): 124–26. http://dx.doi.org/10.1016/j.jacep.2020.09.003.

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Hazinski, Mary F., Ahamed H. Idris, Richard E. Kerber, Andrew Epstein, Dianne Atkins, Wanchun Tang, and Keith Lurie. "Lay Rescuer Automated External Defibrillator (“Public Access Defibrillation”) Programs." Circulation 111, no. 24 (June 21, 2005): 3336–40. http://dx.doi.org/10.1161/circulationaha.105.165674.

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Pugh, P. J., and J. R. Clague. "Successful internal defibrillation following unusual positioning of defibrillator lead." Europace 10, no. 7 (May 30, 2008): 895–96. http://dx.doi.org/10.1093/europace/eun047.

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Makino, H., Y. Saitoh, Y. Mitamura, and T. Mikami. "Implantable defibrillator with high-output pacing function after defibrillation." Proceedings of the IEEE 76, no. 9 (1988): 1187–93. http://dx.doi.org/10.1109/5.9664.

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Journal articles on the topic 'Defibrillation'

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