[Wearable Automatic External Defibrillators].

PubMed

Luo, Huajie; Luo, Zhangyuan; Jin, Xun; Zhang, Leilei; Wang, Changjin; Zhang, Wenzan; Tu, Quan

2015-11-01

Defibrillation is the most effective method of treating ventricular fibrillation(VF), this paper introduces wearable automatic external defibrillators based on embedded system which includes EGG measurements, bioelectrical impedance measurement, discharge defibrillation module, which can automatic identify VF signal, biphasic exponential waveform defibrillation discharge. After verified by animal tests, the device can realize EGG acquisition and automatic identification. After identifying the ventricular fibrillation signal, it can automatic defibrillate to abort ventricular fibrillation and to realize the cardiac electrical cardioversion.

Prophylactic Catheter Ablation for the Prevention of Defibrillator Therapy

PubMed Central

Reddy, Vivek Y.; Reynolds, Matthew R.; Neuzil, Petr; Richardson, Allison W.; Taborsky, Milos; Jongnarangsin, Krit; Kralovec, Stepan; Sediva, Lucie; Ruskin, Jeremy N.; Josephson, Mark E.

2008-01-01

BACKGROUND For patients who have a ventricular tachyarrhythmic event, implantable cardioverter–defibrillators (ICDs) are a mainstay of therapy to prevent sudden death. However, ICD shocks are painful, can result in clinical depression, and do not offer complete protection against death from arrhythmia. We designed this randomized trial to examine whether prophylactic radiofrequency catheter ablation of arrhythmogenic ventricular tissue would reduce the incidence of ICD therapy. METHODS Eligible patients with a history of a myocardial infarction underwent defibrillator implantation for spontaneous ventricular tachycardia or fibrillation. The patients did not receive antiarrhythmic drugs. Patients were randomly assigned to defibrillator implantation alone or defibrillator implantation with adjunctive catheter ablation (64 patients in each group). Ablation was performed with the use of a substrate-based approach in which the myocardial scar is mapped and ablated while the heart remains predominantly in sinus rhythm. The primary end point was survival free from any appropriate ICD therapy. RESULTS The mortality rate 30 days after ablation was zero, and there were no significant changes in ventricular function or functional class during the mean (±SD) follow-up period of 22.5±5.5 months. Twenty-one patients assigned to defibrillator implantation alone (33%) and eight patients assigned to defibrillator implantation plus ablation (12%) received appropriate ICD therapy (antitachycardia pacing or shocks) (hazard ratio in the ablation group, 0.35; 95% confidence interval, 0.15 to 0.78, P = 0.007). Among these patients, 20 in the control group (31%) and 6 in the ablation group (9%) received shocks (P = 0.003). Mortality was not increased in the group assigned to ablation as compared with the control group (9% vs. 17%, P = 0.29). CONCLUSIONS In this randomized trial, prophylactic substrate-based catheter ablation reduced the incidence of ICD therapy in patients with a history of myocardial infarction who received ICDs for the secondary prevention of sudden death. (Current Controlled Trials number, ISRCTN62488166.) PMID:18160685

Spinal cord stimulation for refractory angina in a patient implanted with a cardioverter defibrillator.

PubMed

Ferrero, Paolo; Grimaldi, Roberto; Massa, Riccardo; Chiribiri, Amedeo; De Luca, Anna; Castellano, Maddalena; Cardano, Paola; Trevi, Gian Paolo

2007-01-01

Spinal cord stimulation is currently used to treat refractory angina. Some concerns may arise about the possible interaction concerning the spinal cord stimulator in patients already implanted with a pacemaker or a cardioverter defibrillator. We are going to describe the successful implantation of a spinal cord stimulator in a patient previously implanted with a cardioverter defibrillator.

Marked attenuation of shock burden by the use of antitachycardia pacing therapy in a patient with an implanted cardioverter-defibrillator.

PubMed

Ganjehei, Leila; Nazeri, Alireza; Massumi, Ali; Razavi, Mehdi

2012-01-01

A 76-year-old man was admitted to our institution for elective exchange of his implanted cardioverter-defibrillator generator. Nine years earlier, he had been diagnosed with nonischemic cardiomyopathy and nonsustainable ventricular tachycardia. At that time, he had received a single-chamber implanted cardioverter-defibrillator, which was upgraded to a dual-chamber implanted cardioverter-defibrillator 3 years later. In the course of the current admission, routine device interrogation during exchange of the patient's implanted cardioverter-defibrillator generator revealed 150 episodes of ventricular tachycardia in the preceding 7 months, 137 of which had been successfully treated by antitachycardia pacing therapy without shock. These findings show the remarkable effectiveness of antitachycardia pacing in terminating ventricular tachycardia while preventing the delivery of shocks, minimizing patient discomfort, and avoiding implanted cardioverter-defibrillator battery depletion.

Evaluation of a Unique Defibrillation Unit with Dual-Vector Biphasic Waveform Capabilities: Towards a Miniaturized Defibrillator.

PubMed

Okamura, Hideo; Desimone, Christopher V; Killu, Ammar M; Gilles, Emily J; Tri, Jason; Asirvatham, Roshini; Ladewig, Dejae J; Suddendorf, Scott H; Powers, Joanne M; Wood-Wentz, Christina M; Gray, Peter D; Raymond, Douglas M; Savage, Shelley J; Savage, Walter T; Bruce, Charles J; Asirvatham, Samuel J; Friedman, Paul A

2017-02-01

Automated external defibrillators can provide life-saving therapies to treat ventricular fibrillation. We developed a prototype unit that can deliver a unique shock waveform produced by four independent capacitors that is delivered through two shock vectors, with the rationale of providing more robust shock pathways during emergent defibrillation. We describe the initial testing and feasibility of this unique defibrillation unit, features of which may enable downsizing of current defibrillator devices. We tested our defibrillation unit in four large animal models (two canine and two swine) under general anesthesia. Experimental defibrillation thresholds (DFT) were obtained by delivery of a unique waveform shock pulse via a dual-vector pathway with four defibrillation pads (placed across the chest). DFTs were measured and compared with those of a commercially available biphasic defibrillator (Zoll M series, Zoll Medical, Chelmsford, MA, USA) tested in two different vectors. Shocks were delivered after 10 seconds of stable ventricular fibrillation and the output characteristics and shock outcome recorded. Each defibrillation series used a step-down to failure protocol to define the defibrillation threshold. A total of 96 shocks were delivered during ventricular fibrillation in four large animals. In comparison to the Zoll M series, which delivered a single-vector, biphasic shock, the energy required for successful defibrillation using the unique dual-vector biphasic waveform did not differ significantly (P = 0.65). Our early findings support the feasibility of a unique external defibrillation unit using a dual-vector biphasic waveform approach. This warrants further study to leverage this unique concept and work toward a miniaturized, portable shock delivery system. © 2016 Wiley Periodicals, Inc.

Characterization of available automated external defibrillators in the market based on the product manuals in 2014

PubMed Central

Ho, Chik Leung; Cheng, Ka Wai; Ma, Tze Hang; Wong, Yau Hang; Cheng, Ka Lok; Kam, Chak Wah

2016-01-01

BACKGROUND: To popularize the wide-spread use of automated external defibrillator (AED) to save life in sudden cardiac arrest, we compared the strength and weakness of different types of AEDs to enable a sound selection based on regional requirement. METHODS: This was a retrospective descriptive study. Different types of AEDs were compared according to the information of AEDs from manuals and brochures provided by the manufacturers. Fifteen types of AEDs were divided into 3 groups, basic, intermediate and advanced. RESULTS: Lifeline™ AUTO AED had the best performance in price, portability and user-friendly among AEDs of basic level. It required less time for shock charging. Samaritan PAD defibrillator was superior in price, portability, durability and characteristic among AEDs of intermediate level. It had the longest warranty and highest protection against water and dust. Lifeline™ PRO AED had the best performance in most of the criteria among AEDs of advanced level and offered CPR video and manual mode for laypersons and clinicians respectively. CONCLUSION: Lifeline™ AUTO AED, Samaritan PAD defibrillator, Lifeline™ PRO AED are superior in AEDs of basic, intermediate and advanced levels, respectively. A feasible AED may be chosen by users according to the regional requirement and the current information about the best available products. PMID:27313810

A Magnetic Resonance Imaging-Conditional External Cardiac Defibrillator for Resuscitation Within the Magnetic Resonance Imaging Scanner Bore.

PubMed

Schmidt, Ehud J; Watkins, Ronald D; Zviman, Menekhem M; Guttman, Michael A; Wang, Wei; Halperin, Henry A

2016-10-01

Subjects undergoing cardiac arrest within a magnetic resonance imaging (MRI) scanner are currently removed from the bore and then from the MRI suite, before the delivery of cardiopulmonary resuscitation and defibrillation, potentially increasing the risk of mortality. This precludes many higher-risk (acute ischemic and acute stroke) patients from undergoing MRI and MRI-guided intervention. An MRI-conditional cardiac defibrillator should enable scanning with defibrillation pads attached and the generator ON, enabling application of defibrillation within the seconds of MRI after a cardiac event. An MRI-conditional external defibrillator may improve patient acceptance for MRI procedures. A commercial external defibrillator was rendered 1.5 Tesla MRI-conditional by the addition of novel radiofrequency filters between the generator and commercial disposable surface pads. The radiofrequency filters reduced emission into the MRI scanner and prevented cable/surface pad heating during imaging, while preserving all the defibrillator monitoring and delivery functions. Human volunteers were imaged using high specific absorption rate sequences to validate MRI image quality and lack of heating. Swine were electrically fibrillated (n=4) and thereafter defibrillated both outside and inside the MRI bore. MRI image quality was reduced by 0.8 or 1.6 dB, with the generator in monitoring mode and operating on battery or AC power, respectively. Commercial surface pads did not create artifacts deeper than 6 mm below the skin surface. Radiofrequency heating was within US Food and Drug Administration guidelines. Defibrillation was completely successful inside and outside the MRI bore. A prototype MRI-conditional defibrillation system successfully defibrillated in the MRI without degrading the image quality or increasing the time needed for defibrillation. It can increase patient acceptance for MRI procedures. © 2016 American Heart Association, Inc.

Defibrillator synchronization tester.

PubMed

Demirbilek, Fatma N; Krajnak, Mike; Stolarczyk, George

2009-01-01

A defibrillator sync output signal connector provides an ECG synchronization signal that can be used by some defibrillators for the purpose of performing synchronized cardioversion [1]. This process is used to stop an abnormally fast heart rate or cardiac arrhythmia by the delivery of a therapeutic dose of electric current to the heart during the R-wave of the cardiac cycle. Timing the shock to the R-wave prevents the delivery of the shock during the vulnerable period of the cardiac cycle, which could induce ventricular fibrillation [2]. GE patient monitors include a selectable analog output feature, which provides an analog ECG or arterial blood pressure signal. The blood pressure signal can be used to synchronize balloon pumps to provide cardiac assist to post-MI patients with poor injection fraction. Proper operation requires the defibrillator sync and analog output function to be checked. Checkouts are typically done during planned maintenance and after major part replacements such as patient monitor's main CPU board. Checking out defibrillator sync signals could be done using a GE defibrillator sync tester. The defibrillator sync tester provides a loop back path for the defibrillator sync signals to be displayed on the patient monitor screen and eliminates the need for an external oscilloscope.

Extended charge banking model of dual path shocks for implantable cardioverter defibrillators

PubMed Central

Dosdall, Derek J; Sweeney, James D

2008-01-01

Background Single path defibrillation shock methods have been improved through the use of the Charge Banking Model of defibrillation, which predicts the response of the heart to shocks as a simple resistor-capacitor (RC) circuit. While dual path defibrillation configurations have significantly reduced defibrillation thresholds, improvements to dual path defibrillation techniques have been limited to experimental observations without a practical model to aid in improving dual path defibrillation techniques. Methods The Charge Banking Model has been extended into a new Extended Charge Banking Model of defibrillation that represents small sections of the heart as separate RC circuits, uses a weighting factor based on published defibrillation shock field gradient measures, and implements a critical mass criteria to predict the relative efficacy of single and dual path defibrillation shocks. Results The new model reproduced the results from several published experimental protocols that demonstrated the relative efficacy of dual path defibrillation shocks. The model predicts that time between phases or pulses of dual path defibrillation shock configurations should be minimized to maximize shock efficacy. Discussion Through this approach the Extended Charge Banking Model predictions may be used to improve dual path and multi-pulse defibrillation techniques, which have been shown experimentally to lower defibrillation thresholds substantially. The new model may be a useful tool to help in further improving dual path and multiple pulse defibrillation techniques by predicting optimal pulse durations and shock timing parameters. PMID:18673561

Out-of-hospital defibrillation with automated external defibrillators: postshock analysis should be delayed.

PubMed

Blouin, D; Topping, C; Moore, S; Stiell, I; Afilalo, M

2001-09-01

The American Heart Association protocols for use of automated external defibrillators (AEDs) recommend that a rhythm analysis be done immediately after each defibrillation attempt. However, shock is often followed by electrical silence or marginally organized electrical activity before ventricular fibrillation (VF) or ventricular tachycardia (VT) recurs. The optimal timing of postshock analysis for identification of recurrent VF/VT is unknown. This study examines the time to recurrence of VF/VT after a defibrillation attempt with AED. Over an 18-month period, all tapes from patients with out-of-hospital cardiac arrest who received shocks at least once with an AED were screened for recurrent VF/VT. All cases come from a single emergency medical services system providing basic life support, defibrillation with AED, and intubation with an esophageal-tracheal twin-lumen airway device (Combitube) for a population of 633,511 individuals. Pediatric and traumatic cases were excluded. When VF/VT recurred within 3 minutes of the defibrillation attempt, rhythm strips were printed and included in the study. Two cardiology fellows, blinded to the study objectives, measured the time from defibrillation to recurrent VF/VT for each strip. Over the study period, 222 tapes from 96 patients met the inclusion criteria. Only 44 (20%) occurrences of VF/VT had recurred within 6 seconds of defibrillation, 162 (73%) at 60 seconds, and 200 (90%) at 90 seconds. Eighty percent of VF/VT recurred more than 6 seconds after defibrillation and were missed when using current American Heart Association AED protocols. Subsequent analysis should be postponed until at least 30 seconds after defibrillation. Performing 30 seconds of chest compressions after defibrillation before subsequent AED rhythm analysis would increase AED identification of VF/VT to 52%.

Trainers' Attitudes towards Cardiopulmonary Resuscitation, Current Care Guidelines, and Training

PubMed Central

Mäkinen, M.; Castrén, M.; Nurmi, J.; Niemi-Murola, L.

2016-01-01

Objectives. Studies have shown that healthcare personnel hesitate to perform defibrillation due to individual or organisational attitudes. We aimed to assess trainers' attitudes towards cardiopulmonary resuscitation and defibrillation (CPR-D), Current Care Guidelines, and associated training. Methods. A questionnaire was distributed to CPR trainers attending seminars in Finland (N = 185) focusing on the updated national Current Care Guidelines 2011. The questions were answered using Likert scale (1 = totally disagree, 7 = totally agree). Factor loading of the questionnaire was made using maximum likelihood analysis and varimax rotation. Seven scales were constructed (Hesitation, Nurse's Role, Nontechnical Skill, Usefulness, Restrictions, Personal, and Organisation). Cronbach's alphas were 0.92–0.51. Statistics were Student's t-test, ANOVA, stepwise regression analysis, and Pearson Correlation. Results. The questionnaire was returned by 124/185, 67% CPR trainers, of whom two-thirds felt that their undergraduate training in CPR-D had not been adequate. Satisfaction with undergraduate defibrillation training correlated with the Nontechnical Skills scale (p < 0.01). Participants scoring high on Hesitation scale (p < 0.01) were less confident about their Nurse's Role (p < 0.01) and Nontechnical Skills (p < 0.01). Conclusion. Quality of undergraduate education affects the work of CPR trainers and some feel uncertain of defibrillation. The train-the-trainers courses and undergraduate medical education should focus more on practical scenarios with defibrillators and nontechnical skills. PMID:27144027

Attenuating the defibrillation dosage decreases postresuscitation myocardial dysfunction in a swine model of pediatric ventricular fibrillation

PubMed Central

Berg, Marc D.; Banville, Isabelle L.; Chapman, Fred W.; Walker, Robert G.; Gaballa, Mohammed A.; Hilwig, Ronald W.; Samson, Ricardo A.; Kern, Karl B.; Berg, Robert A.

2009-01-01

Objective The optimal biphasic defibrillation dose for children is unknown. Postresuscitation myocardial dysfunction is common and may be worsened by higher defibrillation doses. Adult-dose automated external defibrillators are commonly available; pediatric doses can be delivered by attenuating the adult defibrillation dose through a pediatric pads/cable system. The objective was to investigate whether unattenuated (adult) dose biphasic defibrillation results in greater postresuscitation myocardial dysfunction and damage than attenuated (pediatric) defibrillation. Design Laboratory animal experiment. Setting University animal laboratory. Subjects Domestic swine weighing 19 ± 3.6 kg. Interventions Fifty-two piglets were randomized to receive biphasic defibrillation using either adult-dose shocks of 200, 300, and 360 J or pediatric-dose shocks of ~50, 75, and 85 J after 7 mins of untreated ventricular fibrillation. Contrast left ventriculograms were obtained at baseline and then at 1, 2, 3, and 4 hrs postresuscitation. Postresuscitation left ventricular ejection fraction and cardiac troponins were evaluated. Measurements and Main Results By design, piglets in the adult-dose group received shocks with more energy (261 ± 65 J vs. 72 ± 12 J, p < .001) and higher peak current (37 ± 8 A vs. 13 ± 2 A, p < .001) at the largest defibrillation dose needed. In both groups, left ventricular ejection fraction was reduced significantly at 1, 2, and 4 hrs from baseline and improved during the 4 hrs postresuscitation. The decrease in left ventricular ejection fraction from baseline was greater after adult-dose defibrillation. Plasma cardiac troponin levels were elevated 4 hrs postresuscitation in 11 of 19 adult-dose piglets vs. four of 20 pediatric-dose piglets (p = .02). Conclusions Unattenuated adult-dose defibrillation results in a greater frequency of myocardial damage and worse postresuscitation myocardial function than pediatric doses in a swine model of prolonged out-of-hospital pediatric ventricular fibrillation cardiac arrest. These data support the use of pediatric attenuating electrodes with adult biphasic automated external defibrillators to defibrillate children. PMID:18496405

Wide variation in cardiopulmonary resuscitation interruption intervals among commercially available automated external defibrillators may affect survival despite high defibrillation efficacy.

PubMed

Snyder, David; Morgan, Carl

2004-09-01

Recent studies have associated interruptions of cardiopulmonary resuscitation imposed by automated external defibrillators (AEDs) with poor resuscitation outcome. In particular, the "hands-off" interval between precordial compressions and subsequent defibrillation shock has been implicated. We sought to determine the range of variation among current-generation AEDs with respect to this characteristic. Seven AEDs from six manufacturers were characterized via stopwatch and arrhythmia simulator with respect to the imposed hands-off interval. All AEDs were equipped with new batteries, and measurements were repeated five times for each AED. A wide variation in the hands-off interval between precordial compressions and shock delivery was observed, ranging from 5.2 to 28.4 secs, with only one AED achieving an interruption of <10 secs. Laboratory and clinical data suggest that this range of variation could be responsible for a more than two-fold variation in patient resuscitation success, an effect that far exceeds any defibrillation efficacy differences that may hypothetically exist. In addition to defibrillation waveform and dose, researchers should consider the hands-off cardiopulmonary resuscitation interruption interval between cardiopulmonary resuscitation and subsequent defibrillation shock to be an important covariate of outcome in resuscitation studies. Defibrillator design should minimize this interval to avoid potential adverse consequences on patient survival.

Changes in transthoracic impedance during sequential biphasic defibrillation.

PubMed

Deakin, Charles D; Ambler, Jonathan J S; Shaw, Steven

2008-08-01

Sequential monophasic defibrillation reduces transthoracic impedance (TTI) and progressively increases current flow for any given energy level. The effect of sequential biphasic shocks on TTI is unknown. We therefore studied patients undergoing elective cardioversion using a biphasic waveform to establish whether this is a phenomenon seen in the clinical setting. Adults undergoing elective DC cardioversion for atrial flutter or fibrillation received sequential transthoracic shocks using an escalating protocol (70J, 100J, 150J, 200J, and 300J) with a truncated exponential biphasic waveform. TTI was calculated through the defibrillator circuit and recorded electronically. Successful cardioversion terminated further defibrillation shocks. A total of 58 patients underwent elective cardioversion. Cardioversion was successful in 93.1% patients. First shock TTI was 92.2 [52.0-126.0]Omega (n=58) and decreased significantly with each sequential shock. Mean TTI in patients receiving five shocks (n=5) was 85.0Omega. Sequential biphasic defibrillation decreases TTI in a similar manner to that seen with monophasic waveforms. The effect is likely during defibrillation during cardiac arrest by the quick succession in which shocks are delivered and the lack of cutaneous blood flow which limits the inflammatory response. The ability of biphasic defibrillators to adjust their waveform according to TTI is likely to minimise any effect of these findings on defibrillation efficacy.

Barriers and facilitators to public access defibrillation in out-of-hospital cardiac arrest: a systematic review.

PubMed

Smith, Christopher M; Lim Choi Keung, Sarah N; Khan, Mohammed O; Arvanitis, Theodoros N; Fothergill, Rachael; Hartley-Sharpe, Christopher; Wilson, Mark H; Perkins, Gavin D

2017-10-01

Public access defibrillation initiatives make automated external defibrillators available to the public. This facilitates earlier defibrillation of out-of-hospital cardiac arrest victims and could save many lives. It is currently only used for a minority of cases. The aim of this systematic review was to identify barriers and facilitators to public access defibrillation. A comprehensive literature review was undertaken defining formal search terms for a systematic review of the literature in March 2017. Studies were included if they considered reasons affecting the likelihood of public access defibrillation and presented original data. An electronic search strategy was devised searching MEDLINE and EMBASE, supplemented by bibliography and related-article searches. Given the low-quality and observational nature of the majority of articles, a narrative review was performed. Sixty-four articles were identified in the initial literature search. An additional four unique articles were identified from the electronic search strategies. The following themes were identified related to public access defibrillation: knowledge and awareness; willingness to use; acquisition and maintenance; availability and accessibility; training issues; registration and regulation; medicolegal issues; emergency medical services dispatch-assisted use of automated external defibrillators; automated external defibrillator-locator systems; demographic factors; other behavioural factors. In conclusion, several barriers and facilitators to public access defibrillation deployment were identified. However, the evidence is of very low quality and there is not enough information to inform changes in practice. This is an area in urgent need of further high-quality research if public access defibrillation is to be increased and more lives saved. PROSPERO registration number CRD42016035543. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Wearable Cardioverter Defibrillators.

PubMed

Ferrick, Aileen M; Tian, David; Vudathaneni, Vijaya; Shevchuk, Olga L; Ferrick, Neal J; Frishman, William

The use of implantable cardioverter defibrillators (ICD) has favorably impacted the prevention and treatment of sudden cardiac death (SCD) associated with ventricular arrhythmias. However, there are situations where an ICD cannot be immediately implanted, even though the patient is at high risk for SCD. The wearable cardioverter defibrillator (WCD) is a unique technology that can bridge this gap for patients. The WCD has been demonstrated to terminate ventricular tachycardia/fibrillation if worn and used correctly. With proper training, it is relatively easy to put on, maintain, and use. Most patients are compliant and are able to consistently wear the device. The WCD negates the infection risk or procedural complications associated with insertion and possible extraction of leads, as with an ICD. In terms of primary prevention of ventricular tachycardia/fibrillation in patients with a left ventricular ejection fraction ≤35%, prospective, randomized studies evaluating the survival of patients utilizing the WCD will need to be performed before evidenced-based criteria for its use can be established. On the basis of current data, WCD use for those awaiting heart transplant, for those with ICD indications status post-ICD explant, and for high-risk SCD patients with possible reversible cardiomyopathy appears to be a reasonable approach on the basis of current data.

A biophysical model for defibrillation of cardiac tissue.

PubMed Central

Keener, J P; Panfilov, A V

1996-01-01

We propose a new model for electrical activity of cardiac tissue that incorporates the effects of cellular microstructure. As such, this model provides insight into the mechanism of direct stimulation and defibrillation of cardiac tissue after injection of large currents. To illustrate the usefulness of the model, numerical stimulations are used to show the difference between successful and unsuccessful defibrillation of large pieces of tissue. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 PMID:8874007

The safe use of automated external defibrillators in a wet environment.

PubMed

Lyster, Tom; Jorgenson, Dawn; Morgan, Carl

2003-01-01

There has been concern regarding potential shock hazards for rescuers or bystanders when a defibrillator is used in a wet environment and the recommended safety procedure, moving the patient to a dry area, is not followed. To measure the electrical potentials associated with the use of an automated external defibrillator (AED) in a realistically modeled wet environment. A raw processed turkey was used as a patient surrogate. The turkey was placed on a cement floor while pool water was applied to the surrounding area. To simulate a rescuer or bystander in the vicinity of a patient, a custom sense probe was constructed. Defibrillation shocks were delivered to the turkey and the probe was used to measure the voltage an operator/bystander would receive at different points surrounding the surrogate. The test was repeated with salt water. The maximum voltage occurred approximately 15 cm from the simulated patient and measured 14 V peak (current 14 mA peak) in the case of pool water, and 30 V peak (current 30 mA peak) in the case of salt water. Thirty volts may result in some minor sensation by the operator or bystander, but is considered unlikely to be hazardous under these circumstances. The maximum currents were lower than allowed by safety standards. Although defibrillation in a wet environment is not recommended practice, our simulation of a patient and a rescuer/bystander in a wet environment did not show significant risk should circumstances demand it.

How implantable cardioverter-defibrillators work and simple programming.

PubMed

Bryant, Randall M

2017-01-01

Following the sudden death of a friend in 1966, Dr Michel Mirowski began pioneering work on the first implantable cardioverter-defibrillator. By 1969 he had developed an experimental model and performed the first transvenous defibrillation. In 1970 he reported on the use of a "standby automatic defibrillator" that was tested successfully in dogs. He postulated that such a device "when adapted for clinical use, might be implanted temporarily or permanently in selected patients particularly prone to develop ventricular fibrillation and thus provide them with some degree of protection from sudden coronary death". In 1980 he reported on the first human implants of an "electronic device designed to monitor cardiac electrical activity, to recognise ventricular fibrillation and ventricular tachyarrhythmias … and then to deliver corrective defibrillatory discharges". Through innovations in circuitry, battery, and capacitor technologies, the current implantable cardioverter-defibrillator is 10 times smaller and exponentially more sophisticated than that first iteration. This article will review the inner workings of the implantable cardioverter-defibrillator and outline several features that make it the wonder in technology that it has become.

Attenuated adult biphasic shocks for prolonged pediatric ventricular fibrillation: support for pediatric automated defibrillators.

PubMed

Berg, Robert A

2004-09-01

To evaluate published data regarding the treatment of prolonged pediatric defibrillation, with special emphasis on the use of attenuated adult biphasic shocks for pediatric defibrillation. Review relevant human and animal literature. Rhythm analysis algorithms from two manufacturers of automated external defibrillators can accurately distinguish shockable from nonshockable rhythms in children. Theoretical considerations and transthoracic impedance data from animals and children suggest that pediatric defibrillation doses should not necessarily vary in a simple weight-based manner. Two piglet studies have established that an attenuated adult biphasic dosage can be successfully used for 3.5- to 24-kg animals in ventricular fibrillation. One study established that the attenuated adult biphasic dosage was at least as safe and effective as the standard monophasic weight-based dosing. This review supports the American Heart Association's new guidelines for pediatric automated external defibrillator usage: "Automated external defibrillators may be used for children 1 to 8 yrs of age who have no signs of circulation. Ideally the device should deliver a pediatric dose. The arrhythmia detection system used in the device should demonstrate high specificity for pediatric shockable rhythms, i.e., it will not recommend delivery of a shock for nonshockable rhythms."

Implantable Cardioverter-defibrillator Therapy for Hypertrophic Cardiomyopathy: Usefulness in Primary and Secondary Prevention.

PubMed

Sarrias, Axel; Galve, Enrique; Sabaté, Xavier; Moya, Àngel; Anguera, Ignacio; Núñez, Elaine; Villuendas, Roger; Alcalde, Óscar; García-Dorado, David

2015-06-01

Hypertrophic cardiomyopathy is a frequent cause of sudden death. Clinical practice guidelines indicate defibrillator implantation for primary prevention in patients with 1 or more risk factors and for secondary prevention in patients with a history of aborted sudden death or sustained ventricular arrhythmias. The aim of the present study was to analyze the follow-up of patients who received an implantable defibrillator following the current guidelines in nonreferral centers for this disease. This retrospective observational study included all patients who underwent defibrillator implantation between January 1996 and December 2012 in 3 centers in the province of Barcelona. The study included 69 patients (mean age [standard deviation], 44.8 [17] years; 79.3% men), 48 in primary prevention and 21 in secondary prevention. The mean number of risk factors per patient was 1.8 in the primary prevention group and 0.5 in the secondary prevention group (P=.029). The median follow-up duration was 40.5 months. The appropriate therapy rate was 32.7/100 patient-years in secondary prevention and 1.7/100 patient-years in primary prevention (P<.001). Overall mortality was 10.1%. Implant-related complications were experienced by 8.7% of patients, and 13% had inappropriate defibrillator discharges. In patients with a defibrillator for primary prevention, the appropriate therapy rate is extremely low, indicating the low predictive power of the current risk stratification criteria. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Interprofessional education and social interaction: The use of automated external defibrillators in team-based basic life support.

PubMed

Onan, Arif; Simsek, Nurettin

2017-04-01

Automated external defibrillators are pervasive computing devices designed for the treatment and management of acute sudden cardiac arrest. This study aims to explain users' actual use behavior in teams formed by different professions taken after a short time span of interaction with automated external defibrillator. Before the intervention, all the participants were certified with the American Heart Association Basic Life Support for healthcare providers. A statistically significant difference was revealed in mean individual automated external defibrillator technical skills between uniprofessional and interprofessional groups. The technical automated external defibrillator team scores were greater for groups with interprofessional than for those with uniprofessional education. The nontechnical automated external defibrillator skills of interprofessional and uniprofessional teams revealed differences in advantage of interprofessional teams. Students positively accept automated external defibrillators if well-defined and validated training opportunities to use them expertly are available. Uniprofessional teams were successfully supported by their members and, thereby, used automated external defibrillator effectively. Furthermore, the interprofessional approach resulted in as much effective teamwork as the uniprofessional approach.

Legal aspects of the application of the lay rescuer automatic external defibrillator (AED) program in South Korea.

PubMed

Bae, Hyuna

2008-04-01

The American Heart Association has stated that the automatic external defibrillator (AED) is a promising method for achieving rapid defibrillation, and emphasized that AED training and use should be available in every community. The demonstrated safety and effectiveness of the AED make it ideally suited for the delivery of early defibrillation by trained laypersons, and the placement of AEDs in selected locations for immediate use by trained laypersons may enable critical intervention that can significantly increase survival from out-of-hospital cardiac arrest. The American Heart Association recommends the installation of AEDs in public locations such as airports, thus allowing laypersons to conduct defibrillation and cardiopulmonary resuscitation on the occasion of adverse cardiopulmonary events. In Korea, the Ministry of Health and Welfare officially prohibits the installation of AEDs in public locations on the grounds that cardiopulmonary resuscitation and defibrillation are understood as medical practices that can be conducted only by licensed medical practitioners. The purpose of this article is to discuss the necessity for AEDs and the appropriate process for their implementation in Korea, by examining the current pre-AED status of Korea and the relevant legal aspects.

Adherence to AHA Guidelines When Adapted for Augmented Reality Glasses for Assisted Pediatric Cardiopulmonary Resuscitation: A Randomized Controlled Trial

PubMed Central

Gervaix, Alain; Haddad, Kevin; Lacroix, Laurence; Schrurs, Philippe; Sahin, Ayhan; Lovis, Christian; Manzano, Sergio

2017-01-01

Background The American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) are nowadays recognized as the world’s most authoritative resuscitation guidelines. Adherence to these guidelines optimizes the management of critically ill patients and increases their chances of survival after cardiac arrest. Despite their availability, suboptimal quality of CPR is still common. Currently, the median hospital survival rate after pediatric in-hospital cardiac arrest is 36%, whereas it falls below 10% for out-of-hospital cardiac arrest. Among emerging information technologies and devices able to support caregivers during resuscitation and increase adherence to AHA guidelines, augmented reality (AR) glasses have not yet been assessed. In order to assess their potential, we adapted AHA Pediatric Advanced Life Support (PALS) guidelines for AR glasses. Objective The study aimed to determine whether adapting AHA guidelines for AR glasses increased adherence by reducing deviation and time to initiation of critical life-saving maneuvers during pediatric CPR when compared with the use of PALS pocket reference cards. Methods We conducted a randomized controlled trial with two parallel groups of voluntary pediatric residents, comparing AR glasses to PALS pocket reference cards during a simulation-based pediatric cardiac arrest scenario—pulseless ventricular tachycardia (pVT). The primary outcome was the elapsed time in seconds in each allocation group, from onset of pVT to the first defibrillation attempt. Secondary outcomes were time elapsed to (1) initiation of chest compression, (2) subsequent defibrillation attempts, and (3) administration of drugs, as well as the time intervals between defibrillation attempts and drug doses, shock doses, and number of shocks. All these outcomes were assessed for deviation from AHA guidelines. Results Twenty residents were randomized into 2 groups. Time to first defibrillation attempt (mean: 146 s) and adherence to AHA guidelines in terms of time to other critical resuscitation endpoints and drug dose delivery were not improved using AR glasses. However, errors and deviations were significantly reduced in terms of defibrillation doses when compared with the use of the PALS pocket reference cards. In a total of 40 defibrillation attempts, residents not wearing AR glasses used wrong doses in 65% (26/40) of cases, including 21 shock overdoses >100 J, for a cumulative defibrillation dose of 18.7 Joules per kg. These errors were reduced by 53% (21/40, P<.001) and cumulative defibrillation dose by 37% (5.14/14, P=.001) with AR glasses. Conclusions AR glasses did not decrease time to first defibrillation attempt and other critical resuscitation endpoints when compared with PALS pocket cards. However, they improved adherence and performance among residents in terms of administering the defibrillation doses set by AHA. PMID:28554878

Risk stratification for implantable cardioverter defibrillator therapy: the role of the wearable cardioverter-defibrillator.

PubMed

Klein, Helmut U; Goldenberg, Ilan; Moss, Arthur J

2013-08-01

The benefit of implantable cardioverter-defibrillator (ICD) therapy depends upon appropriate evaluation of a persisting risk of sudden death and estimation of the patient's overall survival. Assessment of a stable and unchangeable arrhythmogenic substrate is often difficult. Structural abnormality and ventricular dysfunction, the two major risk parameters, may recover, and heart failure symptoms can improve so that ICD therapy may not be indicated. Risk stratification can take time while the patient continues to be at high risk of arrhythmic death, and patients may need temporary bridging by a defibrillator in cases of interrupted ICD therapy. The wearable cardioverter-defibrillator (WCD) combines a long-term electrocardiogram (ECG)-monitoring system with an external automatic defibrillator. The LIfeVest® (ZOLL, Pittsburgh, PA, USA) is composed of a garment, containing two defibrillation patch electrodes on the back, and an elastic belt with a front-defibrillation patch electrode and four non-adhesive ECG electrodes, connected to a monitoring and defibrillation unit. The WCD is a safe and effective tool to terminate ventricular tachycardia/ventricular fibrillation events, unless a conscious patient withholds shock delivery. It may be used in patients in the early phase after acute myocardial infarction with poor left ventricular function, after acute coronary revascularization procedures (percutaneous coronary intervention or coronary artery bypass grafting) and reduced left ventricular ejection fraction (≤35%), in patients with acute heart failure in non-ischaemic cardiomyopathy of uncertain aetiology and prognosis. The WCD may be helpful in subjects with syncope of assumed tachyarrhythmia origin or in patients with inherited arrhythmia syndromes. The WCD may replace ICD implantation in patients waiting for heart transplantation or who need a ventricular-assist device. This review describes the technical details and characteristics of the WCD, discusses its various potential applications, and reports the currently available experience with the wearable defibrillator.

Electromagnetic interference caused by common surgical energy-based devices on an implanted cardiac defibrillator.

PubMed

Paniccia, Alessandro; Rozner, Marc; Jones, Edward L; Townsend, Nicole T; Varosy, Paul D; Dunning, James E; Girard, Guillaume; Weyer, Christopher; Stiegmann, Gregory V; Robinson, Thomas N

2014-12-01

Surgical energy-based devices emit energy, which can interfere with other electronic devices (eg, implanted cardiac pacemakers and/or defibrillators). The purpose of this study was to quantify the amount of unintentional energy (electromagnetic interference [EMI]) transferred to an implanted cardiac defibrillator by common surgical energy-based devices. A transvenous cardiac defibrillator was implanted in an anesthetized pig. The primary outcome measure was the average maximum EMI occurring on the implanted cardiac device during activations of multiple different surgical energy-based devices. The EMI transferred to the implanted cardiac device is as follows: traditional bipolar 30 W .01 ± .004 mV, advanced bipolar .004 ± .003 mV, ultrasonic shears .01 ± .004 mV, monopolar Bovie 30 W coagulation .50 ± .20 mV, monopolar Bovie 30 W blend .92 ± .63 mV, monopolar instrument without dispersive electrode .21 ± .07 mV, plasma energy 3.48 ± .78 mV, and argon beam coagulator 2.58 ± .34 mV. Surgeons can minimize EMI on implanted cardiac defibrillators by preferentially utilizing bipolar and ultrasonic devices. Copyright © 2014 Elsevier Inc. All rights reserved.

A qualitative study to identify barriers to deployment and student training in the use of automated external defibrillators in schools.

PubMed

Zinckernagel, Line; Hansen, Carolina Malta; Rod, Morten Hulvej; Folke, Fredrik; Torp-Pedersen, Christian; Tjørnhøj-Thomsen, Tine

2017-01-19

Student training in use of automated external defibrillators and deployment of such defibrillators in schools is recommended to increase survival after out-of-hospital cardiac arrest. Low implementation rates have been observed, and even at schools with a defibrillator, challenges such as delayed access have been reported. The purpose of this study was to identify barriers to the implementation of defibrillator training of students and deployment of defibrillators in schools. A qualitative study based on semi-structured individual interviews and focus groups with a total of 25 participants, nine school leaders, and 16 teachers at eight different secondary schools in Denmark (2012-2013). Thematic analysis was used to identify regular patterns of meaning using the technology acceptance model and focusing on the concepts of perceived usefulness and perceived ease of use. School leaders and teachers are concerned that automated external defibrillators are potentially dangerous, overly technical, and difficult to use, which was related to their limited familiarity with them. They were ambiguous about whether or not students are the right target group or which grade is suitable for defibrillator training. They were also ambiguous about deployment of defibrillators at schools. Those only accounting for the risk of students, considering their schools to be small, and that time for professional help was limited, found the relevance to be low. Due to safety concerns, some recommended that defibrillators at schools should be inaccessible to students. They lacked knowledge about how they work and are operated, and about the defibrillators already placed at their campuses (e.g., how to access them). Prior training and even a little knowledge about defibrillators were crucial to their perception of student training but not for their considerations on the relevance of their placement at schools. It is crucial for implementation of automated external defibrillators in schools to inform staff about how they work and are operated and that students are an appropriate target group for defibrillator training. Furthermore, it is important to provide schools with a basis for decision making about when to install defibrillators, and to ensure that school staff and students are informed about their placement.

Inconsistent shock advisories for monomorphic VT and Torsade de Pointes--A prospective experimental study on AEDs and defibrillators.

PubMed

Fitzgerald, Abi; Johnson, Meshell; Hirsch, Jan; Rich, Mary-Ann; Fidler, Richard

2015-07-01

Cardiovascular disease and sudden cardiac arrest are the leading causes of death in the United States. Early defibrillation is key to successful resuscitation for patients who experience shockable rhythms during a cardiac arrest. It is therefore vital that the shock advisory of AEDs (automated external defibrillators) or defibrillators in AED mode be reliable and appropriate. The goal of this study was to better understand the performance of multiple lay-rescuer and hospital professional defibrillators in AED mode in their analysis of ventricular arrhythmias. The measurable objectives of this study sought to quantify: 1. No shock advisory for sinus rhythms at any rate. 2. Recognition and shock advisory for ventricular fibrillation (VF). 3. Recognition and shock advisory for monomorphic ventricular tachycardia (VT). 4. Recognition and shock advisory for Torsades de Pointes (TdP). This is a prospective evaluation of two AEDs and four semi-automatic, hospital professional defibrillators. This study represents post-marketing evaluation of FDA approved devices. Each defibrillator was connected to multiple rhythm simulators and presented with simulated ECG waveforms 20 consecutive times at various rates when possible. All four defibrillators and both AEDs tested consistently recognized normal sinus rhythm (NSR) from all rhythm sources, and did not recommend a shock for NSR at any rate (from 80 to 220 bpm). All four defibrillators and both AEDs recognized VF from all rhythm sources tested and recommended a shock 100% of the time. Variations were found in the shock advisory rates among defibrillators when testing simulated VT heart rates at or below 150 bpm. One AED tested did not consistently advise a shock for monomorphic VT or TdP at any tested rate. Lay-rescuer AEDs and professional hospital defibrillators tested in AED mode did not reliably recommend a shock for sustained monomorphic VT or TdP at certain rates, despite the fact that it is a critical component of the currently recommended treatment. These findings require further examination of the risk benefit analysis of shocking or not shocking rhythms such as TdP or pulseless VT. Published by Elsevier Ireland Ltd.

Electromagnetic interference from welding and motors on implantable cardioverter-defibrillators as tested in the electrically hostile work site.

PubMed

Fetter, J G; Benditt, D G; Stanton, M S

1996-08-01

This study was designed to determine the susceptibility of an implanted cardioverter-defibrillator to electromagnetic interference in an electrically hostile work site environment, with the ultimate goal of allowing the patient to return to work. Normal operation of an implanted cardioverter-defibrillator depends on reliable sensing of the heart's electrical activity. Consequently, there is concern that external electromagnetic interference from external sources in the work place, especially welding equipment or motor-generator systems, may be sensed and produce inappropriate shocks or abnormal reed switch operation, temporarily suspending detection of ventricular tachycardia or ventricular fibrillation. The effects of electromagnetic interference on the operation of one type of implantable cardioverter-defibrillator (Medtronic models 7217 and 7219) was measured by using internal event counter monitoring in 10 patients operating arc welders at up to 900 A or working near 200-hp motors and 1 patient close to a locomotive starter drawing up to 400 A. The electromagnetic interference produced two sources of potential interference on the sensing circuit or reed switch operation, respectively: 1) electrical fields with measured frequencies up to 50 MHz produced by the high currents during welding electrode activation, and 2) magnetic fields produced by the current in the welding electrode and cable. The defibrillator sensitivity was programmed to the highest (most sensitive) value: 0.15 mV (model 7219) or 0.3 mV (model 7217). The ventricular tachycardia and ventricular fibrillation therapies were temporarily turned off but the detection circuits left on. None of the implanted defibrillators tested were affected by oversensing of the electric field as verified by telemetry from the detection circuits. The magnetic field from 225-A welding current produced a flux density of 1.2 G; this density was not adequate to close the reed switch, which requires approximately 10 G. Our testing at the work site revealed no electrical interference with this type of defibrillator. Patients were allowed to return to work. The following precautions should be observed by the patient: 1) maintain a minimal distance of 2 ft (61 cm) from the welding arc and cables or large motors, 2) do not exceed tested currents with the welding equipment, 3) wear insulated gloves while operating electrical equipment, 4) verify that electrical equipment is properly grounded, and 5) stop welding and leave the work area immediately if a therapy is delivered or a feeling of lightheadedness is experienced.

[Study on Accurately Controlling Discharge Energy Method Used in External Defibrillator].

PubMed

Song, Biao; Wang, Jianfei; Jin, Lian; Wu, Xiaomei

2016-01-01

This paper introduces a new method which controls discharge energy accurately. It is achieved by calculating target voltage based on transthoracic impedance and accurately controlling charging voltage and discharge pulse width. A new defibrillator is designed and programmed using this method. The test results show that this method is valid and applicable to all kinds of external defibrillators.

New signs to encourage the use of Automated External Defibrillators by the lay public.

PubMed

Smith, Christopher M; Colquhoun, Michael C; Samuels, Marc; Hodson, Mark; Mitchell, Sarah; O'Sullivan, Judy

2017-05-01

Public Access Defibrillation - the use of Automated External Defibrillators (AEDs) by lay bystanders before the arrival of Emergency Medical Services - is an important strategy in delivering prompt defibrillation to victims of out-of-hospital cardiac arrest and can greatly improve survival rates. Such public-access AEDs are used rarely: one barrier might be poor understanding and content of current signage to indicate their presence. The aim of this project was to develop a sign, with public consultation, that better indicated the function of an AED, and an associated poster to encourage its use. Two public surveys were undertaken, in July and December 2015, to investigate perceptions of the current AED location sign recommended for use in the UK and to produce an improved location sign and associated information poster. There were 1895 and 2115 respondents to the surveys. Fewer than half (47.9%, 895/1870) understood what the current location sign indicated. One of four design options for a location sign best explained the indication for (preferred by 56.0%, 1023/1828) and best encouraged the use of a public AED (51.8%, 946/1828). 83.5% (1766/2115) preferred an illustration of a stylised heart trace to the lightning bolt used at present. From five wording options, 'Defibrillator - Heart Restarter' was the most popular (29.4%, 622/2115). An associated poster was developed using design features from the new location sign, findings from the surveys and expert group input regarding its content. This is the first time that public consultation has been used to design a public AED location sign. Effective signage has the potential to help break down the barriers to more widespread use of AEDs in public places. Copyright © 2017 Elsevier B.V. All rights reserved.

Wearable cardioverter defibrillator: Bridge or alternative to implantation?

PubMed Central

Barraud, Jeremie; Cautela, Jennifer; Orabona, Morgane; Pinto, Johan; Missenard, Olivier; Laine, Marc; Thuny, Franck; Paganelli, Franck; Bonello, Laurent; Peyrol, Michael

2017-01-01

The implantable cardioverter-defibrillator (ICD) is effective to prevent sudden cardiac death (SCD) in selected patients with heart disease known to be at high risk for ventricular arrhythmia. Nevertheless, this invasive and definitive therapy is not indicated in patients with potentially transient or reversible causes of sudden death, or in patients with temporary contra-indication for ICD placement. The wearable cardioverter defibrillator (WCD) is increasingly used for SCD prevention both in patients awaiting ICD implantation or with an estimated high risk of ventricular arrhythmia though to be transient. We conducted a review of current clinical uses and benefits of the WCD, and described its technical aspects, limitations and perspectives. PMID:28706588

Current state of knowledge and experts' perspective on the subcutaneous implantable cardioverter-defibrillator.

PubMed

Santini, Massimo; Cappato, Riccardo; Andresen, Dietrich; Brachmann, Johannes; Davies, D Wyn; Cleland, John; Filippi, Alessandro; Gronda, Edoardo; Hauer, Richard; Steinbeck, Gerhard; Steinhaus, David

2009-06-01

ICD implantation is today a well-recognized therapy to prevent sudden cardiac death. The available implantable devices at present need the use of permanent endocavitary leads which may cause, in some instances, serious troubles to the patients (lead dislodgement, ventricular perforation, lead infections, etc.). A new implantable defibrillator provided by only a subcutaneous lead is at present under evaluation. Its potential indications, usefulness benefits, and problems represent an interesting field of investigation and discussion. This paper describes the conclusions recently reached by a panel of experts, with regard to the potential role of an implantable subcutaneous defibrillator in the prevention of sudden cardiac death.

Placement of implantable cardioverter-defibrillators in paediatric and congenital heart defect patients: a pipeline for model generation and simulation prediction of optimal configurations

PubMed Central

Rantner, Lukas J; Vadakkumpadan, Fijoy; Spevak, Philip J; Crosson, Jane E; Trayanova, Natalia A

2013-01-01

There is currently no reliable way of predicting the optimal implantable cardioverter-defibrillator (ICD) placement in paediatric and congenital heart defect (CHD) patients. This study aimed to: (1) develop a new image processing pipeline for constructing patient-specific heart–torso models from clinical magnetic resonance images (MRIs); (2) use the pipeline to determine the optimal ICD configuration in a paediatric tricuspid valve atresia patient; (3) establish whether the widely used criterion of shock-induced extracellular potential (Φe) gradients ≥5 V cm−1 in ≥95% of ventricular volume predicts defibrillation success. A biophysically detailed heart–torso model was generated from patient MRIs. Because transvenous access was impossible, three subcutaneous and three epicardial lead placement sites were identified along with five ICD scan locations. Ventricular fibrillation was induced, and defibrillation shocks were applied from 11 ICD configurations to determine defibrillation thresholds (DFTs). Two configurations with epicardial leads resulted in the lowest DFTs overall and were thus considered optimal. Three configurations shared the lowest DFT among subcutaneous lead ICDs. The Φe gradient criterion was an inadequate predictor of defibrillation success, as defibrillation failed in numerous instances even when 100% of the myocardium experienced such gradients. In conclusion, we have developed a new image processing pipeline and applied it to a CHD patient to construct the first active heart–torso model from clinical MRIs. PMID:23798492

The subcutaneous implantable cardioverter-defibrillator.

PubMed

Grace, Andrew

2014-01-01

To consider the case of need that underpinned the development of the subcutaneous implantable cardioverter-defibrillator (SICD), the preclinical and clinical data obtained so far, its current role and likely future. The data from prospective clinical evaluation of the device demonstrated safety and efficacy leading to Food and Drug Administration approval. This superseded earlier reports from Europe that raised some clinical concerns, previously anticipated through the introduction of new technology. Recent estimates indicate maybe 55% of patients in routine clinical practice needing an ICD are potentially suitable for a subcutaneous device. The SICD provides a useful alternative for high-energy (ICD) therapy in those deemed at risk and who need defibrillation and in whom there are no indications for cardiac resynchronization, bradycardia support or antitachycardia pacing. There is the possibility of both higher specificity and the avoidance of myo-cellular damage with shock delivery, and if these two aspects play out subcutaneous defibrillation could become an option of choice in many settings.

Fixed-energy biphasic waveform defibrillation in a pediatric model of cardiac arrest and resuscitation.

PubMed

Tang, Wanchun; Weil, Max Harry; Jorgenson, Dawn; Klouche, Kada; Morgan, Carl; Yu, Ting; Sun, Shijie; Snyder, David

2002-12-01

For adults, 150-J fixed-energy, impedance-compensating biphasic truncated exponential (ICBTE) shocks are now effectively used in automated defibrillators. However, the high energy levels delivered by adult automated defibrillators preclude their use for pediatric patients. Accordingly, we investigated a method by which adult automated defibrillators may be adapted to deliver a 50-J ICBTE shock for pediatric defibrillation. Prospective, randomized study. A university-affiliated research institution. Domestic piglets. We initially investigated four groups of anesthetized mechanically ventilated piglets weighing 3.8, 7.5, 15, and 25 kg. Ventricular fibrillation was induced with an AC current delivered to the right ventricular endocardium. After 7 mins of untreated ventricular fibrillation, a conventional manual defibrillator was used to deliver up to three 50-J ICBTE shocks. If ventricular fibrillation was not reversed, a 1-min interval of precordial compression preceded a second sequence of up to three shocks. The protocol was repeated until spontaneous circulation was restored, or for a total of 15 mins. In a second set of experiments, we evaluated a 150-J biphasic adult automated defibrillator that was operated in conjunction with energy-reducing electrodes such as to deliver 50-J shocks. The same resuscitation protocol was then exercised on piglets weighing 3.7, 13.5, and 24.2 kg. All animals were successfully resuscitated. Postresuscitation hemodynamic and myocardial function quickly returned to baseline values in both experimental groups, and all animals survived. An adaptation of a 150-J biphasic adult automated defibrillator in which energy-reducing electrodes delivered 50-J shocks successfully resuscitated animals ranging from 3.7 to 25 kg without compromise of postresuscitation myocardial function or survival.

Automated external defibrillators in National Collegiate Athletic Association Division I Athletics.

PubMed

Coris, Eric E; Sahebzamani, Frances; Walz, Steve; Ramirez, Arnold M

2004-01-01

Sudden cardiac death is the leading cause of death in athletes. Evidence on current sudden cardiac death prevention through preparticipation history, physicals, and noninvasive cardiovascular diagnostics has demonstrated a low sensitivity for detection of athletes at high risk of sudden cardiac death. Data are lacking on automated external defibrillator programs specifically initiated to respond to rare dysrhythmia in younger, relatively low-risk populations. Surveys were mailed to the head athletic trainers of all National Collegiate Athletic Association Division I athletics programs listed in the National Athletic Trainers' Association directory. In all, 303 surveys were mailed; 186 departments (61%) responded. Seventy-two percent (133) of responding National Collegiate Athletic Association Division I athletics programs have access to automated external defibrillator units; 54% (101) own their units. Proven medical benefit (55%), concern for liability (51%), and affordability (29%) ranked highest in frequency of reasons for automated external defibrillator purchase. Unit cost (odds ratio = 1.01; 95% confidence interval, 1.01-1.0), donated units (odds ratio = 1.92; confidence interval, 3.66-1.01), institution size (odds ratio =.0001; confidence interval, 1.3 E-4 to 2.2E-05), and proven medical benefit of automated external defibrillators (odds ratio = 24; confidence interval, 72-8.1) were the most significant predictors of departmental defibrillator ownership. Emergency medical service response time and sudden cardiac death event history were not significantly predictive of departmental defibrillator ownership. The majority of automated external defibrillator interventions occurred on nonathletes. Many athletics medicine programs are obtaining automated external defibrillators without apparent criteria for determination of need. Usage and maintenance policies vary widely among departments with unit ownership or access. Programs need to approach the issue of unit acquisition and implementation with knowledge of the surrounding emergency medical service system, geography of their individual sports medicine facilities, numbers and relative risk of their athletes, and budgetary constraints.

Adherence to AHA Guidelines When Adapted for Augmented Reality Glasses for Assisted Pediatric Cardiopulmonary Resuscitation: A Randomized Controlled Trial.

PubMed

Siebert, Johan N; Ehrler, Frederic; Gervaix, Alain; Haddad, Kevin; Lacroix, Laurence; Schrurs, Philippe; Sahin, Ayhan; Lovis, Christian; Manzano, Sergio

2017-05-29

The American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) are nowadays recognized as the world's most authoritative resuscitation guidelines. Adherence to these guidelines optimizes the management of critically ill patients and increases their chances of survival after cardiac arrest. Despite their availability, suboptimal quality of CPR is still common. Currently, the median hospital survival rate after pediatric in-hospital cardiac arrest is 36%, whereas it falls below 10% for out-of-hospital cardiac arrest. Among emerging information technologies and devices able to support caregivers during resuscitation and increase adherence to AHA guidelines, augmented reality (AR) glasses have not yet been assessed. In order to assess their potential, we adapted AHA Pediatric Advanced Life Support (PALS) guidelines for AR glasses. The study aimed to determine whether adapting AHA guidelines for AR glasses increased adherence by reducing deviation and time to initiation of critical life-saving maneuvers during pediatric CPR when compared with the use of PALS pocket reference cards. We conducted a randomized controlled trial with two parallel groups of voluntary pediatric residents, comparing AR glasses to PALS pocket reference cards during a simulation-based pediatric cardiac arrest scenario-pulseless ventricular tachycardia (pVT). The primary outcome was the elapsed time in seconds in each allocation group, from onset of pVT to the first defibrillation attempt. Secondary outcomes were time elapsed to (1) initiation of chest compression, (2) subsequent defibrillation attempts, and (3) administration of drugs, as well as the time intervals between defibrillation attempts and drug doses, shock doses, and number of shocks. All these outcomes were assessed for deviation from AHA guidelines. Twenty residents were randomized into 2 groups. Time to first defibrillation attempt (mean: 146 s) and adherence to AHA guidelines in terms of time to other critical resuscitation endpoints and drug dose delivery were not improved using AR glasses. However, errors and deviations were significantly reduced in terms of defibrillation doses when compared with the use of the PALS pocket reference cards. In a total of 40 defibrillation attempts, residents not wearing AR glasses used wrong doses in 65% (26/40) of cases, including 21 shock overdoses >100 J, for a cumulative defibrillation dose of 18.7 Joules per kg. These errors were reduced by 53% (21/40, P<.001) and cumulative defibrillation dose by 37% (5.14/14, P=.001) with AR glasses. AR glasses did not decrease time to first defibrillation attempt and other critical resuscitation endpoints when compared with PALS pocket cards. However, they improved adherence and performance among residents in terms of administering the defibrillation doses set by AHA. ©Johan N Siebert, Frederic Ehrler, Alain Gervaix, Kevin Haddad, Laurence Lacroix, Philippe Schrurs, Ayhan Sahin, Christian Lovis, Sergio Manzano. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 29.05.2017.

Protein biomarkers identify patients unlikely to benefit from primary prevention implantable cardioverter defibrillators: findings from the Prospective Observational Study of Implantable Cardioverter Defibrillators (PROSE-ICD).

PubMed

Cheng, Alan; Zhang, Yiyi; Blasco-Colmenares, Elena; Dalal, Darshan; Butcher, Barbara; Norgard, Sanaz; Eldadah, Zayd; Ellenbogen, Kenneth A; Dickfeld, Timm; Spragg, David D; Marine, Joseph E; Guallar, Eliseo; Tomaselli, Gordon F

2014-12-01

Primary prevention implantable cardioverter defibrillators (ICDs) reduce all-cause mortality, but the benefits are heterogeneous. Current risk stratification based on left ventricular ejection fraction has limited discrimination power. We hypothesize that biomarkers for inflammation, neurohumoral activation, and cardiac injury can predict appropriate shocks and all-cause mortality in patients with primary prevention ICDs. The Prospective Observational Study of Implantable Cardioverter Defibrillators (PROSe-ICD) enrolled 1189 patients with systolic heart failure who underwent ICD implantation for primary prevention of sudden cardiac death. The primary end point was an ICD shock for adjudicated ventricular tachyarrhythmia. The secondary end point was all-cause mortality. After a median follow-up of 4.0 years, 137 subjects experienced an appropriate ICD shock and 343 participants died (incidence rates of 3.2 and 5.8 per 100 person-years, respectively). In multivariable-adjusted models, higher interleukin-6 levels increased the risk of appropriate ICD shocks. In contrast, C-reactive protein, interleukin-6, tumor necrosis factor-α receptor II, pro-brain natriuretic peptide (pro-BNP), and cardiac troponin T showed significant linear trends for increased risk of all-cause mortality across quartiles. A score combining these 5 biomarkers identified patients who were much more likely to die than to receive an appropriate shock from the ICD. An increase in serum biomarkers of inflammation, neurohumoral activation, and myocardial injury increased the risk for death but poorly predicted the likelihood of an ICD shock. These findings highlight the potential importance of serum-based biomarkers in identifying patients who are unlikely to benefit from primary prevention ICDs. clinicaltrials.gov; Unique Identifier: NCT00733590. © 2014 American Heart Association, Inc.

External defibrillation in the left lateral position--a comparison of manual paddles with self-adhesive pads.

PubMed

Dodd, Tamsin E L; Deakin, Charles D; Petley, Graham W; Clewlow, Frank

2004-12-01

Firm paddle force during defibrillation lowers transthoracic impedance (TTI) and increases transmyocardial current, increasing the chances of successful cardioversion. Current protocols recommend that if defibrillation using the anterior-apical (AA) paddle position fails, the anterior-posterior (AP) position should be used. This generally requires the patient to be placed in the left lateral position with the operator leaning over the patient. Avoiding physical contact with the patient during defibrillation subjectively makes application of firm paddle force difficult in the AP position. We compared TTI between the AA and AP positions and between manual paddles and self-adhesive pads to establish if the AP position precludes firm paddle force and to compare TTI between paddles and self-adhesive pads. Twenty-one consecutive patients undergoing elective cardioversion (age 39-82) were studied. TTI was measured between pairs of manually held paddles and self-adhesive pads using AA placement with the patient supine, and AP placement with the patient left lateral position. Mean TTI using the AP electrode position was lower using manual paddles (66.5 Omega; 95% CI 60.2-72.9 Omega) than that using self-adhesive pads (92.1 Omega; 95% CI 81.5-102.7 Omega; 95% CI between the mean =15.8-35.5 Omega; P <0.0001). TTI was significantly less using the manual paddles compared with self-adhesive pads in both AA and AP positions (P <0.0001). Despite the subjective difficulties of defibrillating patients in the AP position whilst leaning over them, use of manual paddles achieves a lower TTI than that achieved with self-adhesive pads.

Safety aspects for public access defibrillation using automated external defibrillators near high-voltage power lines.

PubMed

Schlimp, C J; Breiteneder, M; Lederer, W

2004-05-01

Automated external defibrillators (AEDs) must combine easy operability and high-quality diagnosis even under unfavorable conditions. This study determined the influence of electromagnetic interference caused by high-voltage power lines with 16.7-Hz alternating current on the quality of AEDs' rhythm analysis. Two AEDs frequently used in Austria were tested near high-voltage power lines (15 kV or 110 kV, alternating current with 16.7 Hz). The defibrillation electrodes were attached either to a proband with true sinus rhythm or to a resuscitation dummy with generated sinus rhythm, ventricular fibrillation, ventricular tachycardia or asystole. Electromagnetic interference was much more prominent in a human's than in a dummy's electrocardiogram and depended on the position of the electrodes and cables in relation to the power line. Near high-voltage power lines the AEDs showed a significant operational fault. One AED interpreted the interference as a motion artifact, even when underlying rhythms were clearly detectable. The other AED interpreted 16.7-Hz oscillation as ventricular fibrillation with consequent shock advice when no underlying rhythm was detected. The tested AEDs neither filter nor recognize a technical interference of 16.7 Hz caused by 15-kV power lines above railway tracks or 110-kV overland power lines, as run by railway companies in Austria, Germany, Norway, Sweden and Switzerland. These failures in AEDs' algorithms for rhythm analysis may cause substantial harm to patients undergoing public access defibrillation. The proper function of AEDs needs to be reconsidered to guarantee patients' safety near high-voltage power lines.

Accelerated Implantable Defibrillator Battery Depletion Secondary to Lithium Cluster Formation: A Case Series.

PubMed

Aggarwal, Ashim; Sarmiento, Joseph J; Charles, David R; Parr, Alan R; Baman, Timir S

2016-04-01

Device failure from unanticipated and precipitous battery depletion is uncommon but can be life-threatening. Multiple mechanisms of battery failure have been previously described in the medical literature. However, in this current case series, we describe the largest cohort of patients (n = 4) with St. Jude (St. Paul, MN, USA) early implantable defibrillator battery depletion attributable to lithium cluster formation causing short circuit and high current drain. Clinicians must be aware of this occult cause of device failure and more studies are needed to determine its true prevalence. © 2015 Wiley Periodicals, Inc.

Inappropriate Implantable Cardioverter-Defibrillator Shocks Attributed to Alternating-Current Leak in a Swimming Pool

PubMed Central

Makaryus, John N.; Angert-Gilman, Julia; Yacoub, Mena; Patel, Apoor

2014-01-01

Implantable cardioverter-defibrillators (ICDs) are the standard of care for preventing sudden cardiac death in patients who are predisposed to malignant ventricular arrhythmias. Causes of inappropriate ICD shock include equipment malfunction, improper arrhythmia evaluation, misinterpretation of myopotentials, and electromagnetic interference. As the number of implanted ICDs has increased, other contributors to inappropriate therapy have become known, such as minimal electrical current leaks that mimic ventricular fibrillation. We present the case of a 63-year-old man with a biventricular ICD who received 2 inappropriate shocks, probably attributable to alternating-current leaks in a swimming pool. In addition, we discuss ICD sensitivity and offer recommendations to avoid similar occurrences. PMID:24512403

How, why, and when may atrial defibrillation find a specific role in implantable devices? A clinical viewpoint.

PubMed

Boriani, Giuseppe; Diemberger, Igor; Biffi, Mauro; Martignani, Cristian; Ziacchi, Matteo; Bertini, Matteo; Valzania, Cinzia; Bronzetti, Gabriele; Rapezzi, Claudio; Branzi, Angelo

2007-03-01

This viewpoint article discusses the potential for incorporation of atrial defibrillation capabilities in modern multi-chamber devices. In the late 1990s, the possibility of using shock-only therapy to treat selected patients with recurrent atrial fibrillation (AF) was explored in the context of the stand-alone atrial defibrillator. The failure of this strategy can be attributed to the technical limitations of the stand-alone device, low tolerance of atrial shocks, difficulties in patient selection, a lack of predictive knowledge about the evolution of AF, and, last but not least, commercial considerations. An open question is how atrial defibrillation capability may now assume a specific new role in devices implanted for sudden death prevention or cardiac resynchronization. For patients who already have indications for implantable devices, device-based atrial defibrillation appears attractive as a "backup" option for managing AF when preventive pharmacological/electrical measures fail. This and several other personalized hybrid therapeutic approaches await exploration, though assessment of their efficacy is methodologically challenging. Achievement of acceptance by patients is an essential premise for any updated atrial defibrillation strategy. Strategies that are being investigated to improve patient tolerance include waveform shaping, pharmacologic modulation of pain, and patient-activated defibrillation (patients might also perceive the problem of discomfort somewhat differently in the context of a backup therapy). The economic impact of implementing atrial defibrillation features in available devices is progressively decreasing, and financial feasibility need not be a major issue. Future studies should examine clinically relevant outcomes and not be limited (as occurred with stand-alone defibrillators) to technical or other soft endpoints.

Modeling the response of normal and ischemic cardiac tissue to electrical stimulation

NASA Astrophysics Data System (ADS)

Kandel, Sunil Mani

Heart disease, the leading cause of death worldwide, is often caused by ventricular fibrillation. A common treatment for this lethal arrhythmia is defibrillation: a strong electrical shock that resets the heart to its normal rhythm. To design better defibrillators, we need a better understanding of both fibrillation and defibrillation. Fundamental mysteries remain regarding the mechanism of how the heart responds to a shock, particularly anodal shocks and the resultant hyperpolarization. Virtual anodes play critical roles in defibrillation, and one cannot build better defibrillators until these mechanisms are understood. We are using mathematical modeling to numerically simulate observed phenomena, and are exploring fundamental mechanisms responsible for the heart's electrical behavior. Such simulations clarify mechanisms and identify key parameters. We investigate how systolic tissue responds to an anodal shock and how refractory tissue reacts to hyperpolarization by studying the dip in the anodal strength-interval curve. This dip is due to electrotonic interaction between regions of depolarization and hyperpolarization following a shock. The dominance of the electrotonic mechanism over calcium interactions implies the importance of the spatial distribution of virtual electrodes. We also investigate the response of localized ischemic tissue to an anodal shock by modeling a regional elevation of extracellular potassium concentration. This heterogeneity leads to action potential instability, 2:1 conduction block (alternans), and reflection-like reentry at the boarder of the normal and ischemic regions. This kind of reflection (reentry) occurs due to the delay between proximal and distal segments to re-excite the proximal segment. Our numerical simulations are based on the bidomain model, the state-of-the-art mathematical description of how cardiac tissue responds to shocks. The dynamic LuoRudy model describes the active properties of the membrane. To model ischemia, the Luo-Rudy model is modified by adding ischemic-related ion currents and concentrations to mimic conditions during the initial phase of ischemia. The stimulus is applied through a unipolar electrode that induces a complicated spatial distribution of transmembrane potential, including adjacent regions of depolarization and hyperpolarization. This research is significant because it uncovers basic properties of excitation that are fundamental for understanding cardiac pacing and defibrillation.

[Subcutaneous implantable cardioverter-defibrillator in prevention of sudden cardiac death in Poland - opinion paper endorsed by the Polish Cardiac Society Working Group on Heart Rhythm].

PubMed

Ptaszyński, Paweł; Grabowski, Marcin; Kowalski, Oskar; Kempa, Maciej; Mitkowski, Przemysław; Przybylski, Andrzej; Sterliński, Maciej

2017-01-01

In the past years, cardiovascular mortality has decreased but despite these cardiovascular diseases are responsible for millions of deaths every year in the world and approximately 25% of which are sudden cardiac death (SCD). Implantable defibrillators (ICD) is proven therapy used in primary and secondary SCD prevention. Currently majority of devices use transvenous leads inserted predominantly into the right heart for both pacing and defibrillation. On the other hand, ICD may cause complica-tions, including inappropriate shocks, device-related infection and lead failure. Problems with transvenous leads prompted the development of a subcutaneous defibrillator (S-ICD) with an electrode system that is placed entirely subcutaneously, outside the thoracic cavity. The device may be useful when venous access is difficult, in young patients and in patients at particular risk of infection. S-ICD is not suitable for patients with indications for bradycardia pacing, cardiac resynchronisation therapy and in cases with tachyarrhythmia easily terminated by antitachycardia pacing.

Testing of Anesthesia Machines and Defibrillators in Healthcare Institutions.

PubMed

Gurbeta, Lejla; Dzemic, Zijad; Bego, Tamer; Sejdic, Ervin; Badnjevic, Almir

2017-09-01

To improve the quality of patient treatment by improving the functionality of medical devices in healthcare institutions. To present the results of the safety and performance inspection of patient-relevant output parameters of anesthesia machines and defibrillators defined by legal metrology. This study covered 130 anesthesia machines and 161 defibrillators used in public and private healthcare institutions, during a period of two years. Testing procedures were carried out according to international standards and legal metrology legislative procedures in Bosnia and Herzegovina. The results show that in 13.84% of tested anesthesia machine and 14.91% of defibrillators device performance is not in accordance with requirements and should either have its results be verified, or the device removed from use or scheduled for corrective maintenance. Research emphasizes importance of independent safety and performance inspections, and gives recommendations for the frequency of inspection based on measurements. Results offer implications for adequacy of preventive and corrective maintenance performed in healthcare institutions. Based on collected data, the first digital electronical database of anesthesia machines and defibrillators used in healthcare institutions in Bosnia and Herzegovina is created. This database is a useful tool for tracking each device's performance over time.

Transthoracic impedance study with large self-adhesive electrodes in two conventional positions for defibrillation.

PubMed

Krasteva, Vessela; Matveev, Mikhail; Mudrov, Nikolay; Prokopova, Rada

2006-10-01

External defibrillation requires the application of high voltage electrical impulses via large external electrodes, placed on selected locations on the thorax surface. The position of the electrodes is one of the major determinants of the transthoracic impedance (TTI) which influences the intracardiac current flow during electric shock and defibrillation success. The variety of factors which influence TTI measurements raised our interest to investigate the range of TTI values and the temporal TTI variance during long-term application of defibrillation self-adhesive electrodes in two conventional positions on the patient's chest--position 1 (sub-clavicular/sub-axillar position) and position 2 (antero-posterior position). The prospective study included 86 randomly selected volunteers (39 male and 49 female, 67 patients with normal skin, 13 patients with dry skin and 6 patients with greasy skin, 16 patients with chest pilosity and 70 patients without chest pilosity). The TTI was measured according to the interelectrode voltage drop obtained by passage of a low-amplitude high-frequency current (32 kHz) between the two self-adhesive electrodes (active area about 92 cm2). For each patient, the TTI values were measured within 10 s, 1 min and 5 min after sticking the electrodes to the skin surface, independently for the two tested electrode positions. We found that the expected TTI range is between 58 Omega and 152 Omega for position 1 and between 55 Omega and 149 Omega for position 2. Although the two TTI ranges are comparable, we measured significantly higher TTI mean of about (107.2 +/- 22.3) Omega for position 1 compared to (96.6 +/- 19.2) Omega for position 2 (p = 0.001). This fact suggested that the antero-posterior position of the electrodes is favourable for defibrillation. Within the investigated time interval of 5 min, we observed a significant TTI reduction with about 6.9% (7.4 Omega/107.2 Omega) for position 1 and about 5.3% (5.1 Omega/96.6 Omega) for position 2. We suppose that the long-term application of self-adhesive electrodes would lead to improvement of the physical conditions for conduction of the defibrillation current and to diminution of energy loss in the electrode-skin contact impedance. We found that gender is important when position 1 is used because women have significantly higher TTI (111 +/- 20.3) Omega compared to the TTI of men (102.6 +/- 24) Omega (p = 0.0442). Although we found some specifics of the electrode-skin contact layer, we can conclude that because of the insignificant differences in TTI, the operator of the defibrillator paddles does not need to take into consideration the skin type and pilosity of the patients. Analysis of the correlations between TTI and the individual patient characteristics (chest size, weight, height, age) showed that these patient characteristics are unreliable factors for prediction of the TTI values and optimal defibrillation pulse parameters and energy.

[Public access defibrillation].

PubMed

Katz, Eugène; Metzger, Jacques-Thierry; Sierro, Christophe; Deac, Monica; Fishman, Daniel; Girod, Grégoire; Potin, Mathieu; Niquille, Marc; Stauffer, Jean-Christoffe; Kehtari, Réza; Sénéchaud, Christophe; Garcia, Wenceslao; Rodriguez, Maria; Fromer, Martin

2008-08-27

Placement of automated external defibrillators (AED) in public facilities and training of the lay persons in basic life support-defibrillation (BLS-D) was recommended by the American Heart Association for the treatment of out-of-hospital cardiac arrest (OHCA). Immediate use of AED result in increase of survival to hospital discharge. Many observation and much less randomized trials describe clinical efficacy of this approach. However, "negative" trials have also been published and some recent data suggest that public access defibrillation (PAD) will have a minimal impact on population survival. In this article various PAD strategies were briefly reviewed. In our opinion installation of AED in public places should be based on the long-term study of local OHCA demography and preceded by widespread BLS training of lay population.

Defibrillation threshold testing fails to show clinical benefit during long-term follow-up of patients undergoing cardiac resynchronization therapy defibrillator implantation.

PubMed

Michowitz, Yoav; Lellouche, Nicolas; Contractor, Tahmeed; Bourke, Tara; Wiener, Isaac; Buch, Eric; Boyle, Noel; Bersohn, Malcolm; Shivkumar, Kalyanam

2011-05-01

The utility of defibrillation threshold testing in patients undergoing implantable cardioverter-defibrillator (ICD) implantation is controversial. Higher defibrillation thresholds have been noted in patients undergoing implantation of cardiac resynchronization therapy defibrillators (CRT-D). Since the risks and potential benefits of testing may be higher in this population, we sought to assess the impact of defibrillation safety margin or vulnerability safety margin testing in CRT-D recipients. A total of 256 consecutive subjects who underwent CRT-D implantation between January 2003 and December 2007 were retrospectively reviewed. Subjects were divided into two groups based on whether (n= 204) or not (n= 52) safety margin testing was performed. Patient characteristics, tachyarrhythmia therapies, procedural results, and clinical outcomes were recorded. Baseline characteristics, including heart failure (HF) severity, were comparable between the groups. Four cases of HF exacerbation (2%), including one leading to one death, were recorded in the tested group immediately post-implantation. No complications were observed in the untested group. After a mean follow-up of 32 ± 20 months, the proportion of appropriate shocks in the two groups was similar (31 vs. 25%, P = 0.49). There were three cases of failed appropriate shocks in the tested group, despite adequate safety margins at implantation, whereas no failed shocks were noted in the untested group. Survival was similar in the two groups. Defibrillation efficacy testing during implant of CRT-D was associated with increased morbidity and did not predict the success of future device therapy or improve survival during long-term follow-up.

[Semiautomatic defibrillation in children].

PubMed

Rodríguez Núñez, A; Iglesias Vázquez, J A

2004-08-01

The main survival factor in cardiac arrest secondary to ventricular fibrillation (VF) is the interval between collapse and defibrillation; consequently, this treatment constitutes one of the most important links in the survival chain in adults. Although VF is a rare cause of out-of-hospital cardiac arrest in children, its detection and treatment is essential because in the pediatric cardiac arrest scenario, VF is the dysrhythmia with the best prognosis. Automated external defibrillators (AED) are simple devices that allow cardiac rhythm to be analyzed; they can also determine whether it is shockable or not with high sensitivity and specificity in adults and children. Currently available evidence has prompted the recommendation of AED use in children older than 1 year without signs of circulation, mainly in the pre-hospital setting and ideally with a dose-limiting device.

Investigation of availability and accessibility of community automated external defibrillators in a territory in Hong Kong.

PubMed

Ho, C L; Lui, C T; Tsui, K L; Kam, C W

2014-10-01

To evaluate the availability and accessibility of community automated external defibrillators in a territory in Hong Kong. Cross-sectional study. Two public hospitals in New Territories West Cluster in Hong Kong. Information about the locations of community automated external defibrillators was obtained from automated external defibrillator suppliers and through community search. Data on locations of out-of-hospital cardiac arrests from August 2010 to September 2013 were obtained from the local cardiac arrest registry of the emergency departments of two hospitals. Sites of both automated external defibrillators and out-of-hospital cardiac arrests were geographically coded and mapped. The number of out-of-hospital cardiac arrests within 100 m of automated external defibrillators per year and the proportion of out-of-hospital cardiac arrests with accessible automated external defibrillators (100 m) were calculated. The number of community automated external defibrillators per 10,000 population and public access defibrillation rate were also calculated and compared with those in other countries. There were a total of 207 community automated external defibrillators in the territory. The number of automated external defibrillators per 10,000 population was 1.942. All facilities with automated external defibrillators in this territory had more than 0.2 out-of-hospital cardiac arrests per automated external defibrillator per year within 100 m. Among all out-of-hospital cardiac arrests, 25.2% could have an automated external defibrillator reachable within 100 m. The public access defibrillation rate was 0.168%. The number and accessibility of community automated external defibrillators in this territory are comparable to those in other developed countries. The placement site of community automated external defibrillators is cost-effective. However, the public access defibrillation rate is low.

Automatic external defibrillator, life vest defibrillator, or both?

PubMed

Richard Conti, C

2010-12-01

The standard of practice for out-of-hospital defibrillation is the implantable cardioverter-defibrillator. However, much has been written and discussed about the use of automated external defibrillators. Not as much has been written about life vest wearable defibrillators. Copyright © 2010 Wiley Periodicals, Inc.

Defibrillation depends on conductivity fluctuations and the degree of disorganization in reentry patterns.

PubMed

Plank, Gernot; Leon, L Joshua; Kimber, Shane; Vigmond, Edward J

2005-02-01

Defibrillation depends on conductivity and disorganization. Cardiac fibrillation is the deterioration of the heart's normally well-organized activity into one or more meandering spiral waves, which subsequently break up into many meandering wave fronts. Delivery of an electric shock (defibrillation) is the only effective way of restoring the normal rhythm. This study focuses on examining whether higher degrees of disorganization requires higher shock strengths to defibrillate and whether microscopic conductivity fluctuations favor shock success. We developed a three-dimensional computer bidomain model of a block of cardiac tissue with straight fibers immersed in a conductive bath. The membrane behavior was described by the Courtemanche human atrial action potential model incorporating electroporation and an acetylcholine- (ACh) dependent potassium current. Intracellular conductivities were varied stochastically around nominal values with variations of up to 50%. A single rotor reentry was initiated and, by adjusting the spatial ACh variation, the level of organization could be controlled. The single rotor could be stabilized or spiral wave breakup could be provoked leading to fibrillatory-like activity. For each level of organization, multiple shock timings and strengths were applied to compute the probability of shock success as a function of shock strength. Our results suggest that the level of the small-scale conductivity fluctuations is a very important factor in defibrillation. A higher variation significantly lowers the required shock strength. Further, we demonstrated that success also heavily depends on the level of organization of the fibrillatory episode. In general, higher levels of disorganization require higher shock strengths to defibrillate.

Automated external defibrillator availability and CPR training among state police agencies in the United States.

PubMed

Hirsch, Lior M; Wallace, Sarah K; Leary, Marion; Tucker, Kathryn D; Becker, Lance B; Abella, Benjamin S

2012-07-01

Access to automated external defibrillators and cardiopulmonary resuscitation (CPR) training are key determinants of cardiac arrest survival. State police officers represent an important class of cardiac arrest first responders responsible for the large network of highways in the United States. We seek to determine accessibility of automated external defibrillators and CPR training among state police agencies. Contact was attempted with all 50 state police agencies by telephone and electronic mail. Officers at each agency were guided to complete a 15-question Internet-based survey. Descriptive statistics of the responses were performed. Attempts were made to contact all 50 states, and 46 surveys were completed (92% response rate). Most surveys were filled out by police leadership or individuals responsible for medical programs. The median agency size was 725 (interquartile range 482 to 1,485) state police officers, with 695 (interquartile range 450 to 1,100) patrol vehicles ("squad cars"). Thirty-three percent of responding agencies (15/46) reported equipping police vehicles with automated external defibrillators. Of these, 53% (8/15) equipped less than half of their fleet with the devices. Regarding emergency medical training, 78% (35/45) of state police agencies reported training their officers in automated external defibrillator usage, and 98% (44/45) reported training them in CPR. One third of state police agencies surveyed equipped their vehicles with automated external defibrillators, and among those that did, most equipped only a minority of their fleet. Most state police agencies reported training their officers in automated external defibrillator usage and CPR. Increasing automated external defibrillator deployment among state police represents an important opportunity to improve first responder preparedness for cardiac arrest care. Copyright © 2012. Published by Mosby, Inc.

[Automatic external defibrillator--mode of operation and clinical use].

PubMed

Wieneke, H; Konorza, T; Breuckmann, F; Reinsch, N; Erbel, R

2008-10-01

Every year about 100,000 persons die from sudden cardiac death (SCD) in Germany. Although many efforts have been undertaken, mortality remains high. Only 2 - 10% of patients with out-off hospital SCD can finally be discharged from hospital after resuscitation. Observational studies show that ventricular fibrillation and ventricular tachycardia are the primary arrhythmias underlying SCD. For both arrhythmias the main determinant for survival is the time between onset and termination by defibrillation. The chance of survival declines by 10% for every minute of delay. These findings prompted the concept of early defibrillation by first responders. Many studies have shown that non-medical professionals, like police men, firemen or security officers, often arrive at the patient more early than emergency medical service. Thus, "smart" automated external defibrillators (AEDs), designed to identify VT/VF and prompt the user when to deliver a shock were introduced. These devices allow lay rescuers to terminate ventricular arrhythmias before the arrival of medical professionals. By this approach the time to defibrillation could be reduced and a significant reduction in mortality could be documented in selected situation. These encouraging results initialled the installation of AED at public places like aircrafts, airports, underground stations and shopping males. Due to the success of this approach doctors are more and more confronted with questions about technical details, reliability and cost effectiveness of these devices. The present review should give an overview about the current studies and guidelines.

The Selective Late Sodium Current Inhibitor Eleclazine, Unlike Amiodarone, Does Not Alter Defibrillation Threshold or Dominant Frequency of Ventricular Fibrillation.

PubMed

Silva, Ana F G; Bonatti, Rodolfo; Batatinha, Julio A P; Nearing, Bruce D; Zeng, Dewan; Belardinelli, Luiz; Verrier, Richard L

2017-03-01

We examined the effects of the selective late INa inhibitor eleclazine on the 50% probability of successful defibrillation (DFT50) before and after administration of amiodarone to determine its suitability for use in patients with implantable cardioverter defibrillators (ICDs). In 20 anesthetized pigs, transvenous active-fixation cardiac defibrillation leads were fluoroscopically positioned into right ventricular apex through jugular vein. ICDs were implanted subcutaneously. Dominant frequency of ventricular fibrillation was analyzed by fast Fourier transform. The measurements were made before drug administration (control), and at 40 minutes after vehicle, eleclazine (2 mg/kg, i.v., bolus over 15 minutes), or subsequent/single amiodarone administration (10 mg/kg, i.v., bolus over 10 minutes). Eleclazine did not alter DFT50, dominant frequency, heart rate, or mean arterial pressure (MAP). Subsequent amiodarone increased DFT50 (P = 0.006), decreased dominant frequency (P = 0.022), and reduced heart rate (P = 0.031) with no change in MAP. Amiodarone alone increased DFT50 (P = 0.005; NS compared to following eleclazine) and decreased dominant frequency (P = 0.003; NS compared to following eleclazine). Selective late INa inhibition with eleclazine does not alter DFT50 or dominant frequency of ventricular fibrillation when administered alone or in combination with amiodarone. Accordingly, eleclazine would not be anticipated to affect the margin of defibrillation safety in patients with ICDs.

Implantable cardioverter defibrillator knowledge and end-of-life device deactivation: A cross-sectional survey.

PubMed

McEvedy, Samantha M; Cameron, Jan; Lugg, Eugene; Miller, Jennifer; Haedtke, Chris; Hammash, Muna; Biddle, Martha J; Lee, Kyoung Suk; Mariani, Justin A; Ski, Chantal F; Thompson, David R; Chung, Misook Lee; Moser, Debra K

2018-01-01

End-of-life implantable cardioverter defibrillator deactivation discussions should commence before device implantation and be ongoing, yet many implantable cardioverter defibrillators remain active in patients' last days. To examine associations among implantable cardioverter defibrillator knowledge, patient characteristics and attitudes to implantable cardioverter defibrillator deactivation. Cross-sectional survey using the Experiences, Attitudes and Knowledge of End-of-Life Issues in Implantable Cardioverter Defibrillator Patients Questionnaire. Participants were classified as insufficient or sufficient implantable cardioverter defibrillator knowledge and the two groups were compared. Implantable cardioverter defibrillator recipients ( n = 270, mean age 61 ± 14 years; 73% male) were recruited from cardiology and implantable cardioverter defibrillator clinics attached to two tertiary hospitals in Melbourne, Australia, and two in Kentucky, the United States. Participants with insufficient implantable cardioverter defibrillator knowledge ( n = 77, 29%) were significantly older (mean age 66 vs 60 years, p = 0.001), less likely to be Caucasian (77% vs 87%, p  = 0.047), less likely to have received implantable cardioverter defibrillator shocks (26% vs 40%, p = 0.031), and more likely to have indications of mild cognitive impairment (Montreal Cognitive Assessment score <24: 44% vs 16%, p < 0.001). Insufficient implantable cardioverter defibrillator knowledge was associated with attitudes suggesting unwillingness to discuss implantable cardioverter defibrillator deactivation, even during the last days towards end of life ( p < 0.05). Implantable cardioverter defibrillator recipients, especially those who are older or have mild cognitive impairment, often have limited knowledge about implantable cardioverter defibrillator deactivation. This study identified several potential teachable moments throughout the patients' treatment trajectory. An interdisciplinary approach is required to ensure that discussions about implantable cardioverter defibrillator deactivation issues are initiated at appropriate time points, with family members ideally also included.

Potential impact of public access defibrillators on survival after out of hospital cardiopulmonary arrest: retrospective cohort study

PubMed Central

Pell, Jill P; Sirel, Jane M; Marsden, Andrew K; Ford, Ian; Walker, Nicola L; Cobbe, Stuart M

2002-01-01

Objective To estimate the potential impact of public access defibrillators on overall survival after out of hospital cardiac arrest. Design Retrospective cohort study using data from an electronic register. A statistical model was used to estimate the effect on survival of placing public access defibrillators at suitable or possibly suitable sites. Setting Scottish Ambulance Service. Subjects Records of all out of hospital cardiac arrests due to heart disease in Scotland in 1991-8. Main outcome measures Observed and predicted survival to discharge from hospital. Results Of 15 189 arrests, 12 004 (79.0%) occurred in sites not suitable for the location of public access defibrillators, 453 (3.0%) in sites where they may be suitable, and 2732 (18.0%) in suitable sites. Defibrillation was given in 67.9% of arrests that occurred in possibly suitable sites for locating defibrillators and in 72.9% of arrests that occurred in suitable sites. Compared with an actual overall survival of 744 (5.0%), the predicted survival with public access defibrillators ranged from 942 (6.3%) to 959 (6.5%), depending on the assumptions made regarding defibrillator coverage. Conclusions The predicted increase in survival from targeted provision of public access defibrillators is less than the increase achievable through expansion of first responder defibrillation to non-ambulance personnel, such as police or firefighters, or of bystander cardiopulmonary resuscitation. Additional resources for wide scale coverage of public access defibrillators are probably not justified by the marginal improvement in survival. What is already known on this topicThree quarters of all deaths from acute coronary events occur before the patient reaches a hospitalDefibrillation is an independent predictor of survival from out of hospital cardiac arrestThe probability of a rhythm being amenable to defibrillation declines with timeInterest in providing public access defibrillators to reduce the time to defibrillation has been growing, but their potential impact on overall survival is unknownWhat this study addsMost arrests occur in sites unsuitable for locating public access defibrillatorsArrests that occur in sites suitable for locating defibrillators already have the best profile in terms of ambulance response time, use of defibrillation, and survival of the patientPublic access defibrillators are less likely to increase survival than expansion of first responder defibrillation or bystander cardiopulmonary resuscitation PMID:12217989

Realistic expectations for public access defibrillation programs.

PubMed

Atkins, Dianne L

2010-06-01

Public access defibrillation programs have increased dramatically over the past 15 years. This review will focus on their effectiveness and operational characteristics and discuss the characteristics of successful programs, which can improve outcomes. Automated external defibrillators increase survival from cardiac arrest when used by a bystander. Recent studies show that the best outcomes are achieved when devices are placed in areas with a high frequency of cardiac arrest and there is ongoing supervision with emergency plans and cardiopulmonary resuscitation training. Programs are cost-effective under these circumstances, but become very inefficient when placed in areas of low risk. There are few adverse events related to the public access defibrillation programs and volunteers are not harmed. Unguided placement results in devices not being used and a decline in organizational structure of the program. As most cardiac arrests occur in the home, the impact on overall survival remains low. Automated external defibrillators are highly effective at reducing death from ventricular fibrillation and easy access in public areas is most effective. Placement must be prioritized based on public health impact and characteristics of the community.

Cardiac arrest: resuscitation and reperfusion.

PubMed

Patil, Kaustubha D; Halperin, Henry R; Becker, Lance B

2015-06-05

The modern treatment of cardiac arrest is an increasingly complex medical procedure with a rapidly changing array of therapeutic approaches designed to restore life to victims of sudden death. The 2 primary goals of providing artificial circulation and defibrillation to halt ventricular fibrillation remain of paramount importance for saving lives. They have undergone significant improvements in technology and dissemination into the community subsequent to their establishment 60 years ago. The evolution of artificial circulation includes efforts to optimize manual cardiopulmonary resuscitation, external mechanical cardiopulmonary resuscitation devices designed to augment circulation, and may soon advance further into the rapid deployment of specially designed internal emergency cardiopulmonary bypass devices. The development of defibrillation technologies has progressed from bulky internal defibrillators paddles applied directly to the heart, to manually controlled external defibrillators, to automatic external defibrillators that can now be obtained over-the-counter for widespread use in the community or home. But the modern treatment of cardiac arrest now involves more than merely providing circulation and defibrillation. As suggested by a 3-phase model of treatment, newer approaches targeting patients who have had a more prolonged cardiac arrest include treatment of the metabolic phase of cardiac arrest with therapeutic hypothermia, agents to treat or prevent reperfusion injury, new strategies specifically focused on pulseless electric activity, which is the presenting rhythm in at least one third of cardiac arrests, and aggressive post resuscitation care. There are discoveries at the cellular and molecular level about ischemia and reperfusion pathobiology that may be translated into future new therapies. On the near horizon is the combination of advanced cardiopulmonary bypass plus a cocktail of multiple agents targeted at restoration of normal metabolism and prevention of reperfusion injury, as this holds the promise of restoring life to many patients for whom our current therapies fail. © 2015 American Heart Association, Inc.

Advances in sudden death prevention: the emerging role of a fully subcutaneous defibrillator.

PubMed

Majithia, Arjun; Estes, N A Mark; Weinstock, Jonathan

2014-03-01

Randomized clinical trials support the use of implantable defibrillators for mortality reduction in specific populations at high risk for sudden cardiac death. Conventional transvenous defibrillator systems are limited by implantation-associated complications, infection, and lead failure, which may lead to delivery of inappropriate shocks and diminish survival. The development of a fully subcutaneous defibrillator may represent a valuable addition to therapies targeted at sudden death prevention. The PubMed database was searched to identify all clinical reports of the subcutaneous defibrillator from 2000 to the present. We reviewed all case series, cohort analyses, and randomized trials evaluating the safety and efficacy of subcutaneous defibrillators. The subcutaneous defibrillator is a feasible development in sudden cardiac death therapy and may be useful particularly to extend defibrillator therapy to patients with complicated anatomy, limited vascular access, and congenital disease. The subcutaneous defibrillator should not be considered in patients with an indication for cardiac pacing or who have ventricular tachycardia responsive to antitachycardia pacing. Further investigation is needed to compare long-term, head-to-head performance of subcutaneous defibrillators and conventional transvenous defibrillator systems. Published by Elsevier Inc.

[Automated external defibrillators, life vest defibrillator, or both?].

PubMed

Conti, C Richard

2012-03-01

As most understand, survival of cardiac arrest victims falls significantly if cardioversion is not performed promptly. The standard of practice for out-of-hospital defibrillation is the implantable cardiac defibrillator; however, much has been written and discussed about the use of automated external defibrillators. Not as much has been written about life vest wearable defibrillators. How to use these devices will be reviewed in this article.

Pacemakers and implantable cardioverter-defibrillators in pediatric patients.

PubMed

Silka, Michael J; Bar-Cohen, Yaniv

2006-11-01

The use of pacemakers and implantable cardioverter-defibrillators (ICDs) in infants, children, and patients with congenital heart disease presents unique challenges and considerations. They include uncommon indications for device implantation, innovative approaches to lead implantation and configuration, and age-dependent and disease-specific aspects of device programming. In this review, the current indications for pacemaker and ICD implantation in young patients are discussed, followed by consideration of the approaches to lead and device placement in very small patients and those with complex congenital heart disease, in whom unique problems may be encountered. The limitations of programmability of current pacemakers and ICDs when used in young patients are discussed, followed by an analysis of long-term device follow-up and potential late complications.

[Training program on cardiopulmonary resuscitation with the use of automated external defibrillator in a university].

PubMed

Boaventura, Ana Paula; Miyadahira, Ana Maria Kazue

2012-03-01

Early defibrillation in cardiopulmonary resuscitation (CPR) receives increasing emphasis on its priority and rapidity. This is an experience report about the implementation of a training program in CPR using a defibrillator in a private university. The training program in basic CPR maneuvers was based on global guidelines, including a theorical course with practical demonstration of CPR maneuvers with the defibrillator, individual practical training and theoretical and practical assessments. About the performance of students in the practical assessment the mean scores obtained by students in the first stage of the course was 26.4 points, while in the second stage the mean was 252.8 points, in the theoretical assessment the mean in the first stage was 3.06 points and in the second 9.0 points. The implementation of programs like this contribute to the effective acquisition of knowledge (theory) and skill (pratice) for the care of CPR victims.

Clinical impact of defibrillation testing at the time of implantable cardioverter-defibrillator insertion.

PubMed

Hadid, Claudio; Atienza, Felipe; Strasberg, Boris; Arenal, Ángel; Codner, Pablo; González-Torrecilla, Esteban; Datino, Tomás; Percal, Tamara; Almendral, Jesús; Ortiz, Mercedes; Martins, Raphael; Martinez-Alzamora, Nieves; Fernandez Aviles, Francisco

2015-01-01

Ventricular fibrillation is routinely induced during implantable cardioverter-defibrillator insertion to assess defibrillator performance, but this strategy is experiencing a progressive decline. We aimed to assess the efficacy of defibrillator therapies and long-term outcome in a cohort of patients that underwent defibrillator implantation with and without defibrillation testing. Retrospective observational series of consecutive patients undergoing initial defibrillator insertion or generator replacement. We registered spontaneous ventricular arrhythmias incidence and therapy efficacy, and mortality. A total of 545 patients underwent defibrillator implantation (111 with and 434 without defibrillation testing). After 19 (range 9-31) months of follow-up, the death rate per observation year (4% vs. 4%; p = 0.91) and the rate of patients with defibrillator-treated ventricular arrhythmic events per observation year (with test: 10% vs. without test: 12%; p = 0.46) were similar. The generalized estimating equations-adjusted first shock probability of success in patients with test (95%; CI 88-100%) vs. without test (98%; CI 96-100%; p = 0.42) and the proportion of successful antitachycardia therapies (with test: 87% vs. without test: 80%; p = 0.35) were similar between groups. There was no difference in the annualized rate of failed first shock per patient and per shocked patient between groups (5% vs. 4%; p = 0.94). In this observational study, that included an unselected population of patients with a defibrillator, no difference was found in overall mortality, first shock efficacy and rate of failed shocks regardless of whether defibrillation testing was performed or not.

Adverse design of defibrillators: turning off the machine when trying to shock.

PubMed

Høyer, Christian S; Christensen, Erika F; Eika, Berit

2008-11-01

A recent publication demonstrated the possibility of erroneous operation of 2 widely used monitor-defibrillators and observed that the design of user interfaces might contribute to error during operation. During an ambulance simulation training exercise for 72 junior internal medicine physicians that called for defibrillation in the management of cardiac arrest, we observed that in 5 of 192 defibrillation attempts by the physicians, the monitor-defibrillator was inadvertently powered off. When the device is inadvertently powered off, recognition and subsequent steps to defibrillate delayed defibrillation an average of 24 seconds (range 14 to 32 seconds). Our analysis of the controls of this monitor-defibrillator found that the device could be powered off even if fully charged and ready to shock. Redesign of the equipment might prevent this inadvertent event.

Public knowledge of how to use an automatic external defibrillator in out-of-hospital cardiac arrest in Hong Kong.

PubMed

Fan, K L; Leung, L P; Poon, H T; Chiu, H Y; Liu, H L; Tang, W Y

2016-12-01

The survival rate of out-of-hospital cardiac arrest in Hong Kong is low. A long delay between collapse and defibrillation is a contributing factor. Public access to defibrillation may shorten this delay. It is unknown, however, whether Hong Kong's public is willing or able to use an automatic external defibrillator. This study aimed to evaluate public knowledge of how to use an automatic external defibrillator in out-of-hospital cardiac arrest. A face-to-face semi-structured questionnaire survey of the public was conducted in six locations with a high pedestrian flow in Hong Kong. In this study, 401 members of the public were interviewed. Most had no training in first aid (65.8%) or in use of an automatic external defibrillator (85.3%). Nearly all (96.5%) would call for help for a victim of out-of-hospital cardiac arrest but only 18.0% would use an automatic external defibrillator. Public knowledge of automatic external defibrillator use was low: 77.6% did not know the location of an automatic external defibrillator in the vicinity of their home or workplace. People who had ever been trained in both first aid and use of an automatic external defibrillator were more likely to respond to and help a victim of cardiac arrest, and to use an automatic external defibrillator. Public knowledge of automatic external defibrillator use is low in Hong Kong. A combination of training in first aid and in the use of an automatic external defibrillator is better than either one alone.

Defibrillator/monitor/pacemakers.

PubMed

2002-02-01

Defibrillator/monitors allow operators to assess and monitor a patient's ECG and, when necessary, deliver a defibrillating shock to the heart. When integral noninvasive pacing capability is added, the resulting device is referred to as a defibrillator/monitor/pacemaker. In this Update Evaluation, we present our findings for one newly evaluated model, the Philips Heartstream XL, and we summarize our findings for the seven previously evaluated models that are still on the market. (Our previous Evaluations were published in the May-June 1993, February 1998, and September 2000 issues of Health Devices.) Defibrillator/monitor/pacemakers are used for a variety of applications within the hospital, as well as by emergency medical services (EMS) personnel and others in the prehospital environment. To help both hospital-based and prehospital users select an appropriate model, we rate the models (1) for each of three in-hospital applications--general crash-cart use, in-hospital transport use, and in-hospital use by basic as well as advanced users--and (2) for prehospital (EMS) use. For in-hospital use, we recommend four of the evaluated models. These received either Preferred or Acceptable ratings for all the applications considered. For prehospital use, we found that five of the models will meet most organizations' needs.

Inductionless or limited shock testing is possible in most patients with implantable cardioverter- defibrillators/cardiac resynchronization therapy defibrillators: results of the multicenter ASSURE Study (Arrhythmia Single Shock Defibrillation Threshold Testing Versus Upper Limit of Vulnerability: Risk Reduction Evaluation With Implantable Cardioverter-Defibrillator Implantations).

PubMed

Day, John D; Doshi, Rahul N; Belott, Peter; Birgersdotter-Green, Ulrika; Behboodikhah, Mahnaz; Ott, Peter; Glatter, Kathryn A; Tobias, Serge; Frumin, Howard; Lee, Byron K; Merillat, John; Wiener, Isaac; Wang, Samuel; Grogin, Harlan; Chun, Sung; Patrawalla, Rob; Crandall, Brian; Osborn, Jeffrey S; Weiss, J Peter; Lappe, Donald L; Neuman, Stacey

2007-05-08

Implantable cardioverter-defibrillators and cardiac resynchronization therapy defibrillators have relied on multiple ventricular fibrillation (VF) induction/defibrillation tests at implantation to ensure that the device can reliably sense, detect, and convert VF. The ASSURE Study (Arrhythmia Single Shock Defibrillation Threshold Testing Versus Upper Limit of Vulnerability: Risk Reduction Evaluation With Implantable Cardioverter-Defibrillator Implantations) is the first large, multicenter, prospective trial comparing vulnerability safety margin testing versus defibrillation safety margin testing with a single VF induction/defibrillation. A total of 426 patients receiving an implantable cardioverter-defibrillator or cardiac resynchronization therapy defibrillator underwent vulnerability safety margin or defibrillation safety margin screening at 14 J in a randomized order. After this, patients underwent confirmatory testing, which required 2 VF conversions without failure at < or = 21 J. Patients who passed their first 14-J and confirmatory tests, irrespective of the results of their second 14-J test, had their devices programmed to a 21-J shock for ventricular tachycardia (VT) or VF > or = 200 bpm and were followed up for 1 year. Of 420 patients who underwent 14-J vulnerability safety margin screening, 322 (76.7%) passed. Of these, 317 (98.4%) also passed 21-J confirmatory tests. Of 416 patients who underwent 14-J defibrillation safety margin screening, 343 (82.5%) passed, and 338 (98.5%) also passed 21-J confirmatory tests. Most clinical VT/VF episodes (32 of 37, or 86%) were terminated by the first shock, with no difference in first shock success. In all observed cases in which the first shock was unsuccessful, subsequent shocks terminated VT/VF without complication. Although spontaneous episodes of fast VT/VF were limited, there was no difference in the odds of first shock efficacy between groups. Screening with vulnerability safety margin or defibrillation safety margin may allow for inductionless or limited shock testing in most patients.

Optimal installation locations for automated external defibrillators in Taipei 7-Eleven stores: using GIS and a genetic algorithm with a new stirring operator.

PubMed

Huang, Chung-Yuan; Wen, Tzai-Hung

2014-01-01

Immediate treatment with an automated external defibrillator (AED) increases out-of-hospital cardiac arrest (OHCA) patient survival potential. While considerable attention has been given to determining optimal public AED locations, spatial and temporal factors such as time of day and distance from emergency medical services (EMSs) are understudied. Here we describe a geocomputational genetic algorithm with a new stirring operator (GANSO) that considers spatial and temporal cardiac arrest occurrence factors when assessing the feasibility of using Taipei 7-Eleven stores as installation locations for AEDs. Our model is based on two AED conveyance modes, walking/running and driving, involving service distances of 100 and 300 meters, respectively. Our results suggest different AED allocation strategies involving convenience stores in urban settings. In commercial areas, such installations can compensate for temporal gaps in EMS locations when responding to nighttime OHCA incidents. In residential areas, store installations can compensate for long distances from fire stations, where AEDs are currently held in Taipei.

Clinical Risk Stratification for Primary Prevention Implantable Cardioverter Defibrillators

PubMed Central

Hardy, Judy; Yee, Raymond; Healey, Jeffrey S.; Birnie, David; Simpson, Christopher S.; Crystal, Eugene; Mangat, Iqwal; Nanthakumar, Kumaraswamy; Wang, Xuesong; Krahn, Andrew D.; Dorian, Paul; Austin, Peter C.; Tu, Jack V.

2015-01-01

Background— A conceptualized model may be useful for understanding risk stratification of primary prevention implantable cardioverter defibrillators considering the competing risks of appropriate implantable cardioverter defibrillator shock versus mortality. Methods and Results— In a prospective, multicenter, population-based cohort with left ventricular ejection fraction ≤35% referred for primary prevention implantable cardioverter defibrillator, we developed dual risk stratification models to determine the competing risks of appropriate defibrillator shock versus mortality using a Fine-Gray subdistribution hazard model. Among 7020 patients referred, 3445 underwent defibrillator implant (79.7% men, median, 66 years [25th, 75th: 58–73]). During 5918 person-years of follow-up, appropriate shock occurred in 204 patients (3.6 shocks/100 person-years) and 292 died (4.9 deaths/100 person-years). Competing risk predictors of appropriate shock included nonsustained ventricular tachycardia, atrial fibrillation, serum creatinine concentration, digoxin or amiodarone use, and QRS duration near 130-ms peak. One-year cumulative incidence of appropriate shock was 0.9% in the lowest risk category, and 1.7%, 2.5%, 4.9%, and 9.3% in low, intermediate, high, and highest risk groups, respectively. Hazard ratios for appropriate shock ranged from 4.04 to 7.79 in the highest 3 deciles (all P≤0.001 versus lowest risk). Cumulative incidence of 1-year death was 0.6%, 1.9%, 3.3%, 6.2%, and 17.7% in lowest, low, intermediate, high, and highest risk groups, respectively. Mortality hazard ratios ranged from 11.48 to 36.22 in the highest 3 deciles (all P<0.001 versus lowest risk). Conclusions— Simultaneous estimation of risks of appropriate shock and mortality can be performed using clinical variables, providing a potential framework for identification of patients who are unlikely to benefit from prophylactic implantable cardioverter defibrillator. PMID:26224792

Survival in Women Versus Men Following Implantation of Pacemakers, Defibrillators, and Cardiac Resynchronization Therapy Devices in a Large, Nationwide Cohort.

PubMed

Varma, Niraj; Mittal, Suneet; Prillinger, Julie B; Snell, Jeff; Dalal, Nirav; Piccini, Jonathan P

2017-05-10

Whether outcomes differ between sexes following treatment with pacemakers (PM), implantable cardioverter defibrillators, and cardiac resynchronization therapy (CRT) devices is unclear. Consecutive US patients with newly implanted PM, implantable cardioverter defibrillators, and CRT devices from a large remote monitoring database between 2008 and 2011 were included in this observational cohort study. Sex-specific all-cause survival postimplant was compared within each device type using a multivariable Cox proportional hazards model, stratified on age and adjusted for remote monitoring utilization and ZIP-based socioeconomic variables. A total of 269 471 patients were assessed over a median 2.9 [interquartile range, 2.2, 3.6] years. Unadjusted mortality rates (MR; deaths/100 000 patient-years) were similar between women versus men receiving PMs (n=115 076, 55% male; MR 4193 versus MR 4256, respectively; adjusted hazard ratio, 0.87; 95% CI, 0.84-0.90; P <0.001) and implantable cardioverter defibrillators (n=85 014, 74% male; MR 4417 versus MR 4479, respectively; adjusted hazard ratio, 0.98; 95% CI, 0.93-1.02; P =0.244). In contrast, survival was superior in women receiving CRT defibrillators (n=61 475, 72% male; MR 5270 versus male MR 7175; adjusted hazard ratio, 0.73; 95% CI, 0.70-0.76; P <0.001) and also CRT pacemakers (n=7906, 57% male; MR 5383 versus male MR 7625, adjusted hazard ratio, 0.69; 95% CI, 0.61-0.78; P <0.001). This relative difference increased with time. These results were unaffected by age or remote monitoring utilization. Women accounted for less than 30% of high-voltage implants and fewer than half of low-voltage implants in a large, nation-wide cohort. Survival for women and men receiving implantable cardioverter defibrillators and PMs was similar, but dramatically greater for women receiving both defibrillator- and PM-based CRT. © 2017 The Authors and St. Jude Medical. Published on behalf of the American Heart Association, Inc., by Wiley.

Transthoracic impedance used to evaluate performance of cardiopulmonary resuscitation during out of hospital cardiac arrest.

PubMed

Stecher, Frederik S; Olsen, Jan-Aage; Stickney, Ronald E; Wik, Lars

2008-12-01

There is a need to measure cardiopulmonary resuscitation (CPR) in order to document whether ambulance personnel follow CPR guidelines. Our goal was to do this using defibrillator technology based on changes in transthoracic impedance (TTI) produced by chest compressions and ventilations. 122 incidents of out-of-hospital cardiac arrest between May 2003 and February 2004 were analysed based on data recorded from defibrillators in Oslo EMS. New software was used to analyze chest compressions and ventilations based on changes in thoracic impedance between the defibrillator pads, as well as ECG and other event data. In total, 25+/-14% (varying from 76% to 3%) of the time chest compressions were not performed on patients without spontaneous circulation (NFR=No Flow Ratio). When adjusting for time spent on analysis of ECG, pulse check and defibrillation, NFR was 20+/-13% (varying from 70% to 3%). Mean compressions delivered per minute was 87+/-16 and the compression rate during active compressions was 117+/-9min(-1). Individual variation was 31-117min(-1) (mean) and 95-144min(-1) (active periods). A mean of 14+/-3ventilations/min was recorded, varying from 8 to 26min(-1). Compared with the rest of the episode, the first 5min had a significantly higher proportion of time without chest compressions; 30+/-17% (p<0.001) and significantly lower mean compression and ventilation rates; 80+/-19min(-1) and 12+/-4min(-1), respectively (p<0.001 in both cases). Core CPR values can be measured from TTI signals by using a standard defibrillator and new software. NFR was 25% (20% adjusted) with great rescuer variability.

Disparities in the use of primary prevention and defibrillator therapy among blacks and women.

PubMed

Gauri, Andre J; Davis, Andrew; Hong, Thomas; Burke, Martin C; Knight, Bradley P

2006-02-01

This study determines whether there are racial or gender disparities in the use of implantable cardioverter-defibrillator therapy for primary prevention of sudden cardiac death. Primary prevention of sudden death with implantable cardioverter-defibrillator therapy has been shown to improve survival for high-risk patients with coronary artery disease and left ventricular dysfunction. The Center for Medicare and Medicaid Services Medicare database from the year 2002 was used to identify patients who were potential candidates for implantable cardioverter-defibrillator therapy on the basis of a combination of International Classification of Diseases, Ninth Revision, Clinical Modification codes that reflected the presence of an ischemic cardiomyopathy. This cohort was analyzed to determine which patients received implantable cardioverter-defibrillator therapy during the same year. The clinical characteristics of the potential implantable cardioverter-defibrillator candidates were compared with those who actually received an implantable cardioverter-defibrillator. A total 132565 Medicare patients hospitalized during 2002 were identified as having an ischemic cardiomyopathy; 10370 (8%) of these patients underwent implantable cardioverter-defibrillator implantation during the same year. The percentage of patients who underwent implantable cardioverter-defibrillator implantation was higher for men compared with women (10.2% vs 3.5%; P<.001) and whites compared with blacks (8.1 vs 5.4; P<.001). After multivariate analysis, age, gender, and race remained independent predictors of implantable cardioverter-defibrillator implantation. Women with an ischemic cardiomyopathy were 65% less likely to receive implantable cardioverter-defibrillator therapy compared with men (P<.001), and black patients were 31% less likely to receive implantable cardioverter-defibrillator therapy compared with patients of other races (P < .001). Use of implantable cardioverter-defibrillator therapy for primary prevention of sudden death among the elderly population identified as having an ischemic cardiomyopathy was significantly lower among women compared with men, and among blacks compared with whites. Further exploration of gender and racial barriers to appropriate implantable cardioverter-defibrillator use for primary prevention is needed.

Hands-On Defibrillation Skills of Pediatric Acute Care Providers During a Simulated Ventricular Fibrillation Cardiac Arrest Scenario

PubMed Central

Bhalala, Utpal S.; Balakumar, Niveditha; Zamora, Maria; Appachi, Elumalai

2018-01-01

Introduction: Timely defibrillation in ventricular fibrillation cardiac arrest (VFCA) is associated with good outcome. While defibrillation skills of pediatric providers have been reported to be poor, the factors related to poor hands-on defibrillation skills of pediatric providers are largely unknown. The aim of our study was to evaluate delay in individual steps of the defibrillation and human and non-human factors associated with poor hands-on defibrillation skills among pediatric acute care providers during a simulated VFCA scenario. Methods: We conducted a prospective observational study of video evaluation of hands-on defibrillation skills of pediatric providers in a simulated VFCA in our children's hospital. Each provider was asked to use pads followed by paddles to provide 2 J/kg shock to an infant mannequin in VFCA. The hands-on skills were evaluated for struggle with any step of defibrillation, defined a priori as >10 s delay with particular step. The data was analyzed using chi-square test with significant p-value < 0.05. Results: A total of 68 acute care providers were evaluated. Median time to first shock was 97 s (IQR: 60–122.5 s) and did not correlate with provider factors, except previous experience with the defibrillator used in study. The number of providers who struggled (>10 s delay) with each of connecting the pads/paddles to the device, using pads/paddles on the mannequin and using buttons on the machine was 34 (50%), 26 (38%), and 31 (46%), respectively. Conclusions: The defibrillation skills of providers in a tertiary care children's hospital are poor. Both human and machine-related factors are associated with delay in defibrillation. Prior use of the study defibrillator is associated with a significantly shorter time-to-first shock as compared to prior use of any other defibrillator or no prior use of any defibrillator. PMID:29740571

Hands-On Defibrillation Skills of Pediatric Acute Care Providers During a Simulated Ventricular Fibrillation Cardiac Arrest Scenario.

PubMed

Bhalala, Utpal S; Balakumar, Niveditha; Zamora, Maria; Appachi, Elumalai

2018-01-01

Introduction: Timely defibrillation in ventricular fibrillation cardiac arrest (VFCA) is associated with good outcome. While defibrillation skills of pediatric providers have been reported to be poor, the factors related to poor hands-on defibrillation skills of pediatric providers are largely unknown. The aim of our study was to evaluate delay in individual steps of the defibrillation and human and non-human factors associated with poor hands-on defibrillation skills among pediatric acute care providers during a simulated VFCA scenario. Methods: We conducted a prospective observational study of video evaluation of hands-on defibrillation skills of pediatric providers in a simulated VFCA in our children's hospital. Each provider was asked to use pads followed by paddles to provide 2 J/kg shock to an infant mannequin in VFCA. The hands-on skills were evaluated for struggle with any step of defibrillation, defined a priori as >10 s delay with particular step. The data was analyzed using chi-square test with significant p -value < 0.05. Results: A total of 68 acute care providers were evaluated. Median time to first shock was 97 s (IQR: 60-122.5 s) and did not correlate with provider factors, except previous experience with the defibrillator used in study. The number of providers who struggled (>10 s delay) with each of connecting the pads/paddles to the device, using pads/paddles on the mannequin and using buttons on the machine was 34 (50%), 26 (38%), and 31 (46%), respectively. Conclusions: The defibrillation skills of providers in a tertiary care children's hospital are poor. Both human and machine-related factors are associated with delay in defibrillation. Prior use of the study defibrillator is associated with a significantly shorter time-to-first shock as compared to prior use of any other defibrillator or no prior use of any defibrillator.

What Is an Automated External Defibrillator?

MedlinePlus

ANSWERS by heart Treatments + Tests What Is an Automated External Defibrillator? An automated external defibrillator (AED) is a lightweight, portable device ... ANSWERS by heart Treatments + Tests What Is an Automated External Defibrillator? detect a rhythm that should be ...

[Problems with placement and using of automated external defibrillators in Czech Republic].

PubMed

Olos, Tomás; Bursa, Filip; Gregor, Roman; Holes, David

2011-01-01

The use of automated external defibrillators improves the survival of adults who suffer from cardiopulmonary arrest. Automated external defibrillators detect ventricular fibrillation with almost perfect sensitivity and specificity. Authors describe the use of automated external defibrillator during cardiopulmonary resuscitation in a patient with sudden cardiac arrest during ice-hockey match. The article reports also the use of automated external defibrillators in children.

Decreasing the time to defibrillation: a comparative study of defibrillator electrode designs.

PubMed

Adams, Bruce D; Easty, David M; Stuffel, Elaine; Hartman, Irma

2005-08-01

Time to defibrillation (T(defib)) is the most important modifiable factor affecting survival from cardiac arrest. Mortality increases by approximately 7--10% for each minute of defibrillation delay. The purpose of this study was to determine whether defibrillator electrode design complexity affects T(defib). This was a randomized sequential design study utilizing a standardized ventricular fibrillation cardiac arrest model for CPR mannequins. We evaluated two common types of defibrillator electrode models: a single connector design and a double connector design that requires an adaptor. We compared the time required by cardiac arrest team leaders to apply the two types of defibrillator electrodes to a manikin, connect them to a defibrillator, and then deliver a first defibrillatory shock. The primary outcome was time to defibrillation. The secondary outcome was difficulty of application as perceived by the physician participants on a 10 cm visual analog scale. Thirty-two residents performed a sequential assessment of both electrodes. The average T(defib) for the double connector model was 42.9s longer than that of the single connector model (87.5s versus 44.6s, p<0.001). As evaluated by the study participants, the single connector model was significantly easier to apply then the double connector model (1.3 cm versus 4.4 cm, p<0.001). The single connector defibrillator electrode design was associated with a significantly shorter T(defib) than the double connector design. It also was judged to be easier to apply in this model. Ergonomic design of defibrillator electrodes can significantly impact time to defibrillation.

Inter-association task force recommendations on emergency preparedness and management of sudden cardiac arrest in high school and college athletic programs: a consensus statement.

PubMed

Drezner, Jonathan A; Courson, Ron W; Roberts, William O; Mosesso, Vincent N; Link, Mark S; Maron, Barry J

2007-03-01

To assist high school and college athletic programs prepare for and respond to sudden cardiac arrest (SCA). This consensus statement summarizes our current understanding of SCA in young athletes, defines the necessary elements for emergency preparedness, and establishes uniform treatment protocols for the management of SCA. SCA is the leading cause of death in young athletes. The increasing presence of and timely access to automated external defibrillators (AEDs) at sporting events provides a means of early defibrillation and the potential for effective secondary prevention of sudden cardiac death. An Inter-Association Task Force was sponsored by the National Athletic Trainers' Association to develop consensus recommendations on emergency preparedness and management of SCA in athletes. Comprehensive emergency planning is needed for high school and college athletic programs to ensure an efficient and structured response to SCA. Essential elements of an emergency action plan include establishing an effective communication system, training of anticipated responders in cardiopulmonary resuscitation and AED use, access to an AED for early defibrillation, acquisition of necessary emergency equipment, coordination and integration of onsite responder and AED programs with the local emergency medical services system, and practice and review of the response plan. Prompt recognition of SCA, early activation of the emergency medical services system, the presence of a trained rescuer to initiate cardiopulmonary resuscitation, and access to early defibrillation are critical in the management of SCA. In any collapsed and unresponsive athlete, SCA should be suspected and an AED applied as soon as possible for rhythm analysis and defibrillation if indicated.

Riata silicone defibrillation lead with normal electrical measures at routine ambulatory check: The role of high-voltage shock testing

PubMed Central

De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

2016-01-01

AIM To describe our experience with shock testing for the evaluation of patients with Riata™ leads. METHODS Among 51 patients with normal baseline electrical parameters, 20 died during follow-up. Of the remaining 31 patients, 15 underwent the test: In 10 cases a defibrillation testing with ventricular fibrillation (VF) induction and in 5 cases a R-wave-synchronized shock (> 20 J, without inducing VF). The test was performed under sedation with Midazolam. RESULTS Twelve patients (80%) had a normal behavior during shock testing: In 8 cases induced VF was correctly detected and treated; in 4 cases of R-wave-synchronized shock electrical parameters remained stable and normal. Three patients (20%) failed the test. One patient with externalized conductors showed a sudden drop of high-voltage impedance (< 10 Ohm) after a 25 J R-wave-synchronized shock. Two other patients with externalized conductors, undergoing defibrillation testing, showed a short-circuit during shock delivery and the implantable cardioverter defibrillator was unable to interrupt VF. CONCLUSION In Riata™ leads the delivery of a low current during routine measurement of high-voltage impedance may not reveal a small short circuit, that can only be evident by attempting to deliver a true shock, either for spontaneous arrhythmias or in the context of a shock testing. PMID:27957252

Feedback control for stabilizing chaotic spiral waves during cardiac ventricular fibrillation

NASA Astrophysics Data System (ADS)

Uzelac, Ilija; Wikswo, John; Gray, Richard

2011-03-01

The cardiac arrhythmias that lead to ventricular fibrillation (VF) arise from electrical spiral waves (SW) rotating within the heart with a characteristic period τ . A single drifting SW can degenerate into a chaotic system of multiple SWs and VF. Hence early SW detection and termination is crucial to prevent VF. Time-delayed feedback control (TDFC) is well known approach for stabilizing unstable periodic orbits embedded in chaotic attractors. We hypothesize that cardiac SWs can be stabilized by TDFC with a time-delay of τ . Implementing this approach will require precise, closed-loop control of the charge delivered to the heart during the defibrillation process. To do this, we have developed a 2 kW arbitrary-waveform voltage-to-current converter (V2CC) with a 1 kHz bandwidth that can deliver up to 5 A at 400 V for 500 ms, and a photodiode system for recording in real time an optical electrocardiogram, OECG(t). The feedback signal driving the V2CC will be the time-difference (OECG(t) - OECG(t-T), where we hypothesize that T is τ , the period of the SW. This may dramatically decrease defibrillation voltages by using a defibrillation waveform customized to the VF event, unlike commercial capacitor defibrillators. Supported in part by NIH R01 HL58241-11 through ARRA 2009.

Current Indications for Implantable Cardioverter Defibrillators in Non-Ischemic Cardiomyopathies and Channelopathies.

PubMed

González-Torrecilla, Esteban; Arenal, Angel; Atienza, Felipe; Datino, Tomás; Bravo, Loreto; Ruiz, Pablo; Ávila, Pablo; Fernández-Avilés, Francisco

2015-01-01

Current indications for implantable cardioverter defibrillators (ICDs) in patients with channelopathies and cardiomyopathies of non-ischemic origin are mainly based on non-randomized evidence. In patients with nonischemic dilated cardiomyopathy (NIDCM), there is a tendency towards a beneficial effect on total mortality of ICD therapy in patients with significant left ventricular (LV) dysfunction. Although an important reduction in sudden cardiac death (SCD) seems to be clearly demonstrated in these patients, a net beneficial effect on total mortality is unclear mostly in cases with good functional status. Risk stratification has been changing over the last two decades in patients with hypertrophic cardiomyopathy (HCM). Its risk profile has been delineated in parallel with the beneficial effect of ICD in high risk patients. Observational results based on "appropriate" ICD interventions do support its usefulness both in primary and secondary SCD prevention in these patients. Novel risk models quantify the rate of sudden cardiac death in these patients on individual basis. Less clear risk stratification is available for cases of arrhythmogenic right ventricular cardiomyopathy (ARVC) and in other uncommon familiar cardiomyopathies. Main features of risk stratification vary among the different channelopathies (long QT syndrome -LQTS-, Brugada syndrome, etc) with great debate on the management of asymptomatic patients. For most familiar cardiomyopathies, ICD therapy is the only accepted strategy in the prevention of SCD. So far, genetic testing has a limited role in risk evaluation and management of the individual patient. This review aims to summarize these criticisms and to refine the current indications of ICD implantation in patients with cardiomyopathies and major channelopathies.

An abdominal active can defibrillator may facilitate a successful generator change when a lead failure is present.

PubMed

Solomon, A J; Moubarak, J B; Drood, J M; Tracy, C M; Karasik, P E

1999-10-01

Defibrillator generator changes are frequently performed on patients with an implantable cardioverter defibrillator in an abdominal pocket. These patients usually have epicardial patches or older endocardial lead systems. At the time of a defibrillator generator change defibrillation may be unsuccessful as a result of lead failure. We tested the hypothesis that an active can defibrillator implanted in the abdominal pocket could replace a non-functioning endocardial lead or epicardial patch. An abdominal defibrillator generator change was performed in 10 patients, (mean age = 67 +/- 13 years, nine men). Initially, a defibrillation threshold (DFT) was obtained using a passive defibrillator and the chronic endocardial or epicardial lead system. DFTs were then performed using an active can emulator and one chronic lead to simulate endocardial or epicardial lead failure. We tested 30 lead configurations (nine endocardial and 21 epicardial). Although a DFT of 7.3 +/- 4.2 joules was obtained with the intact chronic lead system, the active can emulator and one endocardial or epicardial lead still yielded an acceptable DFT of 19.9 +/- 6.1 joules. In addition, a successful implant (DFT < or = 24 joules) could have been accomplished in 28 of 30 (93%) lead configurations. An active can defibrillator in an abdominal pocket may allow for a successful generator change in patients with defibrillator lead malfunction. This would be simpler than abandoning the abdominal implant and moving to a new pectoral device and lead or tunnelling a new endocardial electrode. However, loss of defibrillation capability with a particular complex lead may be a warning of impending loss of other functions (eg. sensing and/or pacing).

21 CFR 870.5325 - Defibrillator tester.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Defibrillator tester. 870.5325 Section 870.5325...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5325 Defibrillator tester. (a) Identification. A defibrillator tester is a device that is connected to the output of a...

21 CFR 870.5325 - Defibrillator tester.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Defibrillator tester. 870.5325 Section 870.5325...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5325 Defibrillator tester. (a) Identification. A defibrillator tester is a device that is connected to the output of a...

21 CFR 870.5325 - Defibrillator tester.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Defibrillator tester. 870.5325 Section 870.5325...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5325 Defibrillator tester. (a) Identification. A defibrillator tester is a device that is connected to the output of a...

21 CFR 870.5325 - Defibrillator tester.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Defibrillator tester. 870.5325 Section 870.5325...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5325 Defibrillator tester. (a) Identification. A defibrillator tester is a device that is connected to the output of a...

21 CFR 870.5325 - Defibrillator tester.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Defibrillator tester. 870.5325 Section 870.5325...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5325 Defibrillator tester. (a) Identification. A defibrillator tester is a device that is connected to the output of a...

Automated external defibrillators and simulated in-hospital cardiac arrests.

PubMed

Rossano, Joseph W; Jefferson, Larry S; Smith, E O'Brian; Ward, Mark A; Mott, Antonio R

2009-05-01

To test the hypothesis that pediatric residents would have shorter time to attempted defibrillation using automated external defibrillators (AEDs) compared with manual defibrillators (MDs). A prospective, randomized, controlled trial of AEDs versus MDs was performed. Pediatric residents responded to a simulated in-hospital ventricular fibrillation cardiac arrest and were randomized to using either an AED or MD. The primary end point was time to attempted defibrillation. Sixty residents, 21 (35%) interns, were randomized to 2 groups (AED = 30, MD = 30). Residents randomized to the AED group had a significantly shorter time to attempted defibrillation [median, 60 seconds (interquartile range, 53 to 71 seconds)] compared with those randomized to the MD group [median, 103 seconds (interquartile range, 68 to 288 seconds)] (P < .001). All residents in the AED group attempted defibrillation at <5 minutes compared with 23 (77%) in the MD group (P = .01). AEDs improve the time to attempted defibrillation by pediatric residents in simulated cardiac arrests. Further studies are needed to help determine the role of AEDs in pediatric in-hospital cardiac arrests.

Electrical Heart Defibrillation with Ion Channel Blockers

NASA Astrophysics Data System (ADS)

Feeney, Erin; Clark, Courtney; Puwal, Steffan

Heart disease is the leading cause of mortality in the United States. Rotary electrical waves within heart muscle underlie electrical disorders of the heart termed fibrillation; their propagation and breakup leads to a complex distribution of electrical activation of the tissue (and of the ensuing mechanical contraction that comes from electrical activation). Successful heart defibrillation has, thus far, been limited to delivering large electrical shocks to activate the entire heart and reset its electrical activity. In theory, defibrillation of a system this nonlinear should be possible with small electrical perturbations (stimulations). A successful algorithm for such a low-energy defibrillator continues to elude researchers. We propose to examine in silica whether low-energy electrical stimulations can be combined with antiarrhythmic, ion channel-blocking drugs to achieve a higher rate of defibrillation and whether the antiarrhythmic drugs should be delivered before or after electrical stimulation has commenced. Progress toward a more successful, low-energy defibrillator will greatly minimize the adverse effects noted in defibrillation and will assist in the development of pediatric defibrillators.

Cardiac pacemaker battery discharge after external electrical cardioversion for broad QRS Complex Tachycardia.

PubMed

Annamaria, Martino; Andrea, Scapigliati; Michela, Casella; Tommaso, Sanna; Gemma, Pelargonio; Antonio, Dello Russo; Roberto, Zamparelli; Stefano, De Paulis; Fulvio, Bellocci; Rocco, Schiavello

2008-08-01

External electrical cardioversion or defibrillation may be necessary in patients with implanted cardiac pacemaker (PM) or implantable cardioverter defibrillator (ICD). Sudden discharge of high electrical energy employed in direct current (DC) transthoracic countershock may damage the PM/ICD system resulting in a series of possible device malfunctions. For this reason, when defibrillation or cardioversion must be attempted in a patient with a PM or ICD, some precautions should be taken, particularly in PM dependent patients, in order to prevent damage to the device. We report the case of a 76-year-old woman with a dual chamber PM implanted in the right subclavicular region, who received two consecutive transthoracic DC shocks to treat haemodynamically unstable broad QRS complex tachycardia after cardiac surgery performed with a standard sternotomic approach. Because of the sternal wound and thoracic drainage tubes together with the severe clinical compromise, the anterior paddle was positioned near the pulse generator. At the following PM test, a complete battery discharge was detected.

Cardiac arrhythmias and degradation into chaotic behavior prevention using feedback control

NASA Astrophysics Data System (ADS)

Uzelac, Ilija; Sidorov, Veniamin; Wikswo, John; Gray, Richard

2012-02-01

During normal heart rhythm, cardiac cells behave as a set of oscillators with a distribution of phases but with the same frequency. The heart as a dynamical system in a phase space representation can be modeled as a set of oscillators that have closed overlapping orbits with the same period. These orbits are not stable and in the case of disruption of the cardiac rhythm, such as due to premature beats, the system will have a tendency to leave its periodic unstable orbits. If these orbits become attracted to phase singularities, their disruption may lead to chaotic behavior, which appears as a life-threating ventricular fibrillation. By using closed-loop feedback in the form of an adjustable defibrillation shock, any drift from orbits corresponding to the normal rhythm can be corrected by forcing the system to maintain its orbits. The delay through the feedback network coincides with the period of normal heart beats. To implement this approach we developed a 1 kW arbitrary waveform voltage-to-current converter with a 1 kHz bandwidth driven by a photodiode system that records an optical electrocardiogram and provides a feedback signal in real time. Our goal is to determine whether our novel method to defibrillate the heart will require much lower energies than are currently utilized in single shock defibrillators.

Is optimal paddle force applied during paediatric external defibrillation?

PubMed

Bennetts, Sarah H; Deakin, Charles D; Petley, Graham W; Clewlow, Frank

2004-01-01

Optimal paddle force minimises transthoracic impedance; a factor associated with increased defibrillation success. Optimal force for the defibrillation of children < or =10 kg using paediatric paddles has previously been shown to be 2.9 kgf, and for children >10 kg using adult paddles is 5.1 kgf. We compared defibrillation paddle force applied during simulated paediatric defibrillation with these optimal values. 72 medical and nursing staff who would be expected to perform paediatric defibrillation were recruited from a University teaching hospital. Participants, blinded to the nature of the study, were asked to simulate defibrillation of an infant manikin (9 months of age) and a child manikin (6 years of age) using paediatric or adult paddles, respectively, according to guidelines. Paddle force (kgf) was measured at the time of simulated shock and compared with known optimal values. Median paddle force applied to the infant manikin was 2.8 kgf (max 9.6, min 0.6), with only 47% operators attaining optimal force. Median paddle force applied to the child manikin was 3.8 kgf (max 10.2, min 1.0), with only 24% of operators attaining optimal force. Defibrillation paddle force applied during paediatric defibrillation often falls below optimal values.

Epicardial implantable cardioverter-defibrillator system placed in a 4.9-kg infant.

PubMed

Bryant, Roosevelt; Aboutalebi, Amir; Kim, Jeffrey J; Kertesz, Naomi; Morales, David L S

2011-01-01

Implantable cardioverter-defibrillators have aided the prevention of sudden cardiac death in adults. The hope is to provide similar benefits to the pediatric population as the devices become smaller. Herein, we present the case of a 4.9-kg, 5-week-old infant boy who presented with cardiopulmonary arrest. After emergency defibrillation, conventional treatment options included long-term hospitalization for later cardioverter-defibrillator implantation, or installation of an external defibrillator with subsequent home telemetry. On the basis of the infant's body dimensions, we decided that an epicardial implantable cardioverter-defibrillator was feasible and the best option. We performed a median sternotomy and placed a Vitality® implantable cardioverter-defibrillator with a 25-cm defibrillator coil and a 35-cm bipolar ventricular lead. The patient experienced no postoperative morbidity or rhythm disturbances and was discharged from the hospital on postoperative day 5. He was placed on β-blocker therapy and has remained well for 3 years.Although external devices can be placed in a small patient, we believe that they are too susceptible to lead damage and lead migration, and that the defibrillator thresholds are less reliable. We think that dysrhythmias even in very small children can be treated effectively and safely with use of an epicardial implantable cardioverter-defibrillator. To our knowledge, this 4.9-kg infant is the smallest patient to have undergone a successful implantation of this kind.

Psychometric properties of the Chinese version of the attitudes towards cardiopulmonary resuscitation with defibrillation (ACPRD-C) among female hospital nurses in Taiwan.

PubMed

Lin, Hsing-Long; Lin, Mei-Hsiang; Ho, Chao-Chung; Fu, Chin-Hua; Koo, Malcolm

2017-07-01

Nurses are often the first responders to in-hospital cardiac emergencies. A positive attitude towards cardiopulmonary resuscitation with defibrillation may contribute to early cardiopulmonary resuscitation and rapid defibrillation, which are associated with enhanced long-term survival. The aim of this study was to translate and adapt the 31-item attitudes towards cardiopulmonary resuscitation with defibrillation and the national resuscitation guidelines (ACPRD) instrument into Chinese and to evaluate its psychometric properties in a sample of Taiwanese hospital nurses. The ACPRD instrument was translated into Chinese using professional translation services. Content validity index based on five experts to refine the translated instrument. The final instrument was applied to a sample of 290 female nurses, recruited from a regional hospital in southern Taiwan, to assess its internal consistency, factor structure, and discriminative validity. The Chinese ACPRD instrument showed good internal consistency (Cronbach's alpha=0.87). Seven factors emerged from the factor analysis. The instrument showed good discriminative validity and were able to differentiate the attitudes of nurses with more experience of defibrillation or cardiopulmonary resuscitation from those with less experience. Nurses working in emergency ward or intensive care unit also showed significantly higher overall scores compared to those working in other units. The Chinese ACPRD demonstrated adequate content validity, internal consistency, sensible factor structure, and good discriminative validity. Among Chinese-speaking nurses, it may be used as a tool for assessing the effectiveness of educational programs that aim to improve their confidence in performing cardiopulmonary resuscitation with defibrillation. Copyright © 2017 Elsevier Ltd. All rights reserved.

[The subcutaneous cardioverter-defibrillator: When less is more].

PubMed

Kuschyk, J; Rudic, B; Akin, I; Borggrefe, M; Röger, S

2015-06-01

In the last few decades, defibrillator therapy has revolutionized treatment of patients at risk for sudden cardiac death. Multiple clinical trials have shown the benefit of implantable cardioverter-defibrillators (ICD) for primary and secondary prevention of sudden cardiac death. Being an entirely subcutaneous system, the S-ICD® avoids important periprocedural and long-term complications associated with transvenous implantable cardioverter-defibrillator (TV-ICD) systems as well as the need for fluoroscopy during implant surgery. In patients with challenging anatomic conditions or after infection, the S-ICD® might be reasonable. In multicenter studies and registries efficacy and safety of the S-ICD® was equal or better to transvenous implantable defibrillators. The cardiac rhythm is detected by the use of 1 of the 3 potential vectors. The S-ICD® automatically selects the most suitable vector for rhythm detection. If ventricular tachyarrhythmia is detected, the device is able to deliver up to five shocks of 80 J, while postshock pacing is available at 50 bpm for 30 s. The implantation technique is different from that of conventional ICDs, but easily learnable by experienced cardiologists. Initially observed hurdles (e.g., inappropriate shocks or infections) have been overcome by standardized implantation techniques, operator learning curves, and modification of algorithms. The S-ICD® predominately might be suitable in all patients with ICD indication except patients with pacing or cardiac resynchronization therapy (CRT) indication, ventricular tachycardia < 170 bpm, negative screening, or in the occasional patient whose arrhythmia might be suppressed by overdrive pacing. The system received CE certification in 2009 and was approved by the FDA in 2012. Currently, in Germany the S-ICD® has been integrated into the DRG system and can be reimbursed as a single chamber ICD.

Inter-association Task Force recommendations on emergency preparedness and management of sudden cardiac arrest in high school and college athletic programs: a consensus statement.

PubMed

Drezner, Jonathan A; Courson, Ron W; Roberts, William O; Mosesso, Vincent N; Link, Mark S; Maron, Barry J

2007-01-01

To assist high school and college athletic programs prepare for and respond to a sudden cardiac arrest (SCA). This consensus statement summarizes our current understanding of SCA in young athletes, defines the necessary elements for emergency preparedness, and establishes uniform treatment protocols for the management of SCA. Sudden cardiac arrest is the leading cause of death in young athletes. The increasing presence of and timely access to automated external defibrillators (AEDs) at sporting events provides a means of early defibrillation and the potential for effective secondary prevention of sudden cardiac death. An Inter-Association Task Force was sponsored by the National Athletic Trainers' Association to develop consensus recommendations on emergency preparedness and management of SCA in athletes. Comprehensive emergency planning is needed for high school and college athletic programs to ensure an efficient and structured response to SCA. Essential elements of an emergency action plan include establishment of an effective communication system, training of anticipated responders in cardiopulmonary resuscitation and AED use, access to an AED for early defibrillation, acquisition of necessary emergency equipment, coordination and integration of on-site responder and AED programs with the local emergency medical services system, and practice and review of the response plan. Prompt recognition of SCA, early activation of the emergency medical services system, the presence of a trained rescuer to initiate cardiopulmonary resuscitation, and access to early defibrillation are critical in the management of SCA. In any collapsed and unresponsive athlete, SCA should be suspected and an AED applied as soon as possible for rhythm analysis and defibrillation if indicated.

Inter Association Task Force recommendations on emergency preparedness and management of sudden cardiac arrest in high school and college athletic programs: a consensus statement.

PubMed

Drezner, Jonathan A; Courson, Ron W; Roberts, William O; Mosesso, Vincent N; Link, Mark S; Maron, Barry J

2007-01-01

To assist high school and college athletic programs prepare for and respond to a sudden cardiac arrest (SCA). This consensus statement summarizes our current understanding of SCA in young athletes, defines the necessary elements for emergency preparedness, and establishes uniform treatment protocols for the management of SCA. Sudden cardiac arrest is the leading cause of death in young athletes. The increasing presence of and timely access to automated external defibrillators (AEDs) at sporting events provides a means of early defibrillation and the potential for effective secondary prevention of sudden cardiac death. An Inter-Association Task Force was sponsored by the National Athletic Trainers' Association to develop consensus recommendations on emergency preparedness and management of SCA in athletes. Comprehensive emergency planning is needed for high school and college athletic programs to ensure an efficient and structured response to SCA. Essential elements of an emergency action plan include establishing an effective communication system, training of anticipated responders in cardiopulmonary resuscitation and AED use, access to an AED for early defibrillation, acquisition of necessary emergency equipment, coordination, and integration of on-site responder and AED programs with the local emergency medical services system, and practice and review of the response plan. Prompt recognition of SCA, early activation of the emergency medical services system, the presence of a trained rescuer to initiate cardiopulmonary resuscitation, and access to early defibrillation are critical in the management of SCA. In any collapsed and unresponsive athlete, SCA should be suspected and an AED applied as soon as possible for rhythm analysis and defibrillation if indicated.

Inter-association task force recommendations on emergency preparedness and management of sudden cardiac arrest in high school and college athletic programs: a consensus statement.

PubMed

Drezner, Jonathan A; Courson, Ron W; Roberts, William O; Mosesso, Vincent N; Link, Mark S; Maron, Barry J

2007-04-01

To assist high school and college athletic programs prepare for and respond to a sudden cardiac arrest (SCA). This consensus statement summarizes our current understanding of SCA in young athletes, defines the necessary elements for emergency preparedness, and establishes uniform treatment protocols for the management of SCA. Sudden cardiac arrest is the leading cause of death in young athletes. The increasing presence of and timely access to automated external defibrillators (AEDs) at sporting events provides a means of early defibrillation and the potential for effective secondary prevention of sudden cardiac death. An Inter-Association Task Force was sponsored by the National Athletic Trainers' Association to develop consensus recommendations on emergency preparedness and management of SCA in athletes. Comprehensive emergency planning is needed for high school and college athletic programs to ensure an efficient and structured response to SCA. Essential elements of an emergency action plan include establishing an effective communication system, training of anticipated responders in cardiopulmonary resuscitation and AED use, access to an AED for early defibrillation, acquisition of necessary emergency equipment, coordination and integration of onsite responder and AED programs with the local emergency medical services system, and practice and review of the response plan. Prompt recognition of SCA, early activation of the emergency medical services system, the presence of a trained rescuer to initiate cardiopulmonary resuscitation, and access to early defibrillation are critical in the management of SCA. In any collapsed and unresponsive athlete, SCA should be suspected and an AED applied as soon as possible for rhythm analysis and defibrillation if indicated.

[Ten years of early defibrillation: "Bochum against sudden cardiac death". Acceptance and critical analysis of using automated external defibrillators].

PubMed

Hanefeld, C; Kloppe, C; Breger, W; Kloppe, A; Mügge, A; Wiemer, M

2015-04-01

There is a comprehensive early defibrillation program in Bochum (Germany); since 2003 a total of 175 automated external defibrillators (AEDs) have been installed in urban areas by the city of Bochum and private companies. These were preferably installed in places with high foot traffic, e.g., public buildings, companies, and event/shopping centers. Approximately 15,000 laypeople who work in the vicinity of the AED locations were trained in the use of defibrillators and in basic resuscitation. In addition, rescue workers on fire trucks and medically trained personnel in physicians' medical practices were equipped as "first responders" with AEDs. After an initiation phase, all available information after each AED use since August 2004 has been collected by the project coordinator. During the period of data collection (August 2004 to August 2013), an AED was used in a total of 17 patients who had suffered sudden cardiac death (SCD) under the project in Bochum. Eleven patients had primary ventricular fibrillation (VF). Six of these survived without neurological deficit. In another 6 patients, a nondefibrillatable rhythm disorder was diagnosed. The AEDs are reliable and showed impeccable rhythm analysis before the instructions to provide any necessary shock. Compared to the number of existing units and an estimated number of 37-100 SCD/100,000, the use of the AEDs only 17 times appears relatively small. To improve the effectiveness of the AED program in Bochum, an analysis of the emergency service responses, which were necessary because of sudden circulatory collapse, is currently being performed. This will allow areas with an increased incidence of SCD to be identified and a plan for the strategic placement of AED and emergency services can be made.

Inter-Association Task Force Recommendations on Emergency Preparedness and Management of Sudden Cardiac Arrest in High School and College Athletic Programs: A Consensus Statement

PubMed Central

Drezner, Jonathan A; Courson, Ron W; Roberts, William O; Mosesso, Vincent N; Link, Mark S; Maron, Barry J

2007-01-01

Objective: To assist high school and college athletic programs prepare for and respond to a sudden cardiac arrest (SCA). This consensus statement summarizes our current understanding of SCA in young athletes, defines the necessary elements for emergency preparedness, and establishes uniform treatment protocols for the management of SCA. Background: Sudden cardiac arrest is the leading cause of death in young athletes. The increasing presence of and timely access to automated external defibrillators (AEDs) at sporting events provides a means of early defibrillation and the potential for effective secondary prevention of sudden cardiac death. An Inter-Association Task Force was sponsored by the National Athletic Trainers' Association to develop consensus recommendations on emergency preparedness and management of SCA in athletes. Recommendations: Comprehensive emergency planning is needed for high school and college athletic programs to ensure an efficient and structured response to SCA. Essential elements of an emergency action plan include establishment of an effective communication system, training of anticipated responders in cardiopulmonary resuscitation and AED use, access to an AED for early defibrillation, acquisition of necessary emergency equipment, coordination and integration of on-site responder and AED programs with the local emergency medical services system, and practice and review of the response plan. Prompt recognition of SCA, early activation of the emergency medical services system, the presence of a trained rescuer to initiate cardiopulmonary resuscitation, and access to early defibrillation are critical in the management of SCA. In any collapsed and unresponsive athlete, SCA should be suspected and an AED applied as soon as possible for rhythm analysis and defibrillation if indicated. PMID:17597956

Hospital variation in time to defibrillation after in-hospital cardiac arrest.

PubMed

Chan, Paul S; Nichol, Graham; Krumholz, Harlan M; Spertus, John A; Nallamothu, Brahmajee K

2009-07-27

Delays to defibrillation are associated with worse survival after in-hospital cardiac arrest, but the degree to which hospitals vary in defibrillation response times and hospital predictors of delays remain unknown. Using hierarchical models, we evaluated hospital variation in rates of delayed defibrillation (>2 minutes) and its impact on survival among 7479 adult inpatients with cardiac arrests at 200 hospitals within the National Registry of Cardiopulmonary Resuscitation. Adjusted rates of delayed defibrillation varied substantially among hospitals (range, 2.4%-50.9%), with hospital-level effects accounting for a significant amount of the total variation in defibrillation delays after adjusting for patient factors. We found a 46% greater odds of patients with identical covariates getting delayed defibrillation at one randomly selected hospital compared with another. Among traditional hospital factors evaluated, however, only bed volume (reference category: <200 beds; 200-499 beds: odds ratio [OR], 0.62 [95% confidence interval {CI}, 0.48-0.80]; >or=500 beds: OR, 0.74 [95% CI, 0.53-1.04]) and arrest location (reference category: intensive care unit; telemetry unit: OR, 1.92 [95% CI, 1.65-2.22]; nonmonitored unit: OR, 1.90 [95% CI, 1.61-2.24]) were associated with differences in rates of delayed defibrillation. Wide variation also existed in adjusted hospital rates of survival to discharge (range, 5.3%-49.6%), with higher survival among hospitals in the top-performing quartile for defibrillation time (compared with the bottom quartile: OR for top quartile, 1.41 [95% CI, 1.11-1.77]). Rates of delayed defibrillation vary widely among hospitals but are largely unexplained by traditional hospital factors. Given its association with improved survival, future research is needed to better understand best practices in the delivery of defibrillation at top-performing hospitals.

Economic impact of longer battery life of cardiac resynchronization therapy defibrillators in Sweden.

PubMed

Gadler, Fredrik; Ding, Yao; Verin, Nathalie; Bergius, Martin; Miller, Jeffrey D; Lenhart, Gregory M; Russell, Mason W

2016-01-01

The objective of this study was to quantify the impact that longer battery life of cardiac resynchronization therapy defibrillator (CRT-D) devices has on reducing the number of device replacements and associated costs of these replacements from a Swedish health care system perspective. An economic model based on real-world published data was developed to estimate cost savings and avoided device replacements for CRT-Ds with longer battery life compared with devices with industry-standard battery life expectancy. Base-case comparisons were performed among CRT-Ds of three manufacturers - Boston Scientific Corporation, St. Jude Medical, and Medtronic - over a 6-year time horizon, as per the available clinical data. As a sensitivity analysis, we evaluated CRT-Ds as well as single-chamber implantable cardioverter defibrillator (ICD-VR) and dual-chamber implantable cardioverter defibrillator (ICD-DR) devices over a longer 10-year period. All costs were in 2015 Swedish Krona (SEK) discounted at 3% per annum. Base-case analysis results show that up to 603 replacements and up to SEK 60.4 million cumulative-associated costs could be avoided over 6 years by using devices with extended battery life. The pattern of savings over time suggests that savings are modest initially but increase rapidly beginning in the third year of follow-up with each year's cumulative savings two to three times the previous year. Evaluating CRT-D, ICD-VR, and ICD-DR devices together over a longer 10-year period, the sensitivity analysis showed 2,820 fewer replacement procedures and associated cost savings of SEK 249.3 million for all defibrillators with extended battery life. Extended battery life is likely to reduce device replacements and associated complications and costs, which may result in important cost savings and a more efficient use of health care resources as well as a better quality of life for heart failure patients in Sweden.

Optimal Installation Locations for Automated External Defibrillators in Taipei 7-Eleven Stores: Using GIS and a Genetic Algorithm with a New Stirring Operator

PubMed Central

Wen, Tzai-Hung

2014-01-01

Immediate treatment with an automated external defibrillator (AED) increases out-of-hospital cardiac arrest (OHCA) patient survival potential. While considerable attention has been given to determining optimal public AED locations, spatial and temporal factors such as time of day and distance from emergency medical services (EMSs) are understudied. Here we describe a geocomputational genetic algorithm with a new stirring operator (GANSO) that considers spatial and temporal cardiac arrest occurrence factors when assessing the feasibility of using Taipei 7-Eleven stores as installation locations for AEDs. Our model is based on two AED conveyance modes, walking/running and driving, involving service distances of 100 and 300 meters, respectively. Our results suggest different AED allocation strategies involving convenience stores in urban settings. In commercial areas, such installations can compensate for temporal gaps in EMS locations when responding to nighttime OHCA incidents. In residential areas, store installations can compensate for long distances from fire stations, where AEDs are currently held in Taipei. PMID:25045396

End-tidal carbon dioxide and defibrillation success in out-of-hospital cardiac arrest.

PubMed

Savastano, Simone; Baldi, Enrico; Raimondi, Maurizio; Palo, Alessandra; Belliato, Mirko; Cacciatore, Elisa; Corazza, Valentina; Molinari, Simone; Canevari, Fabrizio; Danza, Aurora I; De Ferrari, Gaetano M; Iotti, Giorgio Antonio; Visconti, Luigi Oltrona

2017-12-01

Basing on the relationship between the quality of cardiopulmonary resuscitation (CPR) and the responsiveness of VF to the defibrillation we aimed to assess whether the values of ETCO2 in the minute before defibrillation could predict the effectiveness of the shock. We retrospectively evaluated the reports generated by the manual monitor/defibrillator (Corpuls by GS Elektromedizinische Geräte G. Stemple GmbH, Germany) used for cases of VF cardiac arrest from January 2015 to December 2016. The mean ETCO2 value of the minute preceding the shock (METCO2 60 ) was computed. A blind evaluation of the effectiveness of each shock was provided by three cardiologists. A total amount of 207 shocks were delivered for 62 patients. When considering the three tertiles of METCO2 60 (T1:METCO2 60 ≤ 20mmHg; T2: 20mmHg < METCO2 60 ≤ 31mmHg and T3: METCO2 60 > 31mmHg) a statistically significant difference between the percentages of shock success was found (T1: 50%; T2: 63%; T3: 78%; Chi square p=0.003; p for trend <0.001). When the METCO2 60 was lower than 7mmHg no shock was effective and when the METCO260 was higher than 45mmHg no shock was ineffective. Shocks followed by ROSC were preceded by higher values of METCO2 60 as compared either to ineffective shocks or effective ones without ROSC. This is the first demonstration of the relation between ETCO2 and defibrillation effectiveness. Our findings stress the pivotal role of High Quality CPR, monitored via ETCO2, and suggest ETCO2 monitoring as an additional weapon to guide defibrillation. Copyright © 2017 Elsevier B.V. All rights reserved.

The impact of including passive benefits in cost-effectiveness analysis: the case of automated external defibrillators on commercial aircraft.

PubMed

Cram, Peter; Vijan, Sandeep; Wolbrink, Alex; Fendrick, A Mark

2003-01-01

Traditional cost-utility analysis assumes that all benefits from health-related interventions are captured by the quality-adjusted life-years (QALYs) gained by the few individuals whose outcome is improved by the intervention. However, it is possible that many individuals who do not directly benefit from an intervention receive utility, and therefore QALYs, because of the passive benefit (aka sense of security) provided by the existence of the intervention. The objective of this study was to evaluate the impact that varying quantities of passive benefit have on the cost-effectiveness of airline defibrillator programs. A decision analytic model with Markov processes was constructed to evaluate the cost-effectiveness of defibrillator deployment on domestic commercial passenger aircraft over 1 year. Airline passengers were assigned small incremental utility gains (.001-.01) during an estimated 3-hour flight to evaluate the impact of passive benefit on overall cost-effectiveness. In the base case analysis with no allowance for passive benefit, the cost-effectiveness of airline automated external defibrillator deployment was US dollars 34000 per QALY gained. If 1% of all passengers received utility gain of.01, the cost-effectiveness declined to US dollars 30000. Cost-effectiveness was enhanced when the quantity of passive benefit was raised or the percentage of individuals receiving passive benefit increased. Automated external defibrillator deployment on passenger aircraft is likely to be cost-effective. If a small percentage of airline passengers receive incremental utility gains from passive benefit of automated external defibrillator availability, the impact on overall cost-effectiveness may be substantial. Further research should attempt to clarify the magnitude and percentage of patients who receive passive benefit.

Scottish survey of public place defibrillators.

PubMed

Ashimi, A O; Cobbe, S M; Pell, J P

2010-08-01

Public place defibrillators can reduce delays to defibrillation but their cost-effectiveness has not been evaluated in randomised trials. In Scotland, unlike England, no health sector funding has been provided. Nonetheless, anecdotal evidence suggests they are increasing in number. A cross-sectional survey was conducted of all airports, shopping malls, leisure centres, and major train and bus stations to determine whether defibrillators had been purchased and by whom, the training and maintenance arrangements, and whether they had been discharged. Of the 183 eligible sites, 153 (84%) participated. 33 (22%) had at least one defibrillator. Those in airports and shopping malls were purchased privately. Those in leisure centres were bought by charities or local authorities. The majority (97%) provided training to existing staff, but 6 (18%) provided no training to new staff. Only 6 (18%) had a maintenance agreement and 8 (24%) a replacement policy. Only one site permitted public access. Defibrillators had been discharged in 10 (30%) sites. Of the 32 people shocked, 23 (72%) survived until the ambulance arrived. Despite absence of health sector funding, defibrillators are located in 22% of high footfall public places. Those purchasing defibrillators need to ensure adequate maintenance, replacement and training arrangements.

Time-Dependent Changes in Psychosocial Distress in Japanese Patients with Implantable Cardioverter Defibrillators.

PubMed

Saito, Nao; Taru, Chiemi; Miyawaki, Ikuko

2016-12-02

This prospective study clarified changes in the mood states of Japanese patients with implantable cardioverter defibrillators as well as factors related to the mood states. Using a longitudinal repeated-measure design, 29 patients with implantable cardioverter defibrillators completed the Profile of Mood States-Short Form Japanese Version questionnaire before discharge and 1, 4, 7, and 13 months after implantation. One month after discharge, the mood states of the patients with implantable cardioverter defibrillators improved. From 7 to 13 months after discharge, moods deteriorated; 13 months after discharge, moods were equivalent to those at the time of discharge. No relationship with defibrillation experience was detected in this study, but employment, age, sex, and lack of experience of syncopal attack were factors related to poor mood states for patients with implantable cardioverter defibrillators. Therefore, Japanese patients with implantable cardioverter defibrillators with any factor deteriorating their mood state should be monitored so that their mood state does not deteriorate again between six months and one year after implantation.

Ventricular tachycardia

MedlinePlus

... called ablation ) may be done. An implantable cardioverter defibrillator (ICD) may be used. It is a device ... V tach; Tachycardia - ventricular Patient Instructions Implantable cardioverter defibrillator - discharge Images Implantable cardioverter-defibrillator References Garan H. ...

Implantable cardioverter defibrillator - discharge

MedlinePlus

... defibrillation. This device can also work as a pacemaker. What to Expect at Home When you leave ... pubmed/23265327 . Swerdlow CD, Wang PL, Zipes DP. Pacemakers and implantable cardioverter-defibrillators. In: Mann DL, Zipes ...

Chest compression rate feedback based on transthoracic impedance.

PubMed

González-Otero, Digna M; Ruiz de Gauna, Sofía; Ruiz, Jesus; Daya, Mohamud R; Wik, Lars; Russell, James K; Kramer-Johansen, Jo; Eftestøl, Trygve; Alonso, Erik; Ayala, Unai

2015-08-01

Quality of cardiopulmonary resuscitation (CPR) is an important determinant of survival from cardiac arrest. The use of feedback devices is encouraged by current resuscitation guidelines as it helps rescuers to improve quality of CPR performance. To determine the feasibility of a generic algorithm for feedback related to chest compression (CC) rate using the transthoracic impedance (TTI) signal recorded through the defibrillation pads. We analysed 180 episodes collected equally from three different emergency services, each one using a unique defibrillator model. The new algorithm computed the CC-rate every 2s by analysing the TTI signal in the frequency domain. The obtained CC-rate values were compared with the gold standard, computed using the compression force or the ECG and TTI signals when the force was not recorded. The accuracy of the CC-rate, the proportion of alarms of inadequate CC-rate, chest compression fraction (CCF) and the mean CC-rate per episode were calculated. Intervals with CCs were detected with a mean sensitivity and a mean positive predictive value per episode of 96.3% and 97.0%, respectively. Estimated CC-rate had an error below 10% in 95.8% of the time. Mean percentage of accurate alarms per episode was 98.2%. No statistical differences were found between the gold standard and the estimated values for any of the computed metrics. We developed an accurate algorithm to calculate and provide feedback on CC-rate using the TTI signal. This could be integrated into automated external defibrillators and help improve the quality of CPR in basic-life-support settings. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The impact of manual defibrillation technique on no-flow time during simulated cardiopulmonary resuscitation.

PubMed

Perkins, Gavin D; Davies, Robin P; Soar, Jasmeet; Thickett, David R

2007-04-01

Rapid defibrillation is the most effective strategy for establishing return of spontaneous circulation following cardiac arrest due to ventricular fibrillation. The aim of this study is to measure the delay due to of charging the defibrillator during chest compression in an attempt to reduce the duration of the pre-shock pause in between cessation of chest compressions and shock delivery as advocated by the American Heart Association (AHA) guidelines compared to charging the defibrillator immediately following rhythm analysis without resuming chest compressions as recommended by the European Resuscitation Council (ERC). This was a randomised controlled cross over trial comparing pre-shock pause times when defibrillation was performed on a manikin according to the AHA and ERC guidelines using paddles and hands free defibrillation systems. The pre-shock pause between cessation of chest compression and shock delivery was significantly different between techniques (Friedman test, P<0.0001). ERC paddles technique had the greatest pre-shock pause (7.4 s [6.7-11.2]) followed by ERC hands free (7.0 s [6.5-8.5]) and AHA paddles (1.6 s [1.1-2.3]). AHA hands free took the least amount of time (1.5 s [0.8-1.5]). Extrapolating these data to older defibrillators with longer charge times saw pre-shock pause intervals of 9 s (Codemaster XL) and 12 s (Lifepak 20) with the ERC approach. This study demonstrated clinically significant delays to defibrillation by analysing and charging the defibrillator without performing concurrent chest compressions. In a simulated scenario, charging the defibrillator whilst performing chest compressions was perceived as safe and significantly reduced the pre-shock pause between cessation of chest compression and shock delivery.

The role of the wearable cardioverter defibrillator in clinical practice.

PubMed

Chung, Mina K

2014-05-01

The wearable cardioverter defibrillator (WCD) is an option for external monitoring and defibrillation in patients at risk for sudden cardiac arrest caused by ventricular tachycardia or ventricular fibrillation and who are not candidates for or who refuse an implantable cardioverter defibrillator (ICD). WCDs provide monitoring with backup defibrillation protection. WCDs have been used when a patient's condition delays or prohibits ICD implantation, or as a bridge when an indicated ICD must be explanted. WCDs are used for primary prevention of sudden cardiac death during high-risk gap periods early after myocardial infarction, coronary revascularization, or new diagnosis of heart failure. Copyright © 2014 Elsevier Inc. All rights reserved.

Pacemakers and Implantable Defibrillators - Multiple Languages

MedlinePlus

... Multiple Languages → All Health Topics → Pacemakers and Implantable Defibrillators URL of this page: https://medlineplus.gov/languages/ ... List of All Topics All Pacemakers and Implantable Defibrillators - Multiple Languages To use the sharing features on ...

Analysis of transthoracic impedance during real cardiac arrest defibrillation attempts in older children and adolescents: are stacked-shocks appropriate?

PubMed

Niles, Dana E; Nishisaki, Akira; Sutton, Robert M; Brunner, Sara; Stavland, Mette; Mahadevaiah, Shruthi; Meaney, Peter A; Maltese, Matthew R; Berg, Robert A; Nadkarni, Vinay M

2010-11-01

In 2005, the AHA changed the treatment recommendation for shockable rhythms from 3 transthoracic stacked-shocks to a single shock followed by immediate chest compressions. The stacked-shock recommendation was based on low first-shock efficacy of monophasic waveforms and the theoretical decrease in transthoracic impedance (TTI) following each shock. The objective of this study was to characterize TTI following biphasic defibrillation attempts in children ≥ 8 yrs during cardiac arrest to assess whether a stacked-shock approach may be appropriate to improve defibrillation success. TTI (Ohms (Ω)) was collected via standard anterior-apical defibrillator electrode pads during consecutive in-hospital cardiac arrest biphasic defibrillation attempts in children ≥ 8 yrs. Analytic data points for TTI were: 0.1s pre-shock (baseline); post-shock at 0.1, 0.5, 1.0, 1.5, and 2.0 s. TTI variables analyzed with descriptive summaries/paired t-test. p values < 0.05 considered statistically significant after correction for multiple comparisons. Analysis yielded 13 evaluable shock events during 5 cardiac arrests (mean age 14.3 ± 5 yrs, weight 47.4 ± 7.3 kg) between September 2006 and May 2009. Compared to 0.1s pre-shock baseline values (56.8 ± 23.4 Ω), TTI was significantly lower immediately 0.1s post-shock (55.2 ± 22.2 Ω, p = 0.003). Post-shock mean difference from baseline was 1.6 Ω at 0.1s (p = 0.015), 1.4 Ω at 0.5s (p = 0.019) 1.4 Ω at 1.0 s (p = 0.023), 1.1 Ω at 1.5 s (p = 0.028), and 0.95 Ω at 2.0 s (p = 0.096). Time to recharge our clinical defibrillators to standard biphasic shock dose was 2.80 ± 0.05 s. During cardiac arrests in children ≥ 8 yrs, TTI decreased after biphasic shocks, but the limited magnitude and duration of TTI changes suggest that stacked-shocks would not improve defibrillation success. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Low-Energy Defibrillation Failure Correction is Possible Through Nonlinear Analysis of Spatiotemporal Arrhythmia Data

NASA Astrophysics Data System (ADS)

Simonotto, Jennifer; Furman, Michael; Beaver, Thomas; Spano, Mark; Kavanagh, Katherine; Iden, Jason; Hu, Gang; Ditto, William

2004-03-01

Explanted Porcine hearts were Langendorff-perfused, administered a voltage-sensitive fluorescent dye (Di-4-ANEPPS) and illuminated with a ND:Yag laser (532 nm); the change in fluorescence resulting from electrical activity on the heart surface was recorded with an 80 x 80 pixel CCD camera at 1000 frames per second. The heart was put into fibrillation with rapid ventricular pacing and shocks were administered close to the defibrillation threshold. Defibrillation failure data was analyzed using synchronization, space-time volume plots and recurrence quantification. Preliminary spatiotemporal synchronization results reveal a short window of time ( 1 second) after defibrillation failure in which the disordered electrical activity becomes ordered; this ordered period occurs 4-5 seconds after the defibrillation shock. Recurrence analysis of a single time series confirmed these results, thus opening the avenue for dynamic defibrillators that can detect an optimal window for cardioversion.

Internal defibrillation: where we have been and where we should be going?

PubMed

Lévy, Samuel

2005-08-01

Internal cardioversion has been developed as an alternative technique for patients who are resistant to external DC cardioversion of atrial fibrillation (AF) and was found to be associated with higher success rates. It used initially high energies (200-300 J) delivered between an intracardiac catheter and a backplate. Subsequent studies have shown that it is possible to terminate with energies of 1 to 6 Joules, paroxysmal or induced AF in 90 percent of patients and persistent AF in 75 percent of patients, using biphasic shocks delivered between a right atrium-coronary sinus vectors. Consequently, internal atrial defibrillation can be performed under sedation only without the need for general anesthesia. Recently developed external defibrillators, capable of delivering biphasic shocks, have increased the success rates of external cardioversion and reduced the need for internal cardioversion. However, internal defibrillation is still useful in overweight or obese patients, in patients with chronic obstructive pulmonary disease or asthma who are more difficult to defibrillate, and in patients with implanted devices which may be injured by high energy shocks. Low energy internal defibrillation has also proven to be safe and this has prompted the development of implantable devices for terminating AF. The first device used was the Metrix system, a stand-alone atrial defibrillator (without ventricular defibrillation) which was found to be safe and effective in selected groups of patients. Unfortunately, this device is no longer being marketed. Only double chamber defibrillators with pacing capabilities are presently available: the Medtronic GEM III AT, an updated version of the Jewel AF and the Guidant PRIZM AVT. These devices can be patient-activated or programmed to deliver automatically ounce atrial tachyarrhythmias are detected, therapies including pacing or/and shocks. Attempts to define the group of patients who might benefit from these devices are described but the respective role of atrial defibrillators versus other non-pharmacologic therapies for AF, such as surgery and radiofrequency catheter ablation, remains to be determined. Advantages and limitations or atrial defibrillators and approaches to reduce shock related discomfort which may be a concern in some patients, are reviewed. Studies have shown that despite shock discomfort, quality of life was improved in patients with atrial defibrillators and the need for repeated hospitalizations was reduced. The cost of these devices remains a concern for the treatment of a non-lethal arrhythmia. Attention that atrial defibrillators will receive from cardiologists and from the industry in the future, will depend of the long-term results of other non-pharmacological options and of the identification of the group of AF patients which will require restoration and maintenance of sinus rhythm. But there is no doubt that selected subsets of patients with AF could benefit from atrial defibrillation.

Spouses' reflections on implantable cardioverter defibrillator treatment with focus on the future and the end-of-life: a qualitative content analysis.

PubMed

Fluur, Christina; Bolse, Kärstin; Strömberg, Anna; Thylén, Ingela

2014-08-01

To explore future reflections of spouses living with an implantable cardioverter defibrillator recipient with focus on the end-of-life phase in an anticipated palliative phase. A history of or risk for life-threatening arrhythmias may require an implantable cardioverter defibrillator. Despite the life-saving capacity of the device, eventually life will come to an end. As discussion about preferences of shock therapy at end-of-life phase seldom takes place in advance, the implantable cardioverter defibrillator recipients may face defibrillating shocks in the final weeks of their lives, adding to stress and anxiety in patients and their families. Qualitative study with in-depth interviews analysed with a content analysis. Interviews were performed with 18 spouses of medically stable implantable cardioverter defibrillator recipients during 2011-2012. The spouses described how they dealt with changes in life and an uncertain future following the implantable cardioverter defibrillator implantation. Six subcategories conceptualized the spouses' concerns: Aspiring for involvement; Managing an altered relationship; Being attentive to warning signs; Worries for deterioration in the partner's health; Waiting for the defibrillating shock; and Death is veiled in silence. Despite the partner's serious state of health; terminal illness or death and the role of the device was seldom discussed with healthcare professionals or the implantable cardioverter defibrillator recipient. Open and honest communication was requested as important to support coping with an unpredictable life situation and to reduce worries and uncertainty about the future and end-of-life. © 2013 John Wiley & Sons Ltd.

Human Factors Approach to Comparative Usability of Hospital Manual Defibrillators.

PubMed

Fidler, Richard; Johnson, Meshell

2016-04-01

Equipment-related issues have recently been cited as a significant contributor to the suboptimal outcomes of resuscitation management. A systematic evaluation of the human-device interface was undertaken to evaluate the intuitive nature of three different defibrillators. Devices tested were the Physio-Control LifePak 15, the Zoll R Series Plus, and the Philips MRx. A convenience sample of 73 multidisciplinary health care providers from 5 different hospitals participated in this study. All subjects' performances were evaluated without any training on the devices being studied to assess the intuitiveness of the user interface to perform the functions of delivering an Automated External Defibrillator (AED) shock, a manual defibrillation, pacing to achieve 100% capture, and synchronized cardioversion on a rhythm simulator. Times to deliver an AED shock were fastest with the Zoll, whereas the Philips had the fastest times to deliver a manual defibrillation. Subjects took the least time to attain 100% capture for pacing with the Physio-Control device. No differences in performance times were seen with synchronized cardioversion among the devices. Human factors issues uncovered during this study included a preference for knobs over soft keys and a desire for clarity in control panel design. This study demonstrated no clearly superior defibrillator, as each of the models exhibited strengths in different areas. When asked their defibrillator preference, 67% of subjects chose the Philips. This comparison of user interfaces of defibrillators in simulated situations allows the assessment of usability that can provide manufacturers and educators with feedback about defibrillator implementation for these critical care devices. Published by Elsevier Ireland Ltd.

Comparative Evaluation of Four Risk Scores for Predicting Mortality in Patients With Implantable Cardioverter-defibrillator for Primary Prevention.

PubMed

Rodríguez-Mañero, Moisés; Abu Assi, Emad; Sánchez-Gómez, Juan Miguel; Fernández-Armenta, Juan; Díaz-Infante, Ernesto; García-Bolao, Ignacio; Benezet-Mazuecos, Juan; Andrés Lahuerta, Ana; Expósito-García, Víctor; Bertomeu-González, Vicente; Arce-León, Álvaro; Barrio-López, María Teresa; Peinado, Rafael; Martínez-Sande, Luis; Arias, Miguel A

2016-11-01

Several clinical risk scores have been developed to identify patients at high risk of all-cause mortality despite implantation of an implantable cardioverter-defibrillator. We aimed to examine and compare the predictive capacity of 4 simple scoring systems (MADIT-II, FADES, PACE and SHOCKED) for predicting mortality after defibrillator implantation for primary prevention of sudden cardiac death in a Mediterranean country. A multicenter retrospective study was performed in 15 Spanish hospitals. Consecutive patients referred for defibrillator implantation between January 2010 and December 2011 were included. A total of 916 patients with ischemic and nonischemic heart disease were included (mean age, 62 ± 11 years, 81.4% male). Over 33.4 ± 12.9 months, 113 (12.3%) patients died (cardiovascular origin in 86 [9.4%] patients). At 12, 24, 36, and 48 months, mortality rates were 4.5%, 7.6%, 10.8%, and 12.3% respectively. All the risk scores showed a stepwise increase in the risk of death throughout the scoring system of each of the scores and all 4 scores identified patients at greater risk of mortality. The scores were significantly associated with all-cause mortality throughout the follow-up period. PACE displayed the lowest c-index value regardless of whether the population had heart disease of ischemic (c-statistic = 0.61) or nonischemic origin (c-statistic = 0.61), whereas MADIT-II (c-statistic = 0.67 and 0.65 in ischemic and nonischemic cardiomyopathy, respectively), SHOCKED (c-statistic = 0.68 and 0.66, respectively), and FADES (c-statistic = 0.66 and 0.60) provided similar c-statistic values (P ≥ .09). In this nontrial-based cohort of Mediterranean patients, the 4 evaluated risk scores showed a significant stepwise increase in the risk of death. Among the currently available risk scores, MADIT-II, FADES, and SHOCKED provide slightly better performance than PACE. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Do implantable cardioverter defibrillators improve survival in patients with severe left ventricular systolic dysfunction after coronary artery bypass graft surgery?

PubMed

Fazal, Iftikhar A; Bates, Matthew G D; Matthews, Iain G; Turley, Andrew J

2011-06-01

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether implantable cardioverter defibrillators (ICD) improve survival in patients with severe left ventricular systolic dysfunction (LVSD) after coronary artery bypass graft (CABG) surgery. ICDs are designed to terminate potentially fatal cardiac tachyarrhythmias. A right ventricular lead is mandatory for detection, pacing and defibrillation capabilities. Dual chamber ICDs have an additional right atrial lead and are used for patients with conventional atrioventricular pacing indications. More sophisticated, biventricular devices exist to provide cardiac resynchronisation therapy (CRT) in addition to defibrillation (CRT-D). ICDs have been extensively investigated in patients with LVSD post myocardial infarction and in patients with non-ischaemic cardiomyopathy for both secondary prevention (history of ventricular arrhythmias) and primary prevention (deemed high risk for ventricular arrhythmias). This best evidence topic aims to review the evidence and its applicability to patients post CABG. Nine hundred and sixteen papers were identified using the search method outlined. Eight randomised controlled trials, two meta-analyses, and one non-randomised trial, in addition to international guidelines presented the best evidence to answer the clinical question. The current evidence base and guidelines suggest that ICDs should be considered for all patients with LVSD [ejection fraction (EF) ≤30-40%] receiving optimal pharmacological management, who are ≥40 days post MI [four weeks for National Institute for Health and Clinical Excellence (NICE)] and in New York Heart Association (NYHA) class I-III. UK NICE guidelines require in addition; non-sustained ventricular tachycardia (NSVT) on a Holter monitor and inducible ventricular tachycardia at electrophysiological study for EF between 30 and 35%; or a QRS >120 ms if EF <30%. The North American guidelines recommend EF <30% as a threshold for those with NYHA class I symptoms. The evidence is applicable to patients post CABG, provided all the other criteria are met. European Society of Cardiology (ESC) guidelines recommend waiting at least three months (consensus opinion) after revascularisation prior to assessment for an ICD, to allow time for potential recovery of ventricular function.

Computational cardiology: the bidomain based modified Hill model incorporating viscous effects for cardiac defibrillation

NASA Astrophysics Data System (ADS)

Cansız, Barış; Dal, Hüsnü; Kaliske, Michael

2017-10-01

Working mechanisms of the cardiac defibrillation are still in debate due to the limited experimental facilities and one-third of patients even do not respond to cardiac resynchronization therapy. With an aim to develop a milestone towards reaching the unrevealed mechanisms of the defibrillation phenomenon, we propose a bidomain based finite element formulation of cardiac electromechanics by taking into account the viscous effects that are disregarded by many researchers. To do so, the material is deemed as an electro-visco-active material and described by the modified Hill model (Cansız et al. in Comput Methods Appl Mech Eng 315:434-466, 2017). On the numerical side, we utilize a staggered solution method, where the elliptic and parabolic part of the bidomain equations and the mechanical field are solved sequentially. The comparative simulations designate that the viscoelastic and elastic formulations lead to remarkably different outcomes upon an externally applied electric field to the myocardial tissue. Besides, the achieved framework requires significantly less computational time and memory compared to monolithic schemes without loss of stability for the presented examples.

Evaluation of an education and follow-up programme for implantable cardioverter defibrillator-implanted patients.

PubMed

Cinar, Fatma I; Tosun, Nuran; Kose, Sedat

2013-09-01

To determine the experiences, problems and the need for care and education of implantable cardioverter defibrillator-implanted patients and to assess the effects of an education and nurse follow-up programme on their quality of life, anxiety, depression and knowledge level. Although implantable cardioverter defibrillator has become a well-established therapy for people experiencing potentially lethal dysrhythmias, implantable cardioverter defibrillator patients may have physical and psychosocial problems due to the implantation. Applying a planning education and follow-up programme to implantable cardioverter defibrillator-implanted patients may prevent the need for more intensive treatment during the postimplantation period. A mixed methods design that used both qualitative and quantitative data collections and analysis was used for this study. The study was performed in the cardiology department in Turkey between 2009-2010. The data were collected using the 'Semi-Structured Interview Form', 'Form for Assessment of Patients' Knowledge Level about implantable cardioverter defibrillator', 'Spielberger's State-Trait Anxiety Inventory', 'Beck Depression Inventory II' and 'The Short-Form 36 Health Survey'. All forms were completed at the beginning of the study and at six months. The study included 27 patients in the experimental group and 27 patients in the control group. The results showed that the patients were living with various physical and psychosocial problems and insufficient knowledge regarding the implantable cardioverter defibrillator. Education and follow-up programme increased knowledge levels, decreased anxiety and depression scores and improved several subscales of quality of life in the experimental group patients. It was recommended that education and follow-up programme be used for patients scheduled to undergo implantable cardioverter defibrillator implantation, starting before implantation and continuing thereafter, to help patients adapt to a life with implantable cardioverter defibrillator. Planned education and follow-up programme conducted by nurses may improve the knowledge levels and quality of life, anxiety and depression scores of the implantable cardioverter defibrillator-implanted patients. © 2013 Blackwell Publishing Ltd.

Transmural recording of shock potential gradient fields, early postshock activations, and refibrillation episodes associated with external defibrillation of long-duration ventricular fibrillation in swine.

PubMed

Allred, James D; Killingsworth, Cheryl R; Allison, J Scott; Dosdall, Derek J; Melnick, Sharon B; Smith, William M; Ideker, Raymond E; Walcott, Gregory P

2008-11-01

Knowledge of the shock potential gradient (nablaV) and postshock activation is limited to internal defibrillation of short-duration ventricular fibrillation (SDVF). The purpose of this study was to determine these variables after external defibrillation of long-duration VF (LDVF). In six pigs, 115-20 plunge needles with three to six electrodes each were inserted to record throughout both ventricles. After the chest was closed, the biphasic defibrillation threshold (DFT) was determined after 20 seconds of SDVF with external defibrillation pads. After 7 minutes of LDVF, defibrillation shocks that were less than or equal to the SDVF DFT strength were given. For DFT shocks (1632 +/- 429 V), the maximum minus minimum ventricular voltage (160 +/- 100 V) was 9.8% of the shock voltage. Maximum cardiac nablaV (28.7 +/- 17 V/cm) was 4.7 +/- 2.0 times the minimum nablaV (6.2 +/- 3.5 V/cm). Although LDVF did not increase the DFT in five of the six pigs, it significantly lengthened the time to earliest postshock activation following defibrillation (1.6 +/- 2.2 seconds for SDVF and 4.9 +/- 4.3 seconds for LDVF). After LDVF, 1.3 +/- 0.8 episodes of spontaneous refibrillation occurred per animal, but there was no refibrillation after SDVF. Compared with previous studies of internal defibrillation, during external defibrillation much less of the shock voltage appears across the heart and the shock field is much more even; however, the minimum nablaV is similar. Compared with external defibrillation of SDVF, the biphasic external DFT for LDVF is not increased; however, time to earliest postshock activation triples. Refibrillation is common after LDVF but not after SDVF in these normal hearts, indicating that LDVF by itself can cause refibrillation without requiring preexisting heart disease.

[First aid and defibrillation in the workplace: a helpful decision for the public].

PubMed

Calicchia, S; Cangiano, G; Papaleo, B

2012-01-01

Immediate activation of the chain of survival and the CPR training of the lay population, including prompt use of a semiautomatic defibrillator (AED), has been amply shown to reduce mortality due to cardiac arrest, which causes 60,000 deaths per year in Italy alone. This paper proposes a revision of the Italian regulation D.M. 388/03 on First Aid (FA), starting from the assumption that action in the workplace significantly improves the safety not only of workers but of citizens as a whole, especially in places attended by large numbers of people. The proposals, reflecting the recent regulation on early defibrillation, are based on field work done by the ISPESL Training Center (actually merged in INAIL), in cooperation with other institutions, and on a review of the literature and international guidelines. New training models have been tested and introduced in company FA systems, with fresh course content for FA workers and instructors.

Implementation of automated external defibrillators on merchant ships.

PubMed

Oldenburg, Marcus; Baur, Xaver; Schlaich, Clara

2011-01-01

In contrast to cruise ships, ferries and merchant ships are rarely equipped with automated external defibrillators (AEDs). Germany is the first flag state worldwide that legally requires to carry AEDs on seagoing merchant vessels by September 2012 at the latest. The aim of this study was to investigate the effect of training ship officers in the handling of AEDs and to explore their perceptions concerning the user-friendliness of currently available defibrillators. Using four different AEDs, 130 nautical officers performed a total of 400 resuscitation drills. One group (n = 60) used only one device before and after resuscitation training; the other group (n = 70) used all four AEDs in comparison after training. The officers' performances were timed and they were asked by questionnaire about the user-friendliness of each AED. Without resuscitation training, 81.7% of the first mentioned group delivered an effective defibrillation shock. After a 7-hour resuscitation training with special regard to defibrillation, all ship officers (n = 130) used the AED correctly. Among all AEDs, the mean time until start of analysis decreased from 72.4 seconds before to 60.4 seconds after resuscitation training (Wilcoxon test; p < 0.001). The results of the questionnaire and the differences in time to first shock indicated a different user-friendliness of the AEDs. The voice prompts and the screen messages of all AEDs were well understood by all participants. In the second mentioned group, 57.1% regarded feedback information related to depths and frequency of thorax compression as helpful. Nautical officers are able to use AEDs in a timely and effective way with proper training. However, to take advantage of all wanted features of the device (monitoring and resuscitation), the ship management has to observe practical questions of storage, maintenance, signing, training, data management, and transmission. Thus, implementation of the regulations requires proper instructions for the maritime industry by responsible bodies. © 2011 International Society of Travel Medicine.

78 FR 23768 - Agency Information Collection Activities: Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-22

... Beneficiaries Receiving Implantable Cardioverter- Defibrillators for Primary Prevention of Sudden Cardiac Death; Use: CMS provides coverage for implantable cardioverter-defibrillators (ICDs) for secondary prevention... Defibrillators'' on January 27, 2005, indicating that ICDs will be covered for primary prevention of sudden...

Self-Diagnostics Digitally Controlled Pacemaker/Defibrillators: A Design Plan for Incorporating Diagnostics and Digital Control in the schema of a Pacemaker/Defibrillator Design

DTIC Science & Technology

2005-09-01

of a system to store and retrieve digital/ wireless communication information from a pacemaker/ defibrillator, or other device , and to alert medical... wireless communication information from a pacemaker/defibrillator, or other device , and to alert medical personnel when a person is experiencing...with heart, pacing, program, test, sensor , circuit) where the individual needs immediate attention an audible alert will go off at the nurse’s

Public access defibrillation improved the outcome after out-of-hospital cardiac arrest in school-age children: a nationwide, population-based, Utstein registry study in Japan

PubMed Central

Mitani, Yoshihide; Ohta, Kunio; Yodoya, Noriko; Otsuki, Shoichiro; Ohashi, Hiroyuki; Sawada, Hirofumi; Nagashima, Masami; Sumitomo, Naokata; Komada, Yoshihiro

2013-01-01

Aims The purpose of this study was to determine whether implementation of public access defibrillation (PAD) improves the outcome after out-of-hospital cardiac arrest (OHCA) in school-age children at national level. Methods and results We conducted a prospective, nationwide, population-based Japanese Utstein registry study of consecutive OHCA cases in elementary and middle school children (7–15 years of age) who had a bystander-witnessed arrest of presumed cardiac origin during 2005–09 and received pre-hospital resuscitation by emergency responders. The primary endpoint was a favourable neurological outcome 1 month after an arrest. Among 230 eligible patients enrolled, 128 had ventricular fibrillation (VF) as an initial rhythm. Among these 128 patients, 29 (23%) children received a first shock by a bystander. Among these 29 patients, the proportion of the favourable neurological outcome after OHCA was 55%. During the study period, the proportion of patients initially shocked by a bystander among eligible patients increased from 2 to 21% (P = 0.002 for trend). The proportion of patients with a favourable neurological outcome after OHCA increased from 12 to 36% overall (P = 0.006). The collapse to defibrillation time was shorter in bystander-initiated defibrillation when compared with defibrillation by emergency responders (3.3 ± 3.7 vs. 12.9 ± 5.8 min, P < 0.001), and was independently associated with a favourable neurological outcome after OHCA [P = 0.03, odds ratio (OR) per 1 min increase, 0.90 (95% confidence interval 0.82–0.99)]. A non-family member's witness was independently associated with VF as the initial rhythm [P < 0.001, OR 4.03 (2.08–7.80)]. Conclusion Implementation of PAD improved the outcome after OHCA in school-age children at national level in Japan. PMID:23603306

Intraoperative Defibrillation Testing of Subcutaneous Implantable Cardioverter-Defibrillator Systems-A Simple Issue?

PubMed

Frommeyer, Gerrit; Zumhagen, Sven; Dechering, Dirk G; Larbig, Robert; Bettin, Markus; Löher, Andreas; Köbe, Julia; Reinke, Florian; Eckardt, Lars

2016-03-15

The results of the recently published randomized SIMPLE trial question the role of routine intraoperative defibrillation testing. However, testing is still recommended during implantation of the entirely subcutaneous implantable cardioverter-defibrillator (S-ICD) system. To address the question of whether defibrillation testing in S-ICD systems is still necessary, we analyzed the data of a large, standard-of-care prospective single-center S-ICD registry. In the present study, 102 consecutive patients received an S-ICD for primary (n=50) or secondary prevention (n=52). Defibrillation testing was performed in all except 4 patients. In 74 (75%; 95% CI 0.66-0.83) of 98 patients, ventricular fibrillation was effectively terminated by the first programmed internal shock. In 24 (25%; 95% CI 0.22-0.44) of 98 patients, the first internal shock was ineffective and further internal or external shock deliveries were required. In these patients, programming to reversed shock polarity (n=14) or repositioning of the sensing lead (n=1) or the pulse generator (n=5) led to successful defibrillation. In 4 patients, a safety margin of <10 J was not attained. Nevertheless, in these 4 patients, ventricular arrhythmias were effectively terminated with an internal 80-J shock. Although it has been shown that defibrillation testing is not necessary in transvenous ICD systems, it seems particular important for S-ICD systems, because in nearly 25% of the cases the primary intraoperative test was not successful. In most cases, a successful defibrillation could be achieved by changing shock polarity or by optimizing the shock vector caused by the pulse generator or lead repositioning. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

The Use of Automated External Defibrillators in Infants: A Report From the American Red Cross Scientific Advisory Council.

PubMed

Rossano, Joseph W; Jones, Wendell E; Lerakis, Stamatios; Millin, Michael G; Nemeth, Ira; Cassan, Pascal; Shook, Joan; Kennedy, Siobán; Markenson, David; Bradley, Richard N

2015-07-01

Automated external defibrillators (AEDs) have been used successfully in many populations to improve survival for out-of-hospital cardiac arrest. While ventricular fibrillation and pulseless ventricular tachycardia are more prevalent in adults, these arrhythmias do occur in infants. The Scientific Advisory Council of the American Red Cross reviewed the literature on the use of AEDs in infants in order to make recommendations on use in the population. The Cochrane library and PubMed were searched for studies that included AEDs in infants, any external defibrillation in infants, and simulation studies of algorithms used by AEDs on pediatric arrhythmias. There were 4 studies on the accuracy of AEDs in recognizing pediatric arrhythmias. Case reports (n = 2) demonstrated successful use of AED in infants, and a retrospective review (n = 1) of pediatric pads for AEDs included infants. Six studies addressed defibrillation dosages used. The algorithms used by AEDs had high sensitivity and specificity for pediatric arrhythmias and very rarely recommended a shock inappropriately. The energy doses delivered by AEDs were high, although in the range that have been used in out-of-hospital arrest. In addition, there are data to suggest that 2 to 4 J/kg may not be effective defibrillation doses for many children. In the absence of prompt defibrillation for ventricular fibrillation or pulseless ventricular tachycardia, survival is unlikely. Automated external defibrillators should be used in infants with suspected cardiac arrest, if a manual defibrillator with a trained rescuer is not immediately available. Automated external defibrillators that attenuate the energy dose (eg, via application of pediatric pads) are recommended for infants. If an AED with pediatric pads is not available, the AED with adult pads should be used.

Safety and Efficacy of Defibrillator Charging During Ongoing Chest Compressions: A Multicenter Study

PubMed Central

Edelson, Dana P.; Robertson-Dick, Brian J.; Yuen, Trevor C.; Eilevstjønn, Joar; Walsh, Deborah; Bareis, Charles J.; Vanden Hoek, Terry L.; Abella, Benjamin S.

2013-01-01

BACKGROUND Pauses in chest compressions during cardiopulmonary resuscitation have been shown to correlate with poor outcomes. In an attempt to minimize these pauses, the American Heart Association recommends charging the defibrillator during chest compressions. While simulation work suggests decreased pause times using this technique, little is known about its use in clinical practice. METHODS We conducted a multicenter, retrospective study of defibrillator charging at three US academic teaching hospitals between April 2006 and April 2009. Data were abstracted from CPR-sensing defibrillator transcripts. Pre-shock pauses and total hands- off time preceding the defibrillation attempts were compared among techniques. RESULTS A total of 680 charge-cycles from 244 cardiac arrests were analyzed. The defibrillator was charged during ongoing chest compressions in 448 (65.9%) instances with wide variability across the three sites. Charging during compressions correlated with a decrease in median pre-shock pause [2.6 (IQR 1.9–3.8) vs 13.3 (IQR 8.6–19.5) s; p < 0.001] and total hands-off time in the 30 s preceding defibrillation [10.3 (IQR 6.4–13.8) vs 14.8 (IQR 11.0–19.6) s; p < 0.001]. The improvement in hands-off time was most pronounced when rescuers charged the defibrillator in anticipation of the pause, prior to any rhythm analysis. There was no difference in inappropriate shocks when charging during chest compressions (20.0 vs 20.1%; p=0.97) and there was only one instance noted of inadvertent shock administration during compressions, which went unnoticed by the compressor. CONCLUSIONS Charging during compressions is underutilized in clinical practice. The technique is associated with decreased hands-off time preceding defibrillation, with minimal risk to patients or rescuers. PMID:20807672

Association between patient activity and long-term cardiac death in patients with implantable cardioverter-defibrillators and cardiac resynchronization therapy defibrillators.

PubMed

Zhao, Shuang; Chen, Keping; Su, Yangang; Hua, Wei; Chen, Silin; Liang, Zhaoguang; Xu, Wei; Dai, Yan; Liu, Zhimin; Fan, Xiaohan; Hou, Cuihong; Zhang, Shu

2017-05-01

Background Patient activity (PA) has been demonstrated to predict all-cause mortality. However, the association between PA and cardiac death is unclear. Aims The aims of this study were to determine whether PA can predict cardiac death and what is the cut-off of PA to discriminate cardiac death, as well as the mechanism underlying the relationship between PA and survival in patients with home monitoring. Methods This study retrospectively analysed clinical and implantable cardioverter-defibrillator/cardiac resynchronization therapy defibrillator device data in 845 patients. Data regarding PA and PP variability during the first 30-60 days of home monitoring were collected, and mean values were calculated. The primary endpoint was cardiac death, and the secondary endpoint was all-cause mortality. Results The mean PA percentage was 11 ± 5.8%. Based on receiver operating characteristic curve analysis, we determined that a PA cut-off value of 7.84% (113 min) can predict cardiac death. During a mean follow-up period of 31.1 ± 12.9 months (ranging from three to 60 months), PA ≤ 7.84% was associated with increased risks of cardiac death in an unadjusted analysis; after adjusting in a multivariate Cox model, the relationship remained significant between PA≤7.84% and cardiac death (hazard ratio = 3.644, 95% confidence interval = 2.424-5.477, p < 0.001). Moreover, a significant correlation was observed between PA and PP variability ( r = 0.601, p < 0.001). Conclusions A baseline PA ≤ 7.84% was associated with a higher risk of cardiac death in patients who have survived more than three months after implantable cardioverter-defibrillator/cardiac resynchronization therapy defibrillator implantation. PA had a sizable effect on heart rate variability, reflecting autonomic function.

Dutch outcome in implantable cardioverter-defibrillator therapy (DO-IT): registry design and baseline characteristics of a prospective observational cohort study to predict appropriate indication for implantable cardioverter-defibrillator.

PubMed

van Barreveld, M; Dijkgraaf, M G W; Hulleman, M; Boersma, L V A; Delnoy, P P H M; Meine, M; Tuinenburg, A E; Theuns, D A M J; van der Voort, P H; Kimman, G P; Buskens, E; Tijssen, J P G; Bruinsma, N; Verstraelen, T E; Zwinderman, A H; van Dessel, P H F M; Wilde, A A M

2017-10-01

Implantable cardioverter-defibrillators (ICDs) are widely used for the prevention of sudden cardiac death. At present, both clinical benefit and cost-effectiveness of ICD therapy in primary prevention patients are topics of discussion, as only a minority of these patients will eventually receive appropriate ICD therapy. The DO-IT Registry is a nationwide prospective cohort with a target enrolment of 1,500 primary prevention ICD patients with reduced left ventricular function in a setting of structural heart disease. The primary outcome measures are death and appropriate ICD therapy for ventricular tachyarrhythmias. Secondary outcome measures are inappropriate ICD therapy, death of any cause, hospitalisation for ICD related complications and for cardiovascular reasons. As of December 2016, data on demographic, clinical, and ICD characteristics of 1,468 patients have been collected. Follow-up will continue up to 24 months after inclusion of the last patient. During follow-up, clinical and ICD data are collected based on the normal follow-up of these patients, assuming ICD interrogations take place every six months and clinical follow-up is once a year. At baseline, the mean age was 66 (standard deviation [SD] 10) years and 27% were women. The DO-IT Registry represents a real-world nationwide cohort of patients receiving ICDs for primary prevention of sudden cardiac death with reduced left ventricular function in a setting of structural heart disease. The registry investigates the efficacy of the current practice and aims to develop prediction rules to identify subgroups who will not (sufficiently) benefit from ICD implantation and to provide results regarding costs and budget impact of targeted supply of primary preventions ICDs.

Rationale and design of the MONITOR-ICD study: a randomized comparison of economic and clinical effects of automatic remote MONITORing versus control in patients with Implantable Cardioverter Defibrillators.

PubMed

Zabel, Markus; Müller-Riemenschneider, Falk; Geller, J Christoph; Brachmann, Johannes; Kühlkamp, Volker; Dissmann, Rüdiger; Reinhold, Thomas; Roll, Stephanie; Lüthje, Lars; Bode, Frank; Eckardt, Lars; Willich, Stefan N

2014-10-01

Implantable cardioverter defibrillator (ICD) remote follow-up and ICD remote monitoring (RM) are established means of ICD follow-up. The reduction of the number of in-office visits and the time to decision is proven, but the true clinical benefit is still unknown. Cost and cost-effectiveness of RM remain leading issues for its dissemination. The MONITOR-ICD study has been designed to assess costs, cost-effectiveness, and clinical benefits of RM versus standard-care follow-up in a prospective multicenter randomized controlled trial. Patients indicated for single- or dual-chamber ICD are eligible for the study and are implanted an RM-capable Biotronik ICD (Lumax VR-T or Lumax DR-T; Biotronik SE & Co KG, Berlin, Germany). Implantable cardioverter defibrillator programming and alert-based clinical responses in the RM group are highly standardized by protocol. As of December 2011, recruitment has been completed, and 416 patients have been enrolled. Subjects are followed-up for a minimum of 12months and a maximum of 24months, ending in January 2013. Disease-specific costs from a societal perspective have been defined as primary end point and will be compared between RM and standard-care groups. Secondary end points include ICD shocks (including appropriate and inappropriate shocks), cardiovascular hospitalizations and cardiovascular mortality, and additional health economic end points. The MONITOR-ICD study will be an important randomized RM study to report data on a primary economic end point in 2014. Its results on ICD shocks will add to the currently available evidence on clinical benefit of RM. Copyright © 2014 Mosby, Inc. All rights reserved.

[Heart arrest].

PubMed

Chiarella, F; Giovannini, E; Bozzano, A; Caristo, G; Delise, P; Fedele, F; Fera, M S; Lavalle, C; Roghi, A; Valagussa, F

2001-03-01

Cardiac arrest is one of the leading causes of mortality in industrialized countries and is mainly due to ischemic heart disease. According to ISTAT estimates, approximately 45,000 sudden deaths occur annually in Italy whereas according to the World Health Organization, its incidence is 1 per 1000 persons. The most common cause of cardiac arrest is ventricular fibrillation due to an acute ischemic episode. During acute ischemia the onset of a ventricular tachyarrhythmia is sudden, unpredictable and often irreversible and lethal. Each minute that passes, the probability that the patient survives decreases by 10%. For this reason, the first 10 min are considered to be priceless for an efficacious first aid. The possibility of survival depends on the presence of witnesses, on the heart rhythm and on the resolution of the arrhythmia. In the majority of cases, the latter is possible by means of electrical defibrillation followed by the reestablishment of systolic function. An increase in equipment alone does not suffice for efficacious handling of cardiac arrest occurring outside the hospital premises. Above all, an adequate intervention strategy is required. Ambulance personnel must be well trained and capable of intervening rapidly, possibly within the first 5 min. The key to success lies in the diffusion and proper use of defibrillators. The availability of new generation instruments, the external automatic defibrillators, encourages their widespread use. On the territory, these emergencies are the responsibility of the 118 organization based, according to the characteristics specific to each country, on the regulated coordination between the operative command, the crews and the first-aid means. Strategies for the handling of these emergencies within hospitals have been proposed by the Conference of Bethesda and tend to guarantee an efficacious resuscitation with a maximum latency of 2 min between cardiac arrest and the first electric shock. The diffusion of external automatic defibrillators is a preventive measure. Such equipment has permitted early defibrillation by non-medical first-aid personnel. These instruments contain software capable of recognizing an arrhythmia which may be defibrillated and of instructing the operator whether and when to press the defibrillation button. The latest instruments deliver the shock by means of a biphasic wave necessitating a lesser amount of energy which can be provided by lighter condensers. Thus such equipment weighs just a couple of kilograms. As suggested by ILCOR, for reasons of priority, such instruments should not only be available within hospitals and in ambulances but also on the territory, in particular in more crowded places. The availability of external automatic defibrillators in such places should reduce the time latency before intervention and thus increase survival. The ILCOR guidelines have suggested the constitution of an itinerary team well equipped for defibrillation and composed of trained personnel of State Institutions such as the Municipal Police, Traffic Police and the Fire Brigades. With regard to the majority of arrhythmias amenable to defibrillation which occur at home or in less crowded places, other strategies, such as primary prevention and training programs for categories at increased risk, must be employed. Antiarrhythmic drugs have long been considered the best solution for the prevention and treatment of ventricular tachyarrhythmias. However, the approach to these pathologies has drastically changed during the last few years owing to accumulating evidence in favor of defibrillators which may be implanted for the primary and secondary prevention of malignant ventricular arrhythmias. For patients with previous cardiac arrest, randomized studies have proven the advantages of such an approach compared to medical therapy. On the basis of the above, the guidelines for the use of antiarrhythmic implants have been modified. In most western countries, the laws regarding this aspect of medicine have recently been renewed. In the United States, where there is the "Law of the Good Samaritan", in order to protect and acquit persons who give first-aid, many states have adopted new laws which promote the use of external automatic defibrillators. Following recent dispositions by the President of the United States that defibrillators should be present in all Federal properties and on civil aircraft, a new Federal Law is about to pass. Italy lacks legislation regarding the use of defibrillators: in order to rectify this position, which is still anchored to existing dispositions of the civil and penal codes including those regarding the omission of first-aid, a bill entitled "The definition and modalities of the use of the external cardiac defibrillator" has recently been presented.

Treatment of cardiac arrest with rapid defibrillation by police in King County, Washington.

PubMed

Becker, Linda; Husain, Sofia; Kudenchuk, Peter; Doll, Ann; Rea, Tom; Eisenberg, Mickey

2014-01-01

Improving survival from out-of-hospital cardiac arrest is an ongoing challenge for emergency medical services (EMS). Various strategies for shortening the time from collapse to defibrillation have been used, and one is to equip police officers with defibrillators. Objective. We evaluated the programmatic implementation of police defibrillation to determine if such a program could improve the process of care in a high-functioning and mature EMS system. We conducted a prospective observational study of implementation of a police defibrillation in two police departments in King County, Washington, from March 1, 2010 to March 31, 2012. The program was designed to dispatch police specifically to cases with a high suspicion of cardiac arrest, defined as a patient who was unconscious and not breathing normally. We included all nontraumatic out-of-hospital cardiac arrest events that occurred prior to EMS arrival and within the city limits of the two cities. We collected both EMS and police dispatch reports to document times of call receipt, dispatch, and arrival of both agencies. We obtained rhythm recordings when the automated external defibrillators (AEDs) were used by the police. Descriptive statistics were used to measure frequency of police dispatch and to compare times to treatment between patients with a police response and those without. During the study period there were 231 cases of cardiac arrest that occurred prior to EMS arrival eligible for police response in the study communities. Police were dispatched to 124 (54%) of these cases. Of the 124, the police arrived before EMS 37 times, or 16% of the 231 cases. Police performed CPR in 29 of these cases and applied the AED in 21 of them. Of the 21 cases in which the AED was applied for cardiac arrest, a shock was delivered on first analysis for 6 patients. Although the response interval between dispatch to scene arrival was similar for EMS and police (4.5 minutes versus 4.6 minutes respectively, p = 0.08), police were dispatched considerably slower than EMS (1.8 minutes versus 0.6 minutes, p < 0.001). In the current programmatic implementation, police had a measurable but limited involvement in resuscitation. Efforts to address dispatch challenges may improve police involvement.

Police AED programs: a systematic review and meta-analysis.

PubMed

Husain, Sofia; Eisenberg, Mickey

2013-09-01

Approximately 359,400 out-of-hospital cardiac arrests occur in the United States every year, and around 60% of them are treated by emergency medical services (EMS) personnel. In order to alleviate the impact of this public health burden, some communities have trained police officers as first responders so that they can provide cardiopulmonary resuscitation and defibrillation to cardiac arrest patients. This paper is a review of the current literature on the impact of police automated external defibrillators (AEDs) programs in these communities. A literature search of electronic journal databases was conducted to identify articles that evaluated police AED programs and quantified survival rates. The 10 articles that met the inclusion criteria were very heterogeneous in terms of study design, controlling for confounders, outcome definitions, and comparison groups. Two communities found a statistically significant difference in survival and 6 studies reported a statistically significant difference in time to defibrillation after the implementation of these programs. The weighted mean survival rate of the study groups was higher than that of the control groups (p<0.001), as was the weighted mean survival rate of the group first shocked by police compared to those first shocked by EMS (39.4% vs. 28.6%, p<0.001). The pooled relative risk of survival was 1.4 (95% CI: 1.3-1.6). Though there are many challenges in initiating these programs, this literature review shows that time to defibrillation decreased and survival from out-of-hospital cardiac arrests increased with the implementation of police AED programs. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Saving lives with public access defibrillation: A deadly game of hide and seek.

PubMed

Sidebottom, David B; Potter, Ryan; Newitt, Laura K; Hodgetts, Gillian A; Deakin, Charles D

2018-07-01

Early defibrillation is a critical link in the chain of survival. Public access defibrillation (PAD) programmes utilising automated external defibrillators (AEDs) aim to decrease the time-to-first-shock, and improve survival from out-of-hospital cardiac arrest. Effective use of PADs requires rapid location of the device, facilitated by adequate signage. We aimed to therefore assess the quality of signage for PADs in the community. From April 2017 to January 2018 we surveyed community PADs available for public use on the 'Save a Life' AED locator mobile application in and around Southampton, UK. Location and signage characteristics were collected, and the distance from the furthest sign to the AED was measured. Researchers evaluated 201 separate PADs. All devices visited were included in the final analysis. No signage at all was present for 135 (67.2%) devices. Only 15/201 (7.5%) AEDs had signage at a distance from AED itself. In only 5 of these cases (2.5%) was signage mounted more than 5.0 m from the AED. When signage was present, 46 used 2008 ILCOR signage and 15 used 2006 Resuscitation Council (UK) signage. Signage visibility was partially or severely obstructed at 27/66 (40.9%) sites. None of the 45 GP surgeries surveyed used exterior signage or an exterior 24/7 access box. Current signage of PADs is poor and limits the device effectiveness by impeding public awareness and location of AEDs. Recommendations should promote visible signage within the operational radius of each AED. Copyright © 2018 Elsevier B.V. All rights reserved.

[ILCOR recommendation on signage of automated external defibrillators (AEDs)].

PubMed

Truhlár, A

2010-05-01

Early defibrillation is a determinant of survival in both out-of-hospital and in-hospital cardiac arrests from ventricular fibrillation and pulseless ventricular tachycardia. The review summarizes importance of early defibrillation with automated external defibrillators (AED) and presents the International Liaison Committee on Resuscitation (ILCOR) recommendation for universal AED sign. The aim of the recommendation is to unify the AED signs worldwide and to spread the knowledge of this. The public in general, but healthcare professionals particularly, should be able to recognize AED location and use the device immediately in case of cardiac arrest.

Automatic external defibrillators for public access defibrillation: recommendations for specifying and reporting arrhythmia analysis algorithm performance, incorporating new waveforms, and enhancing safety. A statement for health professionals from the American Heart Association Task Force on Automatic External Defibrillation, Subcommittee on AED and Efficacy.

PubMed

1997-01-01

These recommendations are presented to enhance the safety and efficacy of AEDs intended for public access. The task force recommends that manufacturers present developmental and validation data on their own devices, emphasizing high sensitivity for shockable rhythms and high specificity for nonshockable rhythms. Alternative defibrillation waveforms may reduce energy requirements, reducing the size and weight of the device. The highest levels of safety for public access defibrillation are needed. Safe and effective use of AEDs that are widely available and easily handled by non-medical personnel has the potential to dramatically increase survival from cardiac arrest.

Double simultaneous defibrillators for refractory ventricular fibrillation.

PubMed

Leacock, Benjamin W

2014-04-01

Out-of-hospital cardiac arrest is a leading cause of death in the United States. Ventricular fibrillation (VF) is the most common initial rhythm after cardiac arrest. To describe a novel approach to the patient with intractable VF after cardiac arrest. A 51-year old man presented in cardiac arrest after a ST-elevation myocardial infarction. He remained in VF despite receiving typical therapy including cardiopulmonary resuscitation, amiodarone, lidocaine, epinephrine, and five attempts at defibrillation with 200 J using a biphasic defibrillator. VF was eventually terminated with 400 J by the simultaneous use of two biphasic defibrillators. The patient had a full recovery. We present a case and supportive literature for a novel treatment of high-energy defibrillation in a patient with refractory VF. Copyright © 2014 Elsevier Inc. All rights reserved.

Specific considerations with the automatic implantable atrial defibrillator.

PubMed

Jung, W; Wolpert, C; Esmailzadeh, B; Spehl, S; Herwig, S; Schumacher, B; Lewalter, T; Omran, H; Kirchhoff, P G; Lüderitz, B

1998-08-01

Internal atrial defibrillation has been evaluated as an alternative approach to the external technique for more than two decades. Previous studies in animals and humans have shown that internal atrial defibrillation is feasible with relatively low energies. The promising results achieved with internal atrial defibrillation have facilitated the development of an implantable atrial defibrillator (IAD). For any new therapy, it is imperative to demonstrate safety, efficacy, tolerability with improvement in quality of life, and cost-effectiveness compared with therapeutic options already available. Maintenance of sinus rhythm or prolonged duration in arrhythmia-free intervals should be demonstrated clearly with an IAD. Initial clinical experience with the Metrix system indicates stable atrial defibrillation thresholds, appropriate R wave synchronization markers, no shock-induced ventricular proarrhythmia, and excellent detection of atrial fibrillation (AF) with a specificity of 100%. Ventricular proarrhythmia has not been reported for correctly R wave synchronized low-energy shocks when closely coupled to RR intervals, and long-short cycles are avoided. Preliminary experience with the Metrix system suggests that the IAD may offer a therapeutic alternative for a subgroup of patients with drug-refractory, symptomatic, long-lasting, and infrequent episodes of AF. Further efforts must be undertaken to reduce the patient discomfort associated with internal atrial defibrillation in an attempt to make this new therapy acceptable to a larger patient population with AF.

Survey of oral and maxillofacial surgeons' offices in Virginia: anesthesia team characteristics.

PubMed Central

Campbell, Robert L.; Fritz, Gabriel; Campbell, Jeffrey R.

2004-01-01

This survey assesses whether oral and maxillofacial surgeons in the state of Virginia are prepared for inspection of their offices. A survey asking pertinent questions on the availability of specific equipment and the educational qualifications of the anesthesia care team was developed and sent to 155 offices. Seven questions were asked regarding the availability of nurses, types of life support training, (formal or informal), the surgeons and anesthesia care personnel, and the presence of a defibrillator. Questionnaires were short and simple to encourage compliance with the study guidelines. A total of 128 (82.6%) questionnaires were returned. Only 42 of 128 (32.8%) offices employed nurses, and 6 of the 42 nurses were not considered as part of the anesthesia care team. Only 36 of 128 (28.1%) of the offices had assistants with formal anesthesia assistant course training from the American Association of Oral and Maxillofacial Surgeons (AAOMS) or the American Dental Society of Anesthesiology (ADSA). However, 93% of the assistants who participated in the anesthesia had current basic life support training (BLS) training, and 74% of the surgeons had current advanced cardiac life support (ACLS) training. The AAOMS Office Emergency Manual was present in 118 of 128 offices (92.2%), and 124 of 128 offices (96.9%) had defibrillators. The survey suggests that the surgeons are well prepared from the standpoint of having a defibrillator present and the AAOMS Office Emergency Manual available as a template for the team to use in order to answer questions that the inspection team may ask of the primary anesthesia care provider and surgeon. The majority of the surgeons had current ACLS certification, and the office anesthesia assistants had current BLS training. Most of the assistants did not have formal course training, which indicates that on-the-job training is probably the norm. Less than one third of the offices had nurses. PMID:15675260

Delays and errors in cardiopulmonary resuscitation and defibrillation by pediatric residents during simulated cardiopulmonary arrests.

PubMed

Hunt, Elizabeth A; Vera, Kimberly; Diener-West, Marie; Haggerty, Jamie A; Nelson, Kristen L; Shaffner, Donald H; Pronovost, Peter J

2009-07-01

The quality of life support delivered during cardiopulmonary resuscitation affects outcomes. However, little data exist regarding the quality of resuscitation delivered to children and factors associated with adherence to American Heart Association (AHA) resuscitation guidelines. Pediatric residents from an academic, tertiary care hospital. Prospective, observational cohort study of residents trained in the AHA PALS 2000 guidelines managing a high-fidelity mannequin simulator programmed to develop pulseless ventricular tachycardia (PVT). Proportion of residents who: (1) started compressions in < or =1min from onset of PVT, (2) defibrillated in < or =3min and (3) factors associated with time to defibrillation. Seventy of eighty (88%) residents participated. Forty-six of seventy (66%) failed to start compressions within 1min of pulselessness and 23/70 (33%) never started compressions. Only 38/70 (54%) residents defibrillated the mannequin in < or =3min of onset of PVT. There was no significant difference in time elapsed between onset of PVT and defibrillation by level of post-graduate training. However, residents who had previously discharged a defibrillator on either a patient or a simulator compared to those who had not were 87% more likely to successfully defibrillate the mannequin at any point in time (hazard ratio 1.87, 95% CI: 1.08-3.21, p=0.02). Pediatric residents do not meet performance standards set by the AHA. Future curricula should focus training on identified defects including: (1) equal emphasis on "airway and breathing" and "circulation" and (2) hands-on training with using and discharging a defibrillator in order to improve safety and outcomes.

[Sudden cardiac death out of the hospital and early defibrillation].

PubMed

Marín-Huerta, E; Peinado, R; Asso, A; Loma, A; Villacastín, J P; Muñiz, J; Brugada, J

2000-06-01

Since most sudden cardiac death victims show neither symptoms before the event nor other signs or risk factors that would have identified them as a high risk population before their cardiac arrest, emergency out-of-hospital medical services must be improved in order to obtain a higher survival in these patients. Early defibrillation is an essential part of the chain of survival that also includes the early identification of the victim, activation of the emergency medical system, immediate arrival of trained personnel who can perform basic cardiopulmonary resuscitation and early initiation of advanced cardiac life support that would raise the survival rate for sudden cardiac arrest victims. Many studies have demonstrated the enormous importance of early defibrillation in patients with a cardiac arrest due to ventricular fibrillation. The most important predictor of survival in these individuals is the time that elapses until electric defibrillation, the longer the time to defbrillation the lower the number of patients who are eventually discharged. Multiple studies have demonstrated that automatic external defibrillation will reduce the time elapsed to defibrillation and thus improve survival. For these reason, public access defibrillation to allow the use of automatic external defibrillators by minimally trained members of the lay public, has received increasing interest on the part of a groving number of companies, cities or countries. The automatic external defibrillaton, as performed by a lay person is being investigated. The liberalization of its application, if is demonstrated to be effective, will need to be accompanied by legal measures to endorse it and appropriate health education, probably during secondary education.

The history of the coronary care unit.

PubMed

Khush, Kiran K; Rapaport, Elliot; Waters, David

2005-10-01

The first coronary care units were established in the early 1960s in an attempt to reduce mortality from acute myocardial infarction. Pioneering cardiologists recognized the threat of death due to malignant arrhythmias in the postinfarction setting, and developed techniques for successful external defibrillation. The ability to abort sudden death led to continuous monitoring of the cardiac rhythm and an organized system of cardiopulmonary resuscitation, incorporating external defibrillation with cardiac drugs and specialized equipment. Arrhythmia monitoring and cardiopulmonary resuscitation could be performed by trained nursing staff, which eliminated delays in treatment and significantly reduced mortality. These early triumphs in aborting sudden death led to the development of techniques to treat cardiogenic shock, limit infarct size and initiate prehospital coronary care, all of which laid the foundation for the current era of interventional cardiology.

Pharmacy students' retention of knowledge and skills following training in automated external defibrillator use.

PubMed

Kopacek, Karen Birckelbaw; Dopp, Anna Legreid; Dopp, John M; Vardeny, Orly; Sims, J Jason

2010-08-10

To assess pharmacy students' retention of knowledge about appropriate automated external defibrillator use and counseling points following didactic training and simulated experience. Following a lecture on sudden cardiac arrest and automated external defibrillator use, second-year doctor of pharmacy (PharmD) students were assessed on their ability to perform basic life support and deliver a shock at baseline, 3 weeks, and 4 months. Students completed a questionnaire to evaluate recall of counseling points for laypeople/the public. Mean time to shock delivery at baseline was 74 ± 25 seconds, which improved significantly at 3 weeks (50 ± 17 seconds, p < 0.001) and was maintained at 4 months (47 ± 18 seconds, p < 0.001). Recall of all signs and symptoms of sudden cardiac arrest and automated external defibrillator counseling points was diminished after 4 months. Pharmacy students can use automated external defibrillators to quickly deliver a shock and are able to retain this ability after 4 months. Refresher training/courses will be required to improve students' retention of automated external defibrillator counseling points to ensure their ability to deliver appropriate patient education.

Use of automated external defibrillators in US federal buildings: implementation of the Federal Occupational Health public access defibrillation program.

PubMed

Kilaru, Austin S; Leffer, Marc; Perkner, John; Sawyer, Kate Flanigan; Jolley, Chandra E; Nadkarni, Lindsay D; Shofer, Frances S; Merchant, Raina M

2014-01-01

Federal Occupational Health (FOH) administers a nationwide public access defibrillation program in US federal buildings. We describe the use of automated external defibrillators (AEDs) in federal buildings and evaluate survival after cardiac arrest. Using the FOH database, we examined reported events in which an AED was brought to a medical emergency in federal buildings over a 14-year period, from 1999 to 2012. There were 132 events involving an AED, 96 (73%) of which were due to cardiac arrest of cardiac etiology. Of 54 people who were witnessed to experience a cardiac arrest and presented with ventricular fibrillation or ventricular tachycardia, 21 (39%) survived to hospital discharge. Public access defibrillation, along with protocols to install, maintain, and deploy AEDs and train first responders, benefits survival after cardiac arrest in the workplace.

Integration of Attributes from Non-Linear Characterization of Cardiovascular Time-Series for Prediction of Defibrillation Outcomes

PubMed Central

Shandilya, Sharad; Kurz, Michael C.; Ward, Kevin R.; Najarian, Kayvan

2016-01-01

Objective The timing of defibrillation is mostly at arbitrary intervals during cardio-pulmonary resuscitation (CPR), rather than during intervals when the out-of-hospital cardiac arrest (OOH-CA) patient is physiologically primed for successful countershock. Interruptions to CPR may negatively impact defibrillation success. Multiple defibrillations can be associated with decreased post-resuscitation myocardial function. We hypothesize that a more complete picture of the cardiovascular system can be gained through non-linear dynamics and integration of multiple physiologic measures from biomedical signals. Materials and Methods Retrospective analysis of 153 anonymized OOH-CA patients who received at least one defibrillation for ventricular fibrillation (VF) was undertaken. A machine learning model, termed Multiple Domain Integrative (MDI) model, was developed to predict defibrillation success. We explore the rationale for non-linear dynamics and statistically validate heuristics involved in feature extraction for model development. Performance of MDI is then compared to the amplitude spectrum area (AMSA) technique. Results 358 defibrillations were evaluated (218 unsuccessful and 140 successful). Non-linear properties (Lyapunov exponent > 0) of the ECG signals indicate a chaotic nature and validate the use of novel non-linear dynamic methods for feature extraction. Classification using MDI yielded ROC-AUC of 83.2% and accuracy of 78.8%, for the model built with ECG data only. Utilizing 10-fold cross-validation, at 80% specificity level, MDI (74% sensitivity) outperformed AMSA (53.6% sensitivity). At 90% specificity level, MDI had 68.4% sensitivity while AMSA had 43.3% sensitivity. Integrating available end-tidal carbon dioxide features into MDI, for the available 48 defibrillations, boosted ROC-AUC to 93.8% and accuracy to 83.3% at 80% sensitivity. Conclusion At clinically relevant sensitivity thresholds, the MDI provides improved performance as compared to AMSA, yielding fewer unsuccessful defibrillations. Addition of partial end-tidal carbon dioxide (PetCO2) signal improves accuracy and sensitivity of the MDI prediction model. PMID:26741805

Multicenter Automatic Defibrillator Implantation Trial-Subcutaneous Implantable Cardioverter Defibrillator (MADIT S-ICD): Design and clinical protocol.

PubMed

Kutyifa, Valentina; Beck, Christopher; Brown, Mary W; Cannom, David; Daubert, James; Estes, Mark; Greenberg, Henry; Goldenberg, Ilan; Hammes, Stephen; Huang, David; Klein, Helmut; Knops, Reinoud; Kosiborod, Mikhail; Poole, Jeanne; Schuger, Claudio; Singh, Jagmeet P; Solomon, Scott; Wilber, David; Zareba, Wojciech; Moss, Arthur J

2017-07-01

Patients with diabetes mellitus, prior myocardial infarction, older age, and a relatively preserved left ventricular ejection fraction remain at risk for sudden cardiac death that is potentially amenable by the subcutaneous implantable cardioverter defibrillator with a good risk-benefit profile. The launched MADIT S-ICD study is designed to test the hypothesis that post-myocardial infarction diabetes patients with relatively preserved ejection fraction of 36%-50% will have a survival benefit from a subcutaneous implantable cardioverter defibrillator. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

[Semi-automatic defibrillators does not always interpret heart rhythms correctly. Five patients were defibrillated despite non-shockable rhythms].

PubMed

Wangenheim, Burkard; Israelsson, Johan; Lindstaedt, Michael; Carlsson, Jörg

2015-08-04

Automated external defibrillators (AED) have become an important part of the »the chain of survival« in case of sudden cardiac arrest (SCA), where early defibrillation is lifesaving. The American Heart Association demands that AEDs have a specificity of >99 % to recognize normal sinus rhythm and >95 % for the other non-shockable rhythms. Reports on their performance in the field are scarce. We present five cases in which AED recommended shock for apparently non-shockable rhythms. This indicates the necessity to systematically reevaluate AED performance.

A support vector machine for predicting defibrillation outcomes from waveform metrics.

PubMed

Howe, Andrew; Escalona, Omar J; Di Maio, Rebecca; Massot, Bertrand; Cromie, Nick A; Darragh, Karen M; Adgey, Jennifer; McEneaney, David J

2014-03-01

Algorithms to predict shock success based on VF waveform metrics could significantly enhance resuscitation by optimising the timing of defibrillation. To investigate robust methods of predicting defibrillation success in VF cardiac arrest patients, by using a support vector machine (SVM) optimisation approach. Frequency-domain (AMSA, dominant frequency and median frequency) and time-domain (slope and RMS amplitude) VF waveform metrics were calculated in a 4.1Y window prior to defibrillation. Conventional prediction test validity of each waveform parameter was conducted and used AUC>0.6 as the criterion for inclusion as a corroborative attribute processed by the SVM classification model. The latter used a Gaussian radial-basis-function (RBF) kernel and the error penalty factor C was fixed to 1. A two-fold cross-validation resampling technique was employed. A total of 41 patients had 115 defibrillation instances. AMSA, slope and RMS waveform metrics performed test validation with AUC>0.6 for predicting termination of VF and return-to-organised rhythm. Predictive accuracy of the optimised SVM design for termination of VF was 81.9% (± 1.24 SD); positive and negative predictivity were respectively 84.3% (± 1.98 SD) and 77.4% (± 1.24 SD); sensitivity and specificity were 87.6% (± 2.69 SD) and 71.6% (± 9.38 SD) respectively. AMSA, slope and RMS were the best VF waveform frequency-time parameters predictors of termination of VF according to test validity assessment. This a priori can be used for a simplified SVM optimised design that combines the predictive attributes of these VF waveform metrics for improved prediction accuracy and generalisation performance without requiring the definition of any threshold value on waveform metrics. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Cost of a recall of a single-center experience managing the Riata defibrillator lead.

PubMed

Hussain, Sarah; Moorman, Liza; Moorman, J Randall; DiMarco, John P; Malhotra, Rohit; Darby, Andrew; Bilchick, Kenneth; Mangrum, J Michael; Ferguson, John D; Mason, Pamela K

2015-01-15

Riata and Riata ST defibrillator leads (St. Jude Medical, Sylmar, California) were recalled in 2011 due to increased risk of insulation failure leading to externalized cables. Fluoroscopic screening can identify insulation failure, although the relation between mechanical failure and electrical failure is unclear. At the time of the recall, the University of Virginia developed a screening program, including fluoroscopic evaluation, education sessions, device interrogation, and remote monitoring for patients with this defibrillator lead. The aim of this study was to review the outcomes of the screening program, including costs, which were absorbed by our institution. Costs were calculated using Medicare reimbursement estimates. Forty-eight patients participated in the screening program. At initial screening, 31% were found to have evidence of insulation failure but electrical function was normal in all leads. The cost of this program was $35,358.72. The cost per diagnosis of mechanical lead failure was $2,357.25. During 2 years of follow-up, 1 patient experienced Riata lead electrical failure without fluoroscopic evidence of insulation failure. Patients were more likely to have a lead revision if there was evidence of insulation failure. Lead revisions occurred at the time of generator change in 88% of patients with insulation failure but in only 14% of patients with a fluoroscopically normal lead (p = 0.04). The cost of recall-related defibrillator lead revisions was $81,704.55. In conclusion, our Riata screening program added expense without clear benefit to patients. In fact, patients may have been put at more risk by undergoing defibrillator lead revisions based solely on the results of the fluoroscopic screening. Copyright © 2015 Elsevier Inc. All rights reserved.

[Inappropriate analyses of automated external defibrillators used during out-of-hospital cardiac arrests].

PubMed

Ballesteros Peña, Sendoa

2013-04-01

To estimate the frequency of therapeutic errors and to evaluate the diagnostic accuracy in the recognition of shockable rhythms by automated external defibrillators. A retrospective descriptive study. Nine basic life support units from Biscay (Spain). Included 201 patients with cardiac arrest, since 2006 to 2011. The study was made of the suitability of treatment (shock or not) after each analysis and medical errors identified. The sensitivity, specificity and predictive values with 95% confidence intervals were then calculated. A total of 811 electrocardiographic rhythm analyses were obtained, of which 120 (14.1%), from 30 patients, corresponded to shockable rhythms. Sensitivity and specificity for appropriate automated external defibrillators management of a shockable rhythm were 85% (95% CI, 77.5% to 90.3%) and 100% (95% CI, 99.4% to 100%), respectively. Positive and negative predictive values were 100% (95% CI, 96.4% to 100%) and 97.5% (95% CI, 96% to 98.4%), respectively. There were 18 (2.2%; 95% CI, 1.3% to 3.5%) errors associated with defibrillator management, all relating to cases of shockable rhythms that were not shocked. One error was operator dependent, 6 were defibrillator dependent (caused by interaction of pacemakers), and 11 were unclassified. Automated external defibrillators have a very high specificity and moderately high sensitivity. There are few operator dependent errors. Implanted pacemakers interfere with defibrillator analyses. Copyright © 2012 Elsevier España, S.L. All rights reserved.

[LifeVest - a novel treatment option prior to implantable cardioverter defibrillator].

PubMed

Mustafić, Hazrije; Karimzadeh, Soran; Park, Chan-Il

2017-03-01

Implantable cardioverter defibrillation has taken a predominant place in secondary and primary preventions of sudden rhythmic cardiac death in high-risk patients. However, in certain clinical situations, the implantation of definitive system should be postponed. The LifeVest, a portable external cardiac defibrillator system, has emerged as a novel therapeutic option before a final decision.

Effectiveness of automated external defibrillators in high schools in greater Boston.

PubMed

England, Hannah; Hoffman, Caitlin; Hodgman, Thomas; Singh, Sushil; Homoud, Munther; Weinstock, Jonathan; Link, Mark; Estes, N A Mark

2005-06-15

A program using a strategy of donating a single automatic external defibrillator to 35 schools in the Boston area resulted in compliance with American Heart Association guidelines on automatic external defibrillator placement and training and 2 successful resuscitations from sudden cardiac arrest. Participating schools indicated a high degree of satisfaction with the program.

Quality of basic life support when using different commercially available public access defibrillators.

PubMed

Müller, Michael P; Poenicke, Cynthia; Kurth, Maxi; Richter, Torsten; Koch, Thea; Eisold, Carolin; Pfältzer, Adrian; Heller, Axel R

2015-06-21

Basic life support (BLS) guidelines focus on chest compressions with a minimal no-flow fraction (NFF), early defibrillation, and a short perishock pause. By using an automated external defibrillator (AED) lay persons are guided through the process of attaching electrodes and initiating defibrillation. It is unclear, however, to what extent the voice instructions given by the AED might influence the quality of initial resuscitation. Using a patient simulator, 8 different commercially available AEDs were evaluated within two different BLS scenarios (ventricular fibrillation vs. asystole). A BLS certified instructor acted according to the current European Resuscitation Council 2010 Guidelines and followed all of the AED voice prompts. In a second set of scenarios, the rescuer anticipated the appropriate actions and started already before the AED stopped speaking. A BLS scenario without AED served as the control. All scenarios were run three times. The time until the first chest compression was 25 ± 2 seconds without the AED and ranged from 50 ± 3 to 148 ± 13 seconds with the AED depending on the model used. The NFF was .26 ± .01 without the AED and between .37 ± .01 and .72 ± .01 when an AED was used. The perishock pause ranged from 12 ± 0 to 46 ± 0 seconds. The optimized sequence of actions reduced the NFF, which ranged now from .32 ± .01 to .41 ± .01, and the perishock pause ranging from 1 ± 1 to 19 ± 1 seconds. Voice prompts given by commercially available AED merely meet the requirements of current evidence in basic life support. Furthermore, there is a significant difference between devices with regard to time until the first chest compression, perishock pause, no-flow fraction and other objective measures of the quality of BLS. However, the BLS quality may be improved with optimized handling of the AED. Thus, rescuers should be trained on the respective AED devices, and manufacturers should expend more effort in improving user guidance to shorten the NFF and perishock pause.

Implantable or external defibrillators for individuals at increased risk of cardiac arrest: where cost-effectiveness hits fiscal reality.

PubMed

Cram, Peter; Katz, David; Vijan, Sandeep; Kent, David M; Langa, Kenneth M; Fendrick, A Mark

2006-01-01

Implantable cardioverter defibrillators (ICDs) are highly effective at preventing cardiac arrest, but their availability is limited by high cost. Automated external defibrillators (AEDs) are likely to be less effective, but also less expensive. We used decision analysis to evaluate the clinical and economic trade-offs of AEDs, ICDs, and emergency medical services equipped with defibrillators (EMS-D) for reducing cardiac arrest mortality. A Markov model was developed to compare the cost-effectiveness of three strategies in adults meeting entry criteria for the MADIT II Trial: strategy 1, individuals experiencing cardiac arrest are treated by EMS-D; strategy 2, individuals experiencing cardiac arrest are treated with an in-home AED; and strategy 3, individuals receive a prophylactic ICD. The model was then used to quantify the aggregate societal benefit of these three strategies under the conditions of a constrained federal budget. Compared with EMS-D, in-home AEDs produced a gain of 0.05 quality-adjusted life-years (QALYs) at an incremental cost of $5225 ($104,500 per QALY), while ICDs produced a gain of 0.90 QALYs at a cost of $114,660 ($127,400 per QALY). For every $1 million spent on defibrillators, 1.7 additional QALYs are produced by purchasing AEDs (9.6 QALYs/$million) instead of ICDs (7.9 QALYs/$million). Results were most sensitive to defibrillator complication rates and effectiveness, defibrillator cost, and adults' risk of cardiac arrest. Both AEDs and ICDs reduce cardiac arrest mortality, but AEDs are significantly less expensive and less effective. If financial constraints were to lead to rationing of defibrillators, it might be preferable to provide more people with a less effective and less expensive intervention (in-home AEDs) instead of providing fewer people with a more effective and more costly intervention (ICDs).

Psychometric properties of HeartQoL, a core heart disease-specific health-related quality of life questionnaire, in Danish implantable cardioverter defibrillator recipients.

PubMed

Zangger, Graziella; Zwisler, Ann-Dorthe; Kikkenborg Berg, Selina; Kristensen, Marie S; Grønset, Charlotte N; Uddin, Jamal; Pedersen, Susanne S; Oldridge, Neil B; Thygesen, Lau C

2018-01-01

Background Patient-reported health-related quality of life is increasingly used as an outcome measure in clinical trials and as a performance measure to evaluate quality of care. The objective of this study was to assess the psychometric properties of the Danish HeartQoL questionnaire, a core heart disease-specific health-related quality of life questionnaire, in implantable cardioverter defibrillator recipients. Design This study involved cross-sectional and test-retest study designs. Method Implantable cardioverter defibrillator recipients in the cross-sectional study completed the HeartQoL, the Short-Form 36 Health Survey, and the Hospital Anxiety and Depression Scale. The HeartQoL structure, construct-related validity (convergent and discriminative) and reliability (internal consistency) were assessed. HeartQoL reproducibility (test-retest) was assessed in an independent sample of implantable cardioverter defibrillator recipients. Results Mokken scale analysis supported the bi-dimensional structure of HeartQoL among 358 implantable cardioverter defibrillator recipients. Convergent ( r > 0.72) and discriminative validity were confirmed. The HeartQoL scales demonstrated satisfactory internal consistency (Cronbach's alpha > 0.90). Test-retest reliability (two weeks interval) was assessed in 89 implantable cardioverter defibrillator recipients and found to be acceptable for each scale (intra-class correlation > 0.90). Conclusion The Danish HeartQoL questionnaire demonstrated satisfactory key psychometric attributes of validity and reliability in this implantable cardioverter defibrillator population. This study adds support for the HeartQoL as a core heart-specific health-related quality of life questionnaire in a broad group of patients with heart disease including implantable cardioverter defibrillator recipients.

Ascending-ramp biphasic waveform has a lower defibrillation threshold and releases less troponin I than a truncated exponential biphasic waveform.

PubMed

Huang, Jian; Walcott, Gregory P; Ruse, Richard B; Bohanan, Scott J; Killingsworth, Cheryl R; Ideker, Raymond E

2012-09-11

We tested the hypothesis that the shape of the shock waveform affects not only the defibrillation threshold but also the amount of cardiac damage. Defibrillation thresholds were determined for 11 waveforms-3 ascending-ramp waveforms, 3 descending-ramp waveforms, 3 rectilinear first-phase biphasic waveforms, a Gurvich waveform, and a truncated exponential biphasic waveform-in 6 pigs with electrodes in the right ventricular apex and superior vena cava. The ascending, descending, and rectilinear waveforms had 4-, 8-, and 16-millisecond first phases and a 3.5-millisecond rectilinear second phase that was half the voltage of the first phase. The exponential biphasic waveform had a 60% first-phase and a 50% second-phase tilt. In a second study, we attempted to defibrillate after 10 seconds of ventricular fibrillation with a single ≈30-J shock (6 pigs successfully defibrillated with 8-millisecond ascending, 8-millisecond rectilinear, and truncated exponential biphasic waveforms). Troponin I blood levels were determined before and 2 to 10 hours after the shock. The lowest-energy defibrillation threshold was for the 8-milliseconds ascending ramp (14.6±7.3 J [mean±SD]), which was significantly less than for the truncated exponential (19.6±6.3 J). Six hours after shock, troponin I was significantly less for the ascending-ramp waveform (0.80±0.54 ng/mL) than for the truncated exponential (1.92±0.47 ng/mL) or the rectilinear waveform (1.17±0.45 ng/mL). The ascending ramp has a significantly lower defibrillation threshold and at ≈30 J causes 58% less troponin I release than the truncated exponential biphasic shock. Therefore, the shock waveform affects both the defibrillation threshold and the amount of cardiac damage.

Living with life insurance: a qualitative analysis of the experience of male implantable defibrillator recipients in Spain.

PubMed

Palacios-Ceña, Domingo; Losa Iglesias, Marta E; Losa, Marta E; Fernández-de-Las-Peñas, César; Salvadores-Fuentes, Paloma

2011-07-01

The implantation of defibrillators should not be studied simply on the basis of clinical improvement or quality of life: it is also important to understand the significance, which the recipients attach to the defibrillator and their experiences with it. The aim of this work was, therefore, to determine the experience of Spanish implantable defibrillator recipients. A qualitative phenomenological study. Purposeful sampling of male implantable defibrillator recipients older than 18 years of age attended at the defibrillator consultancy at the Hospital Fuenlabrada or belonging to the Heart Patients' Association (Asociación de Pacientes Coronarios, APACOR). A secondary, theoretical sampling was also carried out to gain a more in-depth understanding of certain aspects identified in the first sampling, such as living with the discharges and difficulties during sexual activity. Data were collected using unstructured and semi-structured questionnaires and applying a question guide, field notes and the recipients' personal diaries/letters. Data collection was terminated once theoretical saturation was reached. Data were analysed using the Giorgi method. Finally, the seven themes, which showed what it means to be an implantable cardioverter-defibrillator recipient, were described. The defibrillator is perceived positively and is considered to be a form of life insurance, whereas the discharges are a limiting factor. The recipient's outlook on life changes. Acceptance of the changes resulting from the implant leads to the development of strategies to facilitate everyday life. An understanding of the significance attached by recipients to their disease, diagnosis and treatment allows their behaviour and expectations to be understood. Provide the basis for nursing assessment after discharge, understand the effects of the device in the recipient and track the process of adapting the recipient to daily life. © 2011 Blackwell Publishing Ltd.

Pre-discharge defibrillation testing: Is it still justified?

PubMed

Kempa, Maciej; Królak, Tomasz; Drelich, Łukasz; Budrejko, Szymon; Daniłowicz-Szymanowicz, Ludmiła; Lewicka, Ewa; Kozłowski, Dariusz; Raczak, Grzegorz

2016-01-01

An implantable cardioverter-defibrillator (ICD) is routinely used to prevent sudden cardiac death. Since the introduction of that device into clinical practice, a defibrillation test (the so-called pre-discharge test [PDT]) has been an inseparable part of the ICD implantation procedure. Recently, the usefulness of PDT has been called into question. The aim of this research was to analyze ICD tests performed within two time periods: in years 1995-2001 (period I) and 2007-2010 (period II), in order to compare the results of tests and solutions to all the problems with ICD systems revealed by means of PDT. During period I, 193 tests were performed, among which the ICD system malfunction was observed in 16 cases. Those included: sensing issues, specifically R-wave undersensing during ventricular fibrillation (VF) (7 patients) and T-wave oversensing (4 patients), as well as high defibrillation threshold (DFT) (2 patients) and ICD-pacemaker interaction (3 patients). During period II, among 561 tests, system malfunction was observed in 15 cases. In 1 patient it was VF undersensing, and in the remaining 14 it was high DFT. All the above problems were solved by means of appropriate ICD reprogramming, repositioning of the endocardial defibrillation lead or implantation of an additional subcutaneous defibrillation lead. Contemporary ICD technical solutions, compared to older systems, in most cases allow to avoid sensing problems. The key rationale behind ICD testing is the ability to confirm the efficacy of high-voltage therapy. Despite the increasing maximal defibrillation out-put of devices, and all possible adjustments to the characteristics of the impulse, there is still a group of patients that require additional procedures to ensure the appropriate defibrillation efficacy.

ICD defibrillation failure solved in an unusual fashion.

PubMed

Oliveira, Ricardo Gil; Madeira, Francisco; Ferreira, Ana Rita; Antunes, Susana; Morais, Carlos; Gil, Victor

2010-04-01

An implantable cardioverter defibrillator (ICD) is designed to sense life-threatening ventricular arrhythmias and terminate them, either by rapid pacing or by delivering an electrical shock. Nowadays it is a proven therapy for both primary and secondary prevention of sudden cardiac death. The typical configuration of an ICD consists of a right ventricular sensing/defibrillator lead with two coils (one distal, located in the right ventricle, and one proximal, located at the superior vena cava-right atrium junction) and an active can, the so-called "ventricular triad". Although effective in the vast majority of patients, it could be argued that this is not the most rational arrangement in electrical terms, since the main shock vector is anteriorly displaced in relation to the greater portion of the left ventricular mass. We describe a case of an ICD defibrillation failure that was solved by placing an additional defibrillator lead in a tributary of the coronary sinus.

Patient ECG recording control for an automatic implantable defibrillator

NASA Technical Reports Server (NTRS)

Fountain, Glen H. (Inventor); Lee, Jr., David G. (Inventor); Kitchin, David A. (Inventor)

1986-01-01

An implantable automatic defibrillator includes sensors which are placed on or near the patient's heart to detect electrical signals indicative of the physiology of the heart. The signals are digitally converted and stored into a FIFO region of a RAM by operation of a direct memory access (DMA) controller. The DMA controller operates transparently with respect to the microprocessor which is part of the defibrillator. The implantable defibrillator includes a telemetry communications circuit for sending data outbound from the defibrillator to an external device (either a patient controller or a physician's console or other) and a receiver for sensing at least an externally generated patient ECG recording command signal. The patient recording command signal is generated by the hand held patient controller. Upon detection of the patient ECG recording command, DMA copies the contents of the FIFO into a specific region of the RAM.

Current use of implantable electrical devices in Sweden: data from the Swedish pacemaker and implantable cardioverter-defibrillator registry.

PubMed

Gadler, Fredrik; Valzania, Cinzia; Linde, Cecilia

2015-01-01

The National Swedish Pacemaker and Implantable Cardioverter-Defibrillator (ICD) Registry collects prospective data on all pacemaker and ICD implants in Sweden. We aimed to report the 2012 findings of the Registry concerning electrical devices implantation rates and changes over time, 1 year complications, long-term device longevity and patient survival. Forty-four Swedish implanting centres continuously contribute implantation of pacemakers and ICDs to the Registry by direct data entry on a specific website. Clinical and technical information on 2012 first implants and postoperative complications were analysed and compared with previous years. Patient survival data were obtained from the Swedish population register database. In 2012, the mean pacemaker and ICD first implantation rates were 697 and 136 per million inhabitants, respectively. The number of cardiac resynchronization therapy (CRT) first implantations/million capita was 41 (CRT pacemakers) and 55 (CRT defibrillators), with only a slight increase in CRT-ICD rate compared with 2011. Most device implantations were performed in men. Complication rates for pacemaker and ICD procedures were 5.3 and 10.1% at 1 year, respectively. Device and lead longevity differed among manufacturers. Pacemaker patients were older at the time of first implant and had generally worse survival rate than ICD patients (63 vs. 82% after 5 years). Pacemaker and ICD implantation rates seem to have reached a level phase in Sweden. Implantable cardioverter-defibrillator and CRT implantation rates are very low and do not reflect guideline indications. Gender differences in CRT and ICD implantations are pronounced. Device and patient survival rates are variable, and should be considered when deciding device type. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Charging up the public for automated external defibrillators

PubMed Central

Willoughby DeJesus, Paula

2005-01-01

Public training in the use of automated external defibrillators to treat out-of-hospital cardiac arrests has been receiving increased attention. The implementation of public access defibrillation programs has been the most significant intervention to improve survival in decades. Dramatic success came when we placed automated external defibrillators in the hands of the public to be utilized without an Emergency Medical Services response having to occur. The device is simple to operate – sixth-grade children have demonstrated safe and effective operation. Training should be taken to its elemental level. Cardiopulmonary resuscitation training should not be forgotten; it too should be taken to its simplest form. PMID:15774067

Pharmacy Students' Retention of Knowledge and Skills Following Training in Automated External Defibrillator Use

PubMed Central

Dopp, Anna Legreid; Dopp, John M.; Vardeny, Orly; Sims, J. Jason

2010-01-01

Objectives To assess pharmacy students' retention of knowledge about appropriate automated external defibrillator use and counseling points following didactic training and simulated experience. Design Following a lecture on sudden cardiac arrest and automated external defibrillator use, second-year doctor of pharmacy (PharmD) students were assessed on their ability to perform basic life support and deliver a shock at baseline, 3 weeks, and 4 months. Students completed a questionnaire to evaluate recall of counseling points for laypeople/the public. Assessment Mean time to shock delivery at baseline was 74 ± 25 seconds, which improved significantly at 3 weeks (50 ± 17 seconds, p < 0.001) and was maintained at 4 months (47 ± 18 seconds, p < 0.001). Recall of all signs and symptoms of sudden cardiac arrest and automated external defibrillator counseling points was diminished after 4 months. Conclusion Pharmacy students can use automated external defibrillators to quickly deliver a shock and are able to retain this ability after 4 months. Refresher training/courses will be required to improve students' retention of automated external defibrillator counseling points to ensure their ability to deliver appropriate patient education. PMID:21045951

Ranking Businesses and Municipal Locations by Spatiotemporal Cardiac Arrest Risk to Guide Public Defibrillator Placement.

PubMed

Sun, Christopher L F; Brooks, Steven C; Morrison, Laurie J; Chan, Timothy C Y

2017-03-21

Efforts to guide automated external defibrillator placement for out-of-hospital cardiac arrest (OHCA) treatment have focused on identifying broadly defined location categories without considering hours of operation. Broad location categories may be composed of many businesses with varying accessibility. Identifying specific locations for automated external defibrillator deployment incorporating operating hours and time of OHCA occurrence may improve automated external defibrillator accessibility. We aim to identify specific businesses and municipal locations that maximize OHCA coverage on the basis of spatiotemporal assessment of OHCA risk in the immediate vicinity of franchise locations. This study was a retrospective population-based cohort study using data from the Toronto Regional RescuNET Epistry cardiac arrest database. We identified all nontraumatic public OHCAs occurring in Toronto, ON, Canada, from January 2007 through December 2015. We identified 41 unique businesses and municipal location types with ≥20 locations in Toronto from the YellowPages, Canadian Franchise Association, and the City of Toronto Open Data Portal. We obtained their geographic coordinates and hours of operation from Web sites, by phone, or in person. We determined the number of OHCAs that occurred within 100 m of each location when it was open (spatiotemporal coverage) for Toronto overall and downtown. The businesses and municipal locations were then ranked by spatiotemporal OHCA coverage. To evaluate temporal stability of the rankings, we calculated intraclass correlation of the annual coverage values. There were 2654 nontraumatic public OHCAs. Tim Hortons ranked first in Toronto, covering 286 OHCAs. Starbucks ranked first in downtown, covering 110 OHCAs. Coffee shops and bank machines from the 5 largest Canadian banks occupied 8 of the top 10 spots in both Toronto and downtown. The rankings exhibited high temporal stability with intraclass correlation values of 0.88 (95% confidence interval, 0.83-0.93) in Toronto and 0.79 (95% confidence interval, 0.71-0.86) in downtown. We identified and ranked businesses and municipal locations by spatiotemporal OHCA risk in their immediate vicinity. This approach may help policy makers and funders to identify and prioritize potential partnerships for automated external defibrillator deployment in public-access defibrillator programs. © 2017 American Heart Association, Inc.

Should an implanted defibrillator be considered in patients with vasospastic angina?

PubMed

Eschalier, Romain; Souteyrand, Géraud; Jean, Frédéric; Roux, Antoine; Combaret, Nicolas; Saludas, Yannick; Clerfond, Guillaume; Barber-Chamoux, Nicolas; Citron, Bernard; Lusson, Jean-René; Brugada, Pedro; Motreff, Pascal

2014-01-01

Vasospastic angina is a frequent and well-recognized pathology with a high risk of life-threatening ventricular arrhythmias and sudden cardiac death. The diagnosis of vasospastic angina requires the combination of clinical and electrocardiographic variables and the results of provocation tests, such as ergonovine administration. Smoking cessation is the first step in the management of vasospastic angina. Optimal medical treatment using calcium-channel blockers and/or nitrate derivatives can provide protection, but life-threatening ventricular arrhythmias may occur despite optimal medical treatment and several years after the start of treatment. In this review, we evaluate the role of implantable defibrillators as a complement to optimal medical management in patients with life-threatening ventricular arrhythmias due to vasospastic angina; this role is not well characterized in the literature or guidelines. We discuss the role of implantable defibrillators in secondary prevention in light of three recent cases managed in our departments and a review of the literature. An implantable defibrillator was implanted in two of the three cases of vasospastic angina with ventricular arrhythmias that we managed. We considered secondary prevention by implantable defibrillator to be justified even in the absence of any obvious risk factor. Ventricular arrhythmias recurred during implantable defibrillator follow-up in the two patients implanted. In patients with life-threatening ventricular arrhythmias due to vasospastic angina, an implantable defibrillator should be considered because of the risk of recurrence despite optimal medical management. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Reticular telangiectatic erythema: case report and literature review.

PubMed

Beutler, Bryce D; Cohen, Philip R

2015-01-01

Reticular telangiectatic erythema is a benign cutaneous reaction that may occur in patients who have received a subcutaneous implantable cardioverter-defibrillator. Reticular telangiectatic erythema is characterized by asymptomatic telangiectasias, blanchable erythematous patches, or both overlying and/or adjacent to the subcutaneous implantable cardioverter-defibrillator. We describe a man who developed reticular telangiectatic erythema after receiving a subcutaneous implantable cardioverter-defibrillator and review the salient features of this condition. We also summarize the conditions that can mimic reticular telangiectatic erythema. The features of a man with reticular telangiectatic erythema are presented and the literature on reticular telangiectatic erythema is reviewed. Our patient developed reticular telangiectatic erythema within one month of subcutaneous implantable cardioverter-defibrillator insertion. The subcutaneous manifestations were asymptomatic. The patient concurred to have periodic clinical follow up and his condition will be monitored for any changes. Reticular telangiectatic erythema is a benign condition characterized by the development of erythema, telangiectasia, or both following insertion of a subcutaneous implantable cardioverter-defibrillator. Other subcutaneous implantable cardioverter-defibrillator-related side effects, such as pressure dermatitis and contact dermatitis, can mimic the condition. Reticular telangiectatic erythema can also be observed following insertion of other devices or, rarely, in the absence of inserted devices. Local microcirculatory changes and subcutaneous implantable cardioverter-defibrillator-related obstruction of blood flow have been suggested as possible mechanisms of pathogenesis. The diagnosis can usually be established by clinical presentation. Therefore, patch testing can usually be omitted. Reticular telangiectatic erythema is typically asymptomatic and thus removal of the device is not required.

Radiated radiofrequency immunity testing of automated external defibrillators - modifications of applicable standards are needed

PubMed Central

2011-01-01

Background We studied the worst-case radiated radiofrequency (RF) susceptibility of automated external defibrillators (AEDs) based on the electromagnetic compatibility (EMC) requirements of a current standard for cardiac defibrillators, IEC 60601-2-4. Square wave modulation was used to mimic cardiac physiological frequencies of 1 - 3 Hz. Deviations from the IEC standard were a lower frequency limit of 30 MHz to explore frequencies where the patient-connected leads could resonate. Also testing up to 20 V/m was performed. We tested AEDs with ventricular fibrillation (V-Fib) and normal sinus rhythm signals on the patient leads to enable testing for false negatives (inappropriate "no shock advised" by the AED). Methods We performed radiated exposures in a 10 meter anechoic chamber using two broadband antennas to generate E fields in the 30 - 2500 MHz frequency range at 1% frequency steps. An AED patient simulator was housed in a shielded box and delivered normal and fibrillation waveforms to the AED's patient leads. We developed a technique to screen ECG waveforms stored in each AED for electromagnetic interference at all frequencies without waiting for the long cycle times between analyses (normally 20 to over 200 s). Results Five of the seven AEDs tested were susceptible to RF interference, primarily at frequencies below 80 MHz. Some induced errors could cause AEDs to malfunction and effectively inhibit operator prompts to deliver a shock to a patient experiencing lethal fibrillation. Failures occurred in some AEDs exposed to E fields between 3 V/m and 20 V/m, in the 38 - 50 MHz range. These occurred when the patient simulator was delivering a V-Fib waveform to the AED. Also, we found it is not possible to test modern battery-only-operated AEDs for EMI using a patient simulator if the IEC 60601-2-4 defibrillator standard's simulated patient load is used. Conclusions AEDs experienced potentially life-threatening false-negative failures from radiated RF, primarily below the lower frequency limit of present AED standards. Field strengths causing failures were at levels as low as 3 V/m at frequencies below 80 MHz where resonance of the patient leads and the AED input circuitry occurred. This plus problems with the standard's' prescribed patient load make changes to the standard necessary. PMID:21801368

Radiated radiofrequency immunity testing of automated external defibrillators--modifications of applicable standards are needed.

PubMed

Umberger, Ken; Bassen, Howard I

2011-07-29

We studied the worst-case radiated radiofrequency (RF) susceptibility of automated external defibrillators (AEDs) based on the electromagnetic compatibility (EMC) requirements of a current standard for cardiac defibrillators, IEC 60601-2-4. Square wave modulation was used to mimic cardiac physiological frequencies of 1-3 Hz. Deviations from the IEC standard were a lower frequency limit of 30 MHz to explore frequencies where the patient-connected leads could resonate. Also testing up to 20 V/m was performed. We tested AEDs with ventricular fibrillation (V-Fib) and normal sinus rhythm signals on the patient leads to enable testing for false negatives (inappropriate "no shock advised" by the AED). We performed radiated exposures in a 10 meter anechoic chamber using two broadband antennas to generate E fields in the 30-2500 MHz frequency range at 1% frequency steps. An AED patient simulator was housed in a shielded box and delivered normal and fibrillation waveforms to the AED's patient leads. We developed a technique to screen ECG waveforms stored in each AED for electromagnetic interference at all frequencies without waiting for the long cycle times between analyses (normally 20 to over 200 s). Five of the seven AEDs tested were susceptible to RF interference, primarily at frequencies below 80 MHz. Some induced errors could cause AEDs to malfunction and effectively inhibit operator prompts to deliver a shock to a patient experiencing lethal fibrillation. Failures occurred in some AEDs exposed to E fields between 3 V/m and 20 V/m, in the 38 - 50 MHz range. These occurred when the patient simulator was delivering a V-Fib waveform to the AED. Also, we found it is not possible to test modern battery-only-operated AEDs for EMI using a patient simulator if the IEC 60601-2-4 defibrillator standard's simulated patient load is used. AEDs experienced potentially life-threatening false-negative failures from radiated RF, primarily below the lower frequency limit of present AED standards. Field strengths causing failures were at levels as low as 3 V/m at frequencies below 80 MHz where resonance of the patient leads and the AED input circuitry occurred. This plus problems with the standard's' prescribed patient load make changes to the standard necessary.

Temporal trends in coverage of historical cardiac arrests using a volunteer-based network of automated external defibrillators accessible to laypersons and emergency dispatch centers.

PubMed

Hansen, Carolina Malta; Lippert, Freddy Knudsen; Wissenberg, Mads; Weeke, Peter; Zinckernagel, Line; Ruwald, Martin H; Karlsson, Lena; Gislason, Gunnar Hilmar; Nielsen, Søren Loumann; Køber, Lars; Torp-Pedersen, Christian; Folke, Fredrik

2014-11-18

Although increased dissemination of automated external defibrillators (AEDs) has been associated with more frequent AED use, the trade-off between the number of deployed AEDs and coverage of cardiac arrests remains unclear. We investigated how volunteer-based AED dissemination affected public cardiac arrest coverage in high- and low-risk areas. All public cardiac arrests (1994-2011) and all registered AEDs (2007-2011) in Copenhagen, Denmark, were identified and geocoded. AED coverage of cardiac arrests was defined as historical arrests ≤100 m from an AED. High-risk areas were defined as those with ≥1 arrest every 2 years and accounted for 1.0% of the total city area. Of 1864 cardiac arrests, 18.0% (n=335) occurred in high-risk areas throughout the study period. From 2007 to 2011, the number of AEDs and the corresponding coverage of cardiac arrests increased from 36 to 552 and from 2.7% to 32.6%, respectively. The corresponding increase for high-risk areas was from 1 to 30 AEDs and coverage from 5.7% to 51.3%, respectively. Since the establishment of the AED network (2007-2011), few arrests (n=55) have occurred ≤100 m from an AED with only 14.5% (n=8) being defibrillated before the arrival of emergency medical services. Despite the lack of a coordinated public access defibrillation program, the number of AEDs increased 15-fold with a corresponding increase in cardiac arrest coverage from 2.7% to 32.6% over a 5-year period. The highest increase in coverage was observed in high-risk areas (from 5.7% to 51.3%). AED networks can be used as useful tools to optimize AED placement in community settings. © 2014 American Heart Association, Inc.

Living with life-saving technology - coping strategies in implantable cardioverter defibrillators recipients.

PubMed

Flemme, Inger; Johansson, Ingela; Strömberg, Anna

2012-02-01

To describe coping strategies and coping effectiveness in recipients with an implantable cardioverter defibrillator and to explore factors influencing coping. Implantable cardioverter defibrillators are documented as saving lives and are used to treat ventricular tachycardia and ventricular fibrillation. Despite the implantable cardioverter defibrillator not evidently interfering with everyday life, there is conflicting evidence regarding the psychosocial impact of an implantable cardioverter defibrillator implantation such as anxiety, depression, perceived control and quality of life and how these concerns may relate to coping. Cross-sectional multicentre design. Individuals (n = 147, mean age 63 years, 121 men) who had lived with an implantable cardioverter defibrillator between 6-24 months completed the Jalowiec Coping Scale-60, Hospital Anxiety and Depression Scale, Control Attitude Scale and Quality of Life Index-Cardiac version. Implantable cardioverter defibrillators recipients seldom used coping strategies, and the coping strategies used were perceived as fairly helpful. Optimism was found to be the most frequently used (1·8 SD 0·68) and most effective (2·1 SD 0·48) coping strategy, and recipients perceived moderate control in life. Anxiety (β = 3·5, p ≤ 0·001) and gender (β = 12·3, p = 0·046) accounted for 26% of the variance in the total use of coping strategies, suggesting that the more symptoms of anxiety and being women the greater use of coping strategies. Most recipients with an implantable cardioverter defibrillator did not appraise daily concerns as stressors in need of coping and seem to have made a successful transition in getting on with their lives 6-24 months after implantation. Relevance to clinical practice.  Nurses working with recipients with an implantable cardioverter defibrillator should have a supportive communication so that positive outcomes such as decreased anxiety and increased perceived control and quality of life can be obtained. Through screening for anxiety at follow-up in the outpatient clinic, these recipients perceiving mental strain in their daily life can be identified. © 2011 Blackwell Publishing Ltd.

Automated external defibrillators in schools?

PubMed

Cornelis, Charlotte; Calle, Paul; Mpotos, Nicolas; Monsieurs, Koenraad

2015-06-01

Automated external defibrillators (AEDs) placed in public locations can save lives of cardiac arrest victims. In this paper, we try to estimate the cost-effectiveness of AED placement in Belgian schools. This would allow school policy makers to make an evidence-based decision about an on-site AED project. We developed a simple mathematical model containing literature data on the incidence of cardiac arrest with a shockable rhythm; the feasibility and effectiveness of defibrillation by on-site AEDs and the survival benefit. This was coupled to a rough estimation of the minimal costs to initiate an AED project. According to the model described above, AED projects in all Belgian schools may save 5 patients annually. A rough estimate of the minimal costs to initiate an AED project is 660 EUR per year. As there are about 6000 schools in Belgium, a national AED project in all schools would imply an annual cost of at least 3960 000 EUR, resulting in 5 lives saved. As our literature survey shows that AED use in schools is feasible and effective, the placement of these devices in all Belgian schools is undoubtedly to be considered. The major counter-arguments are the very low incidence and the high costs to set up a school-based AED programme. Our review may fuel the discussion about Whether or not school-based AED projects represent good value for money and should be preferred above other health care interventions.

[Research and Design of a System for Detecting Automated External Defbrillator Performance Parameters].

PubMed

Wang, Kewu; Xiao, Shengxiang; Jiang, Lina; Hu, Jingkai

2017-09-30

In order to regularly detect the performance parameters of automated external defibrillator (AED), to make sure it is safe before using the instrument, research and design of a system for detecting automated external defibrillator performance parameters. According to the research of the characteristics of its performance parameters, combing the STM32's stability and high speed with PWM modulation control, the system produces a variety of ECG normal and abnormal signals through the digital sampling methods. Completed the design of the hardware and software, formed a prototype. This system can accurate detect automated external defibrillator discharge energy, synchronous defibrillation time, charging time and other key performance parameters.

No Electromagnetic Interference Occurred in a Patient with a HeartMate II Left Ventricular Assist System and a Subcutaneous Implantable Cardioverter-Defibrillator.

PubMed

Raman, Ajay Sundara; Shabari, Farshad Raissi; Kar, Biswajit; Loyalka, Pranav; Hariharan, Ramesh

2016-04-01

The use of subcutaneous implantable cardioverter-defibrillators is a novel option for preventing arrhythmia-mediated cardiac death in patients who are at risk of endovascular-device infection or in whom venous access is difficult. However, the potential for electromagnetic interference between subcutaneous defibrillators and left ventricular assist devices is largely unknown. We report the case of a 24-year-old man in whom we observed no electromagnetic interference between a subcutaneous implanted cardioverter-defibrillator and a HeartMate II Left Ventricular Assist System, at 3 different pump speeds. To our knowledge, this is the first report of such findings in this circumstance.

No Electromagnetic Interference Occurred in a Patient with a HeartMate II Left Ventricular Assist System and a Subcutaneous Implantable Cardioverter-Defibrillator

PubMed Central

Raman, Ajay Sundara; Kar, Biswajit; Loyalka, Pranav; Hariharan, Ramesh

2016-01-01

The use of subcutaneous implantable cardioverter-defibrillators is a novel option for preventing arrhythmia-mediated cardiac death in patients who are at risk of endovascular-device infection or in whom venous access is difficult. However, the potential for electromagnetic interference between subcutaneous defibrillators and left ventricular assist devices is largely unknown. We report the case of a 24-year-old man in whom we observed no electromagnetic interference between a subcutaneous implanted cardioverter-defibrillator and a HeartMate II Left Ventricular Assist System, at 3 different pump speeds. To our knowledge, this is the first report of such findings in this circumstance. PMID:27127441

Longevity of implantable cardioverter-defibrillators for cardiac resynchronization therapy in current clinical practice: an analysis according to influencing factors, device generation, and manufacturer.

PubMed

Landolina, Maurizio; Curnis, Antonio; Morani, Giovanni; Vado, Antonello; Ammendola, Ernesto; D'onofrio, Antonio; Stabile, Giuseppe; Crosato, Martino; Petracci, Barbara; Ceriotti, Carlo; Bontempi, Luca; Morosato, Martina; Ballari, Gian Paolo; Gasparini, Maurizio

2015-08-01

Device replacement at the time of battery depletion of implantable cardioverter-defibrillators (ICDs) may carry a considerable risk of complications and engenders costs for healthcare systems. Therefore, ICD device longevity is extremely important both from a clinical and economic standpoint. Cardiac resynchronization therapy defibrillators (CRT-D) battery longevity is shorter than ICDs. We determined the rate of replacements for battery depletion and we identified possible determinants of early depletion in a series of patients who had undergone implantation of CRT-D devices. We retrieved data on 1726 consecutive CRT-D systems implanted from January 2008 to March 2010 in nine centres. Five years after a successful CRT-D implantation procedure, 46% of devices were replaced due to battery depletion. The time to device replacement for battery depletion differed considerably among currently available CRT-D systems from different manufacturers, with rates of batteries still in service at 5 years ranging from 52 to 88% (log-rank test, P < 0.001). Left ventricular lead output and unipolar pacing configuration were independent determinants of early depletion [hazard ratio (HR): 1.96; 95% 95% confidence interval (CI): 1.57-2.46; P < 0.001 and HR: 1.58, 95% CI: 1.25-2.01; P < 0.001, respectively]. The implantation of a recent-generation device (HR: 0.57; 95% CI: 0.45-0.72; P < 0.001), the battery chemistry and the CRT-D manufacturer (HR: 0.64; 95% CI: 0.47-0.89; P = 0.008) were additional factors associated with replacement for battery depletion. The device longevity at 5 years was 54%. High left ventricular lead output and unipolar pacing configuration were associated with early battery depletion, while recent-generation CRT-Ds displayed better longevity. Significant differences emerged among currently available CRT-D systems from different manufacturers. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

[Worldwide experience with automated external defibrillators: What have we achieved? What else can we expect?].

PubMed

Trappe, Hans-Joachim

2016-03-01

In Germany approximately 70,000-100,000 SCD patients die from sudden cardiac death (SCD). SCD is not caused by a single factor but is a multifactorial problem. In 50 % of SCD victims, sudden cardiac death is the first manifestation of heart disease. SCD is caused by ventricular tachyarrhythmias in approximately 90 % of patients, whereas SCD is caused by bradyarrhythmias in 5-10 % of the patients. Risk stratification is not possible in the majority of them prior to the fatal event. Early defibrillation is the method of choice to terminate ventricular fibrillation. Therefore, it is mandatory to install automatic external defibrillators (AED) in places with many people. There is general agreement that early defibrillation with automated external defibrillators (AED) is an effective tool to treat patients with ventricular fibrillation and will improve survival. It seems necessary to teach cardiocompression and AED use, also to children and adolescents. AED therapy "at home" did not improve survival in patients with cardiac arrest and can not be recommended.

Amplitude spectral area: predicting the success of electric shock delivered by defibrillators with different waveforms.

PubMed

Nakagawa, Yoshihide; Sato, Yoji; Kojima, Takeshi; Wakabayashi, Tsutomu; Morita, Seiji; Amino, Mari; Inokuchi, Sadaki

2013-07-20

Prolonged ventricular fibrillation (VF) is associated with a low rate of return of spontaneous circulation (ROSC) following electric shock. Moreover, electric shock that does not reestablish spontaneous circulation causes myocardial dysfunction even if ROSC is subsequently achieved. Amplitude spectral area (AMSA), calculated by analysis of VF waveforms immediately before electric shock, is considered to predict the outcome of electric shock. This study aimed to evaluate the prognostic value of AMSA in relation to waveforms of defibrillators in prehospital settings. The AMSA values of 81 patients with VF confirmed by ambulance crews were compared according to the type of defibrillators with different waveforms and between those with and without ROSC. With a biphasic defibrillator, the mean AMSA was significantly different between the 14 patients who achieved ROSC (25.3 ± 9.5 mV-Hz) and the 43 subjects who did not achieve ROSC (15.4 ± 8.1 mV-Hz; p = 0.0006). No significant difference was seen in the corresponding values when a monophasic defibrillator was used, at 19.1 ± 2.4 mV-Hz for 3 ROSC patients and 16.1 ± 7.5mV-Hz for 21 non-ROSC patients. AMSA may serve as a predictive measure for ROSC following electric shock delivered by a biphasic defibrillator.

Performance of dedicated versus integrated bipolar defibrillator leads with CRT-defibrillators: results from a Prospective Multicenter Study.

PubMed

Freedman, Roger A; Petrakian, Alex; Boyce, Ker; Haffajee, Charles; Val-Mejias, Jesus E; Oza, Ashish L

2009-02-01

Right ventricular (RV) anodal stimulation may occur in cardiac resynchronization therapy defibrillators (CRT-D) when left ventricular (LV) pacing is configured between the LV lead and an electrode on the RV defibrillator lead. RV defibrillator leads can have a dedicated proximal pacing ring electrode (dedicated bipolar) or utilize the distal shocking coil as the proximal pacing electrode (integrated bipolar). This study compares the performance of integrated versus dedicated leads with respect to anodal stimulation incidence, sensing, and inappropriate ventricular tachyarrhythmia detection in patients implanted with CRT-D. Two hundred ninety-two patients were randomly assigned to receive dedicated or integrated bipolar RV leads at the time of CRT-D implantation. Patients were followed for 6 months. Patients with dedicated bipolar RV leads exhibited markedly higher rates of anodal stimulation than did patients with integrated leads. The incidence of anodal stimulation was 64% at implant for dedicated bipolar RV leads compared to 1% for integrated bipolar RV leads. The likelihood of anodal stimulation in patients with dedicated leads fell progressively during the 6-month follow-up (51.5%), but always exceeded the incidence of anodal stimulation in patients with integrated leads (5%). Clinically detectable undersensing and oversensing were very unusual and did not differ significantly between lead designs. There were no inappropriate ventricular tachyarrhythmia detections for either lead type. Integrated bipolar RV defibrillator leads had a significantly lower incidence of RV anodal stimulation when compared to dedicated bipolar RV defibrillation leads, with no clinically detectable oversensing or undersensing, and with no inappropriate ventricular tachyarrhythmia detections for either lead type.

A randomized control hands-on defibrillation study-Barrier use evaluation.

PubMed

Wampler, David; Kharod, Chetan; Bolleter, Scotty; Burkett, Alison; Gabehart, Caitlin; Manifold, Craig

2016-06-01

Chest compressions and defibrillation are the only therapies proven to increase survival in cardiac arrest. Historically, rescuers must remove hands to shock, thereby interrupting chest compressions. This hands-off time results in a zero blood flow state. Pauses have been associated with poorer neurological recovery. This was a blinded randomized control cadaver study evaluating the detection of defibrillation during manual chest compressions. An active defibrillator was connected to the cadaver in the sternum-apex configuration. The sham defibrillator was not connected to the cadaver. Subjects performed chest compressions using 6 barrier types: barehand, single and double layer nitrile gloves, firefighter gloves, neoprene pad, and a manual chest compression/decompression device. Randomized defibrillations (10 per barrier type) were delivered at 30 joules (J) for bare hand and 360J for all other barriers. After each shock, the subject indicated degree of sensation on a VAS scale. Ten subjects participated. All subjects detected 30j shocks during barehand compressions, with only 1 undetected real shock. All barriers combined totaled 500 shocks delivered. Five (1%) active shocks were detected, 1(0.2%) single layer of Nitrile, 3(0.6%) with double layer nitrile, and 1(0.2%) with the neoprene barrier. One sham shock was reported with the single layer nitrile glove. No shocks were detected with fire gloves or compression decompression device. All shocks detected barely perceptible (0.25(±0.05)cm on 10cm VAS scale). Nitrile gloves and neoprene pad prevent (99%) responder's detection of defibrillation of a cadaver. Fire gloves and compression decompression device prevented detection. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Reticular telangiectatic erythema: case report and literature review

PubMed Central

Beutler, Bryce D.; Cohen, Philip R.

2015-01-01

Background: Reticular telangiectatic erythema is a benign cutaneous reaction that may occur in patients who have received a subcutaneous implantable cardioverter-defibrillator. Reticular telangiectatic erythema is characterized by asymptomatic telangiectasias, blanchable erythematous patches, or both overlying and/or adjacent to the subcutaneous implantable cardioverter-defibrillator. Purpose: We describe a man who developed reticular telangiectatic erythema after receiving a subcutaneous implantable cardioverter-defibrillator and review the salient features of this condition. We also summarize the conditions that can mimic reticular telangiectatic erythema. Materials and methods: The features of a man with reticular telangiectatic erythema are presented and the literature on reticular telangiectatic erythema is reviewed. Results: Our patient developed reticular telangiectatic erythema within one month of subcutaneous implantable cardioverter-defibrillator insertion. The subcutaneous manifestations were asymptomatic. The patient concurred to have periodic clinical follow up and his condition will be monitored for any changes. Conclusion: Reticular telangiectatic erythema is a benign condition characterized by the development of erythema, telangiectasia, or both following insertion of a subcutaneous implantable cardioverter-defibrillator. Other subcutaneous implantable cardioverter-defibrillator-related side effects, such as pressure dermatitis and contact dermatitis, can mimic the condition. Reticular telangiectatic erythema can also be observed following insertion of other devices or, rarely, in the absence of inserted devices. Local microcirculatory changes and subcutaneous implantable cardioverter-defibrillator-related obstruction of blood flow have been suggested as possible mechanisms of pathogenesis. The diagnosis can usually be established by clinical presentation. Therefore, patch testing can usually be omitted. Reticular telangiectatic erythema is typically asymptomatic and thus removal of the device is not required. PMID:25692087

Can lay responder defibrillation programmes improve survival to hospital discharge following an out-of-hospital cardiac arrest?

PubMed

Smith, Leigh M; Davidson, Patricia M; Halcomb, Elizabeth J; Andrew, Sharon

2007-11-01

The importance of early defibrillation in improving outcomes and reducing morbidity following out-of-hospital cardiac arrest underscores the importance of examining novel approaches to treatment access. The increasing evidence to support the importance of early defibrillation has increased attention on the potential for lay responders to deliver this therapy. This paper seeks to critically review the literature that evaluates the impact of lay responder defibrillator programs on survival to hospital discharge following an out-of-hospital cardiac arrest in the adult population. The electronic databases, Medline and CINAHL, were searched using keywords including; "first responder", "lay responder", "defibrillation" and "cardiac arrest". The reference lists of retrieved articles and the Internet were also searched. Articles were included in the review if they reported primary data, in the English language, which described the effect of a lay responder defibrillation program on survival to hospital discharge from out-of-hospital cardiac arrest in adults. Eleven studies met the inclusion criteria. The small number of published studies, heterogeneity of study populations and study outcome methods prohibited formal meta-analysis. Therefore, narrative analysis was undertaken. Studies included in this report provided inconsistent findings in relation to survival to hospital discharge following out-of-hospital cardiac arrest. Although there are limited data, the role of the lay responder appears promising in improving the outcome from out-of-hospital cardiac arrest following early defibrillation. Despite the inherent methodological difficulties in studying this population, future research should address outcomes related to morbidity, mortality and cost-effectiveness.

The NO Regular Defibrillation testing In Cardioverter Defibrillator Implantation (NORDIC ICD) trial: concept and design of a randomized, controlled trial of intra-operative defibrillation testing during de novo defibrillator implantation.

PubMed

Bänsch, Dietmar; Bonnemeier, Hendrik; Brandt, Johan; Bode, Frank; Svendsen, Jesper Hastrup; Felk, Angelika; Hauser, Tino; Wegscheider, Karl

2015-01-01

Although defibrillation (DF) testing is still considered a standard procedure during implantable cardioverter-defibrillator (ICD) insertion and has been an essential element of all trials that demonstrated the survival benefit of ICD therapy, there are no large randomized clinical trials demonstrating that DF testing improves clinical outcome and if the outcome would remain the same by omitting DF testing. Between February 2011 and July 2013, we randomly assigned 1077 patients to ICD implantation with (n = 540) or without (n = 537) DF testing. The intra-operative DF testing was standardized across all participating centres. After inducing a fast ventricular tachycardia (VT) with a heart rate ≥240 b.p.m. or ventricular fibrillation (VF) with a low-energy T-wave shock, DF was attempted with an initial 15 J shock. If the shock reversed the VT or VF, DF testing was considered successful and terminated. If unsuccessful, two effective 24 J shocks were administered. If DF was unsuccessful, the system was reconfigured and another DF testing was performed. An ICD shock energy of 40 J had to be programmed in all patients for treatment of spontaneous VT/VF episodes. The primary endpoint was the average efficacy of the first ICD shock for all true VT/VF episodes in each patient during follow-up. The secondary endpoints included the frequency of system revisions, total fluoroscopy, implantation time, procedural serious adverse events, and all-cause, cardiac, and arrhythmic mortality during follow-up. Home Monitoring was used in all patients to continuously monitor the system integrity, device programming and performance. The NO Regular Defibrillation testing In Cardioverter Defibrillator Implantation (NORDIC ICD) trial is one of two large prospective randomized trials assessing the effect of DF testing omission during ICD implantation. NCT01282918. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

A first city-wide early defibrillation project in a German city: 5-year results of the Bochum against sudden cardiac arrest study

PubMed Central

2010-01-01

Background Immediate defibrillation is the decisive determinant of prognosis in patients suffering from cardiac/circulatory arrest caused by ventricular fibrillation (VF). Therefore, various national and international associations recommend that first responders use defibrillators as soon as possible and also recommend public access to early defibrillation programmes. Here we report the results of the first city-wide early defibrillation project in a large German urban area. Methods There were 155 automated external defibrillators (AEDs) put into operation in the Bochum municipal area, and 6,294 people took part in cardiopulmonary resuscitation (CPR) and AED training. Free, accessible AEDs were installed in places with large volumes of people. Additionally, emergency forces were progressively equipped with AEDs. Results Twelve AED administrations prior to the arrival of an emergency physician were recorded and analysed over a period of 5 years (08/2004-08/2009). Rhythm analysis via AED demonstrated VF in seven cases, non-malignant dysrhythmias in four cases and asystole in one case. Two of the seven patients with VF were successfully defibrillated and survived cardiac/circulatory arrest without any neurological sequelae. Eight of the 12 AED applications were performed by laymen. The mean time between switching the unit on and applying the electrodes to the patient was 39 seconds (SD +/-20 sec). On average, another 20 seconds elapsed before the AED recommendation of "shock delivery" was displayed, and a total of 96 seconds elapsed before shock administration (± 56 sec). Conclusion Consistent with other reports, our findings show that the organisation of a city-wide initiative by a project office combining public access and first-responder defibrillation programmes can be safe, feasible and successful. Our experiences confirm that strategic planning of AED placement is a prerequisite for successful, cost-effective resuscitation. PMID:20550655

Electromagnetic Interference in a Private Swimming Pool: Case report.

PubMed

Iskandar, Sandia; Lavu, Madhav; Atoui, Moustapha; Lakkireddy, Dhanunjaya

2015-01-01

Although current lead design and filtering capabilities have greatly improved, Electromagnetic Interference (EMI) from environmental sources has been increasingly reported in patients with Cardiac Implantable Electronic Device (CIED) [1]. Few cases of inappropriate intracardiac Cardioverter Defibrillator (ICD) associated with swimming pool has been described [2]. Here we present a case of 64 year old male who presented with an interesting EMI signal that was subsequently identified to be related to AC current leak in his swimming pool.

Providers issue brief: automated external defibrillators.

PubMed

Rothouse, M

1999-06-25

With expanded access to automatic external defibrillators, hundreds of lives could be saved on a daily basis. By training nonphysician providers, such as emergency medical service personnel or first responders, this life-saving medical equipment could help improve the survival rates for people suffering from cardiac arrest. During the last two years, state lawmakers have begun to enact legislation that develops training standards and provides immunity from civil liability for automatic external defibrillator users.

Initial experience of subcutaneous implantable cardioverter defibrillators in Singapore: a case series and review of the literature

PubMed Central

Lim, Tien Siang Eric; Tan, Boon Yew; Ho, Kah Leng; Lim, Chuh Yih Paul; Teo, Wee Siong; Ching, Chi-Keong

2015-01-01

Transvenous implantable cardioverter defibrillators are a type of implantable cardiac device. They are effective at reducing total and arrhythmic mortality in patients at risk of sudden cardiac death. Subcutaneous implantable cardioverter defibrillators (S-ICDs) are a new alternative that avoids the disadvantages of transvenous lead placement. In this case series, we report on the initial feasibility and safety of S-ICD implantation in Singapore. PMID:26512151

Initial experience of subcutaneous implantable cardioverter defibrillators in Singapore: a case series and review of the literature.

PubMed

Lim, Tien Siang Eric; Tan, Boon Yew; Ho, Kah Leng; Lim, Chuh Yih Paul; Teo, Wee Siong; Ching, Chi-Keong

2015-10-01

Transvenous implantable cardioverter defibrillators are a type of implantable cardiac device. They are effective at reducing total and arrhythmic mortality in patients at risk of sudden cardiac death. Subcutaneous implantable cardioverter defibrillators (S-ICDs) are a new alternative that avoids the disadvantages of transvenous lead placement. In this case series, we report on the initial feasibility and safety of S-ICD implantation in Singapore.

Implantable cardioverter-defibrillator implantation for primary and secondary prevention: indications and outcomes.

PubMed

Pick, Justin M; Batra, Anjan S

2017-01-01

Implantable cardioverter-defibrillators effectively reduce the rate of sudden cardiac death in children. Significant efforts have been made to better characterise the indications for their placement, and over the past two decades there has been a shift in their use from secondary to primary prevention. Primary prevention includes placement in patients thought to be at high risk of sudden cardiac death before the patient experiences any event. Secondary prevention includes placement after a high-risk event including sustained ventricular tachycardia or resuscitated cardiac arrest. Although liberal device implantation may be appealing even in patients having marginal indications, studies have shown high rates of adverse effects including inappropriate device discharges and the need for re-intervention because of hardware malfunction. The indications for placement of an implantable cardioverter-defibrillator, whether for primary or secondary prevention of sudden cardiac death, vary based on cardiac pathology. This review will assist the provider in understanding the risks and benefits of device implantation in order to enhance the shared decision-making capacity of patients, families, and providers.

Towards optogenetic control of spatiotemporal cardiac dynamics

NASA Astrophysics Data System (ADS)

Diaz-Maue, Laura; Luther, Stefan; Richter, Claudia

2018-02-01

Detailed understanding of mechanisms and instabilities underlying the onset, perpetuation, and control of cardiac arrhythmias is required for the development, further optimization, and translation of clinically applicable defibrillation methods. Recently, the potential use of optogenetic tools using structured illumination to control cardiac arrhythmia has been successfully demonstrated and photostimulation turned out to be a promising experimental tool to investigate the dynamics and mechanisms of multi-site pacing strategies for low-energy defibrillation. In order to study the relation between trigger and control mechanisms of arrhythmic cardiac conditions without external affecting factors like eventually damaging fiber poking, it is important to establish a non-invasive photostimulation method. Hence, we applied a custom-configured digital light processing micromirror array operated by a high-speed FPGA, which guarantees a high frequency control of stimulation patterns. The integration into a highly sophisticated optical experiment setup allows us to record photostimulation effects and to proof the light pulse as origin of cardiac excitation. Experiments with transgenic murine hearts demonstrate the successful induction and termination of cardiac dysrhythmia using light crafting tools. However, the complex spatiotemporal dynamics underlying arrhythmia critically depends on the ratio of the characteristic wavelength of arrhythmia and substrate size. Based on the experimental evidence regarding the feasibility of optical defibrillation in small mammals, the transfer in clinically relevant large animal models would be the next milestone to therapeutic translation. Thus, the presented experimental results of optogenetically modified murine hearts function as originator for ongoing studies involving principle design studies for therapeutic applicable optical defibrillation.

Remote monitoring to Improve long-term prognosis in heart failure patients with implantable cardioverter-defibrillators.

PubMed

Ono, Maki; Varma, Niraj

2017-05-01

Strong evidence exists for the utility of remote monitoring in cardiac implantable electronic devices for early detection of arrhythmias and evaluation of system performance. The application of remote monitoring for the management of chronic disease such as heart failure has been an active area of research. Areas covered: This review aims to cover the latest evidence of remote monitoring of implantable cardiac defibrillators in terms of heart failure prognosis. This article also updates the current technology relating to the method and discusses key factors to be addressed in order to better use the approach. PubMed and internet searches were conducted to acquire most recent data and technology information. Expert commentary: Multiparameter monitoring with automatic transmission is useful for heart failure management. Improved adherence to remote monitoring and an optimal algorithm for transmitted alerts and their management are warranted in the management of heart failure.

Gender-Related and Age-Related Differences in Implantable Defibrillator Recipients: Results From the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS").

PubMed

Feldman, Alyssa M; Kersten, Daniel J; Chung, Jessica A; Asheld, Wilbur J; Germano, Joseph; Islam, Shahidul; Cohen, Todd J

2015-12-01

The purpose of this study was to investigate the influences of gender and age on defibrillator lead failure and patient mortality. The specific influences of gender and age on defibrillator lead failure have not previously been investigated. This study analyzed the differences in gender and age in relation to defibrillator lead failure and mortality of patients in the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS"). PAIDLESS includes all patients at Winthrop University Hospital who underwent defibrillator lead implantation between February 1, 1996 and December 31, 2011. Male and female patients were compared within each age decile, beginning at 15 years old, to analyze lead failure and patient mortality. Statistical analyses were performed using Wilcoxon rank-sum test, Fisher's exact test, Kaplan-Meier analysis, and multivariable Cox regression models. P<.05 was considered statistically significant. No correction for multiple comparisons was performed for the subgroup analyses. A total of 3802 patients (2812 men and 990 women) were included in the analysis. The mean age was 70 ± 13 years (range, 15-94 years). Kaplan-Meier analysis found that between 45 and 54 years of age, leads implanted in women failed significantly faster than in men (P=.03). Multivariable Cox regression models were built to validate this finding, and they confirmed that male gender was an independent protective factor of lead failure in the 45 to 54 years group (for male gender: HR, 0.37; 95% confidence interval, 0.14-0.96; P=.04). Lead survival time for women in this age group was 13.4 years (standard error, 0.6), while leads implanted in men of this age group survived 14.7 years (standard error, 0.3). Although there were significant differences in lead failure, no differences in mortality between the genders were found for any ages or within each decile. This study is the first to compare defibrillator lead failure and patient mortality in relation to gender and age deciles at a single large implanting center. Within the 45 to 54 years group, leads implanted in women failed faster than in men. Male gender was found to be an independent protective factor in lead survival. This study emphasizes the complex interplay between gender and age with respect to implantable defibrillator lead failure and mortality.

Patients' perception of implantable cardioverter defibrillator deactivation at the end of life.

PubMed

Hill, Loreena; McIlfatrick, Sonja; Taylor, Brian; Dixon, Lana; Harbinson, Mark; Fitzsimons, Donna

2015-04-01

Individualised care at the end of life requires professional understanding of the patient's perception of implantable cardioverter defibrillator deactivation. The aim was to evaluate the evidence on patients' perception of implantable cardioverter defibrillator deactivation at end of life. Systematic narrative review of empirical studies was published during 2008-2014. Data were collected from six databases, citations from relevant articles and expert recommendations. In all, 18 studies included with collective population of n = 5810. Concept mapping highlighted three themes: (1) Diverse preferences regarding discussion and deactivation. Deactivation was rarely discussed pre-implantation, with some studies demonstrating patients' reluctance to discuss implantable cardioverter defibrillator deactivation at any stage. Two studies found the majority of patients valued such discussions. Diversity was reflected in patients' willingness to deactivate, ranging from 12% (n = 9) in Irish cohort to 79% (n = 195) in Dutch study. (2) Ethical and legal considerations were predominant in Canadian and American literature as patients wanted to contribute but felt the decision should be a doctor's responsibility. Advance directives were uncommon in Europe, and where they existed the implantable cardioverter defibrillator was not mentioned. (3) 'Living in the now' was evident as despite deteriorating symptoms many patients maintained a positive outlook and anticipated surviving more than 10 years. Several studies asserted living longer was more important than quality of life. Patients regard the implantable cardioverter defibrillator as a complex and solely beneficial device, with little insight regarding its potential impact on a peaceful death. This review confirms the need for professionals to discuss with patients and families implantable cardioverter defibrillator functionality and deactivation at appropriate opportunities. © The Author(s) 2014.

Single-coil and dual-coil defibrillator leads and association with clinical outcomes in a complete Danish nationwide ICD cohort.

PubMed

Larsen, Jacob M; Hjortshøj, Søren P; Nielsen, Jens C; Johansen, Jens B; Petersen, Helen H; Haarbo, Jens; Johansen, Martin B; Thøgersen, Anna Margrethe

2016-03-01

The best choice of defibrillator lead in patients with routine implantable cardioverter-defibrillator (ICD) is not settled. Traditionally, most physicians prefer dual-coil leads but the use of single-coil leads is increasing. The purpose of this study was to compare clinical outcomes in patients with single- and dual-coil leads. All 4769 Danish patients 18 years or older with first-time ICD implants from 2007 to 2011 were included from the Danish Pacemaker and ICD Register. Defibrillator leads were 38.9% single-coil leads and 61.1% dual-coil leads. The primary end point was all-cause mortality. Secondary end points were lowest successful energy at implant defibrillation testing, first shock failure in spontaneous arrhythmias, structural lead failure, and lead extraction outcomes. Single-coil leads were associated with lower all-cause mortality with an adjusted hazard ratio of 0.85 (95% confidence interval 0.73-0.99; P = .04). This finding was robust in a supplementary propensity score-matched analysis. However, dual-coil leads were used in patients with slightly higher preimplant morbidity, making residual confounding by indication the most likely explanation for the observed association between lead type and mortality. The lowest successful defibrillation energy was higher using single-coil leads (23.2 ± 4.3 J vs 22.1 ± 3.9 J; P < .001). No significant differences were observed for other secondary end points showing high shock efficacies and low rates of lead failures and extraction complications. Shock efficacy is high for modern ICD systems. The choice between single-coil and dual-coil defibrillator leads is unlikely to have a clinically significant impact on patient outcomes in routine ICD implants. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Atrial electrogram quality in single-pass defibrillator leads with floating atrial bipole in patients with permanent atrial fibrillation and cardiac resynchronization therapy.

PubMed

Sticherling, Christian; Müller, Dirk; Schaer, Beat A; Krüger, Silke; Kolb, Christof

2018-03-27

Many patients receiving cardiac resynchronization therapy (CRT) suffer from permanent atrial fibrillation (AF). Knowledge of the atrial rhythm is important to direct pharmacological or interventional treatment as well as maintaining AV-synchronous biventricular pacing if sinus rhythm can be restored. A single pass single-coil defibrillator lead with a floating atrial bipole has been shown to obtain reliable information about the atrial rhythm but has never been employed in a CRT-system. The purpose of this study was to assess the feasibility of implanting a single coil right ventricular ICD lead with a floating atrial bipole and the signal quality of atrial electrograms (AEGM) in CRT-defibrillator recipients with permanent AF. Seventeen patients (16 males, mean age 73 ± 6 years, mean EF 25 ± 5%) with permanent AF and an indication for CRT-defibrillator placement were implanted with a designated CRT-D system comprising a single pass defibrillator lead with a atrial floating bipole. They were followed-up for 103 ± 22 days using remote monitoring for AEGM transmission. All patients had at last one AEGM suitable for atrial rhythm diagnosis and of 100 AEGM 99% were suitable for visual atrial rhythm assessment. Four patients were discharged in sinus rhythm and one reverted to AF during follow-up. Atrial electrograms retrieved from a single-pass defibrillator lead with a floating atrial bipole can be reliably used for atrial rhythm diagnosis in CRT recipients with permanent AF. Hence, a single pass ventricular defibrillator lead with a floating bipole can be considered in this population. Copyright © 2018 Indian Heart Rhythm Society. Production and hosting by Elsevier B.V. All rights reserved.

Effect of timing and duration of a single chest compression pause on short-term survival following prolonged ventricular fibrillation.

PubMed

Walcott, Gregory P; Melnick, Sharon B; Walker, Robert G; Banville, Isabelle; Chapman, Fred W; Killingsworth, Cheryl R; Ideker, Raymond E

2009-04-01

Pauses during chest compressions are thought to have a detrimental effect on resuscitation outcome. The Guidelines 2005 have recently eliminated the post-defibrillation pause. Previous animal studies have shown that multiple pauses of increasing duration decrease resuscitation success. We investigated the effect of varying the characteristics of a single pause near defibrillation on resuscitation outcome. Part A: 48 swine were anesthetized, fibrillated for 7min and randomized. Chest compressions were initiated for 90s followed by defibrillation and then resumption of chest compressions. Four groups were studied-G2000: 40s pause beginning 20s before, and ending 20s after defibrillation, A1: a 20s pause just before defibrillation, A2: a 20s pause ending 30s prior to defibrillation, and group A3: a 10s pause ending 30s prior to defibrillation. Part B: 12 swine (Group B) were studied with a protocol identical to Part A but with no pause in chest compressions. Primary endpoint was survival to 4h. The survival rate was significantly higher for groups A1, A2, A3, and B (5/12, 7/12, 5/12, and 5/12 survived) than for the G2000 group (0/12, p<0.05). Survival did not differ significantly among groups A1, A2, A3, and B. These results suggest that the Guidelines 2005 recommendation to omit the post-shock pulse check and immediately resume chest compressions may be an important resuscitation protocol change. However, these results also suggest that clinical maneuvers further altering a single pre-shock chest compression pause provide no additional benefit.

Effect of timing and duration of a single chest compression pause on short-term survival following prolonged ventricular fibrillation☆

PubMed Central

Walcott, Gregory P.; Melnick, Sharon B.; Walker, Robert G.; Banville, Isabelle; Chapman, Fred W.; Killingsworth, Cheryl R.; Ideker, Raymond E.

2014-01-01

Background Pauses during chest compressions are thought to have a detrimental effect on resuscitation outcome. The Guidelines 2005 have recently eliminated the post-defibrillation pause. Previous animal studies have shown that multiple pauses of increasing duration decrease resuscitation success. We investigated the effect of varying the characteristics of a single pause near defibrillation on resuscitation outcome. Methods Part A: 48 swine were anesthetized, fibrillated for 7 min and randomized. Chest compressions were initiated for 90 s followed by defibrillation and then resumption of chest compressions. Four groups were studied—G2000: 40 s pause beginning 20 s before, and ending 20 s after defibrillation, A1: a 20 s pause just before defibrillation, A2: a 20 s pause ending 30 s prior to defibrillation, and group A3: a 10 s pause ending 30 s prior to defibrillation. Part B: 12 swine (Group B) were studied with a protocol identical to Part A but with no pause in chest compressions. Primary endpoint was survival to 4 h. Results The survival rate was significantly higher for groups A1, A2, A3, and B (5/12, 7/12, 5/12, and 5/12 survived) than for the G2000 group (0/12, p < 0.05). Survival did not differ significantly among groups A1, A2, A3, and B. Conclusions These results suggest that the Guidelines 2005 recommendation to omit the post-shock pulse check and immediately resume chest compressions may be an important resuscitation protocol change. However, these results also suggest that clinical maneuvers further altering a single pre-shock chest compression pause provide no additional benefit. PMID:19185411

Intracellular calcium and vulnerability to fibrillation and defibrillation in Langendorff-perfused rabbit ventricles.

PubMed

Hwang, Gyo-Seung; Hayashi, Hideki; Tang, Liang; Ogawa, Masahiro; Hernandez, Heidy; Tan, Alex Y; Li, Hongmei; Karagueuzian, Hrayr S; Weiss, James N; Lin, Shien-Fong; Chen, Peng-Sheng

2006-12-12

The role of intracellular calcium (Ca(i)) in defibrillation and vulnerability is unclear. We simultaneously mapped epicardial membrane potential and Ca(i) during shock on T-wave episodes (n=104) and attempted defibrillation episodes (n=173) in 17 Langendorff-perfused rabbit ventricles. Unsuccessful and type B successful defibrillation shocks were followed by heterogeneous distribution of Ca(i), including regions of low Ca(i) surrounded by elevated Ca(i) ("Ca(i) sinkholes") 31+/-12 ms after shock. The first postshock activation then originated from the Ca(i) sinkhole 53+/-14 ms after the shock. No sinkholes were present in type A successful defibrillation. A Ca(i) sinkhole also was present 39+/-32 ms after a shock on T that induced ventricular fibrillation, followed 22+/-15 ms later by propagated wave fronts that arose from the same site. This wave propagated to form a spiral wave and initiated ventricular fibrillation. Thapsigargin and ryanodine significantly decreased the upper limit of vulnerability and defibrillation threshold. We studied an additional 7 rabbits after left ventricular endocardial cryoablation, resulting in a thin layer of surviving epicardium. Ca(i) sinkholes occurred 31+/-12 ms after the shock, followed in 19+/-7 ms by first postshock activation in 63 episodes of unsuccessful defibrillation. At the Ca(i) sinkhole, the rise of Ca(i) preceded the rise of epicardial membrane potential in 5 episodes. There is a heterogeneous postshock distribution of Ca(i). The first postshock activation always occurs from a Ca(i) sinkhole. The Ca(i) prefluorescence at the first postshock early site suggests that reverse excitation-contraction coupling might be responsible for the initiation of postshock activations that lead to ventricular fibrillation.

Defibrillator implantations for primary prevention in the United States: Inappropriate care or inadequate documentation: Insights from the National Cardiovascular Data ICD Registry.

PubMed

Kaiser, Daniel W; Tsai, Vivian; Heidenreich, Paul A; Goldstein, Mary K; Wang, Yongfei; Curtis, Jeptha; Turakhia, Mintu P

2015-10-01

Prior studies have reported that more than 20% of implantable cardioverter-defibrillator (ICD) implantations in the United States do not adhere to trial-based criteria. We sought to investigate the patient characteristics associated with not meeting the inclusion criteria of the clinical trials that have demonstrated the efficacy of primary prevention ICDs. Using data from the National Cardiovascular Data Registry's ICD Registry, we identified patients who received ICDs for primary prevention from January 2006 to December 2008. We determined whether patients met the inclusion criteria of at least 1 of the 4 ICD primary prevention trials: Multicenter Automatic Defibrillator Implantation Trial (MADIT), MADIT-II, Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), and the Multicenter Unsustained Tachycardia Trial (MUSTT). Among 150,264 patients, 86% met criteria for an ICD implantation based on trial data. The proportion of patients who did not meet trial-based criteria increased as age decreased. In multivariate analysis, the significant predictors for not meeting trial criteria included prior cardiac transplantation (odds ratio [OR] 2.1), pediatric electrophysiology operator (OR 2.0), and high-grade atrioventricular conduction disease (OR 1.4). Among National Cardiovascular Data Registry registrants receiving first-time ICDs for primary prevention, the majority met trial-based criteria. Multivariate analyses suggested that many patients who did not meet the trial-based criteria may have had clinical circumstances that warranted ICD implantation. These findings caution against the use of trial-based indications to determine site quality metrics that could penalize sites that care for younger patients. The planned incorporation of appropriate use criteria into the ICD registry may better characterize patient- and site-level quality and performance. Published by Elsevier Inc.

Pacemakers and implantable cardioverter defibrillators--general and anesthetic considerations.

PubMed

Rapsang, Amy G; Bhattacharyya, Prithwis

2014-01-01

A pacemaking system consists of an impulse generator and lead or leads to carry the electrical impulse to the patient's heart. Pacemaker and implantable cardioverter defibrillator codes were made to describe the type of pacemaker or implantable cardioverter defibrillator implanted. Indications for pacing and implantable cardioverter defibrillator implantation were given by the American College of Cardiologists. Certain pacemakers have magnet-operated reed switches incorporated; however, magnet application can have serious adverse effects; hence, devices should be considered programmable unless known otherwise. When a device patient undergoes any procedure (with or without anesthesia), special precautions have to be observed including a focused history/physical examination, interrogation of pacemaker before and after the procedure, emergency drugs/temporary pacing and defibrillation, reprogramming of pacemaker and disabling certain pacemaker functions if required, monitoring of electrolyte and metabolic disturbance and avoiding certain drugs and equipments that can interfere with pacemaker function. If unanticipated device interactions are found, consider discontinuation of the procedure until the source of interference can be eliminated or managed and all corrective measures should be taken to ensure proper pacemaker function should be done. Post procedure, the cardiac rate and rhythm should be monitored continuously and emergency drugs and equipments should be kept ready and consultation with a cardiologist or a pacemaker-implantable cardioverter defibrillator service may be necessary. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Semiautomated external defibrillators for in-hospital early defibrillation: a comparative study.

PubMed

Nocchi, Federico; Derrico, Pietro; Masucci, Gerardina; Capussotto, Carlo; Cecchetti, Corrado; Ritrovato, Matteo

2014-01-01

Semiautomated external defibrillators (AEDs) should be considered as a means to facilitate in-hospital early defibrillation (IHED) in areas where advanced life support rescuers are not readily available. In this study, we aimed to develop a checklist and a measurement protocol to evaluate and compare AEDs by assessing factors that may affect IHED. A clinical and technical comparison of six AEDs was performed. Technical specifications were analyzed, while an emergency team evaluated ergonomics and appropriateness for IHED at Bambino Gesù Children's Hospital. A measurement protocol was implemented, which aimed to assess the ability of defibrillators to recognize shockable and nonshockable rhythms, accuracy of delivered energy, and charging time. Designs of AEDs differed in several features which influence their appropriateness for IHED. Some units showed poor ergonomics and instructions/feedback for cardiopulmonary resuscitation. Differences between defibrillators in recognizing shockable and nonshockable rhythms emerged for polymorphic ventricular tachycardia waveforms and when the frequency and amplitude of input signals varied. Tests for accuracy revealed poor performances at low and high impedance levels for most AEDs. Notably, differences greater than 20 seconds were found in the time from power-on to "ready for discharge." The approach we used to assess AEDs allowed us to evaluate their appropriateness with respect to the organizational context, to measure their parameters, and to compare models. Results showed that ergonomics and/or performances (timing and accuracy) could be improved in each device.

Improvements in logistics could increase survival after out-of-hospital cardiac arrest in Sweden.

PubMed

Strömsöe, A; Afzelius, S; Axelsson, C; Södersved Källestedt, M L; Enlund, M; Svensson, L; Herlitz, J

2013-06-01

In a review based on estimations and assumptions, to report the estimated number of survivors after out-of-hospital cardiac arrest (OHCA) in whom cardiopulmonary resuscitation (CPR) was started and to speculate about possible future improvements in Sweden. An observational study. All ambulance organisations in Sweden. Patients included in the Swedish Cardiac Arrest Registry who suffered an OHCA between January 1, 2008 and December 31, 2010. Approximately 80% of OHCA cases in Sweden in which CPR was started are included. None In 11 005 patients, the 1-month survival rate was 9.4%. There are approximately 5000 OHCA cases annually in which CPR is started and 30-day survival is achieved in up to 500 patients yearly (6 per 100 000 inhabitants). Based on findings on survival in relation to the time to calling for the Emergency Medical Service (EMS) and the start of CPR and defibrillation, it was estimated that, if the delay from collapse to (i) calling EMS, (ii) the start of CPR, and (iii) the time to defibrillation were reduced to <2 min, <2 min, and <8 min, respectively, 300-400 additional lives could be saved. Based on findings relating to the delay to calling for the EMS and the start of CPR and defibrillation, we speculate that 300-400 additional OHCA patients yearly (4 per 100 000 inhabitants) could be saved in Sweden. © 2013 The Association for the Publication of the Journal of Internal Medicine.

Ventricular Fibrillation

MedlinePlus

... heart with a device called an automated external defibrillator (AED). Treatments to prevent sudden cardiac death for ... can even be purchased for your home. Portable defibrillators come with built-in instructions for their use. ...

Clinical efficacy of the wearable cardioverter-defibrillator in acutely terminating episodes of ventricular fibrillation.

PubMed

Auricchio, A; Klein, H; Geller, C J; Reek, S; Heilman, M S; Szymkiewicz, S J

1998-05-15

The findings of our initial study demonstrate for the first time the ability to terminate induced VT/VF reliably (100% of all episodes) by a single, monophasic 230-J shock delivered by the Wearable Cardioverter-Defibrillator (WCD). Although limited by sample size, our data suggest the WCD could be used as a feasible bridge to definitive implantation of an implantable cardioverter-defibrillator in patients in whom risk stratification for sudden death is not completed.

21 CFR 870.5310 - Automated external defibrillator.

Code of Federal Regulations, 2010 CFR

2010-04-01

... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the...

29 CFR 1915.87 - Medical services and first aid.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Defibrillators (Non-Mandatory) 1. First aid supplies are required to be adequate and readily accessible under..., face shields, masks, and eye protection. 4. Employers who provide automated external defibrillators...

29 CFR 1915.87 - Medical services and first aid.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Defibrillators (Non-Mandatory) 1. First aid supplies are required to be adequate and readily accessible under..., face shields, masks, and eye protection. 4. Employers who provide automated external defibrillators...

21 CFR 870.5310 - Automated external defibrillator.

Code of Federal Regulations, 2014 CFR

2014-04-01

... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the...

21 CFR 870.5310 - Automated external defibrillator.

Code of Federal Regulations, 2012 CFR

2012-04-01

... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the...

21 CFR 870.5310 - Automated external defibrillator.

Code of Federal Regulations, 2011 CFR

2011-04-01

... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the...

21 CFR 870.5310 - Automated external defibrillator.

Code of Federal Regulations, 2013 CFR

2013-04-01

... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the...

Remote monitoring: a cost or an investment?

PubMed

Burri, Haran; Heidbüchel, Hein; Jung, Werner; Brugada, Pedro

2011-05-01

Remote management of pacemakers and implantable defibrillators is being increasingly used in Europe, due to its potential to improve follow-up efficiency and patient outcome. However, this paradigm shift needs to be economically viable for it to be sustainable in the long term. This article covers the economic aspects of remote device management, and reviews the current evidence in this field.

14 CFR 121.805 - Crewmember training for in-flight medical events.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) Instruction, to include performance drills, in the proper use of automated external defibrillators. (ii... include performance drills, in the proper use of an automated external defibrillators and in...

14 CFR 121.805 - Crewmember training for in-flight medical events.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) Instruction, to include performance drills, in the proper use of automated external defibrillators. (ii... include performance drills, in the proper use of an automated external defibrillators and in...

14 CFR 121.805 - Crewmember training for in-flight medical events.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) Instruction, to include performance drills, in the proper use of automated external defibrillators. (ii... include performance drills, in the proper use of an automated external defibrillators and in...

14 CFR 121.805 - Crewmember training for in-flight medical events.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) Instruction, to include performance drills, in the proper use of automated external defibrillators. (ii... include performance drills, in the proper use of an automated external defibrillators and in...

14 CFR 121.805 - Crewmember training for in-flight medical events.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) Instruction, to include performance drills, in the proper use of automated external defibrillators. (ii... include performance drills, in the proper use of an automated external defibrillators and in...

Socio-economic analysis of cardiac resynchronization therapy.

PubMed

Field, Michael E; Sweeney, Michael O

2006-12-01

The field of electrical device therapy has benefited from two basically independent lines of investigation demonstrating mortal benefit from either cardiac resynchronization therapy (CRT) or implantable cardioverter-defibrillator (ICD) therapy in patients with heart failure. Current clinical evidence data is insufficient to conclude that CRT-defibrillation (CRTD) offers an advantage over CRT-pacing (CRTP) alone. The cost of adding a defibrillator to the CRTP device is substantial and will act as a barrier to wide scale penetration. Annualized sudden death rates are very low in certain primary prevention populations. Consequently, the potential for overtreatment is very large and the negative costs of ICD therapy are distributed equally among those patients who will have a life saving benefit and those who were "destined" never to require the therapy. The perception that these costs are acceptable if lives are saved is commonly cited as justification for expensive therapy on a population scale, but there is an important and practical difference between costs per unit life saved and costs among patients who really never needed the device. Until the a priori predictors of volumetric response to CRT are better understood, the use of CRTD in class IV patients should be discouraged since ICD therapy is unlikely to extend life in volumetric non-responders. Similarly, the use of CRTD in patients who are "destined" for significant volumetric response is probably unwise since their risk of sudden death is minimized due to favorable substrate modification. Clinical trials comparing conventional ICDs, CRTP and CRTD are necessary to rationalize use of expensive hardware resources among different patient populations. Additionally, the importance of patient preference regarding end of life care should receive greater emphasis. While CRTP may be considered palliative in terminal heart failure, the decision to offer CRTD must include a discussion with the patient regarding mode of death and the potential for the defibrillator to replace a sudden and peaceful death with a prolonged death from progressive pump failure.

Appropriate evaluation and treatment of heart failure patients after implantable cardioverter-defibrillator discharge: time to go beyond the initial shock.

PubMed

Mishkin, Joseph D; Saxonhouse, Sherry J; Woo, Gregory W; Burkart, Thomas A; Miles, William M; Conti, Jamie B; Schofield, Richard S; Sears, Samuel F; Aranda, Juan M

2009-11-24

Multiple clinical trials support the use of implantable cardioverter-defibrillators (ICDs) for prevention of sudden cardiac death in patients with heart failure (HF). Unfortunately, several complicating issues have arisen from the universal use of ICDs in HF patients. An estimated 20% to 35% of HF patients who receive an ICD for primary prevention will experience an appropriate shock within 1 to 3 years of implant, and one-third of patients will experience an inappropriate shock. An ICD shock is associated with a 2- to 5-fold increase in mortality, with the most common cause being progressive HF. The median time from initial ICD shock to death ranges from 168 to 294 days depending on HF etiology and the appropriateness of the ICD therapy. Despite this prognosis, current guidelines do not provide a clear stepwise approach to managing these high-risk patients. An ICD shock increases HF event risk and should trigger a thorough evaluation to determine the etiology of the shock and guide subsequent therapeutic interventions. Several combinations of pharmacologic and device-based interventions such as adding amiodarone to baseline beta-blocker therapy, adjusting ICD sensitivity, and employing antitachycardia pacing may reduce future appropriate and inappropriate shocks. Aggressive HF surveillance and management is required after an ICD shock, as the risk of sudden cardiac death is transformed to an increased HF event risk.

Anesthesia for subcutaneous implantable cardioverter-defibrillator implantation: Perspectives from the clinical experience of a US panel of physicians.

PubMed

Essandoh, Michael K; Mark, George E; Aasbo, Johan D; Joyner, Charles A; Sharma, Saumya; Decena, Beningo F; Bolin, Eric D; Weiss, Raul; Burke, Martin C; McClernon, Timothy R; Daoud, Emile G; Gold, Michael R

2018-05-13

Worldwide adoption of the subcutaneous implantable cardioverter-defibrillator (S-ICD) for preventing sudden cardiac death continues to increase, as longer-term evidence demonstrating the safety and efficacy of the S-ICD expands. As a relatively new technology, comprehensive anesthesia guidance for the management of patients undergoing S-ICD placement is lacking. This article presents advantages and disadvantages of different peri-procedural sedation and anesthesia options for S-ICD implants including general anesthesia, monitored anesthesia care, regional anesthesia, and nonanesthesia personnel administered sedation and analgesia. Guidance, for approaches to anesthesia care during S-ICD implantation, are presented based upon literature review and consensus of a panel of high volume S-ICD implanters, a regional anesthesiologist, and a cardiothoracic anesthesiologist with significant S-ICD experience. The panel developed suggested actions for perioperative sedation, anesthesia, surgical practices and a decision algorithm for S-ICD implantation. While S-ICD implantation currently requires higher sedation than transvenous ICD systems, the panel consensus is that general anesthesia is not required or is obligatory for the majority of patients for the experienced S-ICD implanter. The focus of the implanting physician and the anesthesia services should be to maximize patient comfort and take into consideration patient specific co-morbidities, with a low threshold to consult the anesthesiology team. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Use of Automated External Defibrillators in US Federal Buildings

PubMed Central

Kilaru, Austin S.; Leffer, Marc; Perkner, John; Sawyer, Kate Flanigan; Jolley, Chandra E.; Nadkarni, Lindsay D.; Shofer, Frances S.; Merchant, Raina M.

2014-01-01

Objective Federal Occupational Health (FOH) administers a nationwide public access defibrillation program in US federal buildings. We describe the use of automated external defibrillators (AEDs) in federal buildings and evaluate survival after cardiac arrest. Methods Using the FOH database, we examined reported events in which an AED was brought to a medical emergency in federal buildings over a 14-year period, from 1999 to 2012. Results There were 132 events involving an AED, 96 (73%) of which were due to cardiac arrest of cardiac etiology. Of 54 people who were witnessed to experience a cardiac arrest and presented with ventricular fibrillation or ventricular tachycardia, 21 (39%) survived to hospital discharge. Conclusions Public access defibrillation, along with protocols to install, maintain, and deploy AEDs and train first responders, benefits survival after cardiac arrest in the workplace. PMID:24351893

Emergency dispatcher assistance decreases time to defibrillation in a public venue: a randomized controlled trial.

PubMed

Riyapan, Sattha; Lubin, Jeffrey

2016-03-01

We attempted to determine the effect of prearrival instructions that included the specific location of automated external defibrillators (AEDs) in a public venue on the time to defibrillation in a simulated cardiac arrest scenario using untrained bystanders. The study was a randomized controlled trial at an urban shopping mall. Participants were asked to retrieve an AED and come back to defibrillate a mannequin. Only the experimental group received the location of the AED. We measured the percentage of shocks that were delivered in less than 3 minutes from the start of the scenario and also recorded several other time intervals. Thirty-nine participants completed the study, with 20 participants in the experimental group. The median time to defibrillation in the experimental group was 2.6 minutes (interquartile range, 2.4-2.8) which was significantly less than the control group's median time of 5.9 minutes (interquartile range, 4.38-7.65). Ninety percent (95% confidence interval, 68.3%-98.8%) of the participants in the experimental group defibrillated within 3 minutes, which was significantly different from the control group (10.5%; 95% confidence interval, 1.3%-33.1%). In this study, a prearrival protocol providing participants with the location of the nearest AED in a public building resulted in a significant decrease in the time required to deliver a simulated shock. Further investigations in various types of public settings are needed to confirm the results. Copyright © 2015 Elsevier Inc. All rights reserved.

[In-hospital resuscitation. Concept of first-responder resuscitation using semi-automated external defibrillators (AED)].

PubMed

Hanefeld, C; Lichte, C; Laubenthal, H; Hanke, E; Mügge, A

2006-09-29

The prognosis after in-hospital resuscitation has not significantly improved in the last 40 years. This account presents the results over a three-year period of a hospital-wide emergency plan which implements the use of an automated external defibrillator (AED) by the first responder to the emergency call. 15 "defibrillator points" were installed, which could be reached within 30 s from all wards, out-patient departments and other areas, thus making them accessible for immediate defibrillator application. The hospital personnel is trained periodically in the alarm sequence, cardiopulmonary resuscitation and use of the defibrillator. Data on 57 patients who had sustained a cardiac arrest were prospectively recorded and analysed. In 46 patients (81%) the "on-the-spot" personnel (first-responder) was able to apply AED before arrival of the hospital's resuscitation team. Mean period between arrest alarm and activation of the AED was 2.2 (0.7-4.7) min. Ventricular fibrillation or ventricular tachyarrhythmia was recorded in 40 patients, making immediate shock delivery by AED possible. Restoration of the circulation was achieved in 23 (80%) of the patients and 20 (50%) were discharged home, 17 (43%) without neurological deficit. The high proportion of first-responder AED applications and evaluation of the personnel training indicate a wide acceptance of the emergency plan among the personnel. An immediate resuscitation plan consisting of an integrated programme of early defibrillation is feasible and seems to achieve an improved prognosis for patients who have sustained an in-hospital cardiac arrest.

Routine implantation of cardioverter/defibrillator devices in patients aged 75 years and older with prior myocardial infarction and left ventricular ejection fraction < 30: antagonist viewpoint.

PubMed

Basta, Lofty L

2003-01-01

The Multicenter Automatic Defibrillator Implantation Trial (MADIT II) investigators assert that their results justify the placement of artificial implantable defibrillator cardioverter devices in patients aged 75 years and older with prior myocardial infarction and left ventricular dysfunction (ejection fraction of 30 or less). The authors claim that the results of the trial do not justify this conclusion. The majority of patients were male (84%) and aged 64+/-10 years. Also, 2.8% of patients assigned to the defibrillator group and 1.5% had their device removed. Of the latter subgroup, nine patients (1.3%) received a heart transplant. Twelve had their artificial implantable defibrillator cardioverter device deactivated mostly because of terminal illness. Although the study results show a significant reduction in mortality over the control group (absolute reduction=5.6%), almost the same percentage required hospitalization because of manifestation of congestive heart failure (absolute value 5%; p=0.09). Also, 1.8% had lead problems, 0.7% had infections, and the benefits were only seen after the first year. Caution is needed before the results of this study are applied to a much older cohort comprised mainly of women in whom heart transplant is contraindicated and who have multiple health problems, including cognitive impairment. Artificial implantable cardioverter/defibrillator devices are expensive and this study's results need to be duplicated in other comparable cohorts.

Outcomes of out-of-hospital cardiac arrest by public location in the public-access defibrillation era.

PubMed

Murakami, Yukiko; Iwami, Taku; Kitamura, Tetsuhisa; Nishiyama, Chika; Nishiuchi, Tatsuya; Hayashi, Yasuyuki; Kawamura, Takashi

2014-04-22

The strategy to place public-access automated external defibrillators (AEDs) has not yet been established in real settings. This, prospective, population-based observational study in Osaka, Japan, included consecutive out-of-hospital cardiac arrest (OHCA) patients with resuscitation attempts during 7 years, from January 2005 through December 2011. The trends in the proportion of public-access AED use and 1-month survival with neurologically favorable outcome were evaluated by location. Factors associated with neurologically favorable outcome (defined as cerebral performance category 1 or 2) after ventricular fibrillation were also assessed using multiple logistic regression analysis. A total of 9453 bystander-witnessed OHCAs of cardiac origin were documented and 894 (9.5%) of them occurred at public places. The proportion of public-access AED use significantly increased from 0.0% (0/20) in 2005 to 41.2% (7/17) in 2011 at railway stations and from 0.0% (0/7) to 56.5% (13/23) at sports facilities. Mean time from collapse to shock was 5.0 minutes among those who received shocks with public-access AEDs. The proportion of neurologically favorable outcome was 28.0% (33/118) at railway stations, 51.6% (48/93) at sports facilities, 23.3% (20/86) in public buildings, and 41.9% (13/31) in schools. In multivariate analysis, early defibrillation, irrespective of bystander or emergency medical service (EMS) personnel, was significantly associated with neurologically favorable outcome (adjusted odds ratio for 1-minute increment, 0.89; 95% confidence interval, 0.87 to 0.92). This large, population-based OHCA registry demonstrated that earlier shock, irrespective the shock provider (bystander or EMS personnel), contributed to improving outcome, and a public-access defibrillation program was successfully implemented so that shocks with public-access AEDs were delivered to over 40% of bystander-witnessed OHCAs and time to shock was shortened in some kinds of public places.

Using a Combined Platform of Swarm Intelligence Algorithms and GIS to Provide Land Suitability Maps for Locating Cardiac Rehabilitation Defibrillators

PubMed Central

KAFFASH-CHARANDABI, Neda; SADEGHI-NIARAKI, Abolghasem; PARK, Dong-Kyun

2015-01-01

Background: Cardiac arrest is a condition in which the heart is completely stopped and is not pumping any blood. Although most cardiac arrest cases are reported from homes or hospitals, about 20% occur in public areas. Therefore, these areas need to be investigated in terms of cardiac arrest incidence so that places of high incidence can be identified and cardiac rehabilitation defibrillators installed there. Methods: In order to investigate a study area in Petersburg, Pennsylvania State, and to determine appropriate places for installing defibrillators with 5-year period data, swarm intelligence algorithms were used. Moreover, the location of the defibrillators was determined based on the following five evaluation criteria: land use, altitude of the area, economic conditions, distance from hospitals and approximate areas of reported cases of cardiac arrest for public places that were created in geospatial information system (GIS). Results: The A-P HADEL algorithm results were more precise about 27.36%. The validation results indicated a wider coverage of real values and the verification results confirmed the faster and more exact optimization of the cost function in the PSO method. Conclusion: The study findings emphasize the necessity of applying optimal optimization methods along with GIS and precise selection of criteria in the selection of optimal locations for installing medical facilities because the selected algorithm and criteria dramatically affect the final responses. Meanwhile, providing land suitability maps for installing facilities across hot and risky spots has the potential to save many lives. PMID:26587471

Cost-effectiveness of the implantable cardioverter defibrillator: a review of current evidence.

PubMed

Lynd, Larry D; O'Brien, Bernie J

2003-09-01

Implantable cardioverter defibrillator (ICD) therapy is indicated for patients at risk for sudden cardiac death (SCD) due to ventricular tachycardia (VT) or ventricular fibrillation (VF). The high relative cost of therapy with the ICD versus antiarrhythmic drugs has raised questions regarding its cost-effectiveness. To address these questions, we review the literature on ICD cost-effectiveness. MEDLINE and other databases were searched for articles published since 1980 reporting original data on the cost-effectiveness of ICD versus drug therapy for patients at risk for SCD. Data on costs and life-years were abstracted and studies grouped into decision analysis models and trial-based analyses. Cost-effectiveness ratios were inflated to 2002 US dollars. Thirteen economic studies were included in this review: 6 decision-analytic models, 4 economic analysis alongside randomized controlled trials, and 1 observational study. Two additional studies evaluated the cost-effectiveness of ICDs stratified by mortality risk. Studies varied in time horizon, and in all but one study ICD therapy was more costly than drug therapy. Early models assumed larger survival benefits than were observed in subsequent trials; therefore, ICDs appeared to be more cost-effective (i.e., US dollars 28000-US dollars 60000 per life-year gained). Three large clinical trial-based studies estimated that the cost per life-year gained was between US dollars 30181 and US dollars 185000. Stratified analyses show that patients at higher risk for mortality due to structural heart disease (e.g., left ventricular ejection fraction <35%) benefit more from ICD therapy, resulting in lower cost-effectiveness ratios. ICD therapy continues to evolve with changing methods of implantation and improving technology. Current evidence suggests that ICDs may be a cost-effective option in patients at high risk for VT/VF. The cost-effectiveness of ICD therapy for primary and secondary prevention of SCD depends upon patient characteristics that influence their prior risk of mortality. Further research on patient selection criteria and the measurement of health-related quality of life is required.

AED in Europe. Report on a survey.

PubMed

Bahr, Jan; Bossaert, Leo; Handley, Anthony; Koster, Ruud; Vissers, Bart; Monsieurs, Koen

2010-02-01

Based on the strategies for community defibrillation defined by a joint policy conference of ESC and ERC, we have conducted a survey to identify the current status of AED programmes in Europe. All registered visitors to the website of the ERC were contacted by e-mail and invited to participate in a web-based survey. Of the 983 usable responses, 899 came from 36 European countries, representing a total of 748 million inhabitants. In 11 countries AED use by non-physicians has been implemented partially. All but 3 countries reported that first-tier ambulances are equipped with defibrillators. In 13 countries everybody is allowed to use an AED and in 11 countries anybody who has been trained. In 14 countries there are a few community responder programmes, in 14 countries there are hardly any, and in 7 countries there are none. Thirteen countries have implemented a few on-site responder programmes; in 16 countries there are hardly any such programmes, and in 7 countries none. Programmes for home responders can hardly be found in 19 countries; in-hospital programmes exist in 7 countries nearly everywhere. Only 1 country reported that epidemiologic and/or economic evaluations are carried out nearly everywhere when planning AED programmes. Nationwide registries to collect data from resuscitation attempts have been set up in 4 countries. In 27 countries inventories for AEDs can be found here and there. Much has been achieved concerning the provision and use of AEDs in Europe, but there is still a long way to go. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

Advantage of four-electrode over two-electrode defibrillators

NASA Astrophysics Data System (ADS)

Bragard, J.; Šimić, A.; Laroze, D.; Elorza, J.

2015-12-01

Defibrillation is the standard clinical treatment used to stop ventricular fibrillation. An electrical device delivers a controlled amount of electrical energy via a pair of electrodes in order to reestablish a normal heart rate. We propose a technique that is a combination of biphasic shocks applied with a four-electrode system rather than the standard two-electrode system. We use a numerical model of a one-dimensional ring of cardiac tissue in order to test and evaluate the benefit of this technique. We compare three different shock protocols, namely a monophasic and two types of biphasic shocks. The results obtained by using a four-electrode system are compared quantitatively with those obtained with the standard two-electrode system. We find that a huge reduction in defibrillation threshold is achieved with the four-electrode system. For the most efficient protocol (asymmetric biphasic), we obtain a reduction in excess of 80% in the energy required for a defibrillation success rate of 90%. The mechanisms of successful defibrillation are also analyzed. This reveals that the advantage of asymmetric biphasic shocks with four electrodes lies in the duration of the cathodal and anodal phase of the shock.

Effectiveness of wearable defibrillators: systematic review and quality of evidence.

PubMed

Uyei, Jennifer; Braithwaite, R Scott

2014-04-01

The objectives of this systematic literature review were to identify all published literature on wearable defibrillators, assess the wearable defibrillator's efficacy and effectiveness in general and among specific patient groups, including post-myocardial infarction, post coronary artery bypass grafting or percutaneous coronary intervention, non-ischemic cardiomyopathy, and ischemic cardiomyopathy, and to evaluate the quality of evidence. The search and synthesis was informed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, and the quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation and the Newcastle Ottawa Scale. A total of thirty-six articles and conference abstracts from thirty-three studies were included in the review. It appears that wearable defibrillator use compared with no defibrillator use reduces the chance of ventricular tachycardia and ventricular fibrillation (VT/VF) associated deaths by an absolute risk reduction of approximately 1 percent, achieved by averting approximately 4/5th of all VT/VF associated deaths. The quality of evidence was low to very low quality, such that our confidence in the reported estimates is weak. To validate beneficial results, further investigation using robust study designs conducted by independent researchers is warranted.

Inadvertent transposition of defibrillator coil terminal pins causing inappropriate ICD therapies.

PubMed

Issa, Ziad F

2008-06-01

We report the case of a 65-year-old man with chronic atrial fibrillation (AF) and severe ischemic cardiomyopathy who underwent implantation of a prophylactic single-chamber implantable cardioverter-defibrillator (ICD). The patient experienced inappropriate ICD therapies due to oversensing of pectoral muscle myopotential secondary to reversal of the defibrillator coil terminal pins in the ICD header. Recognizing this possibility is important to avoid misinterpretation of spontaneous oversensing as hardware failure (e.g., lead fracture or insulation breech) and potentially unnecessary ICD system surgical intervention, including lead extraction.

Position of Subcutaneous Implantable Cardioverter-Defibrillators and Possible Interference on Myocardial Perfusion Imaging.

PubMed

Kahaly, Omar Ray; Shafiei, Fereidoon; Hardebeck, Charles; Houmsse, Mahmoud

2017-06-01

Implanted cardioverter-defibrillators can prevent sudden cardiac death in at-risk patients. In comparison with conventional transvenous systems, entirely subcutaneous implantable cardioverter-defibrillators have produced similar reductions in the rate of sudden cardiac death but with fewer sequelae. An infrequently reported drawback of subcutaneous devices, however, is the potential for generating attenuation artifact during nuclear myocardial perfusion imaging. We had concerns about potential attenuation artifact in a 65-year-old man with coronary artery disease but found that having positioned the pulse generator in the midaxillary zone avoided problems.

Could implantable cardioverter defibrillators provide a human model supporting the learned helplessness theory of depression?

PubMed

Goodman, M; Hess, B

1999-01-01

Affective symptoms were examined retrospectively in 25 patients following placement of implantable cardioverter defibrillators (ICD) which can produce intermittent shocks without warning in response to cardiac ventricular arrhythmias. The number of ICD random, uncontrollable discharge shocks and pre-ICD history of psychological distress (i.e., depression and/or anxiety) were documented in all patients using a demographics questionnaire and a standardized behavioral/psychological symptoms questionnaire (i.e., Symptom Checklist-90 Revised). ICD patients were dichotomized into two groups: those without a history of psychological distress prior to ICD (n = 18) and those with a history of psychological distress prior to ICD (n = 7). In ICD patients without a prior history, results indicated that quantity of ICD discharge shocks was significantly predictive of current reported depression (r = 0.45, p = 0.03) and current reported anxiety (r = 0.51, p = 0.02). Conversely, in patients with a reported history of psychological distress, there was no significant relationship found between quantity of discharge shocks and current reported depression or anxiety. This study may provide evidence in support of a human model of learned helplessness in that it supports the notion that exposure to an unavoidable and inescapable aversive stimulus was found to be related to patients' reported depression. Further studies may wish to prospectively consider a larger sample as well as a more comprehensive assessment of premorbid psychological symptoms.

Use of Automated External Defibrillators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gregory K Christensen

In an effort to improve survival from cardiac arrest, the American Heart Association (AHA) has promoted the Chain of Survival concept, describing a sequence of prehospital steps that result in improved survival after sudden cardiac arrest. These interventions include immediate deployment of emergency medical services, prompt cardiopulmonary resuscitation, early defibrillation when indicated, and early initiation of advanced medical care. Early defibrillation has emerged as the most important intervention with survival decreasing by 10% with each minute of delay in defibrillation. Ventricular Fibrillation (VF) is a condition in which there is uncoordinated contraction of the heart cardiac muscle of the ventriclesmore » in the heart, making them tremble rather than contract properly. VF is a medical emergency and if the arrhythmia continues for more than a few seconds, blood circulation will cease, and death can occur in a matter of minutes. During VF, contractions of the heart are not synchronized, blood flow ceases, organs begin to fail from oxygen deprivation and within 10 minutes, death will occur. When VF occurs, the victim must be defibrillated in order to establish the heart’s normal rhythm. On average, the wait for an ambulance in populated areas of the United States is about 11 minutes. In view of these facts, the EFCOG Electrical Safety Task Group initiated this review to evaluate the potential value of deployment and use of automated external defibrillators (AEDs) for treatment of SCA victims. This evaluation indicates the long term survival benefit to victims of SCA is high if treated with CPR plus defibrillation within the first 3-5 minutes after collapse. According to the American Heart Association (AHA), survival rates as high as 74% are possible if treatment and defibrillation is performed in the first 3 minutes. In contrast survival rates are only 5% where no AED programs have been established to provide prompt CPR and defibrillation. ["CPR statistics" American Heart Association] Early intervention with both CPR and defibrillation can result in high long-term survival rates for SCA, as demonstrated by a study investigating the beneficial effects of AED devices at Chicago’s O’Hare and Midway airports. The American Medical Association (AMA) advocates the widespread placement of AEDs [AMA Res. 413, A-02; Res. 424, A-04]; supports increasing government and industry funding for the purchase of AED devices; and encourages the American public to become trained in CPR and the use of AEDs. Some states, including Maryland, have enacted legislation requiring AED devices and a certified responder be available at high school and school-sponsored athletic events due the risk of SCA to athletes (the most common cause of death in young athletes). Ensuring AED availability at Department of Energy (DOE) sites would serve as a means of preventative intervention for over 14,000 DOE employees and 193,000 contract workers. It is estimated 1 per 1,000 adults 35 years of age and older will experience SCA in a given year.« less

Evaluation of a novel ventricular support device with defibrillation capabilities in canine and porcine animal models.

PubMed

Killingsworth, Cheryl R; Rippy, Marian K; Virmani, Renu; Rollins, Dennis L; McGiffin, David C; Ideker, Raymond E

2008-08-01

Sudden death is prevalent in heart failure patients. We tested an implantable ventricular support device consisting of a wireform harness with one or two pairs of integrated defibrillation electrode coils. The device was implanted into six pigs (36-44 kg) through a subxiphoid incision. Peak voltage (V) defibrillation thresholds (DFT) were determined for five test configurations compared with a control transvenous lead (RV to CanPect). Defibrillator can location (abdominal or pectoral) and common coil separation on the implant (0 degrees or 60 degrees ) were studied.(.) The DFT for RV60 to LV60 + CanPect was significantly less than control (348 +/- 57 vs 473 +/- 27 V, P < 0.05). The DFTs for other vectors were similar to control except for RV0 to LV0 + CanAbd (608 +/- 159 V). The device was implanted into 12 adult dogs for 42, 90, or 180 days with DFT and pathological examination performed at the terminal study. Cardiac pressures were determined at baseline, after implantation, and at the terminal study. The DFT was also determined in a separate group of four dogs at 42 days following implantation of the support device with one pair of defibrillation electrodes. The DFTs at implant and explant in dogs with one pair (8 +/- 1.5 Joules [J] and 6 +/- 1.9 J) or two pairs (8 +/- 3.4 J and 7 +/- 1.9 J) of defibrillation electrodes were not significantly different from each other but significantly less than control measured at the terminal study (18 +/- 3.4 J). Left-sided pressures were significantly decreased at explant but within expected normal ranges. Right-sided pressures were not different except for RV systolic. Histopathology indicated mild to moderate epicardial inflammation and fibrosis, consistent with a foreign body healing response. This defibrillation-enabled ventricular support system maintained mechanical functionality for up to 6 months while inducing typical chronic healing responses. The DFT was equal to or lower than a standard transvenous vector.

Inverse Relationship of Blood Pressure to Long-Term Outcomes and Benefit of Cardiac Resynchronization Therapy in Patients With Mild Heart Failure: A Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy Long-Term Follow-Up Substudy.

PubMed

Biton, Yitschak; Moss, Arthur J; Kutyifa, Valentina; Mathias, Andrew; Sherazi, Saadia; Zareba, Wojciech; McNitt, Scott; Polonsky, Bronislava; Barsheshet, Alon; Brown, Mary W; Goldenberg, Ilan

2015-09-01

Previous studies have shown that low blood pressure is associated with increased mortality and heart failure (HF) in patients with left ventricular dysfunction. Cardiac resynchronization therapy (CRT) was shown to increase systolic blood pressure (SBP). Therefore, we hypothesized that treatment with CRT would provide incremental benefit in patients with lower SBP values. The independent contribution of SBP to outcome was analyzed in 1267 patients with left bundle brunch block enrolled in Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT). SBP was assessed as continuous measures and further categorized into approximate quintiles. The risk of long-term HF or death and CRT with defibrillator versus implantable cardioverter defibrillator benefit was assessed in multivariate Cox proportional hazards regression models. Multivariate analysis showed that in the implantable cardioverter defibrillator arm, each 10-mm Hg decrement of SBP was independently associated with a significant 21% (P<0.001) increased risk for HF or death, and patients with lower quintile SBP (<110 mm Hg) experienced a corresponding >2-fold risk-increase. CRT with defibrillator provided the greatest HF or mortality risk reduction in patients with SBP<110 mm Hg hazard ratio of 0.34, P<0.001, when compared with hazard ratio of 0.52, P<0.001, in those with 110>SBP≥136 mm Hg and hazard ratio of 0.94, P=0.808, with SBP>136 mm Hg (P for trend=0.001). In patients with mild HF, prolonged QRS, and left bundle brunch block, low SBP is related to higher risk of mortality or HF with implantable cardioverter defibrillator therapy alone. Treatment with CRT is associated with incremental clinical benefits in patients with lower baseline SBP values. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180271. © 2015 American Heart Association, Inc.

Minimizing pre- and post-defibrillation pauses increases the likelihood of return of spontaneous circulation (ROSC).

PubMed

Sell, Rebecca E; Sarno, Renee; Lawrence, Brenna; Castillo, Edward M; Fisher, Roger; Brainard, Criss; Dunford, James V; Davis, Daniel P

2010-07-01

The three-phase model of ventricular fibrillation (VF) arrest suggests a period of compressions to "prime" the heart prior to defibrillation attempts. In addition, post-shock compressions may increase the likelihood of return of spontaneous circulation (ROSC). The optimal intervals for shock delivery following cessation of compressions (pre-shock interval) and resumption of compressions following a shock (post-shock interval) remain unclear. To define optimal pre- and post-defibrillation compression pauses for out-of-hospital cardiac arrest (OOHCA). All patients suffering OOHCA from VF were identified over a 1-month period. Defibrillator data were abstracted and analyzed using the combination of ECG, impedance, and audio recording. Receiver-operator curve (ROC) analysis was used to define the optimal pre- and post-shock compression intervals. Multiple logistic regression analysis was used to quantify the relationship between these intervals and ROSC. Covariates included cumulative number of defibrillation attempts, intubation status, and administration of epinephrine in the immediate pre-shock compression cycle. Cluster adjustment was performed due to the possibility of multiple defibrillation attempts for each patient. A total of 36 patients with 96 defibrillation attempts were included. The ROC analysis identified an optimal pre-shock interval of <3s and an optimal post-shock interval of <6s. Increased likelihood of ROSC was observed with a pre-shock interval <3s (adjusted OR 6.7, 95% CI 2.0-22.3, p=0.002) and a post-shock interval of <6s (adjusted OR 10.7, 95% CI 2.8-41.4, p=0.001). Likelihood of ROSC was substantially increased with the optimization of both pre- and post-shock intervals (adjusted OR 13.1, 95% CI 3.4-49.9, p<0.001). Decreasing pre- and post-shock compression intervals increases the likelihood of ROSC in OOHCA from VF.

77 FR 74630 - Medical Waivers for Merchant Mariner Credential Applicants With Anti-Tachycardia Devices or...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-17

... Cardioverter Defibrillators AGENCY: Coast Guard, DHS. ACTION: Notice to reopen public comment period. SUMMARY... implantable cardioverter defibrillators (ICDs). The public comment period for the notice expired on October 9...

Electrical storm and calcium signaling: a review.

PubMed

Tsuji, Yukiomi

2011-01-01

Electrical storm (ES), characterized by recurrent ventricular tachycardia/fibrillation, is a serious condition, adversely affecting prognosis in patients with implantable cardioverter/defibrillators. Electrical storm patients often die of progressive heart failure, but the underlying molecular basis is poorly understood. We have recently created an animal model of ES that features repetitive implantable cardioverter/defibrillator firing for recurrent ventricular fibrillation and found that ES events cause striking activation of Ca(2+)/calmodulin-dependent protein kinase II and prominent alteration of Ca(2+)-handling protein phosphorylation, possibly explaining mechanical dysfunction and arrhythmia promotion that characterize ES. Here, the pathophysiology and potential therapeutic strategies for ES, based on experimental and clinical studies by us and others, are described. Copyright © 2011 Elsevier Inc. All rights reserved.

Defibrillation of the Heart With Low Tension Currents in Experimental Conditions.

DTIC Science & Technology

1960-05-04

the coronary vessels. It became clear with the accumulation of subsequent ob- servations that chemical preparations in themselves are not im...the recommended chemopharmaceutical means against difibrillation were directed towards a decrease of the excitability Of the hearti numerous...Intracardiac Conductivity. "Klin. Med." (Clinical Medicine), No 3, 1956. Litman, N., Surgical Treatment of Heart Diseases . Works of the 26th Congress of

Canadian Registry of ICD Implant Testing procedures (CREDIT): current practice, risks, and costs of intraoperative defibrillation testing.

PubMed

Healey, Jeff S; Dorian, Paul; Mitchell, L Brent; Talajic, Mario; Philippon, Francois; Simpson, Chris; Yee, Raymond; Morillo, Carlos A; Lamy, Andre; Basta, Magdy; Birnie, David H; Wang, Xiaoyin; Nair, Girish M; Crystal, Eugene; Kerr, Charles R; Connolly, Stuart J

2010-02-01

There is uncertainty about the proper role of defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion. A prospective registry was conducted at 13 sites in Canada between January 2006 and October 2007. To document the details of DT, the reasons for not conducting DT, and the costs and complications associated with DT. DT was conducted at implantation in 230 of 361 patients (64%). DT was more likely to be conducted for new implants compared with impulse generator replacements (71% vs 32%, P = 0.0001), but was similar for primary and secondary prevention indications (64% vs 63%, P = NS). Among patients not having DT, the reason(s) given were: considered unnecessary (44%); considered unsafe, mainly due to persistent atrial fibrillation (37%); lack of an anesthetist (20%); and, patient or physician preference (6%). When performed, DT consisted of a single successful shock > or = 10J below maximum device output in 65% of cases. A 10J safety-margin was met by 97% of patients, requiring system modification in 2.3%. Major perioperative complications occurred in 4.4% of patients having DT versus 6.6% of patients not having DT (P = NS). ICD insertion was $844 more expensive for patients having DT (P = 0.16), largely due to increased costs ($28,017 vs $24,545) among patients having impulse generator replacement (P = 0.02). DT was not performed in a third of ICD implants, usually due to a perceived lack of need or relative contraindication.

Implantable intravascular defibrillator: defibrillation thresholds of an intravascular cardioverter-defibrillator compared with those of a conventional ICD in humans.

PubMed

Neuzil, Petr; Reddy, Vivek Y; Merkely, Bela; Geller, Laszlo; Molnar, Levente; Bednarek, Jacek; Bartus, Krzysztof; Richey, Mark; Bsee, T J Ransbury; Sanders, William E

2014-02-01

A percutaneous intravascular cardioverter-defibrillator (PICD) has been developed with a right ventricular (RV) single-coil lead and titanium electrodes in the superior vena cava (SVC)-brachiocephalic vein (BCV) region and the inferior vena cava (IVC). To compare defibrillation thresholds (DFTs) of the PICD with those of a conventional ICD in humans. Ten patients with ischemic cardiomyopathy and ejection fraction ≤35% were randomized to initial testing with either PICD or conventional ICD. A standard dual-coil lead was positioned in the RV apex. If randomized to PICD, the device was placed into the vasculature such that 1 titanium electrode was positioned in the SVC-BCV region and the second in the IVC. For PICD DFTs, the RV coil of the conventional ICD lead was connected to the PICD mandrel [shock vector: RV (+) to SVC-BCV (-) + IVC (-)]. When testing the conventional ICD, a subcutaneous pocket was formed in the left pectoralis region and the ICD was connected to the lead system and positioned in the pocket [shock vector: RV (+) to SVC (-) + active can (-)]. Each device was removed before testing with the other. A step-down binary search protocol determined the DFT, with the initial shock being 9 J. The mean PICD DFT was 7.6 ± 3.3 J, and the conventional ICD system demonstrated a mean DFT of 9.5 ± 4.7 J (N = 10; paired t test, P = .28). The intravascular defibrillator has DFTs similar to those of commercially available ICDs. Published by Heart Rhythm Society on behalf of Heart Rhythm Society.

The rationale and design of the Shockless IMPLant Evaluation (SIMPLE) trial: a randomized, controlled trial of defibrillation testing at the time of defibrillator implantation.

PubMed

Healey, Jeff S; Hohnloser, Stefan H; Glikson, Michael; Neuzner, Joerg; Viñolas, Xavier; Mabo, Philippe; Kautzner, Josef; O'Hara, Gilles; Van Erven, Liselot; Gadler, Frederick; Appl, Ursula; Connolly, Stuart J

2012-08-01

Defibrillation testing (DT) has been an integral part of defibrillator (implantable cardioverter defibrillator [ICD]) implantation; however, there is little evidence that it improves outcomes. Surveys show a trend toward ICD implantation without DT, which now exceeds 30% to 60% in some regions. Because there is no evidence to support dramatic shift in practice, a randomized trial is urgently needed. The SIMPLE trial will determine if ICD implantation without any DT is noninferior to implantation with DT. Patients will be eligible if they are receiving their first ICD using a Boston Scientific device (Boston Scientific, Natick, MA). Patients will be randomized to DT or no DT at the time of ICD implantation. In the DT arm, physicians will make all reasonable efforts to ensure 1 successful intraoperative defibrillation at 17 J or 2 at 21 J. The first clinical shock in all tachycardia zones will be set to 31 J for all patients. The primary outcome of SIMPLE will be the composite of ineffective appropriate shock or arrhythmic death. The safety outcome of SIMPLE will include a composite of potentially DT-related procedural complications within 30 days of ICD implantation. Several secondary outcomes will be evaluated, including all-cause mortality and heart failure hospitalization. Enrollment of 2,500 patients with 3.5-year mean follow-up will provide sufficient statistical power to demonstrate noninferiority. The study is being performed at approximately 90 centers in Canada, Europe, Israel, and Asia Pacific with final results expected in 2013. Copyright © 2012 Mosby, Inc. All rights reserved.

iPad2(R) use in patients with implantable cardioverter defibrillators causes electromagnetic interference: the EMIT Study.

PubMed

Kozik, Teri M; Chien, Gianna; Connolly, Therese F; Grewal, Gurinder S; Liang, David; Chien, Walter

2014-04-10

Over 140 million iPads(®) have been sold worldwide. The iPad2(®), with magnets embedded in its frame and Smart Cover and 3G cellular data capability, can potentially cause electromagnetic interference in implantable cardioverter defibrillators. This can lead to potentially life-threatening situations in patients. The goal of this study was to determine whether the iPad2(®) can cause electromagnetic interference in patients with implantable cardioverter defibrillators. Twenty-seven patients with implantable cardioverter defibrillators were studied. The iPad2(®) was held at reading distance and placed directly over the device with cellular data capability activated and deactivated. The manufacturers/models of devices and the patients' body mass index were noted. The presence of electromagnetic interference was detected by using a programmer supplied by each manufacturer. Magnet mode with suspension of anti-tachycardia therapy was triggered in 9 (33%) patients. All occurred when the iPad2(®) was placed directly over the device. The cellular data status did not cause interference and no noise or oversensing was noted. There was no significant difference between the mean body mass index of the groups with or without interference. The iPad2(®) can trigger magnet mode in implantable cardioverter defibrillators when laid directly over the device. This is potentially dangerous if patients should develop life-threatening arrhythmias at the same time. As new electronic products that use magnets are produced, the potential risk to patients with implantable defibrillators needs to be addressed.

Prehospital cardiac arrest survival and neurologic recovery.

PubMed

Hillis, M; Sinclair, D; Butler, G; Cain, E

1993-01-01

Many studies of prehospital defibrillation have been conducted but the effects of airway intervention are unknown and neurologic follow-up has been incomplete. A non-randomized cohort prospective study was conducted to determine the effectiveness of defibrillation in prehospital cardiac arrest. Two ambulance companies in the study area developed a defibrillation protocol and they formed the experimental group. A subgroup of these patients received airway management with an esophageal obturator airway (EOA) or endotracheal intubation (ETT). The control group was composed of patients who suffered a prehospital cardiac arrest and did not receive prehospital defibrillation. All survivors were assessed for residual deficits using the Sickness Impact Profile (SIP) and the Dementia Rating Scale (DRS). A total of 221 patients were studied over a 32-month period. Both the experimental group (N = 161) and the control group (N = 60) were comparable with respect to age, sex distribution, and ambulance response time. Survival to hospital discharge was 2/60 (3.3%) in the control group and 12/161 (6.3%) in the experimental group. This difference is not statistically significant. Survival in the experimental group by airway management technique was basic airway support (3/76 3.9%), EOA (3/67 4.5%), and ETT (6/48 12.5%). The improved effect on survival by ETT management was statistically significant. Survivors had minor differences in memory, work, and recreation as compared to ischemic heart disease patients as measured by the SIP and DRS. No effect of defibrillation was found on survival to hospital discharge. However, endotracheal intubation improved survival in defibrillated patients. Survivors had a good functional outcome.

Single-Coil Defibrillator Leads Yield Satisfactory Defibrillation Safety Margin in Hypertrophic Cardiomyopathy.

PubMed

Okamura, Hideo; Friedman, Paul A; Inoue, Yuko; Noda, Takashi; Aiba, Takeshi; Yasuda, Satoshi; Ogawa, Hisao; Kamakura, Shiro; Kusano, Kengo; Espinosa, Raul E

2016-09-23

Single-coil defibrillator leads have gained favor because of their potential ease of extraction. However, a high defibrillation threshold remains a concern in patients with hypertrophic cardiomyopathy (HCM), and in many cases, dual-coil leads have been used for this patient group. There is little data on using single-coil leads for HCM patients. We evaluated 20 patients with HCM who received an implantable cardioverter-defibrillator (ICD) on the left side in combination with a dual-coil lead. Two sets of defibrillation tests were performed in each patient, one with the superior vena cava (SVC) coil "on" and one with the SVC coil "off". ICDs were programmed to deliver 25 joules (J) for the first attempt followed by maximum energy (35 J or 40 J). Shock impedance and shock pulse width at 25 J in each setting as well as the results of the shock were analyzed. All 25-J shocks in both settings successfully terminated ventricular fibrillation. However, shock impedance and pulse width increased substantially with the SVC coil programmed "off" compared with "on" (66.4±6.1 ohm and 14.0±1.3 ms "off" vs. 41.9±5.0 ohm and 9.3±0.8 ms "on", P<0.0001 respectively). Biphasic 25-J shocks with the SVC coil 'off' successfully terminated ventricular fibrillation in HCM patients, indicating a satisfactory safety margin for 35-J devices. Single-coil leads appear appropriate for left-sided implantation in this patient group. (Circ J 2016; 80: 2199-2203).

77 FR 16038 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-19

... vote on information related to the PMA for the Subcutaneous Implantable Cardioverter Defibrillator (S-ICD) System sponsored by Cameron Health, Inc. The S-ICD is the first implantable defibrillator that...

A rare, late complication after automated implantable cardioverter-defibrillator placement.

PubMed

Shapiro, Michael; Hanon, Sam; Schweitzer, Paul

2004-10-01

This article describes an interesting case of automated implantable cardioverter defibrillator (AICD) extrusion fifteen months after implantation. The case report is followed by a discussion of the causes and treatment of skin erosion following pacemaker/AICD insertion.

Rapid on-site defibrillation versus community program.

PubMed

Fedoruk, J C; Paterson, D; Hlynka, M; Fung, K Y; Gobet, Michael; Currie, Wayne

2002-01-01

For patients who suffer out-of-hospital cardiac arrest, the time from collapse to initial defibrillation is the single most important factor that affects survival to hospital discharge. The purpose of this study was to compare the survival rates of cardiac arrest victims within an institution that has a rapid defibrillation program with those of its own urban community, tiered EMS system. A logistic regression analysis of a retrospective data series (n = 23) and comparative analysis to a second retrospective data series (n = 724) were gathered for the study period September 1994 to September 1999. The first data series included all persons at Casino Windsor who suffered a cardiac arrest. Data collected included: age, gender, death/survival (neurologically intact discharge), presenting rhythm (ventricular fibrillation (VF), ventricular tachycardia (VT), or other), time of collapse, time to arrival of security personnel, time to initiation of cardiopulmonary resuscitation (CPR) prior to defibrillation (when applicable), time to arrival of staff nurse, time to initial defibrillation, and time to return of spontaneous circulation (if any). Significantly, all arrests within this series were witnessed by the surveillance camera systems, allowing time of collapse to be accurately determined rather than estimated. These data were compared to those of similar events, times, and intervals for all patients in the greater Windsor area who suffered cardiac arrest. This second series was based upon the Ontario Prehospital Advanced Life Support (OPALS) Study database, as coordinated by the Clinical Epidemiology Unit of the Ottawa Hospital, University of Ottawa. The Casino Windsor had 23 cases of cardiac arrests. Of the cases, 13 (56.5%) were male and 10 (43.5%) were female. All cases (100%) were witnessed. The average of the ages was 61.1 years, of the time to initial defibrillation was 7.7 minutes, and of the time for EMS to reach the patient was 13.3 minutes. The presenting rhythm was VF/VT in 91% of the case. Fifteen patients were discharged alive from hospital for a 65% survival rate. The Greater Windsor Study area included 668 cases of out-of-hospital cardiac arrest: Of these, 410 (61.4%) were male and 258 (38.6%) were female, 365 (54.6%) were witnessed, and 303 (45.4%) were not witnessed. The initial rhythm was VF/VT was in 34.3%. Thirty-seven (5.5%) were discharged alive from the hospital. This study provides further evidence that PAD Programs may enhance cardiac arrest survival rates and should be considered for any venue with large numbers of adults as well as areas with difficult medical access.

Performing magnetic resonance imaging in patients with implantable pacemakers and defibrillators: results of a European Heart Rhythm Association survey.

PubMed

Marinskis, Germanas; Bongiorni, Maria Grazia; Dagres, Nikolaos; Dobreanu, Dan; Lewalter, Thorsten; Blomström-Lundqvist, Carina

2012-12-01

The purpose of our survey was to evaluate the experience, current practice and attitudes of performing magnetic resonance imaging (MRI) studies in patients with cardiac implantable electronic devices. Fifty-one centre-members of European Heart Rhythm Association Research network have responded to the survey. According to the obtained data, 55.2% of responding centres do not perform MRI scans in patients with non-MRI-certified pacemakers and 65.8% in patients with such implantable cardioverter defibrillators (ICDs). Reported complication rate in patients with non-MRI-certified devices is low and conforms to the literature data. Experience with newer MRI-compatible pacemakers and ICDs is limited to single cases in most centres. This survey shows limited experience with performing MRI studies in patients with implanted pacemakers and ICDs. In concordance with available guidelines, most centres limit MRI scans in patients with non-MRI-certified devices. The implant numbers for MRI-certified devices and experience with performing MRI scans in these patients are still low.

Inappropriate implantable cardioverter defibrillator shocks in fractured Sprint Fidelis leads associated with 'appropriate' interrogation.

PubMed

Farwell, David; Redpath, Calum; Birnie, David; Gollob, Michael; Lemery, Robert; Posan, Emoke; Green, Martin

2008-06-01

We present two patients with fractures within the pace-sense circuit of their Medtronic Sprint Fidelis leads who received inappropriate shocks from their Medtronic defibrillators during device interrogation. This was not simply a coincidence, but due to electromagnetic interference induced within the Sprint Fidelis lead by the device programmer during two-way communication with the defibrillator. Our subsequent investigations have uncovered at least two other similar incidents in Canada. We have also discovered that the Medtronic 'Auto-resume' feature may leave future patients uniquely vulnerable to such inappropriate shocks in the future.

The Girona Territori Cardioprotegit Project: Performance Evaluation of Public Defibrillators.

PubMed

Loma-Osorio, Pablo; Nuñez, Maria; Aboal, Jaime; Bosch, Daniel; Batlle, Pau; Ruiz de Morales, Ester; Ramos, Rafael; Brugada, Josep; Onaga, Hisao; Morales, Alex; Olivet, Josep; Brugada, Ramon

2018-02-01

In recent years, public access defibrillation programs have exponentially increased the availability of automatic external defibrillators (AED) in public spaces but there are no data on their performance in our setting. We conducted a descriptive analysis of the performance of AED since the launch of a public defibrillation program in our region. A retrospective analysis was conducted of electrocardiographic tracings and the performance of AED in a public defibrillation program from June 2011 to June 2015 in the province of Girona, Spain. There were 231 AED activations. Full information was available on 188 activations, of which 82% corresponded to mobile devices and 18% to permanent devices. Asystole was the most prevalent rhythm (42%), while ventricular fibrillation accounted for 23%. The specificity of the device in identifying a shockable rhythm was 100%, but there were 8 false negatives (sensitivity 83%). There were 47 shockable rhythms, with a spontaneous circulation recovery rate of 49% (23 cases). There were no accidents related to the use of the device. Nearly half of the recorded rhythms were asystole. The AED analyzed showed excellent safety and specificity, with moderate sensitivity. Half the patients with a shockable rhythm were successfully treated by the AED. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Vernakalant selectively prolongs atrial refractoriness with no effect on ventricular refractoriness or defibrillation threshold in pigs.

PubMed

Bechard, Jeff; Gibson, John Ken; Killingsworth, Cheryl R; Wheeler, Jeffery J; Schneidkraut, Marlowe J; Huang, Jian; Ideker, Raymond E; McAfee, Donald A

2011-03-01

Vernakalant is a novel antiarrhythmic agent that has demonstrated clinical efficacy for the treatment of atrial fibrillation. Vernakalant blocks, to various degrees, cardiac sodium and potassium channels with a pattern that suggests atrial selectivity. We hypothesized, therefore, that vernakalant would affect atrial more than ventricular effective refractory period (ERP) and have little or no effect on ventricular defibrillation threshold (DFT). Atrial and ventricular ERP and ventricular DFT were determined before and after treatment with vernakalant or vehicle in 23 anesthetized male mixed-breed pigs. Vernakalant was infused at a rate designed to achieve stable plasma levels similar to those in human clinical trials. Atrial and ventricular ERP were determined by endocardial extrastimuli delivered to the right atria or right ventricle. Defibrillation was achieved using external biphasic shocks delivered through adhesive defibrillation patches placed on the thorax after 10 seconds of electrically induced ventricular fibrillation. The DFT was estimated using the Dixon "up-and-down" method. Vernakalant significantly increased atrial ERP compared with vehicle controls (34 ± 8 versus 9 ± 7 msec, respectively) without significantly affecting ventricular ERP or DFT. This is consistent with atrial selective actions and supports the conclusion that vernakalant does not alter the efficacy of electrical defibrillation.

Perceived support from healthcare professionals, shock anxiety and post-traumatic stress in implantable cardioverter defibrillator recipients.

PubMed

Morken, Ingvild M; Bru, Edvin; Norekvål, Tone M; Larsen, Alf I; Idsoe, Thormod; Karlsen, Bjørg

2014-02-01

To investigate (1) the extent to which shock anxiety and perceived support from healthcare professionals are related to post-traumatic stress disease (PTSD) symptoms and (2) the extent to which perceived support from healthcare professionals moderates the relationship between shock anxiety and PTSD symptoms in implantable cardioverter defibrillator recipients. An additional aim was to describe the level of PTSD symptoms and perceptions of support from healthcare professionals. Studies examining PTSD symptoms among implantable cardioverter defibrillator recipients are still sparse. In addition, little is known about how perceived support from healthcare professionals is related to PTSD symptoms. Cross-sectional survey design. Recipients (n = 167) with implantable cardioverter defibrillator attending an outpatient device clinic completed questionnaires assessing shock anxiety, PTSD symptoms and perceived support from healthcare professionals. The results indicated that between ten and 15% of the recipients experienced moderate to severe symptoms of PTSD. Although a majority perceived constructive support from healthcare professionals, 12% perceived nonconstructive support. Regression analysis demonstrated that shock anxiety and perceived nonconstructive support from healthcare professionals had a statistically significant (p < 0·01) association with PTSD symptoms. Moreover, the results suggest that associations between shock anxiety and PTSD symptoms were significantly (p < 0·01) moderated by perceived nonconstructive support from healthcare professionals. Young age, short time since implantation and secondary prevention indication were also significantly associated with PTSD symptoms. The results indicate that nonconstructive support from healthcare professionals can increase the tendency to develop PTSD symptoms, particularly in those who experience shock anxiety. Healthcare professionals should pay more attention to the way in which they communicate information to the recipients during follow-up visits. Clinically based strategies and interventions targeting shock anxiety and PTSD symptoms should be carried out. © 2013 John Wiley & Sons Ltd.

Heart rate turbulence predicts ICD-resistant mortality in ischaemic heart disease.

PubMed

Marynissen, Thomas; Floré, Vincent; Heidbuchel, Hein; Nuyens, Dieter; Ector, Joris; Willems, Rik

2014-07-01

In high-risk patients, implantable cardioverter-defibrillators (ICDs) can convert the mode of death from arrhythmic to pump failure death. Therefore, we introduced the concept of 'ICD-resistant mortality' (IRM), defined as death (a) without previous appropriate ICD intervention (AI), (b) within 1 month after the first AI, or (c) within 1 year after the initial ICD implantation. Implantable cardioverter-defibrillator implantation in patients with a high risk of IRM should be avoided. Implantable cardioverter-defibrillator patients with ischaemic heart disease were included if a digitized 24 h Holter was available pre-implantation. Demographic, electrocardiographic, echocardiographic, and 24 h Holter risk factors were collected at device implantation. The primary endpoint was IRM. Cox regression analyses were used to test the association between predictors and outcome. We included 130 patients, with a mean left ventricular ejection fraction (LVEF) of 33.6 ± 10.3%. During a follow-up of 52 ± 31 months, 33 patients died. There were 21 cases of IRM. Heart rate turbulence (HRT) was the only Holter parameter associated with IRM and total mortality. A higher New York Heart Association (NYHA) class and a lower body mass index were the strongest predictors of IRM. Left ventricular ejection fraction predicted IRM on univariate analysis, and was the strongest predictor of total mortality. The only parameter that predicted AI was non-sustained ventricular tachycardia. Implantable cardioverter-defibrillator implantation based on NYHA class and LVEF leads to selection of patients with a higher risk of IRM and death. Heart rate turbulence may have added value for the identification of poor candidates for ICD therapy. Available Holter parameters seem limited in their ability to predict AI. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2013. For permissions please email: journals.permissions@oup.com.

Resuscitation quality assurance for out-of-hospital cardiac arrest--setting-up an ambulance defibrillator telemetry network.

PubMed

Lyon, R M; Clarke, S; Gowens, P; Egan, G; Clegg, G R

2010-12-01

Out-of-hospital cardiac arrest (OHCA) is a leading cause of pre-hospital mortality. Chest compressions performed during cardiopulmonary resuscitation aim to provide adequate perfusion to the vital organs during cardiac arrest. Poor resuscitation technique and the quality of pre-hospital CPR influences outcome from OHCA. Transthoracic impedance (TTI) measurement is a useful tool in the assessment of the quality of pre-hospital resuscitation by ambulance crews but TTI telemetry has not yet been performed in the United Kingdom. We describe a pilot study to implement a data network to collect defibrillator TTI data via telemetry from ambulances. Prospective, observational pilot study over a 5-month period. Modems were fitted to 40 defibrillators on ambulances based in Edinburgh. TTI data was sent to a receiving computer after resuscitation attempts for OHCA. 58 TTI traces were transmitted during the pilot period. Compliance with the telemetry system was high. The mean ratio of chest compressions was 73% (95% CI 69-77%), the mean chest compression rate was 128 (95% CI 122-134). The mean time interval from chest compression interruption to shock delivery was 27 s (95% CI 22-32 s). Trans-thoracic impedance analysis is an effective means of recording important measures of resuscitation quality including the hands-on-the-chest time, compression rate and defibrillation interval time. TTI data transmission via telemetry is straightforward, efficient and allows resuscitation data to be captured and analysed from a large geographical area. Further research is warranted on the impact of post-resuscitation reporting on the quality of resuscitation delivered by ambulance crews. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Is there any room for shortening hands-off time further when using an AED?

PubMed

Rhee, Joong Eui; Kim, Taeyun; Kim, Kyuseok; Choi, Saewon

2009-02-01

Automated external defibrillators (AEDs) play a very important role in out-of-hospital cardiopulmonary resuscitation (CPR). The mandatory hands-off time imposed by current AEDs is not short enough to bring about the full benefits of rapid defibrillation with an AED into light. The aim of this study is to examine whether a change in the process of charging the capacity and removing explanations from the prompts of the AEDs shortens hands-off time. The operating steps and the voice prompts of the current AEDs were reviewed and the time intervals between the steps and the voice prompts were measured. We modified an AED to fully precharge the capacitor and to contain more concise voice prompts. We had 42 expert rescuers and 50 lay-person rescuers perform 2-rescuer CPR with the modified AED and the old AED, respectively. Using the modified AED significantly reduced hands-off times by 9.95 s (95% CI: 9.67-10.23) in 2-rescuer CPR and by 10.68 s (95% CI: 9.75-11.61) in 1-rescuer CPR (p<0.001). Full precharging of the capacitor and exclusion of explanations from the voice prompts of AEDs can shorten the hands-off time in both 1 and 2-rescuer CPR.

Preliminary Development of an Informational Media Use Measure for Patients with Implanted Defibrillators: Toward a Model of Social-Ecological Assessment of Patient Education and Support.

PubMed

Knoepke, Christopher E; Matlock, Daniel D

2017-11-01

Social work interventions in health care, particularly those that involve working with people being treated for chronic and life-threatening conditions, frequently involve efforts to educate patients about their disease, treatment options, safety planning, medical adherence, and other associated issues. Despite an intuitive notion that patients access information about all of these issues through a variety of media-both inside and outside the clinical encounter, created by professionals and by others-there currently exists no validated means of assessing patients' use of these forms of information. To address this gap, authors first created candidate item measures with input from both physicians and a small group of diverse patients who currently have an implantable cardioverter defibrillator (ICD), a sophisticated cardiac device for which a trajectory model of social work intervention was recently outlined. Authors then surveyed a group of 205 individuals who have these devices, assessing their use of various media to learn about ICDs. They then conducted factor and item analysis to refine and remove poorly performing items while delineating forms of media use by type. The resultant preliminary measure of informational media use can be further refined and adapted for use with any clinical population. © 2017 National Association of Social Workers.

Assessment of knowledge and skills in using an Automated External Defibrillator (AED) by university students. A quasi-experimental study.

PubMed

Basanta Camiño, S; Navarro Patón, R; Freire Tellado, M; Barcala Furelos, R; Pavón Prieto, M P; Fernández López, M; Neira Pájaro, M A

To evaluate layperson (university student) ability to use an automated external defibrillator (AED). A repeated measures quasi-experimental study with non-probabilistic sampling and a control group was carried out. Teacher training degree students at the University of Santiago de Compostela (Spain). The sample consisted of 129 subjects (69% women and 31% men), between 19-47 years of age (mean 23.2±4.7 years). As inclusion criterion, the subjects were required to have no previous knowledge of AED. Times to apply defibrillation with an AED to a mannequin were recorded untrained (T0), after a theoretical and practice explanation lasting less than one minute (T1), and 6 months after the training process (T2). The primary endpoint was the time taken to deliver a defibrillation discharge. The "improvement effect" variable was defined by the absolute time difference between T1 and T0, while the "degree of forgetfulness effect" variable was defined as the absolute difference between T1 and T2. The mean times were T0=67.7s; T1=44.2s; T2=45.9s. The time to apply defibrillation was reduced after explanation training (T1

Factors associated with health-related quality of life among patients with implantable cardioverter defibrillator: identification of foci for nursing intervention.

PubMed

Wong, Florence Mei Fung; Sit, Janet Wing Hung; Wong, Eliza Mi Ling; Choi, Kai Chow

2014-12-01

To explore factors associated with health-related quality of life of patients with implantable cardioverter defibrillators. Substantial evidence indicates that implantable cardioverter defibrillator is proven to increase survival rate by terminating life-threatening arrhythmia. However, this device can negatively affect health-related quality of life. Little is known about factors associated with health-related quality of life of patients with implantable cardioverter defibrillators, particularly in Asian population. A transversal descriptive design was used. Data were collected from a convenience sample of 139 adult patients with implantable cardioverter defibrillators from 4 January-30 April 2012 using the structured questionnaires administered by the researcher and medical record reviews. The Short Form-36 Health Survey version 2 was used to measure health-related quality of life. A total of 139 Chinese patients, including 107 (77·0%) males with a mean age of 63·0 (14·6) years, were selected. The physical component summary was relatively lower, whereas the mental component summary was relatively higher than that of the general Hong Kong Chinese population. Multivariable regression analysis revealed gender, self-care dependence, educational level, atrial fibrillation, diabetes mellitus, anxiety and depression significantly associated with physical or mental quality of life. Depression was a common factor affecting physical and mental quality of life. Self-care dependence, atrial fibrillation, diabetes mellitus, depression and anxiety could be improved. Our findings expand existing knowledge on identifying at-risk patients for having lower quality of life, thus allowing development of appropriate interventions targeting risk factors for improving health-related quality of life of patients with implantable cardioverter defibrillator. © 2014 John Wiley & Sons Ltd.

Validation of a defibrillation lead ventricular volume measurement compared to three-dimensional echocardiography.

PubMed

Haines, David E; Wong, Wilson; Canby, Robert; Jewell, Coty; Houmsse, Mahmoud; Pederson, David; Sugeng, Lissa; Porterfield, John; Kottam, Anil; Pearce, John; Valvano, Jon; Michalek, Joel; Trevino, Aron; Sagar, Sandeep; Feldman, Marc D

2017-10-01

There is increasing evidence that using frequent invasive measures of pressure in patients with heart failure results in improved outcomes compared to traditional measures. Admittance, a measure of volume derived from preexisting defibrillation leads, is proposed as a new technique to monitor cardiac hemodynamics in patients with an implantable defibrillator. The purpose of this study was to evaluate the accuracy of a new ventricular volume sensor (VVS, CardioVol) compared with 3-dimenssional echocardiography (echo) in patients with an implantable defibrillator. Twenty-two patients referred for generator replacement had their defibrillation lead attached to VVS to determine the level of agreement to a volume measurement standard (echo). Two opposite hemodynamic challenges were sequentially applied to the heart (overdrive pacing and dobutamine administration) to determine whether real changes in hemodynamics could be reliably and repeatedly assessed with VVS. Equivalence of end-diastolic volume (EDV) and stroke volume (SV) determined by both methods was also assessed. EDV and SV were compared using VVS and echo. VVS tracked expected physiologic trends. EDV was modulated -10% by overdrive pacing (14 mL). SV was modulated -13.7% during overdrive pacing (-6 mL) and increased over baseline +14.6% (+8 mL) with dobutamine. VVS and echo mean EDVs were found statistically equivalent, with margin of equivalence 13.8 mL (P <.05). Likewise, mean SVs were found statistically equivalent with margin of equivalence 15.8 mL (P <.05). VVS provides an accurate method for ventricular volume assessment using chronically implanted defibrillator leads and is statistically equivalent to echo determination of mean EDV and SV. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Law Enforcement Agency Defibrillation (LEA-D): proceedings of the National Center for Early Defibrillation Police AED Issues Forum.

PubMed

Mosesso, Vincent N; Newman, Mary M; Ornato, Joseph P; Paris, Paul M; Andersen, Leon; Brinsfield, Kathryn; Dunnavant, Gregory R; Frederick, Jay; Groh, William J; Johnston, Steven; Lerner, E Brooke; Murphy, George P; Myerburg, Robert J; Rosenberg, Donald G; Savino, Mitchell; Sayre, Michael R; Sciammarella, Joseph; Schoen, Valerie; Vargo, Philip; van Alem, Anouk; White, Roger D

2002-01-01

Why does LEA-D intervention seem to work in some systems but not others? Panelists agreed that some factors that delay rapid access to treatment, such as long travel distances in rural areas, may represent insurmountable barriers. Other factors, however, may be addressed more readily. These include: absence of a medical response culture, discomfort with the role of medical intervention, insecurity with the use of medical devices, a lack of proactive medical direction, infrequent refresher training, and dependence on EMS intervention. Panelists agreed that successful LEA-D programs possess ten key attributes (Table 6). In the end, the goal remains "early" defibrillation, not "police" defibrillation. It does not matter whether the rescuer wears a blue uniform--or any uniform, for that matter--so long as the defibrillator reaches the victim quickly. If LEA personnel routinely arrive at medical emergencies after other emergency responders or after 8 minutes have elapsed from the time of collapse, an LEA-D program will be unlikely to provide added value. Similarly, if police frequently arrive first, but the department is unwilling or unable to cultivate the attributes of successful LEA-D programs, efforts to improve survival may not be realized. In most communities, however, LEA-D programs have tremendous lifesaving potential and are well worth the investment of time and resources. Law enforcement agencies considering adoption of AED programs should review the frequency with which police arrive first at medical emergencies and LEA response intervals to determine whether AED programs might help improve survival in their communities. It is time for law enforcement agency defibrillation to become the rule, not the exception.

Waveform analysis-guided treatment versus a standard shock-first protocol for the treatment of out-of-hospital cardiac arrest presenting in ventricular fibrillation: results of an international randomized, controlled trial.

PubMed

Freese, John P; Jorgenson, Dawn B; Liu, Ping-Yu; Innes, Jennifer; Matallana, Luis; Nammi, Krishnakant; Donohoe, Rachael T; Whitbread, Mark; Silverman, Robert A; Prezant, David J

2013-08-27

Ventricular fibrillation (VF) waveform properties have been shown to predict defibrillation success and outcomes among patients treated with immediate defibrillation. We postulated that a waveform analysis algorithm could be used to identify VF unlikely to respond to immediate defibrillation, allowing selective initial treatment with cardiopulmonary resuscitation in an effort to improve overall survival. In a multicenter, double-blind, randomized study, out-of-hospital cardiac arrest patients in 2 urban emergency medical services systems were treated with automated external defibrillators using either a VF waveform analysis algorithm or the standard shock-first protocol. The VF waveform analysis used a predefined threshold value below which return of spontaneous circulation (ROSC) was unlikely with immediate defibrillation, allowing selective treatment with a 2-minute interval of cardiopulmonary resuscitation before initial defibrillation. The primary end point was survival to hospital discharge. Secondary end points included ROSC, sustained ROSC, and survival to hospital admission. Of 6738 patients enrolled, 987 patients with VF of primary cardiac origin were included in the primary analysis. No immediate or long-term survival benefit was noted for either treatment algorithm (ROSC, 42.5% versus 41.2%, P=0.70; sustained ROSC, 32.4% versus 33.4%, P=0.79; survival to admission, 34.1% versus 36.4%, P=0.46; survival to hospital discharge, 15.6% versus 17.2%, P=0.55, respectively). Use of a waveform analysis algorithm to guide the initial treatment of out-of-hospital cardiac arrest patients presenting in VF did not improve overall survival compared with a standard shock-first protocol. Further study is recommended to examine the role of waveform analysis for the guided management of VF.

Phone-Delivered Mindfulness Training for Patients with Implantable Cardioverter Defibrillators: Results of a Pilot Randomized Controlled Trial

PubMed Central

Salmoirago-Blotcher, Elena; Crawford, Sybil L.; Carmody, James; Rosenthal, Lawrence; Yeh, Gloria; Stanley, Mary; Rose, Karen; Browning, Clifford; Ockene, Ira S.

2013-01-01

Background The reduction in adrenergic activity and anxiety associated with meditation may be beneficial for patients with implantable cardioverter defibrillators. Purpose To determine the feasibility of a phone-delivered mindfulness intervention in patients with defibrillators and to obtain preliminary indications of efficacy on mindfulness and anxiety. Methods Clinically stable outpatients were randomized to a mindfulness intervention (8 weekly individual phone sessions) or to a scripted follow-up phone call. We used the Hospital Anxiety and Depression Scale and the Five Facets of Mindfulness to measure anxiety and mindfulness; and multivariate linear regression to estimate the intervention effect on pre-post intervention changes in these variables. Results We enrolled 45 patients (23 mindfulness, 22 control; age 43–83; 30 % women). Retention was 93 %; attendance was 94 %. Mindfulness (beta = 3.31; p = .04) and anxiety (beta = − 1.15; p = .059) improved in the mindfulness group. Conclusions Mindfulness training can be effectively phone-delivered and may improve mindfulness and anxiety in cardiac defibrillator outpatients. PMID:23605175

Effects of Late Sodium Current Blockade on Ventricular Refibrillation in a Rabbit Model.

PubMed

Azam, Mohammed Ali; Zamiri, Nima; Massé, Stéphane; Kusha, Marjan; Lai, Patrick F H; Nair, Govind K; Tan, Nigel S; Labos, Christopher; Nanthakumar, Kumaraswamy

2017-03-01

After defibrillation of initial ventricular fibrillation (VF), it is crucial to prevent refibrillation to ensure successful resuscitation outcomes. Inability of the late Na + current to inactivate leads to intracellular Ca 2+ dysregulation and arrhythmias. Our aim was to determine the effects of ranolazine and GS-967, inhibitors of the late Na + current, on ventricular refibrillation. Long-duration VF was induced electrically in Langendorff-perfused rabbit hearts (n=22) and terminated with a defibrillator after 6 minutes. Fibrillating hearts were randomized into 3 groups: treatment with ranolazine, GS-967, or nontreated controls. In the treated groups, hearts were perfused with ranolazine or GS-967 at 2 minutes of VF. In control experiments, perfusion solution was supplemented with isotonic saline in lieu of a drug. Inducibility of refibrillation was assessed after initial long-duration VF by attempting to reinduce VF. Sustained refibrillation was successful in fewer ranolazine-treated (29.17%; P =0.005) or GS-967-treated (45.83%, P =0.035) hearts compared with that in nontreated control hearts (84.85%). In GS-967-treated hearts, significantly more spontaneous termination of initial long-duration VF was observed (66.67%; P =0.01). Ca 2+ transient duration was reduced in ranolazine-treated hearts compared with that in controls ( P =0.05) and also Ca 2+ alternans ( P =0.03). Late Na + current inhibition during long-duration VF reduces the susceptibility to subsequent refibrillation, partially by mitigating dysregulation of intracellular Ca 2+ . These results suggest the potential therapeutic use of ranolazine and GS-967 and call for further testing in cardiac arrest models. © 2017 American Heart Association, Inc.

Safety of sports participation in patients with implantable cardioverter defibrillators: a survey of heart rhythm society members.

PubMed

Lampert, Rachel; Cannom, David; Olshansky, Brian

2006-01-01

Safety of Sports for ICD Patients. The safety of sports participation for patients with implantable cardioverter defibrillators (ICDs) is unknown, and recommendations among physicians may vary widely. The purposes of this study were to determine current practice among patients with ICDs and their physicians regarding sports participation, and to determine how many physicians have cared for patients who have sustained adverse events during sports participation. A survey was mailed to all 1,687 U.S. physician members of the Heart Rhythm Society. Among 614 respondent physicians, recommendations varied widely. Only 10% recommended avoidance of all sports more vigorous than golf. Seventy-six percent recommended avoidance of contact, and 45% recommend avoidance of competitive sports. Most (71%) based restrictions on patients' underlying heart disease. Regardless of recommendations, most physicians (71%) reported caring for patients who participated in sports, including many citing vigorous, competitive sports, most commonly cited were basketball, running, and skiing. ICD shocks during sports were common, cited by 40% of physicians. However, few adverse consequences were reported. One percent of physicians reported known injury to patient (all but 3 minor); 5%, injury to the ICD system, and <1%, failure of shocks to terminate arrhythmia. The most common adverse event reported was lead damage attributed to repetitive-motion activities, most commonly weightlifting and golf. Physician recommendations for sports participation for patients with ICDs varies widely. Many patients with ICDs do participate in vigorous and even competitive sports. While shocks were common, significant adverse events were rare.

Effects of brief training on use of automated external defibrillators by people without medical expertise.

PubMed

Mitchell, K Blake; Gugerty, Leo; Muth, Eric

2008-04-01

This study examined the effect of three types of brief training on the use of automatic external defibrillators (AEDs) by 43 lay users. Because AEDs were recently approved for home use, brief training for nonprofessional users needs investigation. During training, the exposure training group read an article about AEDs that provided no information on how to operate them; the low-training group inspected the AED and read the operating instructions in the paper-based manual but was not allowed to use the device; and the high-training group watched a training video and performed a mock resuscitation using the AED but no manikin. All participants returned 2 weeks later and performed a surprise simulated AED resuscitation on a manikin. Most participants in each training group met criteria of minimally acceptable performance during the simulated manikin resuscitation, as measured by time to first shock, pad placement accuracy, and safety check performance. All participants who committed errors were able to successfully recover from them to complete the resuscitation. Compared with exposure training, the low and high training had a beneficial effect on time to first shock and errors. Untrained users were able to adequately use this AED, demonstrating walk-up-and-use usability, but additional brief training improved user performance. This study demonstrated the importance of providing high-quality but brief training for home AED users. In conjunction with other findings, the current study helps demonstrate the need for well-designed training for consumer medical devices.

Design of the evolution of management strategies of heart failure patients with implantable defibrillators (EVOLVO) study to assess the ability of remote monitoring to treat and triage patients more effectively

PubMed Central

Marzegalli, Maurizio; Landolina, Maurizio; Lunati, Maurizio; Perego, Giovanni B; Pappone, Alessia; Guenzati, Giuseppe; Campana, Carlo; Frigerio, Maria; Parati, Gianfranco; Curnis, Antonio; Colangelo, Irene; Valsecchi, Sergio

2009-01-01

Background Heart failure patients with implantable defibrillators (ICD) frequently visit the clinic for routine device monitoring. Moreover, in the case of clinical events, such as ICD shocks or alert notifications for changes in cardiac status or safety issues, they often visit the emergency department or the clinic for an unscheduled visit. These planned and unplanned visits place a great burden on healthcare providers. Internet-based remote device interrogation systems, which give physicians remote access to patients' data, are being proposed in order to reduce routine and interim visits and to detect and notify alert conditions earlier. Methods The EVOLVO study is a prospective, randomized, parallel, unblinded, multicenter clinical trial designed to compare remote ICD management with the current standard of care, in order to assess its ability to treat and triage patients more effectively. Two-hundred patients implanted with wireless-transmission-enabled ICD will be enrolled and randomized to receive either the Medtronic CareLink® monitor for remote transmission or the conventional method of in-person evaluations. The purpose of this manuscript is to describe the design of the trial. The results, which are to be presented separately, will characterize healthcare utilizations as a result of ICD follow-up by means of remote monitoring instead of conventional in-person evaluations. Trial registration ClinicalTrials.gov: NCT00873899 PMID:19538734

Hybrid bodies and the materiality of everyday life: how people living with pacemakers and defibrillators reinvent everyday routines and intimate relations.

PubMed

Oudshoorn, Nelly

2018-01-01

Technologies inside bodies pose new challenges in a technological culture. For people with pacemakers and defibrillators, activities such as passing security controls at airports, using electromagnetic machines, electrical domestic appliances and electronic devices, and even intimate contacts with their loved ones can turn into events where the proper functioning of their device may be at risk. Anticipation of potentially harmful events and situations thus becomes an important part of the choreography of everyday life. Technologies inside bodies not only pose a challenge for patients living with these devices but also to theorising body-technology relations. Whereas researchers usually address the merging of bodies and technologies, implants ask us to do the opposite as well. How are we to understand human-technology relations in which technologies should not entangle with bodies because they serve other purposes? Based on a study of the daily life practices of people with pacemakers and defibrillators in the Netherlands and the US, I argue that disentanglement work, i.e. work involved to prevent entanglements with objects and people that may inflict harm upon implanted devices, is key to understanding how hybrid bodies can survive in today's densely populated technological landscape. © 2017 Foundation for the Sociology of Health & Illness.

Design and implementation of a fuzzy logic-based state-of-charge meter for Li-ion batteries used in portable defibrillators

NASA Astrophysics Data System (ADS)

Singh, Pritpal; Vinjamuri, Ramana; Wang, Xiquan; Reisner, David

A fuzzy logic-based state-of-charge meter is being developed for Li-ion batteries for potential use in portable defibrillators. ac impedance and voltage recovery measurements have been made which are used as the input parameters for the fuzzy logic model. The load profile for the Li-ion battery packs comprises a continuous 1.4 A constant current discharge periodically interrupted by 10 A pulses. As the battery is cycled the available capacity diminishes and so the number of 10 A pulses that may be delivered decreases. Measurements are being made on a total of three battery packs at three different temperatures (0, 20 and 40 °C) and as expected the number of pulses deliverable by the battery pack diminishes as temperature is decreased. For example, at room temperature the battery pack was initially able to deliver 42 pulses early in the cycle life whereas at 0 °C the battery-pack is only able to initially deliver 12 pulses. The voltage recovery profile upon removal of the 10 A load has been used both in the time domain and frequency domain to develop fuzzy logic models to estimate the number of remaining pulses that the battery-pack can deliver. Accurate models are being developed to estimate the number of pulses that the battery pack can deliver at various stages of its cycle life and at the different temperatures. With sufficient data collected for the battery packs at room temperature accurate fuzzy logic models have been developed for estimation of state-of-charge and implemented in the Motorola MC 68HC12 microcontroller.

Development of a hybrid battery system for an implantable biomedical device, especially a defibrillator/cardioverter (ICD)

NASA Astrophysics Data System (ADS)

Drews, Jürgen; Wolf, R.; Fehrmann, G.; Staub, R.

An implantable defibrillator battery has to provide pulse power capabilities as well as high energy density. Low self-discharge rates are mandatory and a way to check the remaining available capacity is necessary. These requirements are accomplished by a system consisting of a lithium/manganese dioxide 6 V battery, plus a lithium/iodine-cell. The use of a high rate 6 V double-cell design in combination with a high energy density cell reduces the total volume required by the power source within an implantable defibrillator. The design features and performance data of the hybrid system are described.

Marketing defibrillation training programs and bystander intervention support.

PubMed

Sneath, Julie Z; Lacey, Russell

2009-01-01

This exploratory study identifies perceptions of and participation in resuscitation training programs, and bystanders' willingness to resuscitate cardiac arrest victims. While most of the study's participants greatly appreciate the importance of saving someone's life, many indicated that they did not feel comfortable assuming this role. The findings also demonstrate there is a relationship between type of victim and bystanders' willingness to intervene. Yet, bystander intervention discomfort can be overcome with cardiopulmonary resuscitation and defibrillation training, particularly when the victim is a coworker or stranger. Further implications of these findings are discussed and modifications to public access defibrillation (PAD) training programs' strategy and communications are proposed.

Inappropriate shock delivery by implantable cardioverter defibrillator due to electrical interference with washing machine.

PubMed

Chongtham, Dhanaraj Singh; Bahl, Ajay; Kumar, Rohit Manoj; Talwar, K K

2007-05-31

We report a patient with hypertrophic cardiomyopathy who received an inappropriate implantable cardioverter defibrillator shock due to electrical interference from a washing machine. This electrical interference was detected as an episode of ventricular fibrillation with delivery of shock without warning symptoms.

Safety of Electromagnetic Articulography in Patients with Pacemakers and Implantable Cardioverter-Defibrillators

ERIC Educational Resources Information Center

Joglar, Jose A.; Nguyen, Carol; Garst, Diane M.; Katz, William F.

2009-01-01

Purpose: "Electromagnetic articulography (EMA)" uses a helmet to create alternating magnetic fields for tracking speech articulator movement. An important safety consideration is whether EMA magnetic fields interfere with the operation of speakers' pacemakers or implantable cardioverter-defibrillators (ICDs). In this investigation,…

Shock whilst gardening--implantable defibrillators & lawn mowers.

PubMed

Von Olshausen, G; Lennerz, C; Grebmer, C; Pavaci, H; Kolb, C

2014-02-01

Electromagnetic interference with implantable cardioverter defibrillators (ICDs) can cause inappropriate shock delivery or temporary inhibition of ICD functions. We present a case of electromagnetic interference between a lawn mower and an ICD resulting in an inappropriate discharge of the device due to erroneous detection of ventricular fibrillation.

21 CFR 870.5300 - DC-defibrillator (including paddles).

Code of Federal Regulations, 2013 CFR

2013-04-01

... of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart or to terminate other cardiac arrhythmias. This generic type of device includes low energy... either directly across the heart or on the surface of the body. (2) Classification. Class II (performance...

21 CFR 870.5300 - DC-defibrillator (including paddles).

Code of Federal Regulations, 2014 CFR

2014-04-01

... of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart or to terminate other cardiac arrhythmias. This generic type of device includes low energy... either directly across the heart or on the surface of the body. (2) Classification. Class II (performance...

GPs’ use of defibrillators and the national radio network in emergency primary healthcare in Norway

PubMed Central

Zakariassen, Erik; Hunskaar, Steinar

2008-01-01

Objective To study the geographic size of out-of-hours districts, the availability of defibrillators and use of the national radio network in Norway. Design Survey. Setting The emergency primary healthcare system in Norway. Subjects A total of 282 host municipalities responsible for 260 out-of-hours districts. Main outcome measures Size of out-of-hours districts, use of national radio network and access to a defibrillator in emergency situations. Results The out-of-hours districts have a wide range of areas, which gives a large variation in driving time for doctors on call. The median longest transport time for doctors in Norway is 45 minutes. In 46% of out-of-hours districts doctors bring their own defibrillator on emergency callouts. Doctors always use the national radio network in 52% of out-of-hours districts. Use of the radio network and access to a defibrillator are significantly greater in out-of-hours districts with a host municipality of fewer then 5000 inhabitants compared with host municipalities of more than 20 000 inhabitants. Conclusion In half of out-of-hours districts doctors on call always use the national radio network. Doctors in out-of-hours districts with a host municipality of fewer than 5000 inhabitants are in a better state of readiness to attend an emergency, compared with doctors working in larger host municipalities. PMID:18570012

Manual vs. automatic capture management in implantable cardioverter defibrillators and cardiac resynchronization therapy defibrillators.

PubMed

Murgatroyd, Francis D; Helmling, Erhard; Lemke, Bernd; Eber, Bernd; Mewis, Christian; van der Meer-Hensgens, Judith; Chang, Yanping; Khalameizer, Vladimir; Katz, Amos

2010-06-01

The Secura ICD and Consulta CRT-D are the first defibrillators to have automatic right atrial (RA), right ventricular (RV), and left ventricular (LV) capture management (CM). Complete CM was evaluated in an implantable cardioverter defibrillator (ICD) population. Two prospective clinical studies were conducted in 28 centres in Europe and Israel. Automatic CM data were compared with manual threshold measurements, the CM applicability was determined, and adjustments to pacing outputs were analysed. In total, 160 patients [age 64.6 +/- 10.4 years, 77% male, 80 ICD and 80 cardiac resynchronization therapy defibrillator (CRT-D)] were included. The differences between automatic and manual measurements were 2.5 V) due to raised RA threshold in seven (4.4%), high RV threshold in nine (5.6%), and high LV threshold in three patients (3.8%). All high threshold detections and all automatic modulations of pacing output were adjudicated appropriate. Complete CM adjusts pacing output appropriately, permitting a reduction in office visits while it may maximize device longevity. The study was registered at ClinicalTrials.gov identifiers: NCT00526227 and NCT00526162.

Usefulness of emergency medical teams in sport stadiums.

PubMed

Leusveld, E; Kleijn, S; Umans, V A W M

2008-03-01

In August 2006, the new AZ Alkmaar soccer stadium (capacity 17,000) opened. To provide adequate emergency support, medical teams of Red Cross volunteers and coronary care unit and emergency room nurses were formed, and facilities including automated external defibrillators were made available at the stadium. During every match, 3 teams are placed among the spectators. All patients who had cardiac events were stabilized by the teams and transported to the hospital. They formed the study group. From August 2006 to May 2007, >800,000 individuals attended soccer matches at the new stadium. Four cardiac events (3 out-of-hospital-resuscitations for ventricular fibrillation, 1 patient with chest pain) requiring emergency medical support occurred. On-site resuscitations using defibrillators were successful. Two patients with triple-vessel disease subsequently underwent coronary bypass surgery and implantable cardioverter-defibrillator implantation. One patient had single-vessel disease of the circumflex branch, for which he received a coronary stent. All had uneventful recoveries. An acute coronary syndrome was ruled out in the patient presenting with chest pain. In conclusion, the presence of emergency medical teams at a large sport stadium was of vital importance in the immediate care of critically ill patients. On-site resuscitation using automated external defibrillators was lifesaving in all cases. The presence of medical teams equipped with defibrillators and emergency action plans is recommended at large venues that host sports and other activities.

Randomized trial of atrial arrhythmia monitoring to guide anticoagulation in patients with implanted defibrillator and cardiac resynchronization devices.

PubMed

Martin, David T; Bersohn, Malcolm M; Waldo, Albert L; Wathen, Mark S; Choucair, Wassim K; Lip, Gregory Y H; Ip, John; Holcomb, Richard; Akar, Joseph G; Halperin, Jonathan L

2015-07-07

Atrial tachyarrhythmias (ATs) detected by implanted devices are often atrial fibrillation or flutter (AF) associated with stroke. We hypothesized that introduction and termination of anticoagulation based upon AT monitoring would reduce both stroke and bleeding. We randomized 2718 patients with dual-chamber and biventricular defibrillators to start and stop anticoagulation based on remote rhythm monitoring vs. usual office-based follow-up with anticoagulation determined by standard clinical criteria. The primary analysis compared the composite endpoint of stroke, systemic embolism, and major bleeding with the two strategies. The trial was stopped after 2 years median follow-up based on futility of finding a difference in primary endpoints between groups. A total of 945 patients (34.8%) developed AT, 264 meeting study anticoagulation criteria. Adjudicated atrial electrograms confirmed AF in 91%; median time to initiate anticoagulation was 3 vs. 54 days in the intervention and control groups, respectively (P < 0.001). Primary events (2.4 vs. 2.3 per 100 patient-years) did not differ between groups (HR 1.06; 95% CI 0.75-1.51; P = 0.732). Major bleeding occurred at 1.6 vs. 1.2 per 100 patient-years (HR 1.39; 95% CI 0.89-2.17; P = 0.145). In patients with AT, thromboembolism rates were 1.0 vs. 1.6 per 100 patient-years (relative risk -35.3%; 95% CI -70.8 to 35.3%; P = 0.251). Although AT burden was associated with thromboembolism, there was no temporal relationship between AT and stroke. In patients with implanted defibrillators, the strategy of early initiation and interruption of anticoagulation based on remotely detected AT did not prevent thromboembolism and bleeding. IMPACT ClinicalTrials.gov identifier: NCT00559988 ( http://clinicaltrials.gov/ct2/show/NCT00559988?term=NCT00559988&rank=1 ). Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Assessing access to MRI of patients with magnetic resonance-conditional pacemaker and implantable cardioverter defibrillator systems: the Really ProMRI study design.

PubMed

Maglia, Giampiero; Curnis, Antonio; Brieda, Marco; Anaclerio, Matteo; Caccavo, Vincenzo; Bonfanti, Paolo; Melissano, Donato; Caravati, Fabrizio; Giovene, Lisa; Gargaro, Alessio

2015-10-01

Despite the fact that magnetic resonance (MR)-conditional pacemaker and lead systems have been introduced more than 5 years ago, it is still not clear whether they have actually facilitated the access of pacemaker patients to this important diagnostic tool. Factors limiting MR scans in daily practice in patients with MR-conditional cardiac implantable electronic device (CIED) systems may be related to organizational, cultural and sometimes legal aspects. The Really ProMRI registry is an ongoing survey designed to assess the annual rate of MR examinations in patients with MR-conditional implants, with either pacemakers or implantable cardioverter defibrillators, and to detect the main factors limiting MRI. The primary endpoint of the Really ProMRI registry is to assess the current access to MRI of patients with MR-conditional pacemaker or implantable cardioverter defibrillator systems during normal practice. Data in the literature reported a 17% annual incidence of medical conditions requiring MRI in CIED patients. The Really ProMRI registry has been designed to detect 4.5% absolute difference with an 80% statistical power, by recruiting 600 patients already implanted with MR-conditional CIED implant. Patients will be followed up for 1 year, during which they will be asked to refer any prescription, execution or denial of an MR examination by patient questionnaires and original source documents. The ongoing Really ProMRI registry will assess the actual rate of and factors limiting the access to MRI for patients with MR-conditional CIEDs.

Transthoracic impedance for the monitoring of quality of manual chest compression during cardiopulmonary resuscitation.

PubMed

Zhang, Hehua; Yang, Zhengfei; Huang, Zitong; Chen, Bihua; Zhang, Lei; Li, Heng; Wu, Baoming; Yu, Tao; Li, Yongqin

2012-10-01

The quality of cardiopulmonary resuscitation (CPR), especially adequate compression depth, is associated with return of spontaneous circulation (ROSC) and is therefore recommended to be measured routinely. In the current study, we investigated the relationship between changes of transthoracic impedance (TTI) measured through the defibrillation electrodes, chest compression depth and coronary perfusion pressure (CPP) in a porcine model of cardiac arrest. In 14 male pigs weighing between 28 and 34 kg, ventricular fibrillation (VF) was electrically induced and untreated for 6 min. Animals were randomized to either optimal or suboptimal chest compression group. Optimal depth of manual compression in 7 pigs was defined as a decrease of 25% (50 mm) in anterior posterior diameter of the chest, while suboptimal compression was defined as 70% of the optimal depth (35 mm). After 2 min of chest compression, defibrillation was attempted with a 120-J rectilinear biphasic shock. There were no differences in baseline measurements between groups. All animals had ROSC after optimal compressions; this contrasted with suboptimal compressions, after which only 2 of the animals had ROSC (100% vs. 28.57%, p=0.021). The correlation coefficient was 0.89 between TTI amplitude and compression depth (p<0.001), 0.83 between TTI amplitude and CPP (p<0.001). Amplitude change of TTI was correlated with compression depth and CPP in this porcine model of cardiac arrest. The TTI measured from defibrillator electrodes, therefore has the potential to serve as an indicator to monitor the quality of chest compression and estimate CPP during CPR. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Cost-effectiveness of In-home Automated External Defibrillators for Individuals at Increased Risk of Sudden Cardiac Death

PubMed Central

Cram, Peter; Vijan, Sandeep; Katz, David; Fendrick, A Mark

2005-01-01

BACKGROUND/OBJECTIVE In-home automated external defibrillators (AEDs) are increasingly recommended as a means for improving survival of cardiac arrests that occur at home. The current study was conducted to explore the relationship between individuals' risk of cardiac arrest and cost-effectiveness of in-home AED deployment. DESIGN Markov decision model employing a societal perspective. PATIENTS Four hypothetical cohorts of American adults 60 years of age at progressively greater risk for sudden cardiac death (SCD): 1) all adults (annual probability of SCD 0.4%); 2) adults with multiple SCD risk factors (probability 2%); 3) adults with previous myocardial infarction (probability 4%); and 4) adults with ischemic cardiomyopathy unable to receive an implantable defibrillator (probability 6%). INTERVENTION Strategy 1: individuals suffering an in-home cardiac arrest were treated with emergency medical services equipped with AEDs (EMS-D). Strategy 2: individuals suffering an in-home cardiac arrest received initial treatment with an in-home AED, followed by EMS. RESULTS Assuming cardiac arrest survival rates of 15% with EMS-D and 30% with AEDs, the cost per quality-adjusted life-year gained (QALY) of providing in-home AEDs to all adults 60 years of age is $216,000. Costs of providing in-home AEDs to adults with multiple risk factors (2% probability of SCD), previous myocardial infarction (4% probability), and ischemic cardiomyopathy (6% probability) are $132,000, $104,000, and $88,000, respectively. CONCLUSIONS The cost-effectiveness of in-home AEDs is intimately linked to individuals' risk of SCD. However, providing in-home AEDs to all adults over age 60 appears relatively expensive. PMID:15836529

Outcomes After Cardiac Arrest in an Adult Burn Center

DTIC Science & Technology

2013-12-07

defibrillation at our institution, either in the burn operating room (BOR) or burn intensive care unit (BICU). We included patients who experi- enced CA in...of this study design. In other studies, the time between CA and defibrillation and, in children, the time between burn and fluid resuscitation have

McArthur completes a battery charge on the defibrillator during Expedition 12

NASA Image and Video Library

2005-12-16

ISS012-E-12570 (16 Dec. 2005) --- Astronaut William S. (Bill) McArthur Jr., Expedition 12 commander and NASA space station science officer, completes a battery charge on a cardiac defibrillator at the Human Research Facility (HRF) in the Destiny laboratory of the International Space Station.

A Comparative Study of Defibrillator Leads at a Large-Volume Implanting Hospital: Results From the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS").

PubMed

Cohen, Todd J; Asheld, Wilbur J; Germano, Joseph; Islam, Shahidul; Patel, Dhimesh

2015-06-01

The purpose of the study was to examine survival in the implantable defibrillator subset of implanted leads at a large-volume implanting hospital. Implantable lead survival has been the subject of many multicenter studies over the past decade. Fewer large implanting volume single-hospital studies have examined defibrillator lead failure as it relates to patient survival and lead construction. This investigator-initiated retrospective study examined defibrillator lead failure in those who underwent implantation of a defibrillator between February 1, 1996 and December 31, 2011. Lead failure was defined as: failure to capture/sense, abnormal pacing and/or defibrillator impedance, visual insulation defect or lead fracture, extracardiac stimulation, cardiac perforation, tricuspid valve entrapment, lead tip fracture and/or lead dislodgment. Patient characteristics, implant approach, lead manufacturers, lead models, recalled status, patient mortality, and core lead design elements were compared using methods that include Kaplan Meier analysis, univariate and multivariable Cox regression models. A total of 4078 defibrillator leads were implanted in 3802 patients (74% male; n = 2812) with a mean age of 70 ± 13 years at Winthrop University Hospital. Lead manufacturers included: Medtronic: [n = 1834; 801 recalled]; St. Jude Medical: [n = 1707; 703 recalled]; Boston Scientific: [n = 537; 0 recalled]. Kaplan-Meier analysis adjusted for multiple comparisons revealed that both Boston Scientific's and St. Jude Medical's leads had better survival than Medtronic's leads (P<.001 and P=.01, respectively). Lead survival was comparable between Boston Scientific and St. Jude Medical (P=.80). A total of 153 leads failed (3.5% of all leads) during the study. There were 99 lead failures from Medtronic (5.4% failure rate); 56 were recalled Sprint Fidelis leads. There were 36 lead failures from St. Jude (2.1% failure rate); 20 were recalled Riata or Riata ST leads. There were 18 lead failures from Boston Scientific (3.35% failure rate); none were recalled. Kaplan Meier analysis also showed lead failure occurred sooner in the recalled leads (P=.01). A total of 1493 patients died during the study (mechanism of death was largely unknown). There was a significant increase in mortality in the recalled lead group as compared with non-recalled leads (P=.01), but no significant difference in survival when comparing recalled leads from Medtronic with St. Jude Medical (P=.67). A multivariable Cox regression model revealed younger age, history of percutaneous coronary intervention, baseline rhythm other than atrial fibrillation or atrial flutter, combination polyurethane and silicone lead insulation, a second defibrillation coil, and recalled lead status all contributed to lead failure. This study demonstrated a significantly improved lead performance in the Boston Scientific and St. Jude leads as compared with Medtronic leads. Some lead construction variables (insulation and number of coils) also had a significant impact on lead failure, which was independent of the manufacturer. Recalled St. Jude leads performed better than recalled Medtronic leads in our study. Recalled St. Jude leads had no significant difference in lead failure when compared with the other manufacturer's non-recalled leads. Defibrillator recalled lead status was associated with an increased mortality as compared with non-recalled leads. This correlation was independent of the lead manufacturer and clinically significant even when considering known mortality risk factors. These results must be tempered by the largely unknown mechanism of death in these patients.

Nurses' knowledge and skill retention following cardiopulmonary resuscitation training: a review of the literature.

PubMed

Hamilton, Rosemary

2005-08-01

This paper reports a literature review examining factors that enhance retention of knowledge and skills during and after resuscitation training, in order to identify educational strategies that will optimize survival for victims of cardiopulmonary arrest. Poor knowledge and skill retention following cardiopulmonary resuscitation training for nursing and medical staff has been documented over the past 20 years. Cardiopulmonary resuscitation training is mandatory for nursing staff and is important as nurses often discover the victims of in-hospital cardiac arrest. Many different methods of improving this retention have been devised and evaluated. However, the content and style of this training lack standardization. A literature review was undertaken using the Cumulative Index to Nursing and Allied Health Literature, MEDLINE and British Nursing Index databases and the keywords 'cardiopulmonary resuscitation', 'basic life support', 'advanced life support' and 'training'. Papers published between 1992 and 2002 were obtained and their reference lists scrutinized to identify secondary references, of these the ones published within the same 10-year period were also included. Those published in the English language that identified strategies to enhance the acquisition or retention of Cardiopulmonary resuscitation skills and knowledge were included in the review. One hundred and five primary and 157 secondary references were identified. Of these, 24 met the criteria and were included in the final literature sample. Four studies were found pertaining to cardiac arrest simulation, three to peer tuition, four to video self-instruction, three to the use of different resuscitation guidelines, three to computer-based learning programmes, two to voice-activated manikins, two to automated external defibrillators, one to self-instruction, one to gaming and the one to the use of action cards. Resuscitation training should be based on in-hospital scenarios and current evidence-based guidelines, including recognition of sick patients, and should be taught using simulations of a variety of cardiac arrest scenarios. This will ensure that the training reflects the potential situations that nurses may face in practice. Nurses in clinical areas, who rarely see cardiac arrests, should receive automated external defibrillation training and have access to defibrillators to prevent delays in resuscitation. Staff should be formally assessed using a manikin with a feedback mechanism or an expert instructor to ensure that chest compressions and ventilations are adequate at the time of training. Remedial training must be provided as often as required. Resuscitation training equipment should be made available at ward/unit level to allow self-study and practice to prevent deterioration between updates. Video self-instruction has been shown to improve competence in resuscitation. An in-hospital scenario-based video should be devised and tested to assess the efficacy of this medium in resuscitation training for nurses.

[Primary prevention of sudden cardiac death through a wearable cardioverter-defibrillator].

PubMed

Gabrielli, Domenico; Benvenuto, Manuela; Baroni, Matteo; Oliva, Fabrizio; Capucci, Alessandro

2015-01-01

Nowadays, the implantable cardioverter-defibrillator is the gold standard for the prevention of sudden cardiac death due to tachyarrhythmias. However, its use is not free from short and long-term risks. In the last years, the wearable cardioverter-defibrillator (WCD) has become a widespread option for patients who need a safe and reversible protection against ventricular tachyarrhythmias. Notwithstanding this, its everyday application is restricted by several limitations, including the risk of inappropriate shocks, the device size and the need for strict compliance of both patients and caregivers. In this review, we report the most relevant literature data on WCD usage along with the main fields of applications and future perspectives.

EMT-defibrillation: a recipe for saving lives.

PubMed

Paris, P M

1988-05-01

Sudden cardiac death is the number-one cause of death in this country. It has long been known that most of these deaths occur outside of the hospital, therefore necessitating an approach to the problem involving prehospital care. The development of advanced life support emergency medical systems has had a dramatic impact on improving survival in selected communities. Most of the country continues to see little result because of our inability to provide timely defibrillation. Automatic external defibrillators now provide a safe, reliable, proven method to increase the number of "saves" in rural, urban, and suburban communities. This new tool, if widely used, will allow us to save scores of "hearts too good to die."

T-wave alternans negative coronary patients with low ejection and benefit from defibrillator implantation

NASA Technical Reports Server (NTRS)

Hohnloser, S. H.; Ikeda, T.; Bloomfield, D. M.; Dabbous, O. H.; Cohen, R. J.

2003-01-01

In a trial of prophylactic implantation of a defibrillator, a mortality benefit was seen among patients with previous myocardial infarction and a left-ventricular ejection fraction of 0.30 or less. We identified 129 similar patients from two previously published clinical trials in which microvolt T-wave alternans testing was prospectively assessed. At 24 months of follow-up, no sudden cardiac death or cardiac arrest was seen among patients who tested T-wave alternans negative, compared with an event rate of 15.6% among the remaining patients. Testing of T-wave alternans seems to identify patients who are at low risk of ventricular tachyarrhythmic event and who may not benefit from defibrillator therapy.

Reliability systems for implantable cardiac defibrillator batteries

NASA Astrophysics Data System (ADS)

Takeuchi, Esther S.

The reliability of the power sources used in implantable cardiac defibrillators is critical due to the life-saving nature of the device. Achieving a high reliability power source depends on several systems functioning together. Appropriate cell design is the first step in assuring a reliable product. Qualification of critical components and of the cells using those components is done prior to their designation as implantable grade. Product consistency is assured by control of manufacturing practices and verified by sampling plans using both accelerated and real-time testing. Results to date show that lithium/silver vanadium oxide cells used for implantable cardiac defibrillators have a calculated maximum random failure rate of 0.005% per test month.

Practical management of sudden cardiac arrest on the football field.

PubMed

Kramer, Efraim Benjamin; Botha, Martin; Drezner, Jonathan; Abdelrahman, Yasser; Dvorak, Jiri

2012-12-01

Sudden cardiac arrest (SCA) remains a tragic occurrence on the football field. The limits of preparticipation cardiovascular screening make it compulsory that prearranged emergency medical services be available at all football matches to immediately respond to any collapsed player. Management of SCA involves prompt recognition, immediate cardiopulmonary resuscitation (CPR) and early defibrillation. Any football player who collapses without contact with another player or obstacle should be regarded as being in SCA until proven otherwise. An automated external defibrillator (AED), or manual defibrillator if an AED is not available, should be immediately accessible on the field during competitions. This study presents guidelines for a practical and systematic approach to the management of SCA on the football field.

[Magnets, pacemaker and defibrillator: fatal attraction?].

PubMed

Bergamin, C; Graf, D

2015-05-27

This article aims at clarifying the effects of a clinical magnet on pacemakers and Implantable Cardioverter Defibrillators. The effects of electromagnetic interferences on such devices, including interferences linked to electrosurgery and magnetic resonance imaging are also discussed. In general, a magnet provokes a distinctive effect on a pacemaker by converting it into an asynchronous mode of pacing, and on an Implantable Cardioverter Defibrillator by suspending its own antitachyarythmia therapies without affecting the pacing. In the operating room, the magnet has to be used cautiously with precisely defined protocols which respect the type of the device used, the type of intervention planned, the presence or absence of EMI and the pacing-dependency of the patient.

75 FR 70015 - External Defibrillators; Public Workshop

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-16

... all manufacturers of these devices. From January 1, 2005, to July 10, 2010, there were a total of 68 recalls, of which 9 occurred in 2005 increasing to 17 in 2009 (the last complete year for which data are... defibrillators, handling user complaints, conducting recalls, and communicating with users. In some cases, these...

An assessment of public attitudes toward automated external defibrillators.

PubMed

Lubin, Jeffrey; Chung, S Sujin; Williams, Kenneth

2004-07-01

We assessed the familiarity of the general public with automated external defibrillators (AEDs) and their willingness to use them. Shoppers were asked to complete a survey in an AED-equipped suburban shopping mall. 359 surveys were analyzed. Of the participants, 11% were healthcare professionals, 51% had training in CPR or first aid, and 44% had no medical training. Sixty percent were able to define defibrillator adequately. Seventy-one percent stated they would be likely to use an AED to resuscitate a stranger. The most common concerns were fear of using the machine incorrectly (57%) and fear of legal liability (38%). After being told of liability protection from the federal Cardiac Arrest Survival Act, 84% stated they would be likely to use the AED. This increased further to 91% if the participants were given an opportunity to receive training. Although a substantial number of people in this setting were willing to use an AED, education regarding legal liability and proper use of the machines increased the reported likelihood of use. Further public education may be necessary to provide optimally effective public access defibrillation programs.

Magnetic resonance imaging safety in pacemaker and implantable cardioverter defibrillator patients: how far have we come?

PubMed Central

Nordbeck, Peter; Ertl, Georg; Ritter, Oliver

2015-01-01

Magnetic resonance imaging (MRI) has long been regarded a general contraindication in patients with cardiovascular implanted electronic devices such as cardiac pacemakers or cardioverter defibrillators (ICDs) due to the risk of severe complications and even deaths caused by interactions of the magnetic resonance (MR) surrounding and the electric devices. Over the last decade, a better understanding of the underlying mechanisms responsible for such potentially life-threatening complications as well as technical advances have allowed an increasing number of pacemaker and ICD patients to safely undergo MRI. This review lists the key findings from basic research and clinical trials over the last 20 years, and discusses the impact on current day clinical practice. With ‘MR-conditional’ devices being the new standard of care, MRI in pacemaker and ICD patients has been adopted to clinical routine today. However, specific precautions and specifications of these devices should be carefully followed if possible, to avoid patient risks which might appear with new MR technology and further increasing indications and patient numbers. PMID:25796053

State Requirements for Automated External Defibrillators in American Schools: Framing the Debate About Legislative Action.

PubMed

Sherrid, Mark V; Aagaard, Philip; Serrato, Stephanie; Arabadjian, Milla E; Lium, John M; Lium, John D; Greenberg, Henry M

2017-04-04

Installation of automated external defibrillators (AEDs) in schools has been associated with increased survival after sudden cardiac arrest. An authoritative academic research database was interrogated to identify all current state statutes pertaining to AEDs in schools. As of February 2016, 17 of 50 U.S. states (34%) require AED installation in at least some of their schools; the remaining states have no legislation. However, requirements are far from comprehensive in these 17 states. Only 5 states offer unequivocal funding to schools for purchasing AEDs. A minority of U.S. states have legislation requiring AED placement in schools, and even fewer provide funding. State legislatures that have not yet enacted legislation requiring AEDs in schools may look to neighboring states for examples of child and adult lifesaving law. Placement of an AED in schools should be implemented with an emergency response plan that trains staff in the recognition and response to cardiac arrest. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Medium voltage therapy for preventing and treating asystole and PEA in ICDs.

PubMed

Gilman, Byron L; Brewer, James E; Kroll, Kai; Kroll, Mark W

2009-01-01

Sudden cardiac death (SCD) takes up to 500,000 lives each year before a victim can even be treated. To address this the implantable cardioverter defibrillator (ICD) was developed to treat those identified at high risk of SCD. Unfortunately, there are a significant number of cases in which the ICD does not successfully return a victim to normal rhythm and effective perfusion of the blood. The vast majority of cases that are not responsive to the ICD therapy require cardio-pulmonary resuscitation (CPR) according to current resuscitation guidelines. A novel electrical stimulus called medium voltage therapy (MVT) has shown efficacy in producing coronary and carotid blood flow during ventricular fibrillation. This report presents the case that the same stimulus may be effective and feasible for use in ICD patients that do not respond to their ICD therapy, or do not have a rhythm in which, an ICD shock is indicated. The inclusion of MVT technology in implantable devices may be effective in preparing the heart for successful defibrillation or in improving the metabolic condition of the heart to the extent that a pulsatile rhythm may spontaneously develop.

AED use in a passenger during a long-haul flight: repeated defibrillation with a successful outcome.

PubMed

Harve, Heini; Hämäläinen, Olavi; Kurola, Jouni; Silfvast, Tom

2009-04-01

Sudden cardiac arrest is one of the leading causes of death, and early defibrillation of ventricular fibrillation (VF) is the single most important intervention for improving survival. The automated external defibrillator (AED) and the concept of public access defibrillation provide a solution to shorten defibrillation delays. Commercial aircraft create a unique environment for the use of the AED since an emergency medical service system (EMS) response is not available. We review published studies on this subject and describe the case of a passenger who developed VF during an intercontinental flight and was successfully resuscitated despite recurrent episodes of VF. A 60-yr-old man developed VF during a flight from Tokyo to Helsinki. VF frequently recurred and shocks were delivered 21 times altogether. The aircraft was diverted to the city of Kuopio. When the local EMS crew encountered the patient 3 h after the onset of the cardiac arrest, the rhythm again converted to VF and three further shocks were delivered. The patient recovered, and 3 wk later he was transported to his home country, fully alert. There are three large studies reporting placing AEDs on commercial aircraft. No harm for co-passengers or malfunctions were reported. Survival rates have been higher than those obtained by well-performing EMS. According to previous studies, placing AEDs on commercial aircraft is also cost effective. The absence of a suitable diversion destination should not influence the rescuers' decision to attempt CPR on board.

Lack of integration of automated external defibrillators with EMS response may reduce lifesaving potential of public-access defibrillation.

PubMed

Myers, J Brent; French, David; Webb, William

2005-01-01

Automated external defibrillators (AEDs) used for public-access defibrillation (PAD) allow for rapid defibrillation, particularly if the AEDs are incorporated into an organized response plan. This project was undertaken to determine how many PAD AEDs were in North Carolina, how many were properly registered, and how many were integrated into the emergency medical services (EMS) response. Data were collected for this prospective, descriptive study via phone survey, e-mail survey, and/or direct personal interview. Four sources were utilized: 1) state office of EMS AED registration database, 2) AED sales representatives, 3) county EMS agency representatives, and 4) American Heart Association (AHA) training center instructors and regional faculty. The primary endpoint was determining the proportion of AEDs placed in unregistered locations. The state EMS office provided the state registry of AED locations. One-hundred percent of state-recognized AED vendors and county EMS agencies provided data. Twelve of 55 (22%) AHA personnel provided data. Eight hundred eighty-one unique locations were identified. Although AED sales are required by law to be registered, the office of EMS database contained only 99 of the 552 (18%) unique PAD locations identified by the study. A large number of unregistered AEDs are being placed in communities. AEDs placed as part of an organized PAD program improve the rates of survival from sudden cardiac death. In the absence of registration, it is difficult to determine the extent to which these AEDs are part of an organized PAD program.

How, when, and where have rental automated external defibrillators been used in Japan?

PubMed

Ohta, Shoichi; Harikae, Kiyokazu; Sekine, Kazuhiro; Nemoto, Manabu

2014-08-01

Automated external defibrillators (AEDs) have been rented in various places in Japan. When rental AEDs are placed in locations where the probability of sudden cardiac arrest is high and permanent placement of AEDs is difficult, the possibility of improving survival rates might increase. In this preliminary study, we investigated how, when, and where rental AEDs have been used in Japan to clarify their characteristics when used in actual situations and to facilitate better usage in the future. We investigated the total number of AEDs rented, the duration of rental of each AED, the total number of AEDs rented monthly, the rental sites, the frequency and location of use, the number of defibrillations, and the time to defibrillation success for devices rented between January 2008 and December 2010 by a single company in Japan. The number of AEDs rented annually was 590 at 391 sites in 2008, 767 at 465 sites in 2009, and 847 at 477 sites in 2010. More AEDs were rented during the summer. The devices were actually used on 17 individuals, of whom 2 individuals (at a beach and a marathon) underwent defibrillation, and 1 individual (at a marathon) survived. Rental AEDs can play an important role in emergency cases occurring during seasonal and temporary outdoor events. The provision of rental AEDs in locations where permanent AEDs would be unfeasible may offer a useful strategy for efficiently improving survival rates in the future. Copyright © 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Three-year outcome of a nonthoracotomy approach to cardioverter-defibrillator implantation in 189 consecutive patients.

PubMed

Brooks, R; Garan, H; Torchiana, D; Vlahakes, G J; Dziuban, S; Newell, J; McGovern, B A; Ruskin, J N

1994-11-15

To date, no long-term clinical data have been published in patients undergoing a nonthoracotomy approach to cardioverter-defibrillator system implantation. In the present report, 189 consecutive patients prospectively underwent a standardized approach to cardioverter-defibrillator system implantation in which the nonthoracotomy configurations were tested first. If satisfactory defibrillation thresholds were not obtained, thoracotomy was performed during the same intraoperative session. A nonthoracotomy system was successfully implanted in 149 of 189 patients (79%), with a higher success rate (90%) observed in patients who had more recent implantations. The overall rate of complications associated with these systems was low (11%). Over a mean follow-up of 12.5 +/- 9.3 months, 17 patients (9%) died. Three-year total, cardiac, and sudden death-free actuarial survival for all patients was 83 +/- 11%, 88 +/- 7%, and 94 +/- 2%, respectively. Three-year sudden death-free actuarial survival was higher in the nonthoracotomy than in the thoracotomy patients (97 +/- 2% vs 87 +/- 6%, p = 0.047), although total survival was similar (77 +/- 11% vs 83 +/- 7%, p = 0.77). These data suggest that a majority of patients (> 80%) requiring a cardioverter-defibrillator system can undergo implantation using a nonthoracotomy approach. Patients receiving nonthoracotomy systems have 3-year outcomes comparable to those implanted via thoracotomy. If these results are maintained, a nonthoracotomy approach will supplant thoracotomy-implanted systems as the preferred method because of the simpler implant procedure and lower overall cost involved.

Success and failure of the defibrillation shock: insights from a simulation study.

PubMed

Skouibine, K; Trayanova, N; Moore, P

2000-07-01

This simulation study presents a further inquiry into the mechanisms by which a strong electric shock fails to halt life-threatening cardiac arrhythmias. The research uses a model of the defibrillation process that represents a sheet of myocardium as a bidomain. The tissue consists of nonuniformly curved fibers in which spiral wave reentry is initiated. Monophasic defibrillation shocks are delivered via two line electrodes that occupy opposite tissue boundaries. In some simulation experiments, the polarity of the shock is reversed. Electrical activity in the sheet is compared for failed and successful shocks under controlled conditions. The maps of transmembrane potential and activation times calculated during and after the shock demonstrate that weak shocks fail to terminate the reentrant activity via two major mechanisms. As compared with strong shocks, weak shocks result in (1) smaller extension of refractoriness in the areas depolarized by the shock, and (2) slower or incomplete activation of the excitable gap created by deexcitation of the negatively polarized areas. In its turn, mechanism 2 is associated with one or more of the following events: (a) lack of some break excitations, (b) latency in the occurrence of the break excitations, and (c) slower propagation through deexcited areas. Reversal of shock polarity results in a change of the extent of the regions of deexcitation, and thus, in a change in defibrillation threshold. The results of this study indicate the paramount importance of shock-induced deexcitation in both defibrillation and postshock arrhythmogenesis.

Low Energy Multi-Stage Atrial Defibrillation Therapy Terminates Atrial Fibrillation with Less Energy than a Single Shock

PubMed Central

Li, Wenwen; Janardhan, Ajit H.; Fedorov, Vadim V.; Sha, Qun; Schuessler, Richard B.; Efimov, Igor R.

2011-01-01

Background Implantable device therapy of atrial fibrillation (AF) is limited by pain from high-energy shocks. We developed a low-energy multi-stage defibrillation therapy and tested it in a canine model of AF. Methods and Results AF was induced by burst pacing during vagus nerve stimulation. Our novel defibrillation therapy consisted of three stages: ST1 (1-4 low energy biphasic shocks), ST2 (6-10 ultra-low energy monophasic shocks), and ST3 (anti-tachycardia pacing). Firstly, ST1 testing compared single or multiple monophasic (MP) and biphasic (BP) shocks. Secondly, several multi-stage therapies were tested: ST1 versus ST1+ST3 versus ST1+ST2+ST3. Thirdly, three shock vectors were compared: superior vena cava to distal coronary sinus (SVC>CSd), proximal coronary sinus to left atrial appendage (CSp>LAA) and right atrial appendage to left atrial appendage (RAA>LAA). The atrial defibrillation threshold (DFT) of 1BP shock was less than 1MP shock (0.55 ± 0.1 versus 1.38 ± 0.31 J; p =0.003). 2-3 BP shocks terminated AF with lower peak voltage than 1BP or 1MP shock and with lower atrial DFT than 4 BP shocks. Compared to ST1 therapy alone, ST1+ST3 lowered the atrial DFT moderately (0.51 ± 0.46 versus 0.95 ± 0.32 J; p = 0.036) while a three-stage therapy, ST1+ST2+ST3, dramatically lowered the atrial DFT (0.19 ± 0.12 J versus 0.95 ± 0.32 J for ST1 alone, p=0.0012). Finally, the three-stage therapy ST1+ST2+ST3 was equally effective for all studied vectors. Conclusions Three-stage electrotherapy significantly reduces the AF defibrillation threshold and opens the door to low energy atrial defibrillation at or below the pain threshold. PMID:21980076

Diabetes Mellitus and Outcomes of Cardiac Resynchronization With Implantable Cardioverter-Defibrillator Therapy in Older Patients With Heart Failure.

PubMed

Echouffo-Tcheugui, Justin B; Masoudi, Frederick A; Bao, Haikun; Spatz, Erica S; Fonarow, Gregg C

2016-08-01

Large-scale data on outcomes with cardiac resynchronization therapy with defibrillator in patients with diabetes mellitus are limited. We compared outcomes after cardiac resynchronization therapy with defibrillator implantation among patients with heart failure who have diabetes mellitus versus those without diabetes mellitus. Survival curves and covariate adjusted hazard ratio (HR) or odds ratio were used to assess the risks for death, readmission, and device-related complications by diabetes mellitus status among 18 428 patients at least 65 years old receiving cardiac resynchronization therapy with defibrillator from the National Cardiovascular Data Registry, implantable cardioverter-defibrillator registry between 2006 and 2009, with up to 3 years of follow-up. Accounting for differences between groups, compared with those without diabetes mellitus (n=11 345), patients with diabetes mellitus (n=7083) had a higher risk of death both at 1 year (HR, 1.16 [95% confidence interval (CI), 1.05-1.29]; P=0.0037) and 3 years (HR, 1.21 [1.14-1.29]; P<0.001) after device implantation and higher risks of all-cause readmission (sub-HR, 1.16 [1.11-1.21] at 1 year; P<0.0001; sub-HR, 1.15 [1.11-1.19] at 3 years; P<0.0001) and heart failure-related readmission (sub-HR, 1.18 [1.09-1.28] at 1 year; P<0.0001; and sub-HR, 1.22 [1.15-1.30] at 3 years; P<0.0001). Device-related complications within 90 days did not differ between those with and without diabetes mellitus (odds ratio: 0.90 [0.77-1.06]; P=0.37). Interactions of age, sex, ischemic cardiomyopathy, renal failure, or QRS duration were not significant. In older patients with heart failure receiving cardiac resynchronization therapy with defibrillator, diabetes mellitus was independently associated with greater risks of death and rehospitalization, but similar risks of procedural complications. © 2016 American Heart Association, Inc.

Emotions and health: findings from a randomized clinical trial on psychoeducational nursing to patients with implantable cardioverter defibrillator.

PubMed

Kikkenborg Berg, Selina; Støier, Louise; Moons, Philip; Zwisler, Ann-Dorthe; Winkel, Per; Ulrich Pedersen, Preben

2015-01-01

Serious illness will inevitably lead to a fundamental emotional reaction. Traditionally, in interventional treatment or rehabilitation trials, the psychological status of patients with implantable cardioverter defibrillators has been evaluated with anxiety and depression as outcome measures. In caring for these patients, the aim of nursing is to help patients manage life with complex heart disease. The early detection and management of negative emotional response might prevent the development of pathological conditions such as depression. The aims of this study were to (a) describe the trajectory of primary emotions over time in patients with implantable cardioverter defibrillators and (b) examine the potential effects of psychoeducational nursing on primary emotions. During the inclusion period (October 2007 to November 2009), 196 patients with implantable cardioverter defibrillator were randomized (1:1) to rehabilitation versus usual care. Rehabilitation consisted of a psychoeducational nursing component and an exercise training component. This article concerns phase 1, psychoeducational nursing, guided by a theory of nursing, Rosemary Rizzo Parses Human Becoming Practice Methodologies. The outcome measure is the Emotions and Health Scale. The scale consists of 8 primary emotions: joy, agreeableness, surprise, fear, sadness, disgust, anger, and anticipation. Mean (SD) age was 58 (13) years, and 79% of the participants were men. Significant improvements were found in primary emotional responses over time (P < .05) when combining groups. However, no difference in emotional intensity was found between the groups after 3 months of psychoeducational nursing intervention (P > .05). Primary emotions are affected after implantable cardioverter defibrillator implantation. Improvements over time were found. However, it was not possible to detect any effect of a short-term psychoeducational nursing intervention. Evaluating the primary emotions might be a good way for nurses to monitor patients' psychological outcomes because the instrument is sensitive to changes over a short period. Further development of early psychoeducational nursing interventions for patients with implantable cardioverter defibrillators is needed.

Impact of programming strategies aimed at reducing nonessential implantable cardioverter defibrillator therapies on mortality: a systematic review and meta-analysis.

PubMed

Tan, Vern Hsen; Wilton, Stephen B; Kuriachan, Vikas; Sumner, Glen L; Exner, Derek V

2014-02-01

Patients who receive implantable cardioverter defibrillator therapies are at higher risk of death versus those who do not. Programmed settings to reduce nonessential implantable cardioverter defibrillator therapies (therapy reduction programming) have been developed but may have adverse effects. This systematic review and meta-analysis assessed the relationship between therapy reduction programming with the risks of death from any cause, implantable cardioverter defibrillator shocks, and syncope. MEDLINE, EMBASE, and clinicaltrials.gov databases were searched to identify relevant studies. Those that followed patients for ≥6 months and reported mortality were included. Six met the inclusion criteria; 4 randomized (Comparison of Empiric to Physician-Tailored Programming of ICDs [EMPIRIC], Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy [MADIT-RIT], Avoid Delivering Therapies for Non-sustained Arrhythmias in ICD Patients III [ADVANCE III], and Programming Implantable Cardioverter-Defibrillators in Patients with Primary Prevention Indication to Prolong Time to First Shock [PROVIDE]) and 2 prospective studies (Role of Long Detection Window Programming in Patients With Left Ventricular Dysfunction, Non-ischemic Etiology in Primary Prevention Treated with a Biventricular ICD [RELEVANT] and Primary Prevention Parameters Evaluation [PREPARE]). These 6 studies included 7687 (3598 conventional and 4089 therapy reduction programming) patients. Most (77%) participants were men, had a history of ischemic heart disease (56%), and were prescribed β-blockers (84%). Therapy reduction programming was associated with a 30% relative reduction in mortality (95% confidence interval, 16%-41%; P<0.001). No significant heterogeneity among studies was observed (P=0.6). A similar 26% reduction in mortality was observed when only the 4 randomized trials were included (95% confidence interval, 11%-40%; P=0.002). These results were not significantly altered after adjustment for baseline characteristics. No significant difference in the risk of syncope was observed with conventional versus therapy reduction programming (P=0.5). Therapy reduction programming results in a large, significant, and consistent reduction in mortality, with no apparent increase in the risk of syncope.

Implantable cardioverter defibrillator use for primary prevention in ischaemic and non-ischaemic heart disease-indications in the post-DANISH trial era: results of the European Heart Rhythm Association survey.

PubMed

Haugaa, Kristina H; Tilz, Roland; Boveda, Serge; Dobreanu, Dan; Sciaraffia, Elena; Mansourati, Jacques; Papiashvili, Giorgi; Dagres, Nikolaos

2017-04-01

Implantable cardioverter-defibrillator (ICD) is the standard of care for prevention of sudden cardiac death (SCD) in high-risk patients. For primary prevention of SCD, in patients with ischaemic heart disease, there is more robust data on the effect of ICD therapy compared with patients with non-ischaemic heart disease, but current real-life practice may differ substantially. The aim of this European Heart Rhythm Association survey was to evaluate the clinical practice regarding implantation of ICD for primary prevention among European countries in patients with non-ischaemic and ischaemic heart disease. Furthermore, we wanted to investigate the impact of the results of the recently published DANISH trial on clinical practice among European countries. In total, 48 centres from 17 different countries responded to the questionnaire. The majority did not implant ICD for primary prevention on a regular basis in patients with non-ischaemic heart disease despite current guidelines. Also, centres have changed their indications after the recent report on the efficacy of ICD in these patients. In patients with ischaemic heart disease, the guidelines for primary prevention ICD were followed on a regular basis, and no relevant change in indications were reported. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Effects of Blended Cardiopulmonary Resuscitation and Defibrillation E-learning on Nursing Students' Self-efficacy, Problem Solving, and Psychomotor Skills.

PubMed

Park, Ju Young; Woo, Chung Hee; Yoo, Jae Yong

2016-06-01

This study was conducted to identify the educational effects of a blended e-learning program for graduating nursing students on self-efficacy, problem solving, and psychomotor skills for core basic nursing skills. A one-group pretest/posttest quasi-experimental design was used with 79 nursing students in Korea. The subjects took a conventional 2-week lecture-based practical course, together with spending an average of 60 minutes at least twice a week during 2 weeks on the self-guided e-learning content for basic cardiopulmonary resuscitation and defibrillation using Mosby's Nursing Skills database. Self- and examiner-reported data were collected between September and November 2014 and analyzed using descriptive statistics, paired t test, and Pearson correlation. The results showed that subjects who received blended e-learning education had improved problem-solving abilities (t = 2.654) and self-efficacy for nursing practice related to cardiopulmonary resuscitation and defibrillation (t = 3.426). There was also an 80% to 90% rate of excellent postintervention performance for the majority of psychomotor skills, but the location of chest compressions, compression rate per minute, artificial respiration, and verification of patient outcome still showed low levels of performance. In conclusion, blended E-learning, which allows self-directed repetitive learning, may be more effective in enhancing nursing competencies than conventional practice education.

Real-Time Control of the Embedded Waveform for External Defibrillation

DTIC Science & Technology

2001-10-25

independently from transthoracic electrical impedance changes during shock time. Keywords - External defibrillation, real-time control I. INTRODUCTION ...Additional such possibilities may be useful for development a new electrotherapy methods, as electrochemotherapy for cancer treatment [6]. II...Department, Moscow State Institute of Electronic Technology , Moscow, Russia Fig.1. High voltage delivery unit. Report Documentation Page Report Date 25

Risk Stratification in Arrhythmogenic Right Ventricular Cardiomyopathy.

PubMed

Calkins, Hugh; Corrado, Domenico; Marcus, Frank

2017-11-21

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by ventricular arrhythmias and an increased risk of sudden cardiac death. Although structural abnormalities of the right ventricle predominate, it is well recognized that left ventricular involvement is common, particularly in advanced disease, and that left-dominant forms occur. The pathological characteristic of ARVC is myocyte loss with fibrofatty replacement. Since the first detailed clinical description of the disorder in 1982, significant advances have been made in understanding this disease. Once the diagnosis of ARVC is established, the single most important clinical decision is whether a particular patient's sudden cardiac death risk is sufficient to justify placement of an implantable cardioverter-defibrillator. The importance of this decision reflects the fact that ARVC is a common cause of sudden death in young people and that sudden death may be the first manifestation of the disease. This decision is particularly important because these are often young patients who are expected to live for many years. Although an implantable cardioverter-defibrillator can save lives in individuals with this disease, it is also well recognized that implantable cardioverter-defibrillator therapy is associated with both short- and long-term complications. Decisions about the placement of an implantable cardioverter-defibrillator are based on an estimate of a patient's risk of sudden cardiac death, as well as their preferences and values. The primary purpose of this article is to provide a review of the literature that concerns risk stratification in patients with ARVC and to place this literature in the framework of the 3 authors' considerable lifetime experiences in caring for patients with ARVC. The most important parameters to consider when determining arrhythmic risk include electric instability, including the frequency of premature ventricular contractions and sustained ventricular arrhythmia; proband status; extent of structural disease; cardiac syncope; male sex; the presence of multiple mutations or a mutation in TMEM43; and the patient's willingness to restrict exercise and to eliminate participation in competitive or endurance exercise. © 2017 American Heart Association, Inc.

Remote monitoring reduces healthcare use and improves quality of care in heart failure patients with implantable defibrillators: the evolution of management strategies of heart failure patients with implantable defibrillators (EVOLVO) study.

PubMed

Landolina, Maurizio; Perego, Giovanni B; Lunati, Maurizio; Curnis, Antonio; Guenzati, Giuseppe; Vicentini, Alessandro; Parati, Gianfranco; Borghi, Gabriella; Zanaboni, Paolo; Valsecchi, Sergio; Marzegalli, Maurizio

2012-06-19

Heart failure patients with implantable cardioverter-defibrillators (ICDs) or an ICD for resynchronization therapy often visit the hospital for unscheduled examinations, placing a great burden on healthcare providers. We hypothesized that Internet-based remote interrogation systems could reduce emergency healthcare visits. This multicenter randomized trial involving 200 patients compared remote monitoring with standard patient management consisting of scheduled visits and patient response to audible ICD alerts. The primary end point was the rate of emergency department or urgent in-office visits for heart failure, arrhythmias, or ICD-related events. Over 16 months, such visits were 35% less frequent in the remote arm (75 versus 117; incidence density, 0.59 versus 0.93 events per year; P=0.005). A 21% difference was observed in the rates of total healthcare visits for heart failure, arrhythmias, or ICD-related events (4.40 versus 5.74 events per year; P<0.001). The time from an ICD alert condition to review of the data was reduced from 24.8 days in the standard arm to 1.4 days in the remote arm (P<0.001). The patients' clinical status, as measured by the Clinical Composite Score, was similar in the 2 groups, whereas a more favorable change in quality of life (Minnesota Living With Heart Failure Questionnaire) was observed from the baseline to the 16th month in the remote arm (P=0.026). Remote monitoring reduces emergency department/urgent in-office visits and, in general, total healthcare use in patients with ICD or defibrillators for resynchronization therapy. Compared with standard follow-up through in-office visits and audible ICD alerts, remote monitoring results in increased efficiency for healthcare providers and improved quality of care for patients. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00873899.

Real-world geographic variations in the use of cardiac implantable electronic devices - The PANORAMA 2 observational cohort study.

PubMed

Bastian, Dirk; Ebrahim, Iftikhar O; Chen, Ju-Yi; Chen, Mien-Cheng; Huang, Dejia; Huang, Jin-Long; Kuznetsov, Vadim A; Maus, Bärbel; Naik, Ajay M; Verhees, Koen J P; Fagih, Ahmed R Al

2018-06-13

Currently, several geographies around the world remain underrepresented in medical device trials. The PANORAMA 2 study was designed to assess contemporary region-specific differences in clinical practice patterns of patients with cardiac implantable electronic devices (CIEDs). In this prospective, multicenter, observational, multi-national study, baseline and implant data of 4,706 patients receiving Medtronic CIEDs (either de novo device implants, replacements, or upgrades) were analyzed, consisting of: 54% implantable pulse generators (IPGs), 20.3% implantable cardiac defibrillators (ICDs), 15% cardiac resynchronization therapy defibrillators (CRT-Ds), 5.1% cardiac resynchronization therapy pacemakers (CRT-Ps), from 117 hospitals in 23 countries across 4 geographical regions between 2012 and 2016. For all device types, in all regions, there were less females than males enrolled, and women were less likely to have ischemic cardiomyopathy. Implant procedure duration differed significantly across the geographies for all device types. Subjects from emerging countries, women and older patients were less likely to receive a magnetic resonance imaging (MRI)-compatible device. Defibrillation testing differed significantly between the regions. European patients had the highest rates of atrial fibrillation (AF), and the lowest number of implanted single-chamber IPGs. Evaluation of stroke history suggested that the general embolic risk is more strongly associated with stroke than AF. We provide comprehensive descriptive data on patients receiving Medtronic CIEDs from several geographies, some of which are understudied in randomized controlled trials (RCTs). We found significant variations in patient characteristics. Several medical decisions appear to be affected by socioeconomic factors. Long-term follow-up data will help evaluate if these variations require adjustments to outcome expectations. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Early Implantation of Primary Prevention Implantable Cardioverter Defibrillators for Patients with Newly Diagnosed Severe Nonischemic Cardiomyopathy.

PubMed

Voskoboinik, Aleksandr; Bloom, Jason; Taylor, Andrew; Mariani, Justin

2016-09-01

Primary prevention implantable cardioverter defibrillators (ICDs) reduce mortality in selected patients with severe systolic dysfunction. Current guidelines suggest a 3- to 6-month waiting period before implantation. We retrospectively studied 29 consecutive patients with newly diagnosed nonischemic cardiomyopathy (NICM) who underwent primary prevention ICD implantation within 6 months of diagnosis between January 2008 and April 2014. Cardiac MRI (CMR) evaluated left ventricular ejection fraction (LVEF) and regional fibrosis preimplant. The primary end point was "failure to qualify for an ICD at 12 months postimplant," either due to LVEF ≥ 35% or deterioration necessitating mechanical support or transplantation, without appropriate ICD therapy. Secondary end points were appropriate and inappropriate ICD therapy. Baseline mean age was 44.2 ± 14.8 years and median LVEF 16.4%. Median time from diagnosis to implant was 32 days. At 12 months, 17 patients (58.6%) no longer qualified for an ICD, mainly due to LVEF improvement. At follow-up (mean 32.0 ± 20.6 months), three patients received appropriate therapy (one for ventricular fibrillation). All three had CMR late gadolinium enhancement (LGE) and nonsustained ventricular tachycardia (NSVT) preimplant. Cardiac resynchronization at implant predicted LVEF improvement. Early appropriate therapy, particularly for ventricular fibrillation, is infrequent for patients with very severe NICM who have ICDs implanted within 6 months of diagnosis. The majority of these patients would not qualify for an ICD at 12 months postinsertion. In the absence of a multimodality risk score, early ICD insertion should only be considered in selected cases (presence of LGE and NSVT). Wearable cardioverter defibrillators may have a role as a bridge to ICD decision. © 2016 Wiley Periodicals, Inc.

Prognostic role of post-infarction C-reactive protein in patients undergoing implantation of cardioverter-defibrillators: design of the C-reactive protein Assessment after Myocardial Infarction to GUide Implantation of DEfibrillator (CAMI GUIDE) study.

PubMed

Bellocci, Fulvio; Biasucci, Luigi M; Gensini, Gian Franco; Padeletti, Luigi; Raviele, Antonio; Santini, Massimo; Giubilato, Giovanna; Landolina, Maurizio; Biondi-Zoccai, Giuseppe; Raciti, Giovanni; Sassara, Massimo; Castro, Antonello; Kheir, Antoine; Crea, Filippo

2007-04-01

Patients at risk of sudden cardiac death (SCD) after myocardial infarction (MI) can currently be offered effective means of prevention, such as implantable cardioverter-defibrillators (ICD). However, predictors of SCD able to identify those patients who are at higher risk are still lacking. Whether C-reactive protein (CRP), a serum inflammatory marker with established prognostic accuracy after MI, can also be a predictor of SCD is unclear. The CAMI GUIDE study is designed to evaluate the prognostic role of CRP in patients undergoing ICD implantation after MI according to MADIT II criteria (i.e. left ventricular ejection fraction

Safety of transvenous low energy cardioversion of atrial fibrillation in patients with a history of ventricular tachycardia: effects of rate and repolarization time on proarrhythmic risk.

PubMed

Simons, G R; Newby, K H; Kearney, M M; Brandon, M J; Natale, A

1998-02-01

The objective of this study was to assess the safety and efficacy of transvenous low energy cardioversion of atrial fibrillation in patients with ventricular tachycardia and atrial fibrillation and to study the mechanisms of proarrhythmia. Previous studies have demonstrated that cardioversion of atrial fibrillation using low energy, R wave synchronized, direct current shocks applied between catheters in the coronary sinus and right atrium is feasible. However, few data are available regarding the risk of ventricular proarrhythmia posed by internal atrial defibrillation shocks among patients with ventricular arrhythmias or structural heart disease. Atrial defibrillation was performed on 32 patients with monomorphic ventricular tachycardia and left ventricular dysfunction. Shocks were administered during atrial fibrillation (baseline shocks), isoproterenol infusion, ventricular pacing, ventricular tachycardia, and atrial pacing. Baseline shocks were also administered to 29 patients with a history of atrial fibrillation but no ventricular arrhythmias. A total of 932 baseline shocks were administered. No ventricular proarrhythmia was observed after well-synchronized baseline shocks, although rare inductions of ventricular fibrillation occurred after inappropriate T wave sensing. Shocks administered during wide-complex rhythms (ventricular pacing or ventricular tachycardia) frequently induced ventricular arrhythmias, but shocks administered during atrial pacing at identical ventricular rates did not cause proarrhythmia. The risk of ventricular proarrhythmia after well-synchronized atrial defibrillation shocks administered during narrow-complex rhythms is low, even in patients with a history of ventricular tachycardia. The mechanism of proarrhythmia during wide-complex rhythms appears not to be related to ventricular rate per se, but rather to the temporal relationship between shock delivery and the repolarization time of the previous QRS complex.

Electromagnetic Interference in Implantable Defibrillators in Single-Engine Fixed-Wing Aircraft.

PubMed

de Rotte, Alexandra A J; van der Kemp, Peter; Mundy, Peter A; Rienks, Rienk; de Rotte, August A

2017-01-01

Little is known about the possible electromagnetic interferences (EMI) in the single-engine fixed-wing aircraft environment with implantable cardio-defibrillators (ICDs). Our hypothesis is that EMI in the cockpit of a single-engine fixed-wing aircraft does not result in erroneous detection of arrhythmias and the subsequent delivery of an inappropriate device therapy. ICD devices of four different manufacturers, incorporated in a thorax phantom, were transported in a Piper Dakota Aircraft with ICAO type designator P28B during several flights. The devices under test were programmed to the most sensitive settings for detection of electromagnetic signals from their environment. After the final flight the devices under test were interrogated with the dedicated programmers in order to analyze the number of tachycardias detected. Cumulative registration time of the devices under test was 11,392 min, with a mean of 2848 min per device. The registration from each one of the devices did not show any detectable "tachycardia" or subsequent inappropriate device therapy. This indicates that no external signals, which could be originating from electromagnetic fields from the aircraft's avionics, were detected by the devices under test. During transport in the cockpit of a single-engine fixed-wing aircraft, the tested ICDs did not show any signs of being affected by electromagnetic fields originating from the avionics of the aircraft. This current study indicates that EMI is not a potential safety issue for transportation of passengers with an ICD implanted in a single-engine fixed-wing aircraft.de Rotte AAJ, van der Kemp P, Mundy PA, Rienks R, de Rotte AA. Electromagnetic interference in implantable defibrillators in single-engine fixed-wing aircraft. Aerosp Med Hum Perform. 2017; 88(1):52-55.

[Knowledge retain of BLS and BLS-D theoretical contents in a long-term follow-up].

PubMed

Paolini, Enrico; Conti, Elettra; Guerra, Federico; Capucci, Alessandro

2018-03-01

Despite the many recent improvements in basic life support (BLS) and the widespread training to a great number of lay rescuers, out-of-hospital cardiac arrest (OHCA) is still a major cause of death. Nowadays, BLS teaching protocols ask for many concepts to be learned and specific algorithms to be applied, without any available data on how much all these inputs are retained by the students. The present survey aims to evaluate how BLS is really retained by those rescuers (laypersons and nurses) who do not often put it into practice. The first survey was targeted at laypersons who are responsible for security in their work environment. The second survey was targeted at nurses operating in low-intensity wards or out-of-hospital clinics. Both surveys were anonymous and asked specific questions aimed at evaluating how BLS/BLS-D (BLS and defibrillation) information was retained on an average of 3 years after training completion. Lay rescuers showed difficulties in recognizing specific signs of OHCA, were unsure on when to call the emergency medical service and retained few and sometime erroneous information on the correct BLS sequence to perform. The nurses operating in low-intensity settings performed better in terms of OHCA recognition and advanced medical assistance activation, while how to set and operate an automatic external defibrillation was seldom clear. BLS information is usually not retained after a 3-year follow-up by people who are not involved in OHCA management as part of their everyday job. It should be useful to lower the number of concepts taught in current BLS courses in order to focus on the most significant aspects of it, such as prompt emergency medical system activation and early defibrillation.

Perceptions of an implantable cardioverter-defibrillator: A qualitative study of families with a history of sudden life-threatening cardiac events and recommendations to improve care

PubMed Central

Linder, Jarrett; Hidayatallah, Nadia; Stolerman, Marina; McDonald, Thomas V.; Marion, Robert; Walsh, Christine; Dolan, Siobhan

2014-01-01

Objective To identify major concerns associated with implantable cardioverter-defibrillators (ICDs) and to provide recommendations to adult and pediatric physicians involved in the care of patients with ICDs. Background Cardiac ion channelopathies are a well-recognized cause of sudden cardiac death in infants, children, adolescents, and young adults. ICDs are effective in preventing sudden death from fatal arrhythmias in patients with known cardiac channelopathies. There is a paucity of research on the effect of ICDs on quality of life in patients with cardiac channelopathy diagnoses, especially young patients. Methods A qualitative study interviewing patients and families affected by inherited arrhythmias was conducted. Fifty participants with personal or family histories of cardiac events or sudden death were interviewed individually or in focus groups by clinical psychologists. All interviews were transcribed verbatim and then analyzed and coded based on current qualitative research theory to identify themes related to the research question. Twenty-four participants discussed ICDs in their interviews. Results Participants reported concerns about ICDs, and these concerns were categorized into six themes: (1) comprehension and physician-patient communication; (2) anxiety; (3) restrictions and fallacies; (4) complications; (5) utility; and (6) alternative therapy. Participants noted communication breakdowns between providers and their colleagues, and between providers and their patients. Participants and their families experienced many different forms of anxiety, including worry about the aesthetics of the ICDs and fears of being shocked. Multiple restrictions, fallacies, and complications were also cited. Conclusion Interview themes were used to formulate recommendations for counseling and educating patients with ICDs. PMID:25383067

Clinical Usefulness of a Mobile Application for the Appropriate Selection of the Antiarrhythmic Device in Heart Failure.

PubMed

Curcio, Antonio; DE Rosa, Salvatore; Sabatino, Jolanda; DE Luca, Simona; Bochicchio, Angela; Polimeni, Alberto; Santarpia, Giuseppe; Ricci, Pietrantonio; Indolfi, Ciro

2016-07-01

Appropriate selection of implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT) device can be challenging in patients with left ventricular (LV) dysfunction. In this setting, limited information exists about the role of medical applications in helping physicians to choose the most useful device. We developed a medical application that provides guidelines-based algorithms for helping doctors in decision process using the Apache Cordova application programming interface. e-CRTD App was tested in 36 consecutive patients (age 66.4 ± 8.5 years, 31 males) with diagnosis of heart failure (HF) addressed to electrophysiology laboratory for evaluation of ICD (N = 18) or CRT with defibrillator device (CRT-D; N = 18) implantation. Two separate teams evaluated each patient independently: expert electrophysiologists (Group A); cardiologists in training using the App (Group B). The outcomes of the clinical evaluation performed by Groups A and B were similar in 100% of patients in terms of classes of recommendations to device (Class I in eight cases, Class IIa in seven cases, Class III in the remaining 21). Surprisingly, the majority of indications from the general practitioners to cardiac device were inappropriate (N = 17 ICD, and N = 4 CRT-D, Class III); nevertheless, e-CRTD App helped Group B (nonexpert cardiologists) in excluding all these cases. This study describes and validates a mobile application realized to help the decision-making process in HF patients candidate to ICD/CRT-D. This application supports physicians to assess the eligibility for ICD or CRT-D according to current guidelines in patients with LV dysfunction. © 2016 Wiley Periodicals, Inc.

[The Wearable Cardioverter-Defibrillator (WCD)].

PubMed

Helms, Thomas M; Müller, A; Schwab, J O; Bänsch, D; Karle, C; Klingenheben, T; Zugck, C; Perings, C

2015-06-01

While the implantable cardioverter-defibrillator (ICD) has been proven to be the best choice for patients with long-term risk for sudden cardiac arrest/sudden cardiac death (SCA/SCD), the question is how to manage patients with only temporary risk, e.g., during the guidelines-recommended waiting period until the decision for an ICD can be made. These patient groups should be monitored around the clock to guarantee a lifesaving shock within a few minutes, if necessary.These conditions can be accomplished by the wearable cardioverter-defibrillator (WCD) in the outpatient sector. The WCD is worn on the skin and consists of four nonadhesive ECG electrodes as well as three defibrillation electrodes-two at the back and one at the front-embedded in a garment. The defibrillation unit is connected via a cord and can be worn over the shoulder or on a belt. Cardiac events can be recorded and retrospectively analyzed by the treating physician.The WCD is a safe and effective measure to terminate potentially lethal ventricular tachycardia and ventricular fibrillation. It may be used early after myocardial infarction with reduced left ventricular ejection fraction (LVEF), as well as for patients with acute heart failure in nonischemic cardiomyopathy with uncertain cause and prognosis. In addition, it may be used for patients waiting for heart transplantation, for patients who cannot be implanted an ICD due to comorbidities, and for patients after explantation of their ICD, e.g., because of infection until reimplantation.One may expect that risk stratification of patients with the WCD will lead to even better selection for ICD use.

Prospective evaluation of defibrillation threshold and postshock rhythm in young ICD recipients.

PubMed

Radbill, Andrew E; Triedman, John K; Berul, Charles I; Walsh, Edward P; Alexander, Mark E; Webster, Gregory; Cecchin, Frank

2012-12-01

Adaptation of implantable cardioverter defibrillator (ICD) systems to the needs of pediatric and congenital heart patients is problematic due to constraints of vascular and thoracic anatomy. An improved understanding of the defibrillation energy and postshock pacing requirements in such patients may help direct more tailored ICD therapy. We describe the first prospective evaluation of defibrillation threshold (DFT) and postshock rhythm in this population. We prospectively studied patients ≤ 60 kg at time of ICD intervention. DFTs were obtained using a binary search protocol with three VF inductions. Postshock pacing was programmed using a stepwise protocol, lowering the rate prior to each VF induction. Twenty patients were enrolled: 11 had channelopathy, five congenital heart disease, and four cardiomyopathy. The median age was 16 years, median weight 48 kg. Twelve patients had a transvenous high-voltage coil; eight had pericardial +/- subcutaneous coil(s). Median DFT was 7 J (range 3-31 J); 19/20 patients had DFT ≤ 15 J and all patients <25 kg had DFT ≤ 9 J (n = 6). There was no difference in DFT between patients with transvenous versus pericardial +/- subcutaneous coils (median 7 J vs 6 J, P = 0.59). No patient with normal atrioventricular conduction prior to defibrillation required postshock pacing (n = 16). There were no adverse events. These data suggest that many pediatric ICD patients have low DFTs and adequate postshock escape rhythm. This may help determine appropriate parameters for future design of pediatric-specific ICDs. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

Low energy transvenous cardioversion of short duration atrial tachyarrhythmias in humans using a single lead system.

PubMed

Heisel, A; Jung, J; Fries, R; Stopp, M; Sen, S; Schieffer, H; Ozbek, C

1997-01-01

The purpose of this study was to investigate the efficacy and safety of atrial cardioversion using an endocardial single lead system presently used for ventricular defibrillation. The study population consisted of 26 recipients of an ICD in combination with a conventional endocardial single lead system with the proximal spring electrode as anode in the SVC and the distal as cathode in the apex of the RV. Atrial tachyarrhythmias were induced by right atrial burst pacing. If the arrhythmia sustained > 1 minute, biphasic shocks synchronized with the R wave were delivered using the implanted device, beginning with an energy of 4 J. If 4 J failed to terminate the arrhythmia, energy was increased stepwise, if the first shock was successful, a step-down testing was performed after reinduction of atrial tachyarrhythmias. The mean atrial defibrillation threshold was 2.3 +/- 1.2 J (range, 0.5-5 J). A total of 154 shocks were delivered and no adverse effects were observed. The mean defibrillation threshold for atrial flutter was somewhat lower than that for AF (1.8 +/- 1 J vs 2.7 +/- 1.4 J, P = 0.08). There was no correlation between the atrial defibrillation threshold and a history of previously occurring atrial tachyarrhythmias, the kind of the underlying heart disease, a prescription of antiarrhythmic drugs, the dimension of the LA, the LVEF, or the ventricular DFT. Internal atrial cardioversion of short duration atrial tachyarrhythmias using a transvenous single lead system designed for ventricular defibrillation is feasible and safe at low energies, and may have important clinical applications.

Initial clinical experience with ambulatory use of an implantable atrial defibrillator for conversion of atrial fibrillation. Metrix Investigators.

PubMed

Daoud, E G; Timmermans, C; Fellows, C; Hoyt, R; Lemery, R; Dawson, K; Ayers, G M

2000-09-19

A recent study has shown that the implantable atrial defibrillator can restore sinus rhythm in patients with recurrent atrial fibrillation when therapy was delivered under physician observation. The objective of this study was to evaluate the safety and efficacy of ambulatory use of the implantable atrial defibrillator. An atrial defibrillator was implanted in 105 patients (75 men; mean age, 59+/-12 years) with recurrent, symptomatic, drug-refractory atrial fibrillation. After successful 3-month testing, patients could transition to ambulatory delivery of shock therapy. Patients completed questionnaires regarding shock therapy discomfort and therapy satisfaction using a 10-point visual-analog scale (1 represented "not at all," 10 represented "extremely") after each treated episode of atrial fibrillation. During a mean follow-up of 11.7 months, 48 of 105 patients satisfied criteria for transition and received therapy for 275 episodes of atrial fibrillation. Overall shock therapy efficacy was 90% with 1.6+/-1.2 shocks delivered per episode (median, 1). Patients rated shock discomfort as 5.2+/-2.4 for successful therapy and 4.2+/-2.2 for unsuccessful therapy (P:>0.05). The satisfaction score was higher for successful versus unsuccessful therapy (3.4+/-3. 3 versus 8.7+/-1.3, P:<0.05). There was no ventricular proarrhythmia observed throughout the course of this study. Ambulatory use of an implantable atrial defibrillator can safely and successfully convert most episodes of atrial fibrillation, often requiring only a single shock. Successful therapy is associated with high satisfaction and only moderate discomfort.

Automated external defibrillation training on the left or the right side - a randomized simulation study.

PubMed

Stærk, Mathilde; Bødtker, Henrik; Lauridsen, Kasper G; Løfgren, Bo

2017-01-01

Correct placement of the left automated external defibrillator (AED) electrode is rarely achieved. AED electrode placement is predominantly illustrated and trained with the rescuer sitting on the right side of the patient. Placement of the AED electrodes from the left side of the patient may result in a better overview of and access to the left lateral side of the thorax. This study aimed to investigate if training in automated external defibrillation on the left side compared to the right side of a manikin improves left AED electrode placement. Laypeople attending basic life support training were randomized to learn automated external defibrillation from the left or right side of a manikin. After course completion, participants used an AED and placed AED electrodes in a simulated cardiac arrest scenario. In total, 40 laypersons were randomized to AED training on the left (n=19 [missing data =1], 63% female, mean age: 47.3 years) and right (n=20, 75% female, mean age: 48.7 years) sides of a manikin. There was no difference in left AED electrode placement when trained on the left or right side: the mean (SD) distances to the recommended left AED electrode position were 5.9 (2.1) cm vs 6.9 (2.2) cm ( p =0.15) and to the recommended right AED electrode position were 2.6 (1.5) cm vs 1.8 (0.8) cm ( p =0.06), respectively. Training in automated external defibrillation on the left side of a manikin does not improve left AED electrode placement compared to training on the right side.

Beam Profile Disturbances from Implantable Pacemakers or Implantable Cardioverter-Defibrillator Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gossman, Michael S., E-mail: mgossman@tsrcc.com; Comprehensive Heart and Vascular Associates, Heart and Vascular Center, Ashland, KY; Medtronic, Inc., External Research Program, Mounds View, MN

2011-01-01

The medical community is advocating for progressive improvement in the design of implantable cardioverter-defibrillators and implantable pacemakers to accommodate elevations in dose limitation criteria. With advancement already made for magnetic resonance imaging compatibility in some, a greater need is present to inform the radiation oncologist and medical physicist regarding treatment planning beam profile changes when such devices are in the field of a therapeutic radiation beam. Treatment plan modeling was conducted to simulate effects induced by Medtronic, Inc.-manufactured devices on therapeutic radiation beams. As a continuation of grant-supported research, we show that radial and transverse open beam profiles of amore » medical accelerator were altered when compared with profiles resulting when implantable pacemakers and cardioverter-defibrillators are placed directly in the beam. Results are markedly different between the 2 devices in the axial plane and the sagittal planes. Vast differences are also presented for the therapeutic beams at 6-MV and 18-MV x-ray energies. Maximum changes in percentage depth dose are observed for the implantable cardioverter-defibrillator as 9.3% at 6 MV and 10.1% at 18 MV, with worst distance to agreement of isodose lines at 2.3 cm and 1.3 cm, respectively. For the implantable pacemaker, the maximum changes in percentage depth dose were observed as 10.7% at 6 MV and 6.9% at 18 MV, with worst distance to agreement of isodose lines at 2.5 cm and 1.9 cm, respectively. No differences were discernible for the defibrillation leads and the pacing lead.« less

[Knowledge and attitudes of citizens in the Basque Country (Spain) towards cardiopulmonary resuscitation and automatic external defibrillators].

PubMed

Ballesteros-Peña, S; Fernández-Aedo, I; Pérez-Urdiales, I; García-Azpiazu, Z; Unanue-Arza, S

2016-03-01

To explore the training, ability and attitudes towards cardiopulmonary resuscitation and the use of automatic defibrillators among the population of the Basque Country (Spain). A face-to-face survey. Capital cities of the Basque Country. A total of 605 people between 15-64 years of age were randomly selected. Information about the knowledge, perceptions and self-perceived ability to identify and assist cardiopulmonary arrest was requested. A total of 56.4% of the responders were women, 61.8% were occupationally active, and 48.3% had higher education. Thirty-seven percent of the responders claimed to be trained in resuscitation techniques, but only 20.2% considered themselves able to apply such techniques. Public servants were almost 4 times more likely of being trained in defibrillation compared to the rest of workers (OR 3.7; P<.001), while people with elementary studies or no studies were almost 3 times more likely of not being trained in cardiopulmonary resuscitation, in comparison with the rest (OR 2.7; P=.001). A total of 94.7% of the responders considered it "quite or very important" for the general population to be able to apply resuscitation, though 55% considered themselves unable to identify an eye witnessed cardiac arrest, and 40.3% would not recognize a public-access defibrillator. Citizens of the Basque Country consider the early identification and treatment of cardiorespiratory arrest victims to be important, though their knowledge in cardiopulmonary resuscitation and defibrillation is limited. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

Low-Dose, High-Frequency CPR Training Improves Skill Retention of In-Hospital Pediatric Providers

PubMed Central

Niles, Dana; Meaney, Peter A.; Aplenc, Richard; French, Benjamin; Abella, Benjamin S.; Lengetti, Evelyn L.; Berg, Robert A.; Helfaer, Mark A.; Nadkarni, Vinay

2011-01-01

OBJECTIVE: To investigate the effectiveness of brief bedside cardiopulmonary resuscitation (CPR) training to improve the skill retention of hospital-based pediatric providers. We hypothesized that a low-dose, high-frequency training program (booster training) would improve CPR skill retention. PATIENTS AND METHODS: CPR recording/feedback defibrillators were used to evaluate CPR quality during simulated arrest. Basic life support–certified, hospital-based providers were randomly assigned to 1 of 4 study arms: (1) instructor-only training; (2) automated defibrillator feedback only; (3) instructor training combined with automated feedback; and (4) control (no structured training). Each session (time: 0, 1, 3, and 6 months after training) consisted of a pretraining evaluation (60 seconds), booster training (120 seconds), and a posttraining evaluation (60 seconds). Excellent CPR was defined as chest compression (CC) depth ≥ one-third anterior-posterior chest depth, rate ≥ 90 and ≤120 CC per minute, ≤20% of CCs with incomplete release (>2500 g), and no flow fraction ≤ 0.30. MEASUREMENTS AND MAIN RESULTS: Eighty-nine providers were randomly assigned; 74 (83%) completed all sessions. Retention of CPR skills was 2.3 times (95% confidence interval [CI]: 1.1–4.5; P = .02) more likely after 2 trainings and 2.9 times (95% CI: 1.4–6.2; P = .005) more likely after 3 trainings. The automated defibrillator feedback only group had lower retention rates compared with the instructor-only training group (odds ratio: 0.41 [95% CI: 0.17–0.97]; P = .043). CONCLUSIONS: Brief bedside booster CPR training improves CPR skill retention. Our data reveal that instructor-led training improves retention compared with automated feedback training alone. Future studies should investigate whether bedside training improves CPR quality during actual pediatric arrests. PMID:21646262

The clinical benefit of cardiac resynchronization therapy optimization using a device-based hemodynamic sensor in a patient with dilated cardiomyopathy: a case report.

PubMed

Volpicelli, Mario; Covino, Gregorio; Capogrosso, Paolo

2015-12-19

Results on the evolution of the clinical status of patients undergoing cardiac resynchronization therapy with a defibrillator after automatic optimization of their cardiac resynchronization therapy are scarce. We observed a rapid and important change in the clinical status of our non-responding patient following activation of a sensor capable of weekly atrioventricular and interventricular delays' optimization. A 78-year-old Caucasian man presented with dilated cardiomyopathy, left bundle branch block, a left ventricular ejection fraction of 35 %, New York Heart Association class III/IV heart failure, and paroxysmal atrial fibrillation. Our patient was implanted with a cardiac resynchronization device with a defibrillator and the SonRtip atrial lead. Right ventricular and left ventricular leads were also implanted. Because of the recurrence of atrial fibrillation, the automatic optimization was set off at discharge. Consequently, the device did not optimize atrioventricular and interventricular delays (programming at discharge: 125 ms for the atrioventricular delay and 0 ms for the interventriculardelay). Our patient was treated with an anti-arrhythmic drug. Five months after implantation, his clinical status remained impaired (left ventricular ejection fraction = 30 %). The SonR signal amplitude had also decreased from 0.52 g to 0.29 g. Nevertheless, because our patient was no longer presenting with atrial fibrillation, the anti-arrhythmic treatment was stopped and the SonR optimization system was activated. After 2 months of automatic cardiac resynchronization therapy with defibrillator optimization, our patient's clinical status had significantly improved (left ventricular ejection fraction = 60 %, New York Heart Association class II) and the SonR signal amplitude had doubled shortly after the first weekly automatic optimization. In this non-responding patient, device-based automatic cardiac resynchronization therapy optimization was shown to significantly improve his clinical status.

Suppression of the cardiopulmonary resuscitation artefacts using the instantaneous chest compression rate extracted from the thoracic impedance.

PubMed

Aramendi, E; Ayala, U; Irusta, U; Alonso, E; Eftestøl, T; Kramer-Johansen, J

2012-06-01

To demonstrate that the instantaneous chest compression rate can be accurately estimated from the transthoracic impedance (TTI), and that this estimated rate can be used in a method to suppress cardiopulmonary resuscitation (CPR) artefacts. A database of 372 records, 87 shockable and 285 non-shockable, from out-of-hospital cardiac arrest episodes, corrupted by CPR artefacts, was analysed. Each record contained the ECG and TTI obtained from the defibrillation pads and the compression depth (CD) obtained from a sternal CPR pad. The chest compression rates estimated using TTI and CD were compared. The CPR artefacts were then filtered using the instantaneous chest compression rates estimated from the TTI or CD signals. The filtering results were assessed in terms of the sensitivity and specificity of the shock advice algorithm of a commercial automated external defibrillator. The correlation between the mean chest compression rates estimated using TTI or CD was r=0.98 (95% confidence interval, 0.97-0.98). The sensitivity and specificity after filtering using CD were 95.4% (88.4-98.6%) and 87.0% (82.6-90.5%), respectively. The sensitivity and specificity after filtering using TTI were 95.4% (88.4-98.6%) and 86.3% (81.8-89.9%), respectively. The instantaneous chest compression rate can be accurately estimated from TTI. The sensitivity and specificity after filtering are similar to those obtained using the CD signal. Our CPR suppression method based exclusively on signals acquired through the defibrillation pads is as accurate as methods based on signals obtained from CPR feedback devices. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Optimizing a Drone Network to Deliver Automated External Defibrillators.

PubMed

Boutilier, Justin J; Brooks, Steven C; Janmohamed, Alyf; Byers, Adam; Buick, Jason E; Zhan, Cathy; Schoellig, Angela P; Cheskes, Sheldon; Morrison, Laurie J; Chan, Timothy C Y

2017-06-20

Public access defibrillation programs can improve survival after out-of-hospital cardiac arrest, but automated external defibrillators (AEDs) are rarely available for bystander use at the scene. Drones are an emerging technology that can deliver an AED to the scene of an out-of-hospital cardiac arrest for bystander use. We hypothesize that a drone network designed with the aid of a mathematical model combining both optimization and queuing can reduce the time to AED arrival. We applied our model to 53 702 out-of-hospital cardiac arrests that occurred in the 8 regions of the Toronto Regional RescuNET between January 1, 2006, and December 31, 2014. Our primary analysis quantified the drone network size required to deliver an AED 1, 2, or 3 minutes faster than historical median 911 response times for each region independently. A secondary analysis quantified the reduction in drone resources required if RescuNET was treated as a large coordinated region. The region-specific analysis determined that 81 bases and 100 drones would be required to deliver an AED ahead of median 911 response times by 3 minutes. In the most urban region, the 90th percentile of the AED arrival time was reduced by 6 minutes and 43 seconds relative to historical 911 response times in the region. In the most rural region, the 90th percentile was reduced by 10 minutes and 34 seconds. A single coordinated drone network across all regions required 39.5% fewer bases and 30.0% fewer drones to achieve similar AED delivery times. An optimized drone network designed with the aid of a novel mathematical model can substantially reduce the AED delivery time to an out-of-hospital cardiac arrest event. © 2017 American Heart Association, Inc.

An Analysis for Capital Expenditure Decisions at a Naval Regional Medical Center.

DTIC Science & Technology

1981-12-01

Service Equipment Review Committee 1. Portable defibrilator Computed tomographic scanner and cardioscope 2. ECG cart Automated blood cell counter 3. Gas...system sterilizer Gas system sterilizer 4. Automated blood cell Portable defibrilator and counter cardioscope 5. Computed tomographic ECG cart scanner...dictating and automated typing) systems. e. Filing equipment f. Automatic data processing equipment including data communications equipment. g

Contracting Improvements Still Needed in DoD’s FY 2011 Purchases Made Through the Department of Veterans Affairs

DTIC Science & Technology

2012-12-07

Neiman Street Fort Detrick, MD 21702 Federal Supply Schedule 3) W81XWH-11-F-0122 332,069 Parts to rebuild Zoll Defibrillators , including...USA Medical Dept Activity Bldg 42817 Reilly Road Fort Bragg, NC 28310 Federal Supply Schedule 9) W91YTZ-11-F-0064 163,409 Defibrillators /Monitors

Evolution of power sources for implantable cardioverter defibrillators

NASA Astrophysics Data System (ADS)

Crespi, Ann M.; Somdahl, Sonja K.; Schmidt, Craig L.; Skarstad, Paul M.

The evolution of seven generations of power sources for implantable cardioverter defibrillators (ICD) is presented. The packaging efficiency of the power sources has steadily increased, resulting in smaller, lighter batteries while maintaining the required electrical characteristics. The main areas for improvement were reduction of headspace volume, reduction of separator volume, and a change from a two-cell battery to a single cell.

Cardiac Arrest During Medically-Supervised Exercise Training: A Report of Fifteen Successful Defibrillations.

ERIC Educational Resources Information Center

Pyfer, Howard R.; And Others

The Cardio-Pulmonary Research Institute conducted an exercise program for men with a history of coronary heart disease. Over 7 years, there were 15 cases of cardiac arrest during exercise (one for every 6,000 man-hours of exercise). Trained medical personnel were present in all cases, and all were resuscitated by electrical defibrillation with no…

Recent advances in pacemaker and implantable defibrillator therapy for young patients.

PubMed

Walsh, Edward P; Cecchin, Frank

2004-03-01

This review is intended to highlight major clinical advances over the past year related to (1). biventricular pacing as a treatment for dilated myopathy, (2). growing clinical experience with implantable cardioverter defibrillators in pediatrics, (3). technical advances in standard antibradycardia pacing, and (4). an appraisal of the newly updated ACC/AHA/NASPE guidelines for device implant in children and adolescents. Complex rhythm devices are being used more frequently in children. Biventricular pacing to improve ventricular contractility is a rapidly evolving technology that has now been applied to children and young adults with intraventricular conduction delay, such as bundle branch block after cardiac surgery. Implantable defibrillators are also being used for an expanding list of conditions, although lead dysfunction is seen as a fairly common complication in active young patients. Guidelines for device implantation have been developed, but the weight of evidence remains somewhat limited by the paucity of pediatric data in this field. Thanks to refinements in lead design and generator technology, coupled with rapidly expanding clinical indications, pacemakers and implantable defibrillators have become increasingly important components of cardiac therapy for young patients. Expanded multicenter clinical studies will be needed to develop more objective guidelines for use of this advanced technology.

[Successful use of an AED following anterior myocardial infarction].

PubMed

Harding, Ulf; Reifferscheid, Florian; von Olshausen, Klaus

2007-05-01

A participant of the annual Hamburg marathon collapses on the finish line. Medics at the scene find a conscious patient and prepare transport to the finish area medical center. During transport the patient becomes unconscious and pulseless. The medics immediately perform basic life support and cardiopulmonary resuscitation (CPR). An automated external defibrillator (AED) is attached and after analysis of the patient}s heart rhythm the patient is defibrillated twice. The ambulance service reach the scene with a delay. The emergency physician}s ECG shows ventricular fibrillation (VF) and two more defibrillations are delivered. Return of spontaneous circulation can be achieved. After stabilisation the patient is taken to hospital by ambulance. The ECG shows an anterior myocardial infarction and right bundle-branch block. The coronary angioplasty (PTCA) shows single-vessel disease with complete stenosis of the proximal part of the anterior interventricular branch. Revasucarisation is successful and a coronary stent is applied. The patient survives neurologically intact. This case report demonstrates the importance of readily available AED and specially trained medics. By immediately using the AED this patient was defibrillated before the ambulance service and emergency physician arrived at the scene. Spontaneous circulation was restored.

Hidden in plain sight: a crowdsourced public art contest to make automated external defibrillators more visible.

PubMed

Merchant, Raina M; Griffis, Heather M; Ha, Yoonhee P; Kilaru, Austin S; Sellers, Allison M; Hershey, John C; Hill, Shawndra S; Kramer-Golinkoff, Emily; Nadkarni, Lindsay; Debski, Margaret M; Padrez, Kevin A; Becker, Lance B; Asch, David A

2014-12-01

We sought to explore the feasibility of using a crowdsourcing study to promote awareness about automated external defibrillators (AEDs) and their locations. The Defibrillator Design Challenge was an online initiative that asked the public to create educational designs that would enhance AED visibility, which took place over 8 weeks, from February 6, 2014, to April 6, 2014. Participants were encouraged to vote for AED designs and share designs on social media for points. Using a mixed-methods study design, we measured participant demographics and motivations, design characteristics, dissemination, and Web site engagement. Over 8 weeks, there were 13 992 unique Web site visitors; 119 submitted designs and 2140 voted. The designs were shared 48 254 times on Facebook and Twitter. Most designers-voters reported that they participated to contribute to an important cause (44%) rather than to win money (0.8%). Design themes included: empowerment, location awareness, objects (e.g., wings, lightning, batteries, lifebuoys), and others. The Defibrillator Design Challenge engaged a broad audience to generate AED designs and foster awareness. This project provides a framework for using design and contest architecture to promote health messages.

Hidden in Plain Sight: A Crowdsourced Public Art Contest to Make Automated External Defibrillators More Visible

PubMed Central

Griffis, Heather M.; Kilaru, Austin S.; Sellers, Allison M.; Hershey, John C.; Hill, Shawndra S.; Kramer-Golinkoff, Emily; Nadkarni, Lindsay; Debski, Margaret M.; Padrez, Kevin A.; Becker, Lance B.; Asch, David A.

2014-01-01

Objectives. We sought to explore the feasibility of using a crowdsourcing study to promote awareness about automated external defibrillators (AEDs) and their locations. Methods. The Defibrillator Design Challenge was an online initiative that asked the public to create educational designs that would enhance AED visibility, which took place over 8 weeks, from February 6, 2014, to April 6, 2014. Participants were encouraged to vote for AED designs and share designs on social media for points. Using a mixed-methods study design, we measured participant demographics and motivations, design characteristics, dissemination, and Web site engagement. Results. Over 8 weeks, there were 13 992 unique Web site visitors; 119 submitted designs and 2140 voted. The designs were shared 48 254 times on Facebook and Twitter. Most designers–voters reported that they participated to contribute to an important cause (44%) rather than to win money (0.8%). Design themes included: empowerment, location awareness, objects (e.g., wings, lightning, batteries, lifebuoys), and others. Conclusions. The Defibrillator Design Challenge engaged a broad audience to generate AED designs and foster awareness. This project provides a framework for using design and contest architecture to promote health messages. PMID:25320902

[Sudden cardiac death in the youth. Is the new subcutaneous implantable cardioverter defibrillator S-ICD an alternative solution?].

PubMed

Roche, N-C; Stefuriac, M; Dumitrescu, N; Charbonnel, A; Godreuil, C; Bonnevie, L

2015-02-01

Implantable cardioverter defibrillator (ICD) is well-recognized therapy to prevent sudden cardiac death. Classic ICD need the use of permanent endocavitary leads, which may cause serious troubles (lead dislodgement, ventricular perforation, lead infections, etc.). The subcutaneous implantable cardioverter defibrillator (S-ICD) is a new device provided by only a subcutaneous lead. It has been developed for the last five years and it is becoming at present a real alternative to classic ICD. We report a clinical case of a 34 y.o. woman who presented a sudden cardiac death and who benefited the implantation of this new technology. This paper deals with the potential indications, usefulness benefits, and problems of the S-ICD. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

[Effectiveness of preclinical emergency management. Fiction or fact?].

PubMed

Dick, W F

1996-01-01

The current increase in the cost of health care must be considered as a severe threat to the prehospital emergency services system. Two examples have been selected--the patient with polytrauma and the patient in cardiac arrest--to demonstrate the dilemma between a need for objective data and the requirements of emergency patients. Study results obtained in trauma patients indicating that total prehospital time, including scene time, is correlated to patient outcome have led to the conclusion that at the scene treatment by emergency physicians may be dispensable. It has, however also been demonstrated that the time required for medical treatment at the scene is equivalent to 20% of the total scene time, thus representing only a fraction of the total prehospital time. Correlating the total prehospital time or scene time to outcome therefore appears absurd. The treatment principle of aggressive shock treatment in polytrauma needs critical reevaluation on the basis of results obtained by recent preclinical studies in patients with penetrating torso injuries. Small volume resuscitation could not be demonstrated to improve outcome in polytrauma patients, although a slight improvement in patients with brain injury may be assumed. Endotracheal intubation and early artificial ventilation are proven therapeutic principles in polytraumatized patients. Unfortunately, for ethical reasons randomised carefully controlled comparative studies can not be performed in polytrauma patients unless the patient is fully conscious. The importance of endotracheal intubation and artificial ventilation in unconscious trauma patients becomes apparent under conditions of anaesthesia where the application of the endotracheal tube averts regurgitation, aspiration and concomitant morbidity and mortality. The common causes of cardiovascular collapse and their pathomechanisms, as well as the mechanisms of cardiopulmonary resuscitation, have been widely investigated. Nevertheless, various aspects of their application are still controversial. The most recent study results have recommended initial ventilation prior to thoracic compression. New methods of assisting mechanical cardiopulmonary resuscitation, such as ACD CPR or vest CPR, have shown promising results in animal experiments. However, the importance of results obtained by preclinical randomised controlled investigations in humans need to be confirmed by further studies as to outcome. The efficacy of defibrillation in cases of ventricular fibrillation has been clearly demonstrated, particularly with a view to the interval between ventricular fibrillation and defibrillation. It has further been demonstrated that basic cardiopulmonary resuscitation preserves ventricular fibrillation and thus improves the chance of survival. The present generation of defibrillators has been further improved, particularly by the introduction of biphasic defibrillator wave forms, which may reduce the required energy, as well as possible complications, while offering an increase in the efficacy of defibrillation and a reduction in defibrillator size. Scientific emergency medicine is responsible not only for the development and validation of new methods and concepts, but in particular for their application under quality control conditions. Politicians require an improvement in the quality of the validation of emergency measures, although the instruments available for the investigation of these measures are known to be obsolete (experimental models, experimental design). Additionally, the financial support of research in emergency medicine suffers from being accourded low priority by public research funds such as the German Research Fund. However, in view of the rapid application of experimental results to daily practice it should be emphasized that patients also support research in emergency medicine via their direct financial contributions to the health insurance companies.

Defibrillation and resuscitation in a piglet model of pediatric ventricular fibrillation following AHA 2005 guidelines.

PubMed

Zhou, Zhengyu; Wang, Yubin; Zhou, Huiying; Huang, Meng; Liu, Huiting; Hsieh, Chengtai; Xue, Zhimou

2010-08-01

To evaluate the efficacy and safety of defibrillation on children according to AHA 2005 recommendations Pig resembles human in the chest configuration, anatomy and physiology of the cardiovascular and pulmonary systems. Piglets weighing 7.0 Kg ± 1.4kg, 14.0kg ± 2.8kg, 25.0kg ± 5.0kg respectively, which represented children 1 to 8 yr old were induced ventricular fibrillation (VF). An adult biphasic AED was used in conjunction with pediatric attenuating electrodes which could deliver 50-J shock for 2 min and two min of cardiopulmonary resuscitation (CPR) immediately followed it. If VF did not reverse, 70-J shock combined with CPR was used, and the protocol was repeated five times. If an organized cardiac rhythm with mean aortic pressure more than 60 mmHg persisted for an interval of 5 minutes, the animal was regarded as successfully resuscitated. If the AED recognized a "non-shockable" rhythm, CPR was also performed immediately for 2 min. The same resuscitation program was exercised on piglets of manual defibrillator group. Neurologic alertness score, hemodynamic and myocardial functions were evaluated, autopsy was routinely performed to document possible injuries. In the AED group, 14 out of 15 animals, were successfully resuscitated, among them 11 piglets were resuscitated by 50-J defibrillation combined with cardiopulmonary resuscitation, and other three recovered to normal by 1 or 2 times of 70-J shocks and CPR. All animals in manual defibrillator group were successfully resuscitated by 50-J shocks and CPR. Left ventricular ejection fraction and fractional area change were reduced significantly during 3-4 hr post-resuscitation (P<0.05) and returned to baseline ranges at the end of 72 hr. There was no evidence of myocardial and pulmonary damage during autopsy, and neurologic recovery was also normal. Data of blood gas analysis, blood electrolytes and myocardial enzymes does not show any statistically significant difference (P> 0.05) in the groups. 50 J biphasic dose defibrillation combined with effective CPR, successfully terminated VF without adverse effects on myocardial function and survival in a piglet defibrillation model for young children 1 to 8 yr of age. The new guidelines recommendation that one shock immediately followed by CPR is reasonable. Adults AED combined with pediatric electrodes is feasible to the diagnosis and treatment of pediatric VF model. But the user should not rely too much on AED's "automatic" function, but should accumulate and integrate his experience with AED technology.

Impact of city police layperson education and equipment with automatic external defibrillators on patient outcome after out of hospital cardiac arrest.

PubMed

Stein, Philipp; Spahn, Gabriela H; Müller, Stefan; Zollinger, Andreas; Baulig, Werner; Brüesch, Martin; Seifert, Burkhardt; Spahn, Donat R

2017-09-01

Out of hospital cardiac arrest (OHCA) occurs frequently and the outcome is often dismal. Early defibrillation saves lives and brain function in OHCA. The Zurich city police (STAPO) forces were instructed and equipped to provide basic life support (BLS) and to use an AED in 2009. Retrospective observational study comparing period 1 (P1) 2004-2009 before equipping and training of the STAPO and period 2 (P2) 2010-2015 after the implementation. Patients suffering from OHCA of cardiac or presumed cardiac origin in the city of Zurich undergoing CPR by EMS in P1 (n=709) and P2 (n=684) were included. Intervention periods and outcome were compared between the periods. Outcome variables were adjusted for patient age and gender, witnessed status, and defibrillation by the EMS, STAPO, layperson or no defibrillation. In P2, CPR was started by the STAPO in a median of 8 (IQR 6-9) minutes after the arrest and thus significantly earlier (median 3min) than by the EMS (p<0.001). STAPO performed the first defibrillation in a median of 9 (IQR 8-10) minutes and thus significantly earlier (median 6min) than the EMS (p<0.001). Outcome improved significantly in P2: proportion of patients with return of spontaneous circulation (ROSC, P2 35.8%, P1 24.0%, OR 1.8, 95% CI 1.4-2.2, p<0.001), hospital admission (P2 32.2%, P1 21.4%, OR 1.7, 95% CI 1.4-2.2, p<0.001) and survival to hospital discharge (P2 13.6%, P1 6.9%, OR 2.1 95% CI 1.5-3.0, p<0.001). If the patient was firstly defibrillated by the STAPO, ROSC (STAPO 74.4%, adj. OR 2.6, 95% CI 1.3-5.4, p=0.010) and hospital admission (STAPO 72.1%, adj. OR 2.8, 95% CI 1.4-5.6, p=0.005) was higher compared to patients firstly defibrillated by the EMS. Survival to hospital discharge (STAPO 30.2%, adj. OR 1.4, 95% CI 0.7-2.9, p=0.38) was unchanged. Dispatching BLS trained and AED equipped police forces results in earlier and more successful resuscitation of OHCA victims, leading to higher proportions of patients with ROSC, hospital admission and survival to hospital discharge. Copyright © 2017 Elsevier B.V. All rights reserved.

Survival After Application of Automatic External Defibrillators Before Arrival of the Emergency Medical System

PubMed Central

Weisfeldt, Myron L.; Sitlani, Colleen M.; Ornato, Joseph P.; Rea, Thomas; Aufderheide, Tom P.; Davis, Daniel; Dreyer, Jonathan; Hess, Erik P.; Jui, Jonathan; Maloney, Justin; Sopko, George; Powell, Judy; Nichol, Graham; Morrison, Laurie J.

2010-01-01

Objectives The purpose of this study was to assess the effectiveness of contemporary automatic external defibrillator (AED) use. Background In the PAD (Public Access Defibrillation) trial, survival was doubled by focused training of lay volunteers to use an AED in high-risk public settings. Methods We performed a population-based cohort study of persons with nontraumatic out-of-hospital cardiac arrest before emergency medical system (EMS) arrival at Resuscitation Outcomes Consortium (ROC) sites between December 2005 and May 2007. Multiple logistic regression was used to assess the independent association between AED application and survival to hospital discharge. Results Of 13,769 out-of-hospital cardiac arrests, 4,403 (32.0%) received bystander cardiopulmonary resuscitation but had no AED applied before EMS arrival, and 289 (2.1%) had an AED applied before EMS arrival. The AED was applied by health care workers (32%), lay volunteers (35%), police (26%), or unknown (7%). Overall survival to hospital discharge was 7%. Survival was 9% (382 of 4,403) with bystander cardiopulmonary resuscitation but no AED, 24% (69 of 289) with AED application, and 38% (64 of 170) with AED shock delivered. In multivariable analyses adjusting for: 1) age and sex; 2) bystander cardiopulmonary resuscitation performed; 3) location of arrest (public or private); 4) EMS response interval; 5) arrest witnessed; 6) initial shockable or not shockable rhythm; and 7) study site, AED application was associated with greater likelihood of survival (odds ratio: 1.75; 95% confidence interval: 1.23 to 2.50; p < 0.002). Extrapolating this greater survival from the ROC EMS population base (21 million) to the population of the U.S. and Canada (330 million), AED application by bystanders seems to save 474 lives/year. Conclusions Application of an AED in communities is associated with nearly a doubling of survival after out-of-hospital cardiac arrest. These results reinforce the importance of strategically expanding community-based AED programs. PMID:20394876

Sotalol: An important new antiarrhythmic.

PubMed

Anderson, J L; Prystowsky, E N

1999-03-01

Sotalol, the most recently approved oral antiarrhythmic drug, has a unique pharmacologic profile. Its electrophysiology is explained by nonselective beta-blocking action as well as class III antiarrhythmic activity (including fast-activating cardiac membrane-delayed rectifier current blockade), which leads to increases in action potential duration and refractory period throughout the heart and in QT interval on the surface electrocardiogram. Its better hemodynamic tolerance than other beta-blockers may be a result of enhanced inotropy associated with class III activity. Sotalol's ability to suppress ventricular ectopy is similar to that of class I agents and better than that of standard beta-blockers. Unlike class I agents, its use in a postinfarction trial was not associated with increased mortality rate. Therapeutically, it has shown superior efficacy for prevention of recurrent ventricular tachycardia and ventricular fibrillation, which was the basis for its approval. In a randomized study, the Electrophysiologic Study Versus Electrocardiographic Monitoring (ESVEM) trial, sotalol was associated with an increased in-hospital efficacy prediction rate (by Holter monitor or electrophysiologic study), reduced long-term arrhythmic recurrence rate with superior tolerance, and lower mortality rate than class I ("standard") antiarrhythmic drugs. Sotalol was 1 of 2 drugs selected for comparison with implantable defibrillators in the recent National Institutes of Health Antiarrhythmics versus Implantable Defibrillator (AVID) study. Sotalol appears to be a preferred drug for use with implantable defibrillators; unlike some other agents (eg, amiodarone) it does not elevate and, indeed, may lower defibrillation threshold. Although unapproved for this use, sotalol is active against atrial arrhythmias. It has shown efficacy equivalent to propafenone and quinidine in preventing atrial fibrillation recurrence, but it is better tolerated than quinidine and provides excellent rate control during recurrence. Sotalol's major side effects are related to beta-blockade and the risk of torsades de pointes (acceptably small if appropriate precautions are taken). Unlike several other antiarrhythmics (eg, amiodarone), it has no pharmacokinetic drug-drug interactions, is not metabolized, and is entirely renally excreted. Initial dose is 80 mg twice daily, with gradual titration to 240 to 360 mg/day as needed. The daily dose must be reduced in renal failure. On the basis of favorable clinical trials and practice experience, sotalol has shown a steadily growing impact on the treatment of arrhythmias during its 5 years of market availability, a trend that is likely to continue.

Bradycardia, Syncope, and Left Ventricular Noncompaction Cardiomyopathy.

PubMed

Glancy, D Luke; Helmcke, Frederick R; Hoang, Allen P

2017-08-15

A 55-year-old man with syncopal episodes was found to have sinus bradycardia at a rate of 37 beats/min, an episode of nonsustained ventricular tachycardia, and left ventricular noncompaction cardiomyopathy. After placement of a dual-chamber cardioverter defibrillator 4 years ago, he has had no further syncopal episodes, and there have been no defibrillator shocks. Copyright © 2017 Elsevier Inc. All rights reserved.

Haditha General Hospital Under the Economic Support Fund Program Haditha, Iraq

DTIC Science & Technology

2009-06-23

disease from the use of the restrooms. Photos 10 and 11. Heart monitors and defibrillator machines (left) and standing...350 kilometers west of Baghdad, Haditha is a river-side community with an estimated population of 150,000. The hospital, located in the heart of...medical equipment requiring electricity; specifically, several heart monitors and defibrillator machines (Site Photo 10). This equipment appeared

The role of conductivity discontinuities in design of cardiac defibrillation

NASA Astrophysics Data System (ADS)

Lim, Hyunkyung; Cun, Wenjing; Wang, Yue; Gray, Richard A.; Glimm, James

2018-01-01

Fibrillation is an erratic electrical state of the heart, of rapid twitching rather than organized contractions. Ventricular fibrillation is fatal if not treated promptly. The standard treatment, defibrillation, is a strong electrical shock to reinitialize the electrical dynamics and allow a normal heart beat. Both the normal and the fibrillatory electrical dynamics of the heart are organized into moving wave fronts of changing electrical signals, especially in the transmembrane voltage, which is the potential difference between the cardiac cellular interior and the intracellular region of the heart. In a normal heart beat, the wave front motion is from bottom to top and is accompanied by the release of Ca ions to induce contractions and pump the blood. In a fibrillatory state, these wave fronts are organized into rotating scroll waves, with a centerline known as a filament. Treatment requires altering the electrical state of the heart through an externally applied electrical shock, in a manner that precludes the existence of the filaments and scroll waves. Detailed mechanisms for the success of this treatment are partially understood, and involve local shock-induced changes in the transmembrane potential, known as virtual electrode alterations. These transmembrane alterations are located at boundaries of the cardiac tissue, including blood vessels and the heart chamber wall, where discontinuities in electrical conductivity occur. The primary focus of this paper is the defibrillation shock and the subsequent electrical phenomena it induces. Six partially overlapping causal factors for defibrillation success are identified from the literature. We present evidence in favor of five of these and against one of them. A major conclusion is that a dynamically growing wave front starting at the heart surface appears to play a primary role during defibrillation by critically reducing the volume available to sustain the dynamic motion of scroll waves; in contrast, virtual electrodes occurring at the boundaries of small, isolated blood vessels only cause minor effects. As a consequence, we suggest that the size of the heart (specifically, the surface to volume ratio) is an important defibrillation variable.

Comparison of low-energy versus high-energy biphasic defibrillation shocks following prolonged ventricular fibrillation.

PubMed

Walcott, Gregory P; Melnick, Sharon B; Killingsworth, Cheryl R; Ideker, Raymond E

2010-01-01

Since the initial development of the defibrillator, there has been concern that, while delivery of a large electric shock would stop fibrillation, it would also cause damage to the heart. This concern has been raised again with the development of the biphasic defibrillator. To compare defibrillation efficacy, postshock cardiac function, and troponin I levels following 150-J and 360-J shocks. Nineteen swine were anesthetized with isoflurane and instrumented with pressure catheters in the left ventricle, aorta, and right atrium. The animals were fibrillated for 6 minutes, followed by defibrillation with either low-energy (n = 8) or high-energy (n = 11) shocks. After defibrillation, chest compressions were initiated and continued until return of spontaneous circulation (ROSC). Epinephrine, 0.01 mg/kg every 3 minutes, was given for arterial blood pressure < 50 mmHg. Hemodynamic parameters were recorded for four hours. Transthoracic echocardiography was performed and troponin I levels were measured at baseline and four hours following ventricular fibrillation (VF). Survival rates at four hours were not different between the two groups (low-energy, 5 of 8; high-energy, 7 of 11). Results for arterial blood pressure, positive dP/dt (first derivative of pressure measured over time, a measure of left ventricular contractility), and negative dP/dt at the time of lowest arterial blood pressure (ABP) following ROSC were not different between the two groups (p = not significant [NS]), but were lower than at baseline. All hemodynamic measures returned to baseline by four hours. Ejection fractions, stroke volumes, and cardiac outputs were not different between the two groups at four hours. Troponin I levels at four hours were not different between the two groups (12 +/- 11 ng/mL versus 21 +/- 26 ng/mL, p = NS) but were higher at four hours than at baseline (19 +/- 19 ng/mL versus 0.8 +/- 0.5 ng/mL, p < 0.05, groups combined). Biphasic 360-J shocks do not cause more cardiac damage than biphasic 150-J shocks in this animal model of prolonged VF and resuscitation.

Cost-utility analysis of the EVOLVO study on remote monitoring for heart failure patients with implantable defibrillators: randomized controlled trial.

PubMed

Zanaboni, Paolo; Landolina, Maurizio; Marzegalli, Maurizio; Lunati, Maurizio; Perego, Giovanni B; Guenzati, Giuseppe; Curnis, Antonio; Valsecchi, Sergio; Borghetti, Francesca; Borghi, Gabriella; Masella, Cristina

2013-05-30

Heart failure patients with implantable defibrillators place a significant burden on health care systems. Remote monitoring allows assessment of device function and heart failure parameters, and may represent a safe, effective, and cost-saving method compared to conventional in-office follow-up. We hypothesized that remote device monitoring represents a cost-effective approach. This paper summarizes the economic evaluation of the Evolution of Management Strategies of Heart Failure Patients With Implantable Defibrillators (EVOLVO) study, a multicenter clinical trial aimed at measuring the benefits of remote monitoring for heart failure patients with implantable defibrillators. Two hundred patients implanted with a wireless transmission-enabled implantable defibrillator were randomized to receive either remote monitoring or the conventional method of in-person evaluations. Patients were followed for 16 months with a protocol of scheduled in-office and remote follow-ups. The economic evaluation of the intervention was conducted from the perspectives of the health care system and the patient. A cost-utility analysis was performed to measure whether the intervention was cost-effective in terms of cost per quality-adjusted life year (QALY) gained. Overall, remote monitoring did not show significant annual cost savings for the health care system (€1962.78 versus €2130.01; P=.80). There was a significant reduction of the annual cost for the patients in the remote arm in comparison to the standard arm (€291.36 versus €381.34; P=.01). Cost-utility analysis was performed for 180 patients for whom QALYs were available. The patients in the remote arm gained 0.065 QALYs more than those in the standard arm over 16 months, with a cost savings of €888.10 per patient. Results from the cost-utility analysis of the EVOLVO study show that remote monitoring is a cost-effective and dominant solution. Remote management of heart failure patients with implantable defibrillators appears to be cost-effective compared to the conventional method of in-person evaluations. ClinicalTrials.gov NCT00873899; http://clinicaltrials.gov/show/NCT00873899 (Archived by WebCite at http://www.webcitation.org/6H0BOA29f).

Tunnel Propagation Following Defibrillation with ICD Shocks: Hidden Postshock Activations in the Left Ventricular Wall Underlie Isoelectric Window

PubMed Central

Constantino, Jason; Long, Yun; Ashihara, Takashi; Trayanova, Natalia A.

2010-01-01

Background Following near-defibrillation threshold (DFT) shocks from an ICD, the first postshock activation that leads to defibrillation failure arises focally after an isolelectric window (IW). The mechanisms underlying the IW remain incompletely understood. Objective The goal of this study was to provide mechanistic insight into the origins of postshock activations and IW following ICD shocks, and to link shock outcome to the preshock state of the ventricles. We hypothesized that the non-uniform ICD field results in the formation of an intramural excitable area (tunnel) only in the LV free wall, through which both pre-existing and new shock-induced wavefronts propagate during the IW. Methods Simulations were conducted using a realistic 3-D model of defibrillation in the rabbit ventricles. Biphasic ICD shocks of varying strengths were delivered to 27 different fibrillatory states. Results Following near-DFT shocks, regardless of preshock state, the main postshock excitable area was always located within LV free wall, creating an intramural tunnel. Either preexisting fibrillatory or shock-induced wavefronts propagated during the IW (duration of up to 74ms) in this tunnel and emerged as breakthroughs on LV epicardium. Preshock activity within the LV played a significant role in shock outcome: large number of preshock filaments resulted in an IW associated with tunnel propagation of preexisting rather than shock-induced wavefronts. Furthermore, shocks were more likely to succeed if LV excitable area was smaller. Conclusions The LV intramural excitable area is the primary reason for near-DFT failure. Any intervention that decreases the extent of this area will improve the likelihood of defibrillation success. PMID:20348028

The benefits of a simplified method for CPR training of medical professionals: a randomized controlled study.

PubMed

Allan, Katherine S; Wong, Natalie; Aves, Theresa; Dorian, Paul

2013-08-01

We developed and tested a training method for basic life support incorporating defibrillator feedback during simulated cardiac arrest (CA) to determine the impact on the quality and retention of CPR skills. 298 subjects were randomized into 3 groups. All groups received a 2h training session followed by a simulated CA test scenario, immediately after training and at 3 months. Controls used a non-feedback defibrillator during training and testing. Group 1 was trained and tested with an audiovisual feedback defibrillator. During training, Group 1 reviewed quantitative CPR data from the defibrillator. Group 2 was trained as per Group 1, but was tested using the non-feedback defibrillator. The primary outcome was difference in compression depth between groups at initial testing. Secondary outcomes included differences in rate, depth at retesting, compression fraction, and self-assessment. Groups 1 and 2 had significantly deeper compressions than the controls (35.3 ± 7.6 mm, 43.7 ± 5.8 mm, 42.2 ± 6.6 mm for controls, Groups 1 and 2, P=0.001 for Group 1 vs. controls; P=0.001 for Group 2 vs. controls). At three months, CPR depth was maintained in all groups but remained significantly higher in Group 1 (39.1 ± 9.9 mm, 47.0 ± 7.4 mm, 42.2 ± 8.4 mm for controls, Groups 1 and 2, P=0.001 for Group 1 vs. control). No significant differences were noted between groups in compression rate or fraction. A simplified 2h training method using audiovisual feedback combined with quantitative review of CPR performance improved CPR quality and retention of these skills. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Comparison of outcomes in patients undergoing defibrillation threshold testing at the time of implantable cardioverter-defibrillator implantation versus no defibrillation threshold testing.

PubMed

Hall, Burr; Jeevanantham, Vinodh; Levine, Ethan; Daubert, James; McNitt, Scott; Hall, Freburr; Jeevanantham, Vinodh; Levine, Ethan; Daubert, James; McNitt, Scott; Hall, Fred Morady And Frank Pelosiburr; Jeevanantham, Vinodh; Levine, Ethan; Daubert, James; McNitt, Scott; Morady, Fred Morady And Frank Pelosid; Pelosi, Frank

2007-01-01

Inability to perform defibrillation threshold (DFT) testing during implantable cardioverter defibrillator (ICD) implantation due to co-morbidities may influence long-term survival. Retrospective review at The University of Michigan (1999-2004) identified 55 patients undergoing ICD implantation without DFT testing ("No-DFT group"). A randomly selected sample of patients (n = 57) undergoing standard DFT testing ("DFT group") was compared in terms of appropriate shocks, clinical shock efficacy and all-cause mortality. DFT testing was withheld due to hypotension, atrial fibrillation with inability to exclude left atrial thrombus, left ventricular thrombus, CHF and/or ischemia. The No-DFT group had a similar appropriate shock rate, but lower total survival (69.1% vs. 91.2%, p = 0.004) than the DFT group. The No-DFT group had a higher incidence of ventricular fibrillation (VF) episodes (9.1% vs. 3.1%, p = 0.037), and deaths attributable to VF (3 of 17 deaths vs. 0 of 5 deaths) compared to the DFT group. Multivariate analysis found a trend toward increased risk of death in the No-DFT group (HR 3.18, 95% CI 0.82-12.41, p = 0.095) after adjusting for baseline differences in gender distribution, NYHA class and prior CABG. In summary, overall mortality was higher in the No-DFT group. More deaths attributable to VF occurred in the No-DFT group. Thus, DFT testing should therefore remain the standard of care. Nevertheless, ICD therapy should not be withheld in patients who meet appropriate implant criteria simply on the basis of clinical scenarios that preclude routine DFT testing. (Cardiol J 2007; 14: 463-469).

Automated external defibrillation training on the left or the right side – a randomized simulation study

PubMed Central

Stærk, Mathilde; Bødtker, Henrik; Lauridsen, Kasper G; Løfgren, Bo

2017-01-01

Background Correct placement of the left automated external defibrillator (AED) electrode is rarely achieved. AED electrode placement is predominantly illustrated and trained with the rescuer sitting on the right side of the patient. Placement of the AED electrodes from the left side of the patient may result in a better overview of and access to the left lateral side of the thorax. This study aimed to investigate if training in automated external defibrillation on the left side compared to the right side of a manikin improves left AED electrode placement. Methods Laypeople attending basic life support training were randomized to learn automated external defibrillation from the left or right side of a manikin. After course completion, participants used an AED and placed AED electrodes in a simulated cardiac arrest scenario. Results In total, 40 laypersons were randomized to AED training on the left (n=19 [missing data =1], 63% female, mean age: 47.3 years) and right (n=20, 75% female, mean age: 48.7 years) sides of a manikin. There was no difference in left AED electrode placement when trained on the left or right side: the mean (SD) distances to the recommended left AED electrode position were 5.9 (2.1) cm vs 6.9 (2.2) cm (p=0.15) and to the recommended right AED electrode position were 2.6 (1.5) cm vs 1.8 (0.8) cm (p=0.06), respectively. Conclusion Training in automated external defibrillation on the left side of a manikin does not improve left AED electrode placement compared to training on the right side. PMID:29066936

Cardiopulmonary resuscitation by trained responders versus lay persons and outcomes of out-of-hospital cardiac arrest: A community observational study.

PubMed

Park, Yoo Mi; Shin, Sang Do; Lee, Yu Jin; Song, Kyoung Jun; Ro, Young Sun; Ahn, Ki Ok

2017-09-01

The study aims to compare bystander processes of care (cardiopulmonary resuscitation (CPR) and defibrillation) and outcomes for witnessed presumed cardiac etiology in OHCA patients in whom initial resuscitation was provided by dedicated trained responder (TR) versus lay person (LP) bystanders. Data on witnessed and presumed cardiac OHCA in adults (15 years or older) from 2011 to 2015 in a metropolitan city with 10 million persons were collected, excluding cases in which the information on TRs, bystander CPR, defibrillation, and clinical outcomes was unknown. Exposure variables were TRs who were legally designated with CPR education and response and LPs who were bystanders who witnessed the OHCA by chance. The primary/secondary/tertiary outcomes were a good cerebral performance category (CPC) of 1 or 2, survival to discharge, and bystander defibrillation. A multivariable logistic regression analysis was used to calculate the adjusted odds ratio (AOR) with 95% confidence intervals (CIs), adjusting for potential confounders. Of 20,984 OHCA events, 6475 cases were ultimately analyzed. The TR group constituted 6.4% of the cases, and the patients showed significantly better survival and a good CPC. From the multivariable logistic regression analysis of the outcomes, by comparing the TR group with the LP group, the AOR (95% CIs) was 1.49 (1.04-2.15) for a good CPC, 1.59 (1.20-2.11) for survival to discharge, and 10.02 (7.04-14.26) for bystander defibrillation. The TR group witnessed a relatively low proportion of OHCA but was associated with better survival outcomes and good neurological recovery through higher CPR rates and defibrillation of adults older than 15 years with witnessed OHCA in a metropolitan city. Copyright © 2017 Elsevier B.V. All rights reserved.

Association between transthoracic impedance and electrical cardioversion success with biphasic defibrillators: An analysis of 1055 shocks for atrial fibrillation and flutter.

PubMed

Sadek, Mouhannad M; Chaugai, Varsha; Cleland, Mark J; Zakutney, Timothy J; Birnie, David H; Ramirez, F Daniel

2018-03-13

The relevance of transthoracic impedance (TTI) to electrical cardioversion (ECV) success for atrial tachyarrhythmias when using biphasic waveform defibrillators is unknown. TTI is predictive of ECV success with contemporary defibrillators. De-identified data stored in biphasic defibrillator memory cards from ECV attempts for atrial fibrillation (AF) or atrial flutter (AFL) over a 2-year period at our center were evaluated. ECV success, defined as arrhythmia termination and ≥ 1 sinus beat, was adjudicated by 2 blinded cardiac electrophysiologists. The association between TTI and ECV success was assessed via Cochrane-Armitage trend and Spearman rank correlation tests, as well as simple and multivariable logistic regression. The influence of TTI on the number of shocks and on cumulative energy delivered per patient was also examined. 703 patients (593 with AF, 110 with AFL) receiving 1055 shocks were included. Last shock success was achieved in 88.0% and 98.2% of patients with AF and AFL, respectively. In patients with AF, TTI was positively associated with last shock failure (P trend  =0.019), the need for multiple shocks (P trend  <0.001), and cumulative energy delivered (ρ = 0.348; P < 0.001). After adjusting for first shock energy, 10-Ω increments in TTI were associated with odds ratios of 1.36 (95% CI: 1.24-1.49) and 1.22 (95% CI: 1.09-1.37) for first and last shock failure, respectively (P < 0.001 for both). Although contemporary defibrillators are designed to compensate for TTI, this variable continues to be associated with ECV failure in patients with AF. Strategies to lower TTI during ECV for AF may improve procedural success. © 2018 Wiley Periodicals, Inc.

Longevity of implantable cardioverter defibrillators: a comparison among manufacturers and over time.

PubMed

von Gunten, Simon; Schaer, Beat A; Yap, Sing-Chien; Szili-Torok, Tamas; Kühne, Michael; Sticherling, Christian; Osswald, Stefan; Theuns, Dominic A M J

2016-05-01

Longevity of implantable cardioverter defibrillators (ICDs) is crucial for patients and healthcare systems as replacements impact on infection rates and cost-effectiveness. Aim was to determine longevity using very large databases of two teaching hospitals with a high number of replacements and a rather homogeneous distribution among manufacturers. The study population consists of all patients in whom an ICD was inserted in. All ICD manufacturers operating in Switzerland and the Netherlands and all implanted ICDs were included. Implantable cardioverter defibrillator replacements due to normal battery depletion were considered events, and other replacements were censored. Longevity was assessed depending on manufacturers, pacing mode, implant before/after 2006, and all parameters combined. We analysed data from 3436 patients in whom 4881 ICDs [44.2% VVI-ICDs, 27.4% DDD-ICDs, 26.3% cardiac resynchronization therapy (CRT)-ICDs, 2.0% subcutaneous ICDs] were implanted. The four major manufacturers had implant shares between 18.4 and 31.5%. Replacement due to battery depletion (27.4%) was performed for 1339 ICDs. Patient survival at 5 years was 80.1%. Longevity at 5 years improved in contemporary compared with elderly ICDs [63.9-80.6% across all ICDs, of 73.7-92.1% in VVIs, 58.2-76.1% in DDDs, and of 47.1-66.3% in CRT defibrillators, all P value < 0.05]. Remarkable differences were seen among manufacturers, and those with better performance in elderly ICDs were not those with better performance in contemporary ones. Implantable cardioverter defibrillator longevity increased in contemporary models independent of manufacturer and pacing mode. Still, significant differences exist among manufacturers. These results might impact on device selection. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

Primary Prevention of Sudden Death in Patients With Valvular Cardiomyopathy.

PubMed

Rodríguez-Mañero, Moisés; Barrio-López, María Teresa; Assi, Emad Abu; Expósito-García, Víctor; Bertomeu-González, Vicente; Sánchez-Gómez, Juan Miguel; González-Torres, Luis; García-Bolao, Ignacio; Gaztañaga, Larraitz; Cabanas-Grandío, Pilar; Iglesias-Bravo, José Antonio; Arce-León, Álvaro; la Huerta, Ana Andrés; Fernández-Armenta, Juan; Peinado, Rafael; Arias, Miguel Angel; Díaz-Infante, Ernesto

2016-03-01

Few data exist on the outcomes of valvular cardiomyopathy patients referred for defibrillator implantation for primary prevention. The aim of the present study was to describe the outcomes of this cardiomyopathy subgroup. This multicenter retrospective study included consecutive patients referred for defibrillator implantation to 15 Spanish centers in 2010 and 2011, and to 3 centers after 1 January 2008. Of 1174 patients, 73 (6.2%) had valvular cardiomyopathy. These patients had worse functional class, wider QRS, and a history of atrial fibrillation vs patients with ischemic (n=659; 56.1%) or dilated (n=442; 37.6%) cardiomyopathy. During a follow-up of 38.1 ± 21.3 months, 197 patients (16.7%) died, without significant differences among the groups (19.2% in the valvular cardiomyopathy group, 15.8% in the ischemic cardiomyopathy group, and 17.9% in the dilated cardiomyopathy group; P=.2); 136 died of cardiovascular causes (11.6%), without significant differences among the groups (12.3%, 10.5%, and 13.1%, respectively; P=.1). Although there were no differences in the proportion of appropriate defibrillator interventions (13.7%, 17.9%, and 18.8%; P=.4), there was a difference in inappropriate interventions (8.2%, 7.1%, and 12.0%, respectively; P=.03). All-cause and cardiovascular mortality in patients with valvular cardiomyopathy were similar to those in other patients referred for defibrillator implantation. They also had similar rates of appropriate interventions. These data suggest that defibrillator implantation in this patient group confers a similar benefit to that obtained by patients with ischemic or dilated cardiomyopathy. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Defibrillation testing in everyday medical practice during implantable cardioverter defibrillator implantation in France: analysis from the LEADER registry.

PubMed

Sadoul, Nicolas; Defaye, Pascal; Mouton, Elisabeth; Bizeau, Olivier; Dupuis, Jean-Marc; Blangy, Hugues; Delarche, Nicolas; Blanc, Jean-Jacques; Lazarus, Arnaud

2013-11-01

Defibrillation testing (DT) is usually performed during implantable cardioverter defibrillator (ICD) implantation. We conducted a multicentre prospective study to determine the DT procedures used in everyday practice, to compare the characteristics of patients with or without DT, and to compare severe adverse events in these two populations during implantation and follow-up. The LEADER registry enrolled 904 patients included for primo-implantation of a single (n=261), dual (n=230) or triple (n=429) defibrillation system in 42 French centres. Baseline characteristics of patients (62.0 ± 13.5 years; 88% men; primary indication 62%) who underwent ventricular fibrillation (VF) induction (VF induction group, n=810) and those who did not (untested group, n=94, representing 10.4% of the entire study population) revealed that the untested group were older (P<0.01), had a lower left ventricular ejection fraction, a wider QRS complex and a higher New York Heart Association class and were more often implanted for primary prevention (P<0.001 for all). The main reason given for not performing ICD testing was poor haemodynamic condition (59/94). At 1 year, the cumulative survival rate was 95% in tested patients and 85% in untested patients (P<0.001), mainly because of heart failure deaths. There was one sudden cardiac death in the VF induction group and none in the untested group (P=1.000). In this study, more than 10% of ICD patients were implanted without VF induction. Untested patients appeared to be sicker than tested patients, with a more severe long-term outcome, but without any difference in mortality due to arrhythmic events. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Healthcare Utilization and Expenditures Associated With Appropriate and Inappropriate Implantable Defibrillator Shocks.

PubMed

Turakhia, Mintu P; Zweibel, Steven; Swain, Andrea L; Mollenkopf, Sarah A; Reynolds, Matthew R

2017-02-01

In patients with implantable cardioverter-defibrillators, healthcare utilization (HCU) and expenditures related to shocks have not been quantified. We performed a retrospective cohort study of patients with implantable cardioverter-defibrillators identified from commercial and Medicare supplemental claims databases linked to adjudicated shock events from remote monitoring data. A shock event was defined as ≥1 spontaneous shocks delivered by an implanted device. Shock-related HCU was ascertained from inpatient and outpatient claims within 7 days following a shock event. Shock events were adjudicated and classified as inappropriate or appropriate, and HCU and expenditures, stratified by shock type, were quantified. Of 10 266 linked patients, 963 (9.4%) patients (61.3±13.6 years; 81% male) had 1885 shock events (56% appropriate, 38% inappropriate, and 6% indeterminate). Of these events, 867 (46%) had shock-related HCU (14% inpatient and 32% outpatient). After shocks, inpatient cardiovascular procedures were common, including echocardiography (59%), electrophysiology study or ablation (34%), stress testing (16%), and lead revision (11%). Cardiac catheterization was common (71% and 51%), but percutaneous coronary intervention was low (6.5% and 5.0%) after appropriate and inappropriate shocks. Expenditures related to appropriate and inappropriate shocks were not significantly different. After implantable cardioverter-defibrillator shock, related HCU was common, with 1 in 3 shock events followed by outpatient HCU and 1 in 7 followed by hospitalization. Use of invasive cardiovascular procedures was substantial, even after inappropriate shocks, which comprised 38% of all shocks. Implantable cardioverter-defibrillator shocks seem to trigger a cascade of health care. Strategies to reduce shocks could result in cost savings. © 2017 American Heart Association, Inc.

Acute and Long-term Results After Contemporary Subcutaneous Implantable Cardioverter-defibrillator Implantation: A Single-center Experience.

PubMed

Arias, Miguel A; Pachón, Marta; Akerström, Finn; Puchol, Alberto; Martín-Sierra, Cristina; Rodríguez-Padial, Luis

2017-12-05

The subcutaneous implantable cardioverter-defibrillator (S-ICD) has emerged as an alternative to the transvenous defibrillator. The incidence of complications is similar, with inappropriate shocks (IS) being more frequent than those occurring with contemporary programming of transvenous defibrillators. Several improvements have been implemented after the S-ICD was approved for use in Europe in 2009. This study reports the results of S-ICD use in a single center, whose experience began late, at the end of 2013. Prospective observational study including consecutive patients with defibrillator indication and no indication for either permanent pacing or cardiac resynchronization who underwent S-ICD implantation. Implant data and long-term follow-up were analyzed. An S-ICD was implanted in 50 patients who were deemed suitable after electrocardiographic screening. The mean age was 46.9±15 (range, 15-78) years and 72% were male. Thirty eight percent had left ventricular ejection fraction ≤ 35%. The most frequent heart disease was ischemic heart disease (34%), followed by hypertrophic cardiomyopathy (18%). The intermuscular technique was used, with 3 incisions in 10% and 2 incisions in the remaining 90%. Ventricular fibrillation was induced in 49 patients, with 100% effectiveness in their conversion. After a mean follow-up of 18.1 (range, 2.3-44.8) months, there were no late complications requiring surgical revision, the rate of IS was 0%, and 1 patient (2%) experienced appropriate shocks. Improvements in technology, implant technique and device programming, along with appropriate patient selection, have led to outstanding acute and long-term results, especially regarding the absence of both IS and complications requiring surgical revision. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Cost effectiveness and cost utility model of public place defibrillators in improving survival after prehospital cardiopulmonary arrest.

PubMed

Walker, Andrew; Sirel, Jane M; Marsden, Andrew K; Cobbe, Stuart M; Pell, Jill P

2003-12-06

To determine the cost effectiveness and cost utility of locating defibrillators in all major airports, railway stations, and bus stations throughout Scotland. Economic modelling exercise with data from Heartstart (Scotland). Parameters used in economic model included direct costs derived for increased accident and emergency attendances, increased hospital bed days, purchase and maintenance of defibrillators, and training in their use; life years gained calculated from increased discharges from hospital and mean survival after discharge; utility (quality of life) obtained from published data. Sensitivity analyses tested the robustness of model. Future gains discounted at 1.5% a year and future costs at 6%. Whole of Scotland. Records of all prehospital cardiac arrests due to presumed heart disease that occurred in a major airport, railway, or bus station between May 1991 and March 1998 and were not witnessed by ambulance or medical staff. Observed survival to hospital admission and observed survival to discharge. Predicted survival calculated by applying observed survival in patients attended by ambulance staff within three minutes to those who waited longer. The total discounted direct costs were 18 325 pounds sterling a year. The cost per life year gained was 29 625 pounds sterling (49 625 dollars, 43 151 Euros) and the cost per quality adjusted life year (QALY) gained was pound 41 146 (68 924 dollars, 59 932 Euros). More widespread provision of public place defibrillators would increase these figures. The cost per QALY calculated for public place defibrillators represents poorer value for money than some alternative strategies for improving survival after prehospital cardiopulmonary arrest, such as the use of other trained first responders. The figure exceeds the commonly discussed cut off levels for funding in the United Kingdom and United States of pound 30 000 and 50 000 dollars per QALY, respectively.

Superiority of Biphasic Over Monophasic Defibrillation Shocks is Attributable to Less Intracellular Calcium Transient Heterogeneity

PubMed Central

Hwang, Gyo-Seung; Tang, Liang; Joung, Boyoung; Morita, Norishige; Hayashi, Hideki; Karagueuzian, Hrayr S.; Weiss, James N.; Lin, Shien-Fong; Chen, Peng-Sheng

2008-01-01

Objectives To test the hypothesis that superiority of biphasic waveform (BW) over monophasic waveform (MW) defibrillation shocks is attributable to less intracellular calcium (Cai) transient heterogeneity. Background The mechanism by which BW shocks have a higher defibrillation efficacy than MW shocks remains unclear. Methods We simultaneously mapped epicardial membrane potential (Vm) and Cai during 6 ms MW and 3/3 ms BW shocks in 19 Langendorff-perfused rabbit ventricles. After shock, the percentage of depolarized area was plotted over time. The maximum (peak) postshock values (VmP and CaiP, respectively) were used to measure heterogeneity. Higher VmP and CaiP imply less heterogeneity. Results The defibrillation threshold was for BW and MW shocks were 288±99 V and 399±155 V, respectively (p=0.0005). Successful BW shocks had higher VmP (88±9 %) and CaiP (70±13 %) than unsuccessful MW shocks (VmP 76 %±10, p<0.001; CaiP, 57±8 %, p<0.001) of the same shock strength. In contrast, for unsuccessful BW and MW shocks of the same shock strengths, the VmP and CaiP were not significantly different. MW shocks more frequently created regions of low Cai surrounded by regions of high Cai (postshock Cai sinkholes). The defibrillation threshold for MW and BW shocks became similar after disabling the sarcoplasmic reticulum with thapsigargin and ryanodine. Conclusions The greater efficacy of BW shocks is directly related to their less heterogeneous effects on shock-induced sarcoplasmic reticulum Ca release and Cai transients. Less heterogeneous Cai transients reduces the probability of Cai sinkhole formation, thereby preventing the postshock reinitiation of VF. PMID:18755345

Superiority of biphasic over monophasic defibrillation shocks is attributable to less intracellular calcium transient heterogeneity.

PubMed

Hwang, Gyo-Seung; Tang, Liang; Joung, Boyoung; Morita, Norishige; Hayashi, Hideki; Karagueuzian, Hrayr S; Weiss, James N; Lin, Shien-Fong; Chen, Peng-Sheng

2008-09-02

The purpose of this study was to test the hypothesis that superiority of biphasic waveform (BW) over monophasic waveform (MW) defibrillation shocks is attributable to less intracellular calcium (Ca(i)) transient heterogeneity. The mechanism by which BW shocks have a higher defibrillation efficacy than MW shocks remains unclear. We simultaneously mapped epicardial membrane potential (Vm) and Ca(i) during 6-ms MW and 3-ms/3-ms BW shocks in 19 Langendorff-perfused rabbit ventricles. After shock, the percentage of depolarized area was plotted over time. The maximum (peak) post-shock values (VmP and Ca(i)P, respectively) were used to measure heterogeneity. Higher VmP and Ca(i)P imply less heterogeneity. The defibrillation thresholds for BW and MW shocks were 288 +/- 99 V and 399 +/- 155 V, respectively (p = 0.0005). Successful BW shocks had higher VmP (88 +/- 9%) and Ca(i)P (70 +/- 13%) than unsuccessful MW shocks (VmP 76 +/- 10%, p < 0.001; Ca(i)P 57 +/- 8%, p < 0.001) of the same shock strength. In contrast, for unsuccessful BW and MW shocks of the same shock strengths, the VmP and Ca(i)P were not significantly different. The MW shocks more frequently created regions of low Ca(i) surrounded by regions of high Ca(i) (post-shock Ca(i) sinkholes). The defibrillation threshold for MW and BW shocks became similar after disabling the sarcoplasmic reticulum (SR) with thapsigargin and ryanodine. The greater efficacy of BW shocks is directly related to their less heterogeneous effects on shock-induced SR Ca release and Ca(i) transients. Less heterogeneous Ca(i) transients reduces the probability of Ca(i) sinkhole formation, thereby preventing the post-shock reinitiation of ventricular fibrillation.

Inadvertent defibrillator lead placement into the left ventricle after MitraClip implantation: A case report.

PubMed

Santarpia, Giuseppe; Passafaro, Francesco; Pasceri, Eugenia; Mongiardo, Annalisa; Curcio, Antonio; Indolfi, Ciro

2018-05-01

Inadvertent pacemaker/defibrillator lead placement into the left ventricle is an unusual cardiac device-related complication and its diagnosis is not always easy and often misunderstood. Thromboembolic events are frequently associated with this procedural complication. Percutaneous lead extraction should be performed when diagnosis is made early after device implantation while long-life oral anticoagulation is a wise option when the diagnosis is delayed and the lead is not removed. A 65-year-old man affected by dilated cardiomyopathy, previously treated with a percutaneous mitral valve repair, with 2 MitraClip devices, and later with dual chamber cardioverter/defibrillator implantation, returned in outpatient clinics 2 months after discharge for deterioration of dyspnea; transthoracic echocardiography revealed that the shock lead had been accidentally placed in the apex of the left ventricle. The unintentional lead malposition through the iatrogenic atrial septal defect and its presence into the mitral valve orifice, together with the 2 clip devices implanted, generated an acceleration of transvalvular diastolic flow, determining a moderate stenosis of the mitral valve, as well as promoting a worsening of the degree of valvular regurgitation. Oral anticoagulation therapy was started and a mechanical lead extraction was percutaneously performed. A new defibrillator lead was later appropriately positioned in the apex of the right ventricle. The patient was discharged 3 days after intervention and the follow-up, performed 1 month after discharge, was uneventful. Complex interventional procedures and implantation of multiple devices can increase procedural troubles and the risk of mechanical complications related to pacemaker/defibrillator implantation. Careful observation of the QRS complex morphology on the electrocardiogram (ECG), during paced rhythm, and the achievement of the echocardiographic examination, in the postprocedural phase, allow an early diagnosis of lead malposition.

Revolving back to the basics in cardiopulmonary resuscitation.

PubMed

Roppolo, L P; Wigginton, J G; Pepe, P E

2009-05-01

Since the 1970s, most of the research and debate regarding interventions for cardiopulmonary arrest have focused on advanced life support (ALS) therapies and early defibrillation strategies. During the past decade, however, international guidelines for cardiopulmonary resuscitation (CPR) have not only emphasized the concept of uninterrupted chest compressions, but also improvements in the timing, rate and quality of those compressions. In essence, it has been a ''revolution'' in resuscitation medicine in terms of ''coming full circle'' to the 1960s when basic CPR was first developed. Recent data have indicated the need for minimally-interrupted chest compressions with an accompanying emphasis toward removing rescue ventilation altogether in sudden cardiac arrest, at least in the few minutes after a sudden unheralded collapse. In other studies, transient delays in defibrillation attempts and ALS interventions are even recommended so that basic CPR can be prioritized to first restore and maintain better coronary artery perfusion. New devices have now been developed to modify, in real-time, the performance of basic CPR, during both training and an actual resuscitative effort. Several new adjuncts have been created to augment chest compressions or enhance venous return and evolving technology may now be able to identify ventricular fibrillation (VF) without interrupting chest compressions. A renewed focus on widespread CPR training for the average person has also returned to center stage with ground-breaking training initiatives including validated video-based adult learning courses that can reliably teach and enable long term retention of basic CPR skills and automated external defibrillator (AED) use.

Public knowledge of automatic external defibrillators in a large U.S. urban community.

PubMed

Gonzalez, Mariana; Leary, Marion; Blewer, Audrey L; Cinousis, Marisa; Sheak, Kelsey; Ward, Michael; Merchant, Raina M; Becker, Lance B; Abella, Benjamin S

2015-07-01

Sudden cardiac arrest (SCA) strikes over 40,000 people in the public environment annually in the U.S., but despite evidence-based interventions such as prompt CPR and defibrillation, less than 25% of patients survive public SCA events. Effective use of automated external defibrillators (AEDs), especially by lay bystanders, represents an important strategy to improve survival rates. Previous investigations in Europe and Asia have demonstrated variable public awareness of AEDs; layperson knowledge of AEDs in the U.S. is poorly characterized. To measure understanding of AEDs among the general public, at multiple sites within a busy urban transportation system. Surveys were administered at two high-volume train stations in Philadelphia, Pennsylvania between April and June, 2013. A total of 514 surveys were completed. Two thirds (66%) of respondents were able to correctly identify an AED and its purpose, and just over half (58%) of respondents reported willingness to use an AED in an emergency situation. Less than 10% of respondents presented with a hypothetical SCA scenario spontaneously mentioned using an AED when asked what actions they would take. In this cross-sectional survey, public knowledge about AEDs and their use was high; however, a smaller number of respondents expressed thoughts of using the device in an emergency situation and demonstrated willingness to serve as a responder. Increased education and training efforts, as well as potential interventions such as 911 dispatcher-assisted AED use may help improve bystander response in SCA events. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Incidence and outcome of out-of-hospital cardiac arrest with public-access defibrillation. A descriptive epidemiological study in a large urban community.

PubMed

Sasaki, Mie; Iwami, Taku; Kitamura, Tetsuhisa; Nomoto, Shinichi; Nishiyama, Chika; Sakai, Tomohiko; Tanigawa, Kayo; Kajino, Kentaro; Irisawa, Taro; Nishiuchi, Tatsuya; Hayashida, Sumito; Hiraide, Atsushi; Kawamura, Takashi

2011-01-01

Detailed characteristics of those who experience an out-of-hospital cardiac arrest (OHCA) with public-access defibrillation (PAD) are unknown. A prospective, population-based observational study involving consecutive OHCA patients with emergency responder resuscitation attempts was conducted from July 1, 2004 through December 31, 2008 in Osaka City. We extracted data for OHCA patients shocked by a public-access automated external defibrillator (AED) and evaluated the patients' and rescuers' characteristics. The main outcome measure was neurologically favorable 1-month survival. During the study period, 10,375 OHCA patients were registered and of 908 patients suffering ventricular fibrillation arrest, 53 (6%) received public-access AED shocks by lay-rescuers, with the proportion increasing from 0% in 2004 to 11% in 2008 (P for trend<0.001). Railway stations (34%) were the places where PAD shocks were most frequently delivered, followed by nursing homes (11%), medical facilities (9%), and fitness facilities (7%). In 57% of cases, the subject received public-access AED shocks delivered by non-medical persons, including employees of railway companies (13%), school teachers (6%), employees of fitness facilities (6%), and security guards (6%). The proportion of neurologically favorable 1-month survival tended to increase from 0% in 2005 to 58% in 2008 (P for trend=0.081). Railway stations are the most common places where shocks by public-access AEDs were delivered in large urban communities of Japan, and among lay-rescuers railway station workers use AEDs more frequently.

Wearable cardioverter defibrillator: a life vest till the life boat (ICD) arrives.

PubMed

Francis, Johnson; Reek, Sven

2014-01-01

It is well established that implantable cardioverter defibrillator (ICD) is a life saving device ensuring protection against life threatening ventricular arrhythmias. But there are certain situations like a recent myocardial infarction where the standard guidelines do not recommend the implantation of an ICD while the patient can still be at a risk of demise due to a life threatening ventricular arrhythmia. There could also be a temporary indication for protection while explanting an infected ICD system. The wearable cardioverter defibrillator (WCD) is a device which comes to the rescue in such situations. In this brief review, we discuss the historical aspects of the development of a WCD, technical aspects as well as the clinical trial data and real world scenario of its use. Copyright © 2013 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Sudden cardiac death in hemodialysis patients: an in-depth review.

PubMed

Green, Darren; Roberts, Paul R; New, David I; Kalra, Philip A

2011-06-01

Sudden cardiac death (SCD) is the leading cause of death in hemodialysis patients, accounting for death in up to one-quarter of this population. Unlike in the general population, coronary artery disease and heart failure often are not the underlying pathologic processes for SCD; accordingly, current risk stratification tools are inadequate when assessing these patients. Factors assuming greater importance in hemodialysis patients may include left ventricular hypertrophy, electrolyte shift, and vascular calcification. Knowledge regarding SCD in hemodialysis patients is insufficient, in part reflecting the lack of an agreed-on definition of SCD in this population, although epidemiologic studies suggest the most common times for SCD to occur are toward the end of the long 72-hour weekend interval between dialysis sessions and in the 12 hours immediately after hemodialysis. Accordingly, it is hypothesized that the dialysis procedure itself may have important implications for SCD. Supporting this is recognition that hemodialysis is associated with both ventricular arrhythmias and dynamic electrocardiographic changes. Importantly, echocardiography and electrocardiography may show changes that are modifiable by alterations to dialysis prescription. The most effective preventative strategy in the general population, implanted cardioverter-defibrillator devices, are less effective in the presence of chronic kidney disease and have not been studied adequately in dialysis patients. Last, many dialysis patients experience SCD despite not fulfilling current criteria for implantation, making appropriate allocation of defibrillators uncertain. Copyright © 2011 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Constitutively Active Acetylcholine-Dependent Potassium Current Increases Atrial Defibrillation Threshold by Favoring Post-Shock Re-Initiation

PubMed Central

Bingen, Brian O.; Askar, Saïd F. A.; Neshati, Zeinab; Feola, Iolanda; Panfilov, Alexander V.; de Vries, Antoine A. F.; Pijnappels, Daniël A.

2015-01-01

Electrical cardioversion (ECV), a mainstay in atrial fibrillation (AF) treatment, is unsuccessful in up to 10–20% of patients. An important aspect of the remodeling process caused by AF is the constitutive activition of the atrium-specific acetylcholine-dependent potassium current (IK,ACh → IK,ACh-c), which is associated with ECV failure. This study investigated the role of IK,ACh-c in ECV failure and setting the atrial defibrillation threshold (aDFT) in optically mapped neonatal rat cardiomyocyte monolayers. AF was induced by burst pacing followed by application of biphasic shocks of 25–100 V to determine aDFT. Blocking IK,ACh-c by tertiapin significantly decreased DFT, which correlated with a significant increase in wavelength during reentry. Genetic knockdown experiments, using lentiviral vectors encoding a Kcnj5-specific shRNA to modulate IK,ACh-c, yielded similar results. Mechanistically, failed ECV was attributed to incomplete phase singularity (PS) removal or reemergence of PSs (i.e. re-initiation) through unidirectional propagation of shock-induced action potentials. Re-initiation occurred at significantly higher voltages than incomplete PS-removal and was inhibited by IK,ACh-c blockade. Whole-heart mapping confirmed our findings showing a 60% increase in ECV success rate after IK,ACh-c blockade. This study provides new mechanistic insight into failing ECV of AF and identifies IK,ACh-c as possible atrium-specific target to increase ECV effectiveness, while decreasing its harmfulness. PMID:26487066

Effective date of requirement for premarket approval for automated external defibrillator systems. Final rule.

PubMed

2015-01-29

The Food and Drug Administration (FDA or the Agency) is issuing a final order to require the filing of premarket approval applications (PMA) for automated external defibrillator (AED) systems, which consist of an AED and those AED accessories necessary for the AED to detect and interpret an electrocardiogram and deliver an electrical shock (e.g., pad electrodes, batteries, adapters, and hardware keys for pediatric use).

[Tachycardia detection in implantable cardioverter-defibrillators by Sorin/LivaNova : Algorithms, pearls and pitfalls].

PubMed

Kolb, Christof; Ocklenburg, Rolf

2016-09-01

For physicians involved in the treatment of patients with implantable cardioverter-defibrillators (ICDs) the knowledge of tachycardia detection algorithms is of paramount importance. This knowledge is essential for adequate device selection during de-novo implantation, ICD replacement, and for troubleshooting during follow-up. This review describes tachycardia detection algorithms incorporated in ICDs by Sorin/LivaNova and analyses their strengths and weaknesses.

Emergency response planning and sudden cardiac arrests in high schools after automated external defibrillator legislation.

PubMed

Watson, Andrew M; Kannankeril, Prince J; Meredith, Mark

2013-12-01

To compare medical emergency response plan (MERP) and automated external defibrillator (AED) prevalence and define the incidence and outcomes of sudden cardiac arrest (SCA) in high schools before and after AED legislation. In 2011, Tennessee Secondary School Athletic Association member schools were surveyed regarding AED placement, MERPs, and on-campus SCAs within the last 5 years. Results were compared with a similar study conducted in 2006, prior to legislation requiring AEDs in schools. Of the schools solicited, 214 (54%, total enrollment 182 289 students) completed the survey. Compared with 2006, schools in the 2011 survey had a significantly higher prevalence of MERPs (84% vs 71%, P < .001), annual practice (56% vs 36%, P < .001), medical emergency communication systems (80% vs 62%, P < .001), and defibrillators (90% vs 47%, P < .001). No differences were noted in the prevalence of cardiopulmonary resuscitation training (20% vs 17%, P = .58) or full compliance with American Heart Association guidelines (11% vs 7%, P = .16). Twenty-two SCA victims were identified, yielding a 5-year incidence of 1 in 10 schools. After state legislation, schools demonstrated a significant increase in MERPs and on-campus defibrillators but rates of cardiopulmonary resuscitation training and overall compliance with guidelines remained low. Copyright © 2013 Mosby, Inc. All rights reserved.

Evaluation of outpatients experiencing implantable cardioverter defibrillator shocks associated with minimal symptoms.

PubMed

Hamer, M E; Clair, W K; Wilkinson, W E; Greenfield, R A; Pritchett, E L; Page, R L

1994-05-01

Patients receiving minimally symptomatic shocks from their implantable cardioverter defibrillators were studied prospectively using transtelephonic ECG loop monitoring. The time course to the first subsequent shock was evaluated. Twenty-nine consecutive patients who received a shock preceded by mild palpitations or no symptoms were given a transtelephonic ECG loop monitor and instructed to activate the monitor if a subsequent shock occurred. Kaplan-Meier analysis was used to quantitate the time to first shock during the study period. The point estimate +/- standard error of patients receiving a shock during the study period was 31% +/- 9% at 30 days, 41% +/- 9% at 60 days, and 60% +/- 9% at 120 days. The ECG was successfully transmitted in 7 of 13 patients who had shocks in the 60-day monitoring period, and demonstrated inappropriate shocks in 6 of 7. Determination of the cause of shock led to a change in subsequent management in all 7 patients. We conclude that the incidence of inappropriate shocks may be higher than estimated previously in patients with minimal symptoms prior to the shock. There are thousands of patients with implantable cardioverter defibrillators that have no storage function for treated tachycardias; transtelephonic ECG loop monitoring can determine the cause of implantable cardioverter defibrillator discharge in these patients, and the diagnosis is invaluable in their management.

Review of the management of sudden cardiac arrest on the football field.

PubMed

Kramer, Efraim; Dvorak, Jiri; Kloeck, Walter

2010-06-01

Football is the most popular sport on earth. When a young, fit popular player suddenly collapses and dies during play, the tragic event is frequently screened and publicised worldwide. The reported incidence of sudden cardiac arrest (SCA) varies from 1:65,000 to 1:200,000 athletes. A broad spectrum of cardiac and non-cardiac causes have been implicated, and regular precompetition medical assessments are recommended as a preventive measure. Immediate cardiopulmonary resuscitation and early defibrillation is the treatment for SCA. High success rates can be achieved if this is initiated promptly, preferably within seconds of the arrest. Trained medical responders must be allowed to respond, ideally with a defibrillator (manual or automated) in hand, to a player who suddenly and unexpectedly collapses and remains unresponsive on the field. Immediate defibrillation of a pulseless ventricular tachycardia or ventricular fibrillation, within 1 to 2 min of onset, has a successful cardioversion rate exceeding 90%. Medical responders should be well trained and rehearsed in the recognition of SCA, including distractors such as seizures, myoclonic jerks and agonal (gasping) breathing. Prompt initiation of chest compressions on the field, together with early defibrillation, will result in many athletes' lives being saved by immediate implementation of these simple recommendations.

Wearable Cardioverter-Defibrillators following Cardiac Surgery-A Single-Center Experience.

PubMed

Heimeshoff, Jan; Merz, Constanze; Ricklefs, Marcel; Kirchhoff, Felix; Haverich, Axel; Bara, Christoph; Kühn, Christian

2018-06-20

 A wearable cardioverter-defibrillator (WCD) can terminate ventricular fibrillation and ventricular tachycardias via electrical shock and thus give transient protection from sudden cardiac death. We investigated its role after cardiac surgery.  We retrospectively analyzed all patients who were discharged with a WCD from cardiac surgery department. The WCD was prescribed for patients with a left ventricular ejection fraction (LVEF) of ≤35% or an explanted implantable cardioverter-defibrillator (ICD).  A total of 100 patients were included in this study, the majority ( n  = 59) had received coronary artery bypass graft surgery. The median wearing time of a WCD patient was 23.5 hours per day. LVEF was 28.9 ± 8% after surgery and improved in the follow-up to 36.7 ± 11% ( p  < 0.001). Three patients were successfully defibrillated. Ten patients experienced ventricular tachycardias. No inappropriate shocks were given. An ICD was implanted in 25 patients after the WCD wearing period.  Ventricular arrhythmias occurred in 13% of the investigated patients. LVEF improved significantly after 3 months, and thus a permanent ICD implantation was avoided in several cases. Sternotomy did not impair wearing time of the WCD. A WCD can effectively protect patients against ventricular tachyarrhythmias after cardiac surgery. Georg Thieme Verlag KG Stuttgart · New York.

The upper limit of vulnerability of the heart

NASA Astrophysics Data System (ADS)

Mazeh, Nachaat

Fibrillation is a major cause of death worldwide and it affects a very large part of the population. Its mechanism is not fully understood and the immediate remedy is to defibrillate. While defibrillation has been very successful, defibrillators apply a shock strength that could itself reinduce fibrillation. There exists an upper limit of vulnerability above which a shock does not induce reentry and therefore does not expose the patient to the reinduction of fibrillation. This upper limit of vulnerability has been predicted theoretically and observed experimentally, but the mechanism of the upper limit has not been well understood. This work will investigate the upper limit of vulnerability using a computer simulation. The bidomain model of the cardiac tissue has been used extensively for the past thirty years. The Beeler-Reuter model of the membrane kinetics has also been used in conjunction with the bidomain. This computer simulation of the bidomain and the Beeler-Reuter model will allow us to investigate the response of the induced virtual electrodes necessary to produce reentry. We will look at the vulnerable window and investigate the upper limit above which defibrillators can safely apply any shock strength to stop a fibrillation. One main conclusion is that widespread, random heterogeneities must be included in our model of cardiac tissue in order to predict an upper limit of vulnerability.

The implantable cardioverter defibrillator: technology, indications, and impact on cardiovascular survival.

PubMed

Bhatia, Atul; Cooley, Ryan; Berger, Marcie; Blanck, Zalmen; Dhala, Anwer; Sra, Jasbir; Axtell-Mcbride, Kathleen; Vandervort, Cheryl; Akhtar, Masood

2004-06-01

Since the introduction of the implantable cardioverter defibrillator (ICD) for the management of patients with high risk of arrhythmic SCD, there has been increasing use of this device. Its basic promise to effectively terminate ventricular tachycardia (VT)-ventricular fibrillation (VF) has been repeatedly met. In several randomized trials, the ICD has been shown to be superior to conventional anti-arrhythmic therapy, both in patients with documented VT-VF (secondary prevention) and those with high risk such as left ventricular ejection fraction and no prior sustained VT-VF (primary prevention). In both groups, the ICD showed overall and cardiac mortality reduction. The device now can more accurately detect VT-VF and differentiate these from other arrhythmias through a series of algorithms and direct-chamber sensing. Therapy options include painless antitachycardia pacing, low-energy cardioversion, and high-energy defibrillation. The technique implant is now simple as a pacemaker with one lead attached to an active (hot) can functioning as the other electrode. Among other improvements is its weight, volume, multiprogrammability, and storage of information,dual-chamber pacing and sensing, dual-chamber defibrillation, and addition of biventricular pacing for cardiac synchronization. It is anticipated that further improvement in ICD technology will take place and the list of indications will grow.

Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands.

PubMed

Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

2016-06-21

The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich's flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

Symmetrical compression distance for arrhythmia discrimination in cloud-based big-data services.

PubMed

Lillo-Castellano, J M; Mora-Jiménez, I; Santiago-Mozos, R; Chavarría-Asso, F; Cano-González, A; García-Alberola, A; Rojo-Álvarez, J L

2015-07-01

The current development of cloud computing is completely changing the paradigm of data knowledge extraction in huge databases. An example of this technology in the cardiac arrhythmia field is the SCOOP platform, a national-level scientific cloud-based big data service for implantable cardioverter defibrillators. In this scenario, we here propose a new methodology for automatic classification of intracardiac electrograms (EGMs) in a cloud computing system, designed for minimal signal preprocessing. A new compression-based similarity measure (CSM) is created for low computational burden, so-called weighted fast compression distance, which provides better performance when compared with other CSMs in the literature. Using simple machine learning techniques, a set of 6848 EGMs extracted from SCOOP platform were classified into seven cardiac arrhythmia classes and one noise class, reaching near to 90% accuracy when previous patient arrhythmia information was available and 63% otherwise, hence overcoming in all cases the classification provided by the majority class. Results show that this methodology can be used as a high-quality service of cloud computing, providing support to physicians for improving the knowledge on patient diagnosis.

Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands

NASA Astrophysics Data System (ADS)

Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

2016-06-01

The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich’s flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

Overcoming Spatial and Temporal Barriers to Public Access Defibrillators Via Optimization

PubMed Central

Sun, Christopher L. F.; Demirtas, Derya; Brooks, Steven C.; Morrison, Laurie J.; Chan, Timothy C.Y.

2016-01-01

BACKGROUND Immediate access to an automated external defibrillator (AED) increases the chance of survival from out-of-hospital cardiac arrest (OHCA). Current deployment usually considers spatial AED access, assuming AEDs are available 24 h a day. OBJECTIVES We sought to develop an optimization model for AED deployment, accounting for spatial and temporal accessibility, to evaluate if OHCA coverage would improve compared to deployment based on spatial accessibility alone. METHODS This was a retrospective population-based cohort study using data from the Toronto Regional RescuNET cardiac arrest database. We identified all nontraumatic public-location OHCAs in Toronto, Canada (January 2006 through August 2014) and obtained a list of registered AEDs (March 2015) from Toronto emergency medical services. We quantified coverage loss due to limited temporal access by comparing the number of OHCAs that occurred within 100 meters of a registered AED (assumed 24/7 coverage) with the number that occurred both within 100 meters of a registered AED and when the AED was available (actual coverage). We then developed a spatiotemporal optimization model that determined AED locations to maximize OHCA actual coverage and overcome the reported coverage loss. We computed the coverage gain between the spatiotemporal model and a spatial-only model using 10-fold cross-validation. RESULTS We identified 2,440 atraumatic public OHCAs and 737 registered AED locations. A total of 451 OHCAs were covered by registered AEDs under assumed 24/7 coverage, and 354 OHCAs under actual coverage, representing a coverage loss of 21.5% (p < 0.001). Using the spatiotemporal model to optimize AED deployment, a 25.3% relative increase in actual coverage was achieved over the spatial-only approach (p < 0.001). CONCLUSIONS One in 5 OHCAs occurred near an inaccessible AED at the time of the OHCA. Potential AED use was significantly improved with a spatiotemporal optimization model guiding deployment. PMID:27539176

Cardiopulmonary resuscitation and automatic external defibrillator training in schools: "is anyone learning how to save a life?".

PubMed

Hart, Devin; Flores-Medrano, Oscar; Brooks, Steve; Buick, Jason E; Morrison, Laurie J

2013-09-01

Bystander resuscitation efforts, such as cardiopulmonary resuscitation (CPR) and use of an automatic external defibrillator (AED), save lives in cardiac arrest cases. School training in CPR and AED use may increase the currently low community rates of bystander resuscitation. The study objective was to determine the rates of CPR and AED training in Toronto secondary schools and to identify barriers to training and training techniques. This prospective study consisted of telephone interviews conducted with key school staff knowledgeable about CPR and AED teaching. An encrypted Web-based tool with prespecified variables and built-in logic was employed to standardize data collection. Of 268 schools contacted, 93% were available for interview and 83% consented to participate. Students and staff were trained in CPR in 51% and 80% of schools, respectively. Private schools had the lowest training rate (39%). Six percent of schools provided AED training to students and 47% provided AED training to staff. Forty-eight percent of schools had at least one AED installed, but 25% were unaware if their AED was registered with emergency services dispatch. Cost (17%), perceived need (11%), and school population size (10%) were common barriers to student training. Frequently employed training techniques were interactive (32%), didactic instruction (30%) and printed material (16%). CPR training rates for staff and students were moderate overall and lowest in private schools, whereas training rates in AED use were poor in all schools. Identified barriers to training include cost and student population size (perceived to be too small to be cost-effective or too large to be implemented). Future studies should assess the application of convenient and cost-effective teaching alternatives not presently in use.

Team-focused Cardiopulmonary Resuscitation: Prehospital Principles Adapted for Emergency Department Cardiac Arrest Resuscitation.

PubMed

Johnson, Blake; Runyon, Michael; Weekes, Anthony; Pearson, David

2018-01-01

Out-of-hospital cardiac arrest has high rates of morbidity and mortality, and a growing body of evidence is redefining our approach to the resuscitation of these high-risk patients. Team-focused cardiopulmonary resuscitation (TFCPR), most commonly deployed and described by prehospital care providers, is a focused approach to cardiac arrest care that emphasizes early defibrillation and high-quality, minimally interrupted chest compressions while de-emphasizing endotracheal intubation and intravenous drug administration. TFCPR is associated with statistically significant increases in survival to hospital admission, survival to hospital discharge, and survival with good neurologic outcome; however, the adoption of similar streamlined resuscitation approaches by emergency physicians has not been widely reported. In the absence of a deliberately streamlined approach, such as TFCPR, other advanced therapies and procedures that have not shown similar survival benefit may be prioritized at the expense of simpler evidence-based interventions. This review examines the current literature on cardiac arrest resuscitation. The recent prehospital success of TFCPR is highlighted, including the associated improvements in multiple patient-centered outcomes. The adaptability of TFCPR to the emergency department (ED) setting is also discussed in detail. Finally, we discuss advanced interventions frequently performed during ED cardiac arrest resuscitation that may interfere with early defibrillation and effective high-quality chest compressions. TFCPR has been associated with improved patient outcomes in the prehospital setting. The data are less compelling for other commonly used advanced resuscitation tools and procedures. Emergency physicians should consider incorporating the TFCPR approach into ED cardiac arrest resuscitation to optimize delivery of those interventions most associated with improved outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

Machine Learning Algorithm Predicts Cardiac Resynchronization Therapy Outcomes: Lessons From the COMPANION Trial.

PubMed

Kalscheur, Matthew M; Kipp, Ryan T; Tattersall, Matthew C; Mei, Chaoqun; Buhr, Kevin A; DeMets, David L; Field, Michael E; Eckhardt, Lee L; Page, C David

2018-01-01

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in heart failure patients with reduced left ventricular function and intraventricular conduction delay. However, individual outcomes vary significantly. This study sought to use a machine learning algorithm to develop a model to predict outcomes after CRT. Models were developed with machine learning algorithms to predict all-cause mortality or heart failure hospitalization at 12 months post-CRT in the COMPANION trial (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure). The best performing model was developed with the random forest algorithm. The ability of this model to predict all-cause mortality or heart failure hospitalization and all-cause mortality alone was compared with discrimination obtained using a combination of bundle branch block morphology and QRS duration. In the 595 patients with CRT-defibrillator in the COMPANION trial, 105 deaths occurred (median follow-up, 15.7 months). The survival difference across subgroups differentiated by bundle branch block morphology and QRS duration did not reach significance ( P =0.08). The random forest model produced quartiles of patients with an 8-fold difference in survival between those with the highest and lowest predicted probability for events (hazard ratio, 7.96; P <0.0001). The model also discriminated the risk of the composite end point of all-cause mortality or heart failure hospitalization better than subgroups based on bundle branch block morphology and QRS duration. In the COMPANION trial, a machine learning algorithm produced a model that predicted clinical outcomes after CRT. Applied before device implant, this model may better differentiate outcomes over current clinical discriminators and improve shared decision-making with patients. © 2018 American Heart Association, Inc.

Differentiation of ventricular and supraventricular tachycardias based on the analysis of the first postpacing interval after sequential anti-tachycardia pacing in implantable cardioverter-defibrillator patients.

PubMed

Arenal, Angel; Ortiz, Mercedes; Peinado, Rafael; Merino, Jose L; Quesada, Aurelio; Atienza, Felipe; Alberola, Arcadio García; Ormaetxe, Jose; Castellanos, Eduardo; Rodriguez, Juan C; Pérez, Nicasio; García, Javier; Boluda, Luis; del Prado, Mario; Artés, Antonio

2007-03-01

Current discrimination algorithms do not completely avoid inappropriate tachycardia detection. This study analyzes the discrimination capability of the changes of the first postpacing interval (FPPI) after successive bursts of anti-tachycardia pacing (ATP) trains in implantable cardioverter-defibrillator (ICD)-recorded tachycardias. We included 50 ICD patients in this prospective study. We hypothesized that the FPPI variability (FPPIV) when comparing bursts with different numbers of beats would be shorter in ventricular tachycardias (VTs) compared with supraventricular tachycardias (SVTs). The ATP (5-10 pulses, 91% of tachycardia cycle length) was programmed for tachycardias >240 ms. Anti-tachycardia pacing was delivered during 37 sinus tachycardias (STs) in an exercise test, 96 induced VTs in an electrophysiological study, and 198 spontaneous episodes (144 VTs and 54 SVTs). The FPPI remained stable after all ATP bursts in VT but changed continuously in SVT; when comparing bursts of 5 and 10 pulses, the FPPIV was shorter in VT (34 +/- 65 vs.138 +/- 69, P<.0001, in all T and 12 +/- 20 vs. 138 +/- 69, P<.0001, in T>or=320 ms) than in SVT. In T>or=320 ms an FPPIV

Optimal geometry toward uniform current density electrodes

NASA Astrophysics Data System (ADS)

Song, Yizhuang; Lee, Eunjung; Woo, Eung Je; Seo, Jin Keun

2011-07-01

Electrodes are commonly used to inject current into the human body in various biomedical applications such as functional electrical stimulation, defibrillation, electrosurgery, RF ablation, impedance imaging, and so on. When a highly conducting electrode makes direct contact with biological tissues, the induced current density has strong singularity along the periphery of the electrode, which may cause painful sensation or burn. Especially in impedance imaging methods such as the magnetic resonance electrical impedance tomography, we should avoid such singularity since more uniform current density underneath a current-injection electrode is desirable. In this paper, we study an optimal geometry of a recessed electrode to produce a well-distributed current density on the contact area under the electrode. We investigate the geometry of the electrode surface to minimize the edge singularity and produce nearly uniform current density on the contact area. We propose a mathematical framework for the uniform current density electrode and its optimal geometry. The theoretical results are supported by numerical simulations.

Cardioverter-defibrillator implantation in myeloma-associated cardiac amyloidosis

PubMed Central

Campanile, Alfonso; Sozzi, Fabiola B; Canetta, Ciro; Danzi, Gian Battista

2013-01-01

A 62-year-old woman with multiple myeloma and light-chain amyloidosis with significant heart involvement developed an in-hospital cardiac arrest. After cardiopulmonary resuscitation, a stable sinus rhythm without any cerebral damage was restored, and the patient was admitted to the coronary care unit. A cardioverter-defibrillator was implanted, and it successfully intervened in two sustained ventricular tachycardia episodes and one ventricular fibrillation episode, which were recorded during hospitalization. After achieving discrete cardiac compensation, the patient was transferred to the emergency medicine department where she underwent chemotherapy for multiple myeloma. The patient died 40 days after admission from refractory heart failure. In the literature, there are studies that describe the use of cardioverter-defibrillator implantation in cardiac amyloidosis; however, at present, there is no evidence of a beneficial effect on survival with the use of this intervention. A high index of suspicion for amyloid heart disease and early diagnosis are critical to improving outcomes. PMID:24294034

Cardioverter-defibrillator implantation in myeloma-associated cardiac amyloidosis.

PubMed

Campanile, Alfonso; Sozzi, Fabiola B; Canetta, Ciro; Danzi, Gian Battista

2013-01-01

A 62-year-old woman with multiple myeloma and light-chain amyloidosis with significant heart involvement developed an in-hospital cardiac arrest. After cardiopulmonary resuscitation, a stable sinus rhythm without any cerebral damage was restored, and the patient was admitted to the coronary care unit. A cardioverter-defibrillator was implanted, and it successfully intervened in two sustained ventricular tachycardia episodes and one ventricular fibrillation episode, which were recorded during hospitalization. After achieving discrete cardiac compensation, the patient was transferred to the emergency medicine department where she underwent chemotherapy for multiple myeloma. The patient died 40 days after admission from refractory heart failure. In the literature, there are studies that describe the use of cardioverter-defibrillator implantation in cardiac amyloidosis; however, at present, there is no evidence of a beneficial effect on survival with the use of this intervention. A high index of suspicion for amyloid heart disease and early diagnosis are critical to improving outcomes.

Posttraumatic stress symptoms and predicted mortality in patients with implantable cardioverter-defibrillators: results from the prospective living with an implanted cardioverter-defibrillator study.

PubMed

Ladwig, Karl-Heinz; Baumert, Jens; Marten-Mittag, Birgitt; Kolb, Christof; Zrenner, Bernhard; Schmitt, Claus

2008-11-01

Cardiac disease and treatment with an implantable cardioverter-defibrillator (ICD) may be psychologically traumatic. Posttraumatic stress disorder (PTSD) is generally overlooked in cardiac patients, and no study to date (to our knowledge) has evaluated the effect of PTSD symptoms on the prognosis in patients with ICDs. To test whether PTSD symptoms at baseline predict long-term mortality risk in patients with ICDs. Prospective cohort study with a mean follow-up period of 5.1 years, accounting for 743 person-years observed. Data were derived from the Living With an Implanted Cardioverter-Defibrillator-Study, which initially included 211 patients with ICDs routinely attending the German Heart Center Munich outpatient clinic. The Impact of Event Scale-Revised was used in 147 patients (125 men and 22 women) who qualified for the "A" criterion of PTSD (survival of a life-threatening event). Thirty-eight patients scoring in the upper quartile of the scale constituted the PTSD index group. Mortality risk per 1000 person-years as assessed by Cox proportional hazards regression analysis based on an appropriate model fit (area under the curve, >0.80). Index patients experienced more anxiety and depression, had more cardiac symptoms, but showed no differences in left ventricular ejection fraction status or extent of ICD discharges compared with non-index patients. Forty-five patients (30.6%) died during the follow-up period. The relative mortality risk (multivariate adjusted for age, sex, diabetes mellitus, left ventricular ejection fraction, beta-blocker prescription, prior resuscitation, ICD shocks received, depression, and anxiety) hazard ratio was 3.45 (95% confidence interval, 1.57-7.60; P = .002) for the PTSD group. Compared with 55 fatal events per 1000 person-years in patients without PTSD, the long-term absolute mortality risk accounted for 80 fatal events per 1000 person-years in patients with PTSD. The adverse effect of PTSD symptoms on the long-term mortality risk in ICD-treated cardiac event survivors, independent of disease severity, supports the need for routinely applied interdisciplinary psychosocial aftercare.

Malfunctions of Implantable Cardiac Devices in Patients Receiving Proton Beam Therapy: Incidence and Predictors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gomez, Daniel R., E-mail: dgomez@mdanderson.org; Poenisch, Falk; Pinnix, Chelsea C.

2013-11-01

Purpose: Photon therapy has been reported to induce resets of implanted cardiac devices, but the clinical sequelae of treating patients with such devices with proton beam therapy (PBT) are not well known. We reviewed the incidence of device malfunctions among patients undergoing PBT. Methods and Materials: From March 2009 through July 2012, 42 patients with implanted cardiac implantable electronic devices (CIED; 28 pacemakers and 14 cardioverter-defibrillators) underwent 42 courses of PBT for thoracic (23, 55%), prostate (15, 36%), liver (3, 7%), or base of skull (1, 2%) tumors at a single institution. The median prescribed dose was 74 Gy (relativemore » biological effectiveness; range 46.8-87.5 Gy), and the median distance from the treatment field to the CIED was 10 cm (range 0.8-40 cm). Maximum proton and neutron doses were estimated for each treatment course. All CIEDs were checked before radiation delivery and monitored throughout treatment. Results: Median estimated peak proton and neutron doses to the CIED in all patients were 0.8 Gy (range 0.13-21 Gy) and 346 Sv (range 11-1100 mSv). Six CIED malfunctions occurred in 5 patients (2 pacemakers and 3 defibrillators). Five of these malfunctions were CIED resets, and 1 patient with a defibrillator (in a patient with a liver tumor) had an elective replacement indicator after therapy that was not influenced by radiation. The mean distance from the proton beam to the CIED among devices that reset was 7.0 cm (range 0.9-8 cm), and the mean maximum neutron dose was 655 mSv (range 330-1100 mSv). All resets occurred in patients receiving thoracic PBT and were corrected without clinical incident. The generator for the defibrillator with the elective replacement indicator message was replaced uneventfully after treatment. Conclusions: The incidence of CIED resets was about 20% among patients receiving PBT to the thorax. We recommend that PBT be avoided in pacing-dependent patients and that patients with any type of CIED receiving thoracic PBT be followed closely.« less

Tpeak - Tend and Tpeak - Tend /QT ratio as markers of ventricular arrhythmia risk in cardiac resynchronization therapy patients.

PubMed

Barbhaiya, Chirag; Po, Jose Ricardo F; Hanon, Sam; Schweitzer, Paul

2013-01-01

Cardiac resynchronization therapy (CRT) increases transmural dispersion of repolarization (TDR) and can be pro-arrhythmic. However, overall arrhythmia risk was not increased in large-scale CRT clinical trials. Increased TDR as measured by T(peak ) -T(end) (TpTe) was associated with arrhythmia risk in CRT in a single-center study. This study investigates whether QT interval, TpTe, and TpTe/QT ratio are associated with ventricular arrhythmias in patients with CRT-defibrillator (CRT-D). Post-CRT-D implant electrocardiograms of 128 patients (age 71.3 years ± 10.3) with at least 2 months of follow-up at our institution's device clinic (mean follow-up of 28.5 months ± 17) were analyzed for QT interval, TpTe, and TpTe/QT ratio. Incidence of ventricular arrhythmias was determined based on routine and directed device interrogations. Appropriate implantable cardioverter-defibrillator therapy for sustained ventricular tachycardia or ventricular fibrillation was delivered in 18 patients (14%), and nonsustained ventricular tachycardia (NSVT) was detected but did not require therapy in 58 patients (45%). Patients who received appropriate defibrillator therapy had increased TpTe/QT ratio (0.24 ± 0.03 ms vs 0.20 ± 0.04, P = 0.0002) and increased TpTe (105.56 ± 20.36 vs 87.82 ± 22.32 ms, P = 0.002), and patients with NSVT had increased TpTe/QT ratio (0.22 ± 0.04 vs 0.20 ± 0.04, P = 0.016). Increased QT interval was not associated with risk of ventricular arrhythmia. The relative risk for appropriate defibrillator therapy of T(p) T(e) /QT ratio ≥ 0.25 was 3.24 (P = 0.016). Increased TpTe and increased TpTe/QT ratio are associated with increased incidence of ventricular arrhythmias in CRT-D. The utility of TpTe interval and TpTe/QT ratio as potentially modifiable risk factors for ventricular arrhythmias in CRT requires further study. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

Property evaluations of dry-cast reconstituted bacterial cellulose/tamarind xyloglucan biocomposites.

PubMed

de Souza, Clayton F; Lucyszyn, Neoli; Woehl, Marco A; Riegel-Vidotti, Izabel C; Borsali, Redouane; Sierakowski, Maria Rita

2013-03-01

We describe the mechanical defibrillation of bacterial cellulose (BC) followed by the dry-cast generation of reconstituted BC films (RBC). Xyloglucan (XGT), extracted from tamarind seeds, was incorporated into the defibrillated cellulose at various compositions, and new films were created using the same process. Microscopy and contact angle analyses of films revealed an increase in the microfibre adhesion, a reduced polydispersity in the diameters of the microfibrils and increased hydrophobic behaviour as a function of %XGT. X-ray diffraction analysis revealed changes to the crystallographic planes of the RBC and the biocomposite films with preferential orientation along the (110) plane. Compared with BC, RBC/XGT biocomposite with 10% XGT exhibited improvement in its thermal properties and in Young's modulus. These results indicated a reorganisation of the microfibres with mechanical treatment, which when combined with hydrocolloids, can create cellulose-based materials that could be applied as scaffolding for tissue engineering and drug release. Copyright © 2012 Elsevier Ltd. All rights reserved.

Layperson training for cardiopulmonary resuscitation: when less is better.

PubMed

Roppolo, Lynn P; Saunders, Timothy; Pepe, Paul E; Idris, Ahamed H

2007-06-01

Basic cardiopulmonary resuscitation, including use of automated external defibrillators, unequivocally saves lives. However, even when motivated, those wishing to acquire training traditionally have faced a myriad of barriers including the typical time commitment (3-4 h) and the number of certified instructors and equipment caches required. The recent introduction of innovative video-based self-instruction, utilizing individualized inflatable manikins, provides an important breakthrough in cardiopulmonary-resuscitation training. Definitive studies now show that many dozens of persons can be trained simultaneously to perform basic cardiopulmonary resuscitation, including appropriate use of an automated external defibrillator, in less than 30 min. Such training not only requires much less labor intensity and avoids the need for multiple certified instructors, but also, because it is largely focused on longer and more repetitious performance of skills, these life-saving lessons can be retained for long periods of time. Simpler to set-up and implement, the half-hour video-based self-instruction makes it easier for employers, churches, civic groups, school systems and at-risk persons at home to implement such training and it will likely facilitate more frequent re-training. It is now hoped that the ultimate benefit will be more lives saved in communities worldwide.

Cost-Utility Analysis of the EVOLVO Study on Remote Monitoring for Heart Failure Patients With Implantable Defibrillators: Randomized Controlled Trial

PubMed Central

Landolina, Maurizio; Marzegalli, Maurizio; Lunati, Maurizio; Perego, Giovanni B; Guenzati, Giuseppe; Curnis, Antonio; Valsecchi, Sergio; Borghetti, Francesca; Borghi, Gabriella; Masella, Cristina

2013-01-01

Background Heart failure patients with implantable defibrillators place a significant burden on health care systems. Remote monitoring allows assessment of device function and heart failure parameters, and may represent a safe, effective, and cost-saving method compared to conventional in-office follow-up. Objective We hypothesized that remote device monitoring represents a cost-effective approach. This paper summarizes the economic evaluation of the Evolution of Management Strategies of Heart Failure Patients With Implantable Defibrillators (EVOLVO) study, a multicenter clinical trial aimed at measuring the benefits of remote monitoring for heart failure patients with implantable defibrillators. Methods Two hundred patients implanted with a wireless transmission–enabled implantable defibrillator were randomized to receive either remote monitoring or the conventional method of in-person evaluations. Patients were followed for 16 months with a protocol of scheduled in-office and remote follow-ups. The economic evaluation of the intervention was conducted from the perspectives of the health care system and the patient. A cost-utility analysis was performed to measure whether the intervention was cost-effective in terms of cost per quality-adjusted life year (QALY) gained. Results Overall, remote monitoring did not show significant annual cost savings for the health care system (€1962.78 versus €2130.01; P=.80). There was a significant reduction of the annual cost for the patients in the remote arm in comparison to the standard arm (€291.36 versus €381.34; P=.01). Cost-utility analysis was performed for 180 patients for whom QALYs were available. The patients in the remote arm gained 0.065 QALYs more than those in the standard arm over 16 months, with a cost savings of €888.10 per patient. Results from the cost-utility analysis of the EVOLVO study show that remote monitoring is a cost-effective and dominant solution. Conclusions Remote management of heart failure patients with implantable defibrillators appears to be cost-effective compared to the conventional method of in-person evaluations. Trial Registration ClinicalTrials.gov NCT00873899; http://clinicaltrials.gov/show/NCT00873899 (Archived by WebCite at http://www.webcitation.org/6H0BOA29f). PMID:23722666

Pediatric defibrillation after cardiac arrest: initial response and outcome

PubMed Central

Rodríguez-Núñez, Antonio; López-Herce, Jesús; García, Cristina; Domínguez, Pedro; Carrillo, Angel; Bellón, Jose María

2006-01-01

Introduction Shockable rhythms are rare in pediatric cardiac arrest and the results of defibrillation are uncertain. The objective of this study was to analyze the results of cardiopulmonary resuscitation that included defibrillation in children. Methods Forty-four out of 241 children (18.2%) who were resuscitated from inhospital or out-of-hospital cardiac arrest had been treated with manual defibrillation. Data were recorded according to the Utstein style. Outcome variables were a sustained return of spontaneous circulation (ROSC) and one-year survival. Characteristics of patients and of resuscitation were evaluated. Results Cardiac disease was the major cause of arrest in this group. Ventricular fibrillation (VF) or pulseless ventricular tachycardia (PVT) was the first documented electrocardiogram rhythm in 19 patients (43.2%). A shockable rhythm developed during resuscitation in 25 patients (56.8%). The first shock (dose, 2 J/kg) terminated VF or PVT in eight patients (18.1%). Seventeen children (38.6%) needed more than three shocks to solve VF or PVT. ROSC was achieved in 28 cases (63.6%) and it was sustained in 19 patients (43.2%). Only three patients (6.8%), however, survived at 1-year follow-up. Children with VF or PVT as the first documented rhythm had better ROSC, better initial survival and better final survival than children with subsequent VF or PVT. Children who survived were older than the finally dead patients. No significant differences in response rate were observed when first and second shocks were compared. The survival rate was higher in patients treated with a second shock dose of 2 J/kg than in those who received higher doses. Outcome was not related to the cause or the location of arrest. The survival rate was inversely related to the duration of cardiopulmonary resuscitation. Conclusion Defibrillation is necessary in 18% of children who suffer cardiac arrest. Termination of VF or PVT after the first defibrillation dose is achieved in a low percentage of cases. Despite a sustained ROSC being obtained in more than one-third of cases, the final survival remains low. The outcome is very poor when a shockable rhythm develops during resuscitation efforts. New studies are needed to ascertain whether the new international guidelines will contribute to improve the outcome of pediatric cardiac arrest. PMID:16882339

In-flight automated external defibrillator use and consultation patterns

PubMed Central

Brown, AM; Rittenberger, JC; Ammon, CM; Harrington, S; Guyette, FX

2010-01-01

Background Limited information exists about the in-flight use and outcomes associated with automatic external defibrillators (AED) on commercial airlines. Methods We collected self-reported cases of AED use to an airline consultation service from three US airlines between May 2004 and March 2009. We reviewed all available data files, related consult forms, and recordings. For each case, demographics, initial rhythm, shock delivery/success, survival to admission, and ground medical consultation use were obtained. Success was defined as the return of a perfusing rhythm. Initial rhythms were classified as: sinus, heart block, SVT, atrial fibrillation/flutter, asystole, PEA and VF/VT. Results There were a total of 169 AED applications with 40 cardiac arrests. The mean ages were 58 years (SD 15) and 63 years (SD 12) respectively; both populations were 64% male. AEDs were applied for monitoring in 129 (76%) cases with initial rhythms of: sinus 114 (88%); atrial fibrillation/flutter 7 (5%); complete heart block 4 (3%); and SVT 4 (3%). Presenting rhythms among the cardiac arrest population were: asystole 16 (40%); ventricular fibrillation/ventricular tachycardia 10 (25%); and PEA 14 (35%). Fourteen patients were defibrillated including nine of the 10 patients with initial VF/VT and five for the presence of VF/VT after resuscitation for initial PEA/asystole. Defibrillation was advised but not performed in the remaining case of initial VF/VT and no medical consult was obtained. All five successful defibrillations occurred in patients with initial VF/VT. There were 6 (15%; 95% CI 3–27%) survivors with 5 occurring after successful defibrillation for initial VF/VT and one with return of a perfusing rhythm after CPR for a junctional rhythm. Survival in those with VF/VT was 5/10 (50%; 95% CI 14–86%). Medications were delivered twice. The median time to first shock was 19 (IQR 12–24) seconds from AED application. Medical consultation was obtained in 56 (33%) of the 169 AED cases and 14 (35%) of the cardiac arrests. Conclusion AEDs resulted in 50% survival among those with VT/VF in-flight and 14% overall survival for cardiac arrest. Survival is poor among patients presenting with non-shockable rhythms. AEDs are used extensively for in-flight monitoring with significant rhythms identified. Ground medical consultation is sought in only one-third of AED uses and cardiac arrests. PMID:20128705

Overview of implantable cardioverter defibrillator and cardiac resynchronisation therapy in heart failure management

PubMed Central

Chia, Pow-Li; Foo, David

2016-01-01

Clinical trials have established the benefits of implantable cardioverter defibrillators (ICDs) and cardiac resynchronisation therapy (CRT) in the treatment of heart failure patients. As adjuncts to guideline-directed medical therapy, ICDs confer mortality benefits from sudden cardiac arrest, while CRT reduces mortality, hospitalisation rates and improves functional capacity. This review discusses the use of ICDs and CRT devices in heart failure management, outlining the evidence supporting their use, indications and contraindications. PMID:27440409

Computational studies of transthoracic and transvenous defibrillation in a detailed 3-D human thorax model.

PubMed

Jorgenson, D B; Haynor, D R; Bardy, G H; Kim, Y

1995-02-01

A method for constructing and solving detailed patient-specific 3-D finite element models of the human thorax is presented for use in defibrillation studies. The method utilizes the patient's own X-ray CT scan and a simplified meshing scheme to quickly and efficiently generate a model typically composed of approximately 400,000 elements. A parameter sensitivity study on one human thorax model to examine the effects of variation in assigned tissue resistivity values, level of anatomical detail included in the model, and number of CT slices used to produce the model is presented. Of the seven tissue types examined, the average left ventricular (LV) myocardial voltage gradient was most sensitive to the values of myocardial and blood resistivity. Incorrectly simplifying the model, for example modeling the heart as a homogeneous structure by ignoring the blood in the chambers, caused the average LV myocardial voltage gradient to increase by 12%. The sensitivity of the model to variations in electrode size and position was also examined. Small changes (< 2.0 cm) in electrode position caused average LV myocardial voltage gradient values to increase by up to 12%. We conclude that patient-specific 3-D finite element modeling of human thoracic electric fields is feasible and may reduce the empiric approach to insertion of implantable defibrillators and improve transthoracic defibrillation techniques.

Effect of defibrillation threshold testing on effectiveness of the subcutaneous implantable cardioverter defibrillator.

PubMed

Peddareddy, Lakshmi; Merchant, Faisal M; Leon, Angel R; Smith, Paige; Patel, Akshar; El-Chami, Mikhael F

2018-06-12

Defibrillation threshold (DFT) testing is recommended with the subcutaneous ICD (SICD). To describe first shock efficacy for appropriate SICD therapies stratified by the presence of implant DFT testing. We reviewed all patients receiving SICDs at our institution and stratified them based on whether implant DFT testing was performed. Appropriate shocks were reviewed to see if ventricular tachycardia/ventricular fibrillation (VT/VF) terminated with a single shock. First shock efficacy was stratified by implant DFT status. 178 patients implanted with SICDs and followed in our center were included in this study. Of these, 135 (76 %) underwent DFT testing (DFT (+) group). In the DFT (+) 80 appropriate shocks were needed to treat 69 episodes of VT/VF. The first shock was effective in 61 out of 69 episodes (88.4 %), whereas multiple shocks were required to terminate VT/VF in the remaining 8 episodes. Among 43 patients without implant DFT testing (DFT (-) group), 20 appropriate shocks to treat 17 episodes of VT/VF occurred in 7 patients. VT/VF was successfully terminated with the first shock in 16 out of 17 episodes (first shock efficacy 94.1 %). There was no significant difference in first shock effectiveness between those with and without implant DFT testing (p = 0.97). A strategy that omits DFT testing at implant did not appear to compromise the effictiveness of the SICD. These data suggest that routine DFT testing at SICD implant might not be necessary. Randomized trials are needed to confirm this finding. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Battery longevity of implantable cardioverter-defibrillators and cardiac resynchronization therapy defibrillators: technical, clinical and economic aspects. An expert review paper from EHRA.

PubMed

Boriani, Giuseppe; Merino, Josè; Wright, David J; Gadler, Fredrik; Schaer, Beat; Landolina, Maurizio

2018-05-10

In recent years an extension of devices longevity has been obtained for implantable cardioverter-defibrillators (ICDs), including ICDs for cardiac resynchronization therapy (CRT-D) through improved battery chemistry and device technology and this implies important clinical benefits (reduced need for device replacements and associated complications, particularly infections), as well as economic benefits, in line with patient preferences and needs. From a clinical point of view, the availability of this improvement in technology allows to better tune the choice of the device to be implanted, taking into account that the reasons supporting the value of an extended device longevity as a clinical priority may differ according to the clinical setting (purely electrical diseases or left ventricular dysfunction/heart failure, respectively). From an economic point of view, extension of device longevity may have an important impact in reducing long-term costs of device therapy, with substantial daily savings in favour of devices with extended longevity, up to 30%, depending on clinical scenarios. In studies based on projections, an extension of device longevity allowed to calculate that the cost per day of ICDs may be substantially reduced, and this allows to overcome the frequent perception of ICD and CRT-D devices as treatments with unaffordable costs and to overturn the misconception that up-front costs are the only metric with which to value device treatments. In view of its clinical and economic value, device longevity should be a determining factor in device choice by physicians and healthcare commissioners and should be appropriately considered and valued in comparative tenders.

Correlation-based pattern recognition for implantable defibrillators.

PubMed Central

Wilkins, J.

1996-01-01

An estimated 300,000 Americans die each year from cardiac arrhythmias. Historically, drug therapy or surgery were the only treatment options available for patients suffering from arrhythmias. Recently, implantable arrhythmia management devices have been developed. These devices allow abnormal cardiac rhythms to be sensed and corrected in vivo. Proper arrhythmia classification is critical to selecting the appropriate therapeutic intervention. The classification problem is made more challenging by the power/computation constraints imposed by the short battery life of implantable devices. Current devices utilize heart rate-based classification algorithms. Although easy to implement, rate-based approaches have unacceptably high error rates in distinguishing supraventricular tachycardia (SVT) from ventricular tachycardia (VT). Conventional morphology assessment techniques used in ECG analysis often require too much computation to be practical for implantable devices. In this paper, a computationally-efficient, arrhythmia classification architecture using correlation-based morphology assessment is presented. The architecture classifies individuals heart beats by assessing similarity between an incoming cardiac signal vector and a series of prestored class templates. A series of these beat classifications are used to make an overall rhythm assessment. The system makes use of several new results in the field of pattern recognition. The resulting system achieved excellent accuracy in discriminating SVT and VT. PMID:8947674

Contemporary rates and outcomes of single- vs. dual-coil implantable cardioverter defibrillator lead implantation: data from the Israeli ICD Registry.

PubMed

Leshem, Eran; Suleiman, Mahmoud; Laish-Farkash, Avishag; Konstantino, Yuval; Glikson, Michael; Barsheshet, Alon; Goldenberg, Ilan; Michowitz, Yoav

2017-09-01

Dual-coil leads were traditionally considered standard of care due to lower defibrillation thresholds (DFT). Higher complication rates during extraction with parallel progression in implantable cardioverter defibrillator (ICD) technology raised questions on dual coil necessity. Prior substudies found no significant outcome difference between dual and single coils, although using higher rates of DFT testing then currently practiced. We evaluated the temporal trends in implantation rates of single- vs. dual-coil leads and determined the associated adverse clinical outcomes, using a contemporary nation-wide ICD registry. Between July 2010 and March 2015, 6343 consecutive ICD (n = 3998) or CRT-D (n = 2345) implantation patients were prospectively enrolled in the Israeli ICD Registry. A follow-up of at least 1 year of 2285 patients was available for outcome analysis. The primary endpoint was all-cause mortality. Single-coil leads were implanted in 32% of our cohort, 36% among ICD recipients, and 26% among CRT-D recipients. Secondary prevention indication was associated with an increased rate of dual-coil implantation. A significant decline in dual-coil leads with reciprocal incline of single coils was observed, despite low rates of DFT testing (11.6%) during implantation, which also declined from 31 to 2%. In the multivariate Cox model analysis, dual- vs. single-coil lead implantation was not associated with an increased risk of mortality [hazard ratio (HR) = 1.23; P= 0.33], heart failure hospitalization (HR = 1.34; P=0.13), appropriate (HR = 1.25; P= 0.33), or inappropriate ICD therapy (HR = 2.07; P= 0.12). Real-life rates of single-coil lead implantation are rising while adding no additional risk. These results of single-coil safety are reassuring and obtained, despite low and contemporary rates of DFT testing. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Risk of Sprint Fidelis defibrillator lead failure is highly dependent on age.

PubMed

Girerd, Nicolas; Nonin, Emilie; Pinot, Julien; Morel, Elodie; Flys, Carine; Scridon, Alina; Chevalier, Philippe

2011-01-01

In 2007, Medtronic Sprint Fidelis defibrillator leads were taken off the market due to a high rate of lead failure. Current data do not allow for risk stratification of patients with regard to lead failure. We sought to determine predictors of Sprint Fidelis lead failure. Between 2004 and 2007, 269 Sprint Fidelis leads were implanted in 258 patients in our centre. Variables associated with lead failure were assessed by the Kaplan-Meier method and a Cox survival model. During a median follow-up of 2.80 years (maximum 5.32), we observed 33 (12.3%) Sprint Fidelis lead failures (5-year survival, 65.6% ± 7.5%). In univariate analysis, age was the only predictor of lead failure (hazard ratio [HR] for 1-year increase 0.97; 95% confidence interval [CI] 0.95-0.99; p=0.009). Patients aged<62.5 years (median) had a significantly increased risk of lead failure compared with patients aged>62.5 years (HR 2.80; CI 1.30-6.02; p=0.009). Survival without Sprint Fidelis lead failure was 55.6% ± 10.4%) in patients aged<62.5 years (24/134 leads) vs 78.6% ± 8.8% in patients aged>62.5 years (9/135 leads). The annual incidence of lead failure in patients aged<62.5 years was 11.6% ± 4.9% during the fourth year after implantation and 22.9% ± 13.2% during the fifth year. Overall, we found a higher rate of Sprint Fidelis lead dysfunction than previously described. Lead failure was much more frequent in younger patients. Our results emphasize the need for close follow-up of younger patients with Sprint Fidelis leads and suggest that, in these patients, the implantation of a new implantable cardioverter defibrillator lead at the time of generator replacement might be reasonable. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Association of amplitude spectral area of the ventricular fibrillation waveform with survival of out-of-hospital ventricular fibrillation cardiac arrest.

PubMed

Indik, Julia H; Conover, Zacherie; McGovern, Meghan; Silver, Annemarie E; Spaite, Daniel W; Bobrow, Bentley J; Kern, Karl B

2014-09-30

Previous investigations of out-of-hospital cardiac arrest (OHCA) have shown that the waveform characteristic amplitude spectral area (AMSA) can predict successful defibrillation and return of spontaneous circulation (ROSC) but has not been studied previously for survival. To determine whether AMSA computed from the ventricular fibrillation (VF) waveform is associated with pre-hospital ROSC, hospital admission, and hospital discharge. Adults with witnessed OHCA and an initial rhythm of VF from an Utstein style database were studied. AMSA was measured prior to each shock and averaged for each subject (AMSA-avg). Factors such as age, sex, number of shocks, time from dispatch to monitor/defibrillator application, first shock AMSA, and AMSA-avg that could predict pre-hospital ROSC, hospital admission, and hospital discharge were analyzed by logistic regression. Eighty-nine subjects (mean age 62 ± 15 years) with a total of 286 shocks were analyzed. AMSA-avg was associated with pre-hospital ROSC (p = 0.003); a threshold of 20.9 mV-Hz had a 95% sensitivity and a 43.4% specificity. Additionally, AMSA-avg was associated with hospital admission (p < 0.001); a threshold of 21 mV-Hz had a 95% sensitivity and a 54% specificity and with hospital discharge (p < 0.001); a threshold of 25.6 mV-Hz had a 95% sensitivity and a 53% specificity. First-shock AMSA was also predictive of pre-hospital ROSC, hospital admission, and discharge. Time from dispatch to monitor/defibrillator application was associated with hospital admission (p = 0.034) but not pre-hospital ROSC or hospital discharge. AMSA is highly associated with pre-hospital ROSC, survival to hospital admission, and hospital discharge in witnessed VF OHCA. Future studies are needed to determine whether AMSA computed during resuscitation can identify patients for whom continuing current resuscitation efforts would likely be futile. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Early risk of mortality after coronary artery revascularization in patients with left ventricular dysfunction and potential role of the wearable cardioverter defibrillator.

PubMed

Zishiri, Edwin T; Williams, Sarah; Cronin, Edmond M; Blackstone, Eugene H; Ellis, Stephen G; Roselli, Eric E; Smedira, Nicholas G; Gillinov, A Marc; Glad, Jo Ann; Tchou, Patrick J; Szymkiewicz, Steven J; Chung, Mina K

2013-02-01

Implantation of implantable cardioverter defibrillator for prevention of sudden cardiac death is deferred for 90 days after coronary revascularization, but mortality may be highest early after cardiac procedures in patients with ventricular dysfunction. We determined mortality risk in postrevascularization patients with left ventricular ejection fraction ≤35% and compared survival with those discharged with a wearable cardioverter defibrillator (WCD). Hospital survivors after surgical (coronary artery bypass graft surgery) or percutaneous (percutaneous coronary intervention [PCI]) revascularization with left ventricular ejection fraction ≤35% were included from Cleveland Clinic and national WCD registries. Kaplan-Meier, Cox proportional hazards, propensity score-matched survival, and hazard function analyses were performed. Early mortality hazard was higher among 4149 patients discharged without a defibrillator compared with 809 with WCDs (90-day mortality post-coronary artery bypass graft surgery 7% versus 3%, P=0.03; post-PCI 10% versus 2%, P<0.0001). WCD use was associated with adjusted lower risks of long-term mortality in the total cohort (39%, P<0.0001) and both post-coronary artery bypass graft surgery (38%, P=0.048) and post-PCI (57%, P<0.0001) cohorts (mean follow-up, 3.2 years). In propensity-matched analyses, WCD use remained associated with lower mortality (58% post-coronary artery bypass graft surgery, P=0.002; 67% post-PCI, P<0.0001). Mortality differences were not attributable solely to therapies for ventricular arrhythmia. Only 1.3% of the WCD group had a documented appropriate therapy. Patients with left ventricular ejection fraction ≤35% have higher early compared to late mortality after coronary revascularization, particularly after PCI. As early hazard seemed less marked in WCD users, prospective studies in this high-risk population are indicated to confirm whether WCD use as a bridge to left ventricular ejection fraction improvement or implantable cardioverter defibrillator implantation can improve outcomes after coronary revascularization.

Utilization trends and clinical outcomes in patients implanted with a single- vs a dual-coil implantable cardioverter-defibrillator lead: Insights from the ALTITUDE Study.

PubMed

Hsu, Jonathan C; Saxon, Leslie A; Jones, Paul W; Wehrenberg, Scott; Marcus, Gregory M

2015-08-01

Historically, the most commonly implanted implantable cardioverter-defibrillator (ICD) lead is dual coil. Conventional wisdom holds that single-coil leads may be less effective than dual-coil leads, but easier to extract. No contemporary large-scale studies have evaluated the relative epidemiology of these 2 leads or compared their respective clinical outcomes. We sought to evaluate trends in single- vs dual-coil ICD lead implantation and differences in clinical outcomes. We evaluated 129,520 ICD recipients enrolled in the LATITUDE remote monitoring system between 2004 and 2014. Kaplan-Meier analyses and Cox proportional hazards regression analyses were used for univariate and multivariate survival analysis, respectively. The majority of ICD recipients received a dual-coil lead (n = 110,330 [85.2%]). Single-coil lead implantation increased from 1.9% to 55.2% between 2004 and 2014. After adjusting for age, sex, device type, and year of implant, single-coil lead implantation was associated with a greater odds of induction for defibrillation testing (odds ratio 1.05; 95% confidence interval [CI] 1.01-1.09; P = .0274), a higher rate of lead being taken out of service (hazard ratio 1.19; 95% CI 1.06-1.33; P = .0032), and a decreased mortality rate (hazard ratio 0.91; 95% CI 0.87-0.96; P = .0004). In a 795 patient subset with adjudicated shock outcomes, first shock success was no different (87.0% in single coil vs 86.1% in dual coil; P = .8473). In a large real-world US population, single-coil lead implantation rates increased substantially between 2004 and 2014. Single-coil lead implantation was associated with more frequent defibrillation testing and the lead being taken out of service, but was not associated with increased mortality or more frequent defibrillation failure. Copyright © 2015 Heart Rhythm Society. All rights reserved.

Fire fighters as basic life support responders: a study of successful implementation.

PubMed

Høyer, Christian Bjerre; Christensen, Erika Frischknecht

2009-04-02

First responders are recommended as a supplement to the Emergency Medical Services (EMS) in order to achieve early defibrillation. Practical and organisational aspects are essential when trying to implement new parts in the "Chain of Survival"; areas to address include minimizing dispatch time, ensuring efficient and quick communication, and choosing areas with appropriate driving distances. The aim of this study was to implement a system using Basic Life Support (BLS) responders equipped with an automatic external defibrillator in an area with relatively short emergency medical services' response times. Success criteria for implementation was defined as arrival of the BLS responders before the EMS, attachment (and use) of the AED, and successful defibrillation. This was a prospective observational study from September 1, 2005 to December 31, 2007 (28 months) in the city of Aarhus, Denmark. The BLS responder system was implemented in an area up to three kilometres (driving distance) from the central fire station, encompassing approximately 81,500 inhabitants. The team trained on each shift and response times were reduced by choice of area and by sending the alarm directly to the fire brigade dispatcher. The BLS responders had 1076 patient contacts. The median response time was 3.5 minutes (25th percentile 2.75, 75th percentile 4.25). The BLS responders arrived before EMS in 789 of the 1076 patient contacts (73%). Cardiac arrest was diagnosed in 53 cases, the AED was attached in 29 cases, and a shockable rhythm was detected in nine cases. Eight were defibrillated using an AED. Seven of the eight obtained return of spontaneous circulation (ROSC). Six of the seven obtaining ROSC survived more than 30 days. In this study, the implementation of BLS responders may have resulted in successful resuscitations. On basis of the close corporation between all participants in the chain of survival this project contributed to the first link: short response time and trained personnel to ensure early defibrillation.

Fire fighters as basic life support responders: A study of successful implementation

PubMed Central

Høyer, Christian Bjerre; Christensen, Erika Frischknecht

2009-01-01

Background First responders are recommended as a supplement to the Emergency Medical Services (EMS) in order to achieve early defibrillation. Practical and organisational aspects are essential when trying to implement new parts in the "Chain of Survival"; areas to address include minimizing dispatch time, ensuring efficient and quick communication, and choosing areas with appropriate driving distances. The aim of this study was to implement a system using Basic Life Support (BLS) responders equipped with an automatic external defibrillator in an area with relatively short emergency medical services' response times. Success criteria for implementation was defined as arrival of the BLS responders before the EMS, attachment (and use) of the AED, and successful defibrillation. Methods This was a prospective observational study from September 1, 2005 to December 31, 2007 (28 months) in the city of Aarhus, Denmark. The BLS responder system was implemented in an area up to three kilometres (driving distance) from the central fire station, encompassing approximately 81,500 inhabitants. The team trained on each shift and response times were reduced by choice of area and by sending the alarm directly to the fire brigade dispatcher. Results The BLS responders had 1076 patient contacts. The median response time was 3.5 minutes (25th percentile 2.75, 75th percentile 4.25). The BLS responders arrived before EMS in 789 of the 1076 patient contacts (73%). Cardiac arrest was diagnosed in 53 cases, the AED was attached in 29 cases, and a shockable rhythm was detected in nine cases. Eight were defibrillated using an AED. Seven of the eight obtained return of spontaneous circulation (ROSC). Six of the seven obtaining ROSC survived more than 30 days. Conclusion In this study, the implementation of BLS responders may have resulted in successful resuscitations. On basis of the close corporation between all participants in the chain of survival this project contributed to the first link: short response time and trained personnel to ensure early defibrillation. PMID:19341457

Simulation exercise to improve retention of cardiopulmonary resuscitation priorities for in-hospital cardiac arrests: A randomized controlled trial.

PubMed

Sullivan, Nancy J; Duval-Arnould, Jordan; Twilley, Marida; Smith, Sarah P; Aksamit, Deborah; Boone-Guercio, Pam; Jeffries, Pamela R; Hunt, Elizabeth A

2015-01-01

Traditional American Heart Association (AHA) cardiopulmonary resuscitation (CPR) curriculum focuses on teams of two performing quality chest compressions with rescuers on their knees but does not include training specific to In-Hospital Cardiac Arrests (IHCA), i.e. patient in hospital bed with large resuscitation teams and sophisticated technology available. A randomized controlled trial was conducted with the primary goal of evaluating the effectiveness and ideal frequency of in-situ training on time elapsed from call for help to; (1) initiation of chest compressions and (2) successful defibrillation in IHCA. Non-intensive care unit nurses were randomized into four groups: standard AHA training (C) and three groups that participated in 15 min in-situ IHCA training sessions every two (2M), three (3M) or six months (6M). Curriculum included specific choreography for teams to achieve immediate chest compressions, high chest compression fractions and rapid defibrillation while incorporating use of a backboard, stepstool. More frequent training was associated with decreased median (IQR) seconds to: starting compressions: [C: 33(25-40) vs. 6M: 21(15-26) vs. 3M: 14(10-20) vs. 2M: 13(9-20); p < 0.001]; and defibrillation: [C: 157(140-254) vs. 6M: 138(107-158) vs. 3M: 115(101-119) vs. 2M: 109(98-129); p < 0.001]. A composite outcome of key priorities, compressions within 20s, defibrillation within 180 s and use of a backboard, revealed improvement with more frequent training sessions: [C:5%(1/18) vs. 6M: 23%(4/17) vs. 3M: 56%(9/16) vs. 2M: 73%(11/15); p < 0.001]. Results revealed short in-situ training sessions conducted every 3 months are effective in improving timely initiation of chest compressions and defibrillation in IHCA. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

In-vivo measurement of relationship between applied current amplitude and current density magnitude from 10 mA to 110 mA.

PubMed

DeMonte, Tim P; Wang, Dinghui; Ma, Weijing; Gao, Jia-Hong; Joy, Michael L G

2009-01-01

Current density imaging (CDI) is a magnetic resonance imaging (MRI) technique used to quantitatively measure current density vectors throughout the volume of an object/subject placed in the MRI system. Electrical current pulses are applied externally to the object/subject and are synchronized with the MRI sequence. In this work, CDI is used to measure average current density magnitude in the torso region of an in-vivo piglet for applied current pulse amplitudes ranging from 10 mA to 110 mA. The relationship between applied current amplitude and current density magnitude is linear in simple electronic elements such as wires and resistors; however, this relationship may not be linear in living tissue. An understanding of this relationship is useful for research in defibrillation, human electro-muscular incapacitation (e.g. TASER(R)) and other bioelectric stimulation devices. This work will show that the current amplitude to current density magnitude relationship is slightly nonlinear in living tissue in the range of 10 mA to 110 mA.

The availability, condition and employability of automated external defibrillators in large city centres in the Netherlands.

PubMed

Huig, Isabelle C; Boonstra, Linda; Gerritsen, Patricia C; Hoeks, Sanne E

2014-10-01

In the Netherlands there are, at the time of writing, no clear guidelines about the implementation of automated external defibrillators (AEDs). An observational study was conducted to investigate the current status of AEDs in city centres in the Netherlands looking specifically at the availability, condition and employability of the AEDs. The shopping areas in the old city centres of the six largest cities in the Netherlands were included in the study. After the AEDs had been identified, a questionnaire was used to determine the availability, condition and employability of the AED. In total 130 AEDs were found and 122 included in the study. The following results were found: 40% of the AEDs were not visible (range 21-64), 29% were not indicated with a sign (range 19-41), 7% had an empty battery (range 0-23), 16% of the defipads had expired (range 0-31) and in 98% of the AEDs a trained employee was present (range 96-100). After combining these results, 71% of the AEDs were available for use (range 61-93), 70% were in a good condition (range 46-82) and 70% were employable (range 58-93). The results show a major variability between cities. Our study demonstrates that although national guidelines have not been implemented, a reasonable amount of AEDs can be found. However there is certainly room for improvement in the current availability, condition and employability of AEDs in city centres in the Netherlands. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

High-rate lithium/manganese dioxide batteries; the double cell concept

NASA Astrophysics Data System (ADS)

Drews, Jürgen; Wolf, Rüdiger; Fehrmann, Gerd; Staub, Roland

An implantable defibrillator battery has to provide pulse-power capabilities as well as high energy density. Low self-discharge rates are mandatory and an ability to check the state of charge is required. To accomplish these requirements, a lithium/manganese dioxide battery with a modified active cathode mass has been developed. Usage of a double cell design increases significantly the battery performance within an implantable defibrillator. The design features of a high-rate, pulse-power, manganese dioxide double cell are described.

Using left-ventricular-only pacing to eliminate T-wave oversensing in a biventricular implantable cardiac defibrillator.

PubMed

Khoo, Clarence; Bennett, Matthew; Chakrabarti, Santabhanu; LeMaitre, John; Tung, Stanley K K

2013-02-01

A man aged 75 years and with nonischemic cardiomyopathy had implantation of a biventricular implantable cardiac defibrillator (ICD). Consistent biventricular pacing was limited by intermittent T-wave oversensing (TWOS). A strategy of left-ventricular-only pacing was used to eliminate TWOS. This strategy obviates the need to reduce ventricular sensitivity and thus may be an effective alternative to biventricular pacing complicated by TWOS. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

A Comparison of the Fatigue Performance of Woven and Non-Woven CFRP (carbon Fibre Reinforced Plastics)

DTIC Science & Technology

1985-06-01

certain polymer fibres may defibrillate through exposure to fatigae loading and 20severe environments and subsequently also fail by fibre...fibre by weight than two non-woven plies.- The laminates were stored in a controlled environment at 230C and 652 relative humidity for at least 3 months...instability triggered by the defibrillation . tn fatisue the resin and the fibre/matrix interface become damaged ind are len able to support the fibres, thus

Inappropriate Implantable Cardioverter-Defibrillator Shock from QRS Double Counting in the Setting of Hyperkalemia.

PubMed

Dadlani, Akash; Dukes, Jonathan W; Badhwar, Nitish

2016-03-01

This case shows the complexity of arrhythmia management in patients with implantable cardioverter-defibrillators (ICDs) who present with hyperkalemia. In order to prevent inappropriate ICD shock, consideration should be given to the suspension of ICD therapies while intensive care treatment of extreme electrolyte derangements is being pursued. Patients in these setting should be closely monitored until their electrocardiograms have normalized, after which the device can safely be reactivated. Copyright © 2016 Elsevier Inc. All rights reserved.

Cellular defibrillation: interaction of micro-scale electric fields with voltage-gated ion channels.

PubMed

Kargol, Armin; Malkinski, Leszek; Eskandari, Rahmatollah; Carter, Maya; Livingston, Daniel

2015-09-01

We study the effect of micro-scale electric fields on voltage-gated ion channels in mammalian cell membranes. Such micro- and nano-scale electric fields mimic the effects of multiferroic nanoparticles that were recently proposed [1] as a novel way of controlling the function of voltage-sensing biomolecules such as ion channels. This article describes experimental procedures and initial results that reveal the effect of the electric field, in close proximity of cells, on the ion transport through voltage-gated ion channels. We present two configurations of the whole-cell patch-clamping apparatus that were used to detect the effect of external stimulation on ionic currents and discuss preliminary results that indicate modulation of the ionic currents consistent with the applied stimulus.

Sudden cardiac death in adults with congenital heart disease.

PubMed

Yap, Sing-Chien; Harris, Louise

2009-12-01

Sudden cardiac death is one of the leading causes of death in patients with congenital heart disease, especially in patients with repaired cyanotic and left heart obstructive lesions. While the overall annual incidence of sudden cardiac death is relatively low, estimated at 0.09% per year, this nonetheless represents a many-fold increase over that of comparable age-matched control populations. The most frequent cause of sudden cardiac death is believed to be arrhythmic, usually ventricular arrhythmia. Most studies investigating risk factors for ventricular arrhythmia and/or sudden cardiac death have focused on patients with repaired tetralogy of Fallot and patients with Mustard/Senning repair for complete transposition of the great arteries. Despite a multitude of risk factors, their predictive value for the occurrence of sudden cardiac death is relatively low. Current experience with implantable cardioverter defibrillators in this patient population is limited to observational studies and the selection of patients for prophylactic implantable cardioverter defibrillator implantation is impeded both by the absence of randomized trials and weak predictors. Catheter ablation of ventricular tachycardia has emerged as a promising therapy for abolishing or reducing the burden of arrhythmia but experience is still limited and the impact on long-term outcome uncertain. Future studies will have to focus on improving risk stratification of patients with congenital heart disease.

[Fitness to drive in patients with implanted cardioverter-defibrillator].

PubMed

Klein, H H

2012-09-01

A physician who takes care for patients with implanted cardioverter-defibrillator (ICD) must inform them about their fitness to drive since these patients carry a higher risk for the occurrence of syncope or sudden cardiac death at the wheel. The driver's license law in Germany does not mention patients with ICD. The fitness to drive of patients with ICD is covered by the Advisory Board for Traffic Medicine in Germany (Bundesanstalt für Straßenwesen). These guidelines, however, are outdated and cannot be used to inform patients. Actually, these guidelines are under revision. Currently, the position paper of the German Society of Cardiology on "Fitness to drive and cardiovascular diseases" together with a recently published Dutch paper on this topic forms the basis of these recommendations. One week after ICD implantation for primary or one month after implantation for secondary prevention the patient may resume to drive. After adequate shocks the fitness to drive can be expected 2-4 months (3 months) later. The assessment of the fitness to drive has to be performed individually, taking into account also possible other influencing factors. In individual cases it appears to be justified that patients with ICD work as professional drivers. © Georg Thieme Verlag KG Stuttgart · New York.

Automated external defibrillators in the hospital: A case of medical reversal.

PubMed

Stewart, John A

2018-05-01

Automated external defibrillators (AEDs) emerged in the 1980s as an important innovation in pre-hospital emergency cardiac care (ECC). In the years since, the American Heart Association (AHA) and the International Liaison Committee for Resuscitation (ILCOR) have promoted AED technology for use in hospitals as well, resulting in the widespread purchase and use of AED-capable defibrillators. In-hospital use of AEDs now appears to have decreased survival from cardiac arrests. This article will look at the use of AEDs in hospitals as a case of "medical reversal." Medical reversal occurs when an accepted, widely used treatment is found to be ineffective or even harmful. This article will discuss the issue of AEDs in the hospital using a conceptual framework provided by recent work on medical reversal. It will go on to consider the implications of the reversal for in-hospital resuscitation programs and emergency medicine more generally. Copyright © 2017 The Author. Published by Elsevier Inc. All rights reserved.

Who left the defibrillator on?

PubMed

Gosbee, John

2004-05-01

Two related scenarios involving defibrillator devices reveal how inadvertent hazardous design can go unnoticed until engineers or patient safety personnel use human factors engineering (HFE) analysis. The first adverse event, in which the device was inadvertently turned off while being used to externally pace the patient's heart, resulted in an increased length of stay. The second scenario describes a similar close call and the useless acts of sanctioning the nurse and firing the engineer technician. Feedback to the end user about a device's status is an important design issue. It does not take much expertise to detect when there are problems with "dialogue" from the device to the person (that is, feedback). Many HFE issues have been cited in emergency care areas, and many medical devices--not just defibrillators--do not have readable and understandable feedback to the end user or the kind of automation that would make the wrong action harder to accomplish. All the interactions of multifunction devices with end users in a hectic, noisy, and dynamic environment need to be usability tested and validated. Nurses and engineering personnel can be trained to more easily see HFE design issues--and not dismiss them as individual failings or "someone else's job." Medical device companies are starting to follow the guidelines and regulations that should help prevent adverse events. The defibrillator's design problems had successfully masqueraded as "expected" glitches with hospital electrical utilities, personnel shortcomings, and personality problems. Adverse events related to seemingly simple devices can be prevented with HFE analysis.

[Ethics in intensive care and euthanasia : With respect to inactivating defibrillators at the end of life in terminally ill patients].

PubMed

Trappe, H-J

2017-04-01

In critically ill patients, intensive care medical procedures allow diseases to be cured or controlled that were considered incurable many years ago. For patients with terminal heart failure or heart disease with other severe comorbidities (cancer, stroke), the questions whether the deactivation of defibrillators is appropriate or must be regarded as active euthanasia may arise. Notable cases from the author's hospital are analyzed. The literature on the topic euthanasia and basic literature regarding defibrillator therapy are discussed. It is undisputed that patients as part of their self-determination have the right to renounce treatment. Active euthanasia and the thereby deliberate induction of death is prohibited by law in Germany and will be prosecuted. Passive euthanasia is the omission or reduction of possibly life-prolonging treatment measures. Passive euthanasia requires the patient's consent and is legally and ethically permissible. Indirect euthanasia takes into account acceleration of death as a side effect of a medication. Unpunishable assisted suicide ("assisted suicide") is the mere assistance of self-controlled and self-determined death. Assisted suicide is fundamentally not a criminal offense in Germany. Deactivation of a defibrillator is a treatment discontinuation, which is only permitted in accordance with the wishes of the patient. It is not a question of passive or active euthanasia. Involvement of a local ethics committee and/or legal consultation is certainly useful and sometimes also allows previously unrecognized questions to be answered.

Magnetic resonance imaging during untreated ventricular fibrillation reveals prompt right ventricular overdistention without left ventricular volume loss.

PubMed

Berg, Robert A; Sorrell, Vincent L; Kern, Karl B; Hilwig, Ronald W; Altbach, Maria I; Hayes, Melinda M; Bates, Kathryn A; Ewy, Gordon A

2005-03-08

Most out-of-hospital ventricular fibrillation (VF) is prolonged (>5 minutes), and defibrillation from prolonged VF typically results in asystole or pulseless electrical activity. Recent visual epicardial observations in an open-chest, open-pericardium model of swine VF indicate that blood flows from the high-pressure arterial system to the lower-pressure venous system during untreated VF, thereby overdistending the right ventricle and apparently decreasing left ventricular size. Therefore, inadequate left ventricular stroke volume after defibrillation from prolonged VF has been postulated as a major contributor to the development of pulseless rhythms. Ventricular dimensions were determined by MRI for 30 minutes of untreated VF in a closed-chest, closed-pericardium model in 6 swine. Within 1 minute of untreated VF, mean right ventricular volume increased by 29% but did not increase thereafter. During the first 5 minutes of untreated VF, mean left ventricular volume increased by 34%. Between 20 and 30 minutes of VF, stone heart occurred as manifested by dramatic thickening of the myocardium and concomitant substantial decreases in left ventricular volume. In this closed-chest swine model of VF, substantial right ventricular volume changes occurred early and did not result in smaller left ventricular volumes. The changes in ventricular volumes before the late development of stone heart do not explain why defibrillation from brief duration VF (<5 minutes) typically results in a pulsatile rhythm with return of spontaneous circulation, whereas defibrillation from prolonged VF (5 to 15 minutes) does not.

Radiofrequency ablation for benign thyroid nodules.

PubMed

Bernardi, S; Stacul, F; Zecchin, M; Dobrinja, C; Zanconati, F; Fabris, B

2016-09-01

Benign thyroid nodules are an extremely common occurrence. Radiofrequency ablation (RFA) is gaining ground as an effective technique for their treatment, in case they become symptomatic. Here we review what are the current indications to RFA, its outcomes in terms of efficacy, tolerability, and cost, and also how it compares to the other conventional and experimental treatment modalities for benign thyroid nodules. Moreover, we will also address the issue of treating with this technique patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD), as it is a rather frequent occurrence that has never been addressed in detail in the literature.

Automatic remote monitoring utilizing daily transmissions: transmission reliability and implantable cardioverter defibrillator battery longevity in the TRUST trial.

PubMed

Varma, Niraj; Love, Charles J; Schweikert, Robert; Moll, Philip; Michalski, Justin; Epstein, Andrew E

2018-04-01

Benefits of automatic remote home monitoring (HM) among implantable cardioverter defibrillator (ICD) patients may require high transmission frequency. However, transmission reliability and effects on battery longevity remain uncertain. We hypothesized that HM would have high transmission success permitting punctual guideline based follow-up, and improve battery longevity. This was tested in the prospective randomized TRUST trial. Implantable cardioverter defibrillator patients were randomized post-implant 2:1 to HM (n = 908) (transmit daily) or to Conventional in-person monitoring [conventional management (CM), n = 431 (HM disabled)]. In both groups, five evaluations were scheduled every 3 months for 15 months. Home Monitoring technology performance was assessed by transmissions received vs. total possible, and number of scheduled HM checks failing because of missed transmissions. Battery longevity was compared in HM vs. CM at 15 months, and again in HM 3 years post-implant using continuously transmitted data. Transmission success per patient was 91% (median follow-up of 434 days). Overall, daily HM transmissions were received in 315 795 of a potential 363 450 days (87%). Only 55/3759 (1.46%) of unsuccessful scheduled evaluations in HM were attributed to transmission loss. Shock frequency and pacing percentage were similar in HM vs. CM. Fifteen month battery longevity was 12% greater in HM (93.2 ± 8.8% vs. 83.5 ± 6.0% CM, P < 0.001). In extended follow-up of HM patients, estimated battery longevity was 50.9 ± 9.1% (median 52%) at 36 months. Automatic remote HM demonstrated robust transmission reliability. Daily transmission load may be sustained without reducing battery longevity. Home Monitoring conserves battery longevity and tracks long term device performance. ClinicalTrials.gov; NCT00336284.

Pediatric resident resuscitation skills improve after "rapid cycle deliberate practice" training.

PubMed

Hunt, Elizabeth A; Duval-Arnould, Jordan M; Nelson-McMillan, Kristen L; Bradshaw, Jamie Haggerty; Diener-West, Marie; Perretta, Julianne S; Shilkofski, Nicole A

2014-07-01

Previous studies reveal pediatric resident resuscitation skills are inadequate, with little improvement during residency. The Accreditation Council for Graduate Medical Education highlights the need for documenting incremental acquisition of skills, i.e., "Milestones". We developed a simulation-based teaching approach "Rapid Cycle Deliberate Practice" (RCDP) focused on rapid acquisition of procedural and teamwork skills (i.e., "first-five minutes" (FFM) resuscitation skills). This novel method utilizes direct feedback and prioritizes opportunities for learners to "try again" over lengthy debriefing. Pediatric residents from an academic medical center. Prospective pre-post interventional study of residents managing a simulated cardiopulmonary arrest. Main outcome measures include: (1) interval between onset of pulseless ventricular tachycardia to initiation of compressions and (2) defibrillation. Seventy pediatric residents participated in the pre-intervention and fifty-one in the post-intervention period. Baseline characteristics were similar. The RCDP-FFM intervention was associated with a decrease in: no-flow fraction: [pre: 74% (5-100%) vs. post: 34% (26-53%); p<0.001)], no-blow fraction: [pre: 39% (22-64%) median (IQR) vs. post: 30% (22-41%); p=0.01], and pre-shock pause: [pre: 84 s (26-162) vs. post: 8s (4-18); p<0.001]. Survival analysis revealed RCDP-FFM was associated with starting compressions within 1 min of loss of pulse: [Adjusted Hazard Ratio (HR): 3.8 (95% CI: 2.0-7.2)] and defibrillating within 2 min: [HR: 1.7 (95% CI: 1.03-2.65)]. Third year residents were significantly more likely than first years to defibrillate within 2 min: [HR: 2.8 (95% CI: 1.5-5.1)]. Implementation of the RCDP-FFM was associated with improvement in performance of key measures of quality life support and progressive acquisition of resuscitation skills during pediatric residency. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Psychological Effects of Automated External Defibrillator Training A randomized trial

PubMed Central

Meischke, Hendrika; Diehr, Paula; Phelps, Randi; Damon, Susan; Rea, Tom

2011-01-01

Objectives The objective of this study was to test if an Automated External Defibrillator (AED) training program would positively affect the mental health of family members of high risk patients. Methods 305 ischemic heart disease patients and their family members were randomized to one of four AED training programs: two video-based training programs and two face-to-face training programs that emphasized self-efficacy and perceived control. Patients and family members were surveyed at baseline, 3 and 9 months post ischemic event on demographic characteristics, measures of quality of life (SF=36) , self-efficacy and perceived control. For this study, family members were the focus rather than the patients. Results Regression analyses showed that family members in the face-to-face training programs did not score better on any of the mental health status variables than family members who participated in the other training programs but for an increase in self-efficacy beliefs at 3 months post training. Conclusion The findings suggest that a specifically designed AED training program emphasizing self-efficacy and perceived control beliefs is not likely to enhance family member mental health. PMID:21411144

Lithium-manganese dioxide cells for implantable defibrillator devices-Discharge voltage models

NASA Astrophysics Data System (ADS)

Root, Michael J.

The discharge potential behavior of lithium-manganese dioxide cells designed for implantable cardiac defibrillators was characterized as a function of extent of cell depletion for tests designed to discharge the cells for times between 1 and 7 years. The discharge potential curves may be separated into two segments from 0 ≤ x ≤ ∼0.51 and ∼0.51 ≤ x ≤ 1.00, where x is the dimensionless extent of discharge referenced to the rated cell capacity. The discharge potentials conform to Tafel kinetics in each segment. This behavior allows the discharge potential curves to be predicted for an arbitrary discharge load and long term discharge performance may be predicted from short term test results. The discharge potentials may subsequently be modeled by fitting the discharge curves to empirical functions like polynomials and Padé approximants. A function based on the Nernst equation that includes a term accounting for nonideal interactions between lithium ions and the cathode host material, such as the Redlich-Kister relationship, also may be used to predict discharge behavior.

Cardiovascular emergency preparedness in recreation facilities at major US universities: college fitness center emergency readiness.

PubMed

Herbert, William G; Herbert, David L; McInnis, Kyle J; Ribisl, Paul M; Franklin, Barry A; Callahan, Mandy; Hood, Aaron W

2007-01-01

Recent American Heart Association/American College of Sports Medicine (AHA/ACSM) guidelines advocate preparticipation screening, planning, and rehearsal for emergencies and automated external defibrillators in all health/fitness facilities. The authors evaluated adherence to these recommendations at 158 recreational service departments in major US universities (51% response rate for 313 institutions queried). Many made their facilities available to unaffiliated residents, with 39% offering programs for those with special medical conditions. Only 18% performed universal preparticipation screening. Twenty-seven percent reported having 1 or more exercise-related instances of cardiac arrest or sudden cardiac death within the past 5 years. Seventy-three percent had an automated external defibrillator, but only 6% reported using it in an emergency. Almost all had written emergency plans, but only 50% posted their plans, and only 27% performed the recommended quarterly emergency drills. The authors' findings suggest low awareness of and adherence to the AHA/ACSM recommendations for identifying individuals at risk for exercise-related cardiovascular complications and for handling such emergencies in university-based fitness facilities. (

"Pseudo" Faraday cage: a solution for telemetry link interaction between a left ventricular assist device and an implantable cardioverter defibrillator.

PubMed

Jacob, Sony; Cherian, Prasad K; Ghumman, Waqas S; Das, Mithilesh K

2010-09-01

Patients implanted with left ventricular assist devices (LVAD) may have implantable cardioverter defibrillators (ICD) implanted for sudden cardiac death prevention. This opens the possibility of device-device communication interactions and thus interferences. We present a case of such interaction that led to ICD communication failure following the activation of an LVAD. In this paper, we describe a practical solution to circumvent the communication interference and review the communication links of ICDs and possible mechanisms of ICD-LVAD interactions.

TED-Time and life saving External Defibrillator for home-use.

PubMed

Weiss, Teddy A; Rosenheck, Shimon; Gorni, Shraga; Katz, Ioni; Mendelbaum, Mendel; Gilon, Dan

2014-06-01

Sudden Cardiac Death--SCD --is a major unmet health problem that needs urgent and prompt solution. AICDs are very expensive, risky and indicated for a small group of patients, at the highest risk. AEDs--Automatic External Defibrillators--are designed for public places and although safe, cannot enter the home-market due to their cost and need for constant, high-cost maintenance. We developed TED, a low-cost AED that derives its energy off the mains, designed for home-use, to save SCD victims' lives. Copyright © 2014 Elsevier Inc. All rights reserved.

[Clinical development of the automatic implantable defibrillator over 35 years: A success story].

PubMed

Steinbeck, G

2015-06-01

After 12 years of development and experimental evaluation, the first automatic implantable cardioverter-defibrillator (ICD) was implanted in man on February 4, 1980. This overview describes the technical and functional developments over 35 years from a simple shock-box, weighing 292 g, to the sophisticated 80 g device of today, delivering graded therapy to sustained ventricular arrhythmias and biventricular stimulation to treat heart failure. Finally, a special tribute is given to Michel Mirowski, one of the inventors of the ICD, as scientist and physician dedicated to patient care.

The Number of Recalled Leads is Highly Predictive of Lead Failure: Results From the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS").

PubMed

Kersten, Daniel J; Yi, Jinju; Feldman, Alyssa M; Brahmbhatt, Kunal; Asheld, Wilbur J; Germano, Joseph; Islam, Shahidul; Cohen, Todd J

2016-12-01

The purpose of this study was to determine if implantation of multiple recalled defibrillator leads is associated with an increased risk of lead failure. The authors of the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS") have previously reported a relationship between recalled lead status, lead failure, and patient mortality. This substudy analyzes the relationship in a smaller subset of patients who received more than one recalled lead. The specific effects of having one or more recalled leads have not been previously examined. This study analyzed lead failure and mortality of 3802 patients in PAIDLESS and compared outcomes with respect to the number of recalled leads received. PAIDLESS includes all patients at Winthrop University Hospital who underwent defibrillator lead implantation between February 1, 1996 and December 31, 2011. Patients with no recalled ICD leads, one recalled ICD lead, and two recalled ICD leads were compared using the Kaplan-Meier method and log-rank test. Sidak adjustment method was used to correct for multiple comparisons. All calculations were performed using SAS 9.4. P-values <.05 were considered statistically significant. This study included 4078 total ICD leads implanted during the trial period. There were 2400 leads (59%) in the no recalled leads category, 1620 leads (40%) in the one recalled lead category, and 58 leads (1%) in the two recalled leads category. No patient received more than two recalled leads. Of the leads categorized in the two recalled leads group, 12 experienced lead failures (21%), which was significantly higher (P<.001) than in the no recalled leads group (60 failures, 2.5%) and one recalled lead group (81 failures; 5%). Multivariable Cox's regression analysis found a total of six significant predictive variables for lead failure including the number of recalled leads (P<.001 for one and two recalled leads group). The number of recalled leads is highly predictive of lead failure. Lead-based multivariable Cox's regression analysis produced a total of six predictive variable categories for lead failure, one of which was the number of recalled leads. Kaplan-Meier analysis showed that the leads in the two recalled leads category failed faster than both the no recalled lead and one recalled lead groups. The greater the number of recalled leads to which patients are exposed, the greater the risk of lead failure.

Factors associated with anxiety and depression among patients with implantable cardioverter defibrillator.

PubMed

Wong, Mei Fung Florence

2017-05-01

To identify factors associated with anxiety and depression of patients with implantable cardioverter defibrillators. Implantable cardioverter defibrillator is effective to increase survival from life-threatening arrhythmias, but it lowers health-related quality of life. Anxiety and depression had significant negative association with health-related quality of life. However, knowledge about factors associated with these two negative emotions in this specific population is inadequate. A cross-sectional descriptive design was conducted. Secondary analysis was performed to address the aim. A convenience sampling of patients with implantable cardioverter defibrillators was performed. Anxiety and depression were measured by the Hospital Anxiety and Depression Scale through face-to-face interview. Stepwise multivariable regression results showed that older age (aged 60-69 and ≥70: B = 2·08 and 3·31, p = 0·039 and <0·001), self-care dependence (B = 3·47, p < 0·001), being married (B = -2·21, p = 0·004) and having ischaemic heart disease (B = -1·80, p = 0·008) were significantly associated with depression. However, there was no significant factor associated with anxiety. Factors associated with depression among patients with implantable cardioverter defibrillator are identified. Older age (aged ≥60) and more self-care dependence have positive, but being married and having ischaemic heart disease have negative association with depression. Strategies to reduce psychological distress are highlighted. The study findings direct the care to improve health-related quality of life by reducing and controlling vulnerabilities arising from depression. Patients who are older people (≥aged 60) and more self-care dependent perceive higher depression. Nursing strategies are suggested to reduce depression especially for those who are older people and more self-care dependent. Early screening is essential to provide immediate care for reducing vulnerabilities arising from depression. Performing comprehensive assessment for self-care ability and providing adequate assistance are crucial. Family involvement may reduce depression through providing physical and psychosocial support. © 2016 John Wiley & Sons Ltd.

Survey of pediatric resident experiences with resuscitation training and attendance at actual cardiopulmonary arrests.

PubMed

Hunt, Elizabeth A; Patel, Sachin; Vera, Kimberly; Shaffner, Donald H; Pronovost, Peter J

2009-01-01

The literature suggests pediatric residents are inadequately prepared to perform resuscitation maneuvers when a child suffers a cardiopulmonary arrest (CPA). Our objective was to characterize the resuscitation training and CPA resuscitation experience of residents, including hands on experience with discharging a defibrillator. : Cross-sectional survey. Tertiary care, academic pediatric residency program. Pediatric residents. Seventy-six of 80 (95%) pediatric residents responded. The median (interquartile range) number of CPAs attended increased significantly by level of training, with some attending as many as 20 CPAs during residency (postgraduate year [PGY]1: 2.0 [1.0-3.0] vs. PGY2: 5.0 [3.0-8.0] vs. PGY3: 10.0 [5.0-12.0], p < 0.001). Nine of 25 (36%) senior residents had led a resuscitation. The proportion of third-year residents who had attended at least 1 CPA in the following locations was: general ward 20 of 25 (80%), Emergency Department 18 of 25 (72%), Neonatal intensive care unit 24 of 25 (96%), pediatric intensive care unit 23 of 25 (92%), and secondary training hospital 19 of 25 (76%). Twelve of 76 (16%) residents had discharged a defibrillator on an actual patient; however, 25 of 76 (33%) had never discharged a defibrillator, either on a patient or during training exercises. Although most residents had received required training in American Heart Association Basic Life Support and Pediatric Advance Life Support (i.e., BLS and PALS), 6 of 76 (8%) residents had never taken basic life support and 4 of 48 (8%) of upper level residents had never taken pediatric advanced life support. Multivariate analysis revealed that level of training, pediatric advanced life support training, and attendance at a mock code in the past year were not independently associated with having discharged a defibrillator (i.e., patient, mannequin, etc.), whereas attendance at an institutional Code Team training course was. Almost every pediatric resident was involved in attempting to resuscitate a child suffering a CPA, yet many were inadequately trained to respond. Formal mechanisms are needed to guarantee adequate resuscitation training for pediatric residents, especially regarding participation in basic life support and hands on defibrillator training.

Mortality reduction in relation to implantable cardioverter defibrillator programming in the Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy (MADIT-RIT).

PubMed

Ruwald, Anne-Christine; Schuger, Claudio; Moss, Arthur J; Kutyifa, Valentina; Olshansky, Brian; Greenberg, Henry; Cannom, David S; Estes, N A Mark; Ruwald, Martin H; Huang, David T; Klein, Helmut; McNitt, Scott; Beck, Christopher A; Goldstein, Robert; Brown, Mary W; Kautzner, Josef; Shoda, Morio; Wilber, David; Zareba, Wojciech; Daubert, James P

2014-10-01

The benefit of novel implantable cardioverter defibrillator (ICD) programming in reducing inappropriate ICD therapy and mortality was demonstrated in Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy (MADIT-RIT). However, the cause of mortality reduction remains incompletely evaluated. We aimed to identify factors associated with mortality, with focus on ICD therapy and programming in the MADIT-RIT population. In MADIT-RIT, 1500 patients with a primary prophylactic indication for ICD or cardiac resynchronization therapy with defibrillator were randomized to 1 of 3 different ICD programming arms: conventional programming (ventricular tachycardia zone ≥170 beats per minute), high-rate programming (ventricular tachycardia zone ≥200 beats per minute), and delayed programming (60-second delay before therapy ≥170 beats per minute). Multivariate Cox models were used to assess the influence of time-dependent appropriate and inappropriate ICD therapy (shock and antitachycardia pacing) and randomized programming arm on all-cause mortality. During an average follow-up of 1.4±0.6 years, 71 of 1500 (5%) patients died: cardiac in 40 patients (56.3%), noncardiac in 23 patients (32.4%), and unknown in 8 patients (11.3%). Appropriate shocks (hazard ratio, 6.32; 95% confidence interval, 3.13-12.75; P<0.001) and inappropriate therapy (hazard ratio, 2.61; 95% confidence interval, 1.28-5.31; P=0.01) were significantly associated with an increased mortality risk. There was no evidence of increased mortality risk in patients who experienced appropriate antitachycardia pacing only (hazard ratio, 1.02; 95% confidence interval, 0.36-2.88; P=0.98). Randomization to conventional programming was identified as an independent predictor of death when compared with patients randomized to high-rate programming (hazard ratio, 2.0; 95% confidence interval, 1.06-3.71; P=0.03). In MADIT-RIT, appropriate shocks, inappropriate ICD therapy, and randomization to conventional ICD programming were independently associated with an increased mortality risk. Appropriate antitachycardia pacing was not related to an adverse outcome. clinicaltrials.gov Unique identifier: NCT00947310. © 2014 American Heart Association, Inc.

Tablet-based cardiac arrest documentation: a pilot study.

PubMed

Peace, Jack M; Yuen, Trevor C; Borak, Meredith H; Edelson, Dana P

2014-02-01

Conventional paper-based resuscitation transcripts are notoriously inaccurate, often lacking the precision that is necessary for recording a fast-paced resuscitation. The aim of this study was to evaluate whether a tablet computer-based application could improve upon conventional practices for resuscitation documentation. Nurses used either the conventional paper code sheet or a tablet application during simulated resuscitation events. Recorded events were compared to a gold standard record generated from video recordings of the simulations and a CPR-sensing defibrillator/monitor. Events compared included defibrillations, medication deliveries, and other interventions. During the study period, 199 unique interventions were observed in the gold standard record. Of these, 102 occurred during simulations recorded by the tablet application, 78 by the paper code sheet, and 19 during scenarios captured simultaneously by both documentation methods These occurred over 18 simulated resuscitation scenarios, in which 9 nurses participated. The tablet application had a mean sensitivity of 88.0% for all interventions, compared to 67.9% for the paper code sheet (P=0.001). The median time discrepancy was 3s for the tablet, and 77s for the paper code sheet when compared to the gold standard (P<0.001). Similar to prior studies, we found that conventional paper-based documentation practices are inaccurate, often misreporting intervention delivery times or missing their delivery entirely. However, our study also demonstrated that a tablet-based documentation method may represent a means to substantially improve resuscitation documentation quality, which could have implications for resuscitation quality improvement and research. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The Italian subcutaneous implantable cardioverter-defibrillator survey: S-ICD, why not?

PubMed

Botto, Giovanni Luca; Forleo, Giovanni B; Capucci, Alessandro; Solimene, Francesco; Vado, Antonello; Bertero, Giovanni; Palmisano, Pietro; Pisanò, Ennio; Rapacciuolo, Antonio; Infusino, Tommaso; Vicentini, Alessandro; Viscusi, Miguel; Ferrari, Paola; Talarico, Antonello; Russo, Giovanni; Boriani, Giuseppe; Padeletti, Luigi; Lovecchio, Mariolina; Valsecchi, Sergio; D'Onofrio, Antonio

2017-11-01

A recommendation for a subcutaneous-implantable cardioverter-defibrillator (S-ICD) has been added to recent European Society of Cardiology Guidelines. However, the S-ICD is not ideally suitable for patients who need pacing. The aim of this survey was to analyse the current practice of ICD implantation and to evaluate the actual suitability of S-ICD. The survey 'S-ICD Why Not?' was an independent initiative taken by the Italian Heart Rhythm Society (AIAC). Clinical characteristics, selection criteria, and factors guiding the choice of ICD type were collected in consecutive patients who underwent ICD implantation in 33 Italian centres from September to December 2015. A cardiac resynchronization therapy (CRT) device was implanted in 39% (369 of 947) of patients undergoing de novo ICD implantation. An S-ICD was implanted in 12% of patients with no CRT indication (62 of 510 with available data). S-ICD patients were younger than patients who received transvenous ICD, more often had channelopathies, and more frequently received their device for secondary prevention of sudden death. More frequently, the clinical reason for preferring a transvenous ICD over an S-ICD was the need for pacing (45%) or for antitachycardia pacing (36%). Nonetheless, only 7% of patients fulfilled conditions for recommending permanent pacing, and 4% of patients had a history of monomorphic ventricular tachycardia that might have been treatable with antitachycardia pacing. The vast majority of patients needing ICD therapy are suitable candidates for S-ICD implantation. Nevertheless, it currently seems to be preferentially adopted for secondary prevention of sudden death in young patients with channelopathies. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

Significant Discrepancy Between Estimated and Actual Longevity in St. Jude Medical Implantable Cardioverter-Defibrillators.

PubMed

Doppalapudi, Harish; Barrios, James; Cuellar, Jose; Gannon, Melanie; Yamada, Takumi; Kumar, Vineet; Maddox, William R; Plumb, Vance J; Brown, Todd M; McElderry, H Tom

2017-05-01

Real-time estimated longevity has been reported in pacemakers for several years, and was recently introduced in implantable cardioverter-defibrillators (ICDs). We sought to evaluate the accuracy of this longevity estimate in St. Jude Medical (SJM) ICDs, especially as the device battery approaches depletion. Among patients with SJM ICDs who underwent generator replacements due to reaching elective replacement indicator (ERI) at our institution, we identified those with devices that provided longevity estimates and reviewed their device interrogations in the 18 months prior to ERI. Significant discrepancy was defined as a difference of more than 12 months between estimated and actual longevity at any point during this period. Forty-six patients with Current/Promote devices formed the study group (40 cardiac resynchronization therapy [CRT] and 6 single/dual chamber). Of these, 34 (74%) had significant discrepancy between estimated and actual longevity (28 CRT and all single/dual). Longevity was significantly overestimated by the device algorithm (mean maximum discrepancy of 18.8 months), more in single/dual than CRT devices (30.5 vs. 17.1 months). Marked discrepancy was seen at voltages ≥2.57 volts, with maximum discrepancy at 2.57 volts (23 months). The overall longevity was higher in the discrepant group of CRT devices than in the nondiscrepant group (67 vs. 61 months, log-rank P = 0.03). There was significant overestimation of longevity in nearly three-fourths of Current/Promote SJM ICDs in the last 18 months prior to ERI. Longevity estimates of SJM ICDs may not be reliable for making clinical decisions on frequency of follow-up, as the battery approaches depletion. © 2017 Wiley Periodicals, Inc.

Cardioversion Efficacy Using Pulsed Biphasic or Biphasic Truncated Exponential Waveforms: A Randomized Clinical Trial.

PubMed

Schmidt, Anders S; Lauridsen, Kasper G; Adelborg, Kasper; Torp, Peter; Bach, Leif F; Jepsen, Simon M; Hornung, Nete; Deakin, Charles D; Rickers, Hans; Løfgren, Bo

2017-03-08

Several different defibrillators are currently used for cardioversion and defibrillation of cardiac arrhythmias. The efficacy of a novel pulsed biphasic (PB) waveform has not been compared to other biphasic waveforms. Accordingly, this study aims to compare the efficacy and safety of PB shocks with biphasic truncated exponential (BTE) shocks in patients undergoing cardioversion of atrial fibrillation or -flutter. This prospective, randomized study included patients admitted for elective direct current cardioversion. Patients were randomized to receive cardioversion using either PB or BTE shocks. We used escalating shocks until sinus rhythm was obtained or to a maximum of 4 shocks. Patients randomized to PB shocks received 90, 120, 150, and 200 J and patients randomized to BTE shocks received 100, 150, 200, and 250 J, as recommended by the manufacturers. In total, 69 patients (51%) received PB shocks and 65 patients (49%) BTE shocks. Successful cardioversion, defined as sinus rhythm 4 hours after cardioversion, was achieved in 43 patients (62%) using PB shocks and in 56 patients (86%) using BTE shocks; ratio 1.4 (95% CI 1.1-1.7) ( P =0.002). There was no difference in safety (ie, myocardial injury judged by changes in high-sensitive troponin I levels; ratio 1.1) (95% CI 1.0-1.3), P =0.15. The study was terminated prematurely because of an adverse event. Cardioversion using a BTE waveform was more effective when compared with a PB waveform. There was no difference in safety between the 2 waveforms, as judged by changes in troponin I levels. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02317029. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Ventricular tachyarrhythmias and mortality in patients with an implantable cardioverter defibrillator: impact of depression in the MIDAS cohort.

PubMed

Mastenbroek, Mirjam H; Versteeg, Henneke; Jordaens, Luc; Theuns, Dominic A M J; Pedersen, Susanne S

2014-01-01

We examined whether depression is independently associated with implantable cardioverter defibrillator (ICD) therapy for ventricular tachyarrhythmias and mortality. A cohort of 430 consecutive patients with a first-time ICD (79% men; mean [standard deviation] age = 57.8 [12.1] years) completed the Hospital Anxiety and Depression Scale 1 day before implantation. During follow-up, the ICD was interrogated at 3-month intervals. Cox proportional hazard regression analyses were used to examine the impact of depression on time to first appropriate ICD therapy and all-cause mortality during a median follow-up period of 3.8 years. Of all patients, 108 (25.1%) were depressed. Depression was not associated with time to first appropriate ICD therapy (unadjusted hazard ratio [HR] = 1.07, 95% confidence interval [CI] = 0.73-1.56). However, depression was associated with an increased risk for all-cause mortality (unadjusted HR = 2.18, 95% CI = 1.36-3.49). Depression remained independently associated with all-cause mortality (HR = 1.94, 95% CI = 1.06-3.54, p = .031), after adjusting for demographic and clinical characteristics. Patients who remained depressed during the first 3 months after implantation were at greatest risk for dying (HR = 2.88, 95% CI = 1.29-6.45, p = .010). The current study showed that depression at the time of implant is not associated with time to first appropriate ICD therapy but almost doubled the risk for all-cause mortality in patients with an ICD. Patients with persistent depression during the first 3 months after implantation face the greatest risk of dying. Current evidence indicates that multifactorial interventions are likely to be the most successful in terms of reducing distress. Whether this translates into enhanced survival has yet to be determined.

Perceptions of healthcare professionals' support, shock anxiety and device acceptance among implantable cardioverter defibrillator recipients.

PubMed

Morken, Ingvild M; Norekvål, Tone M; Bru, Edvin; Larsen, Alf I; Karlsen, Bjørg

2014-09-01

To investigate the extent to which perceived support from healthcare professionals and shock anxiety is related to device acceptance among implantable cardioverter defibrillator recipients. Device acceptance can be influenced by several factors, one of which is shock anxiety associated with poor device acceptance. Reduced shock anxiety, as well as increased device acceptance, has been reported after psycho-educational programmes. As healthcare professionals appear to play a significant role in providing support and education during regular follow-up visits, they may constitute an important social support system that could be another factor influencing device acceptance. However, little is known about the relationship between perceived support from healthcare professionals and device acceptance among recipients. A cross-sectional survey design. A sample comprising implantable cardioverter defibrillator recipients completed questionnaires assessing perceived support from healthcare professionals, shock anxiety and device acceptance. Demographic and clinical data were collected by self-report and from medical records in September-October 2010. The descriptive results indicated that approximately 85% of the recipients experienced high device acceptance. Regression analysis demonstrated that constructive support from healthcare professionals was positively associated with device acceptance and moderated the negative relationship between shock anxiety and device acceptance. Non-constructive support and shock anxiety had a negative statistical association with device acceptance. Healthcare professionals may represent a valuable constructive support system that can enhance device acceptance among implantable cardioverter defibrillator recipients, partly by preventing shock anxiety from leading to poor device acceptance. Non-constructive communication on the part of healthcare professionals could hinder device acceptance. © 2014 John Wiley & Sons Ltd.

Efficacy and safety of nitroglycerin for preventing venous spasm during contrast-guided axillary vein puncture for pacemaker or defibrillator leads implantation.

PubMed

Duan, Xu; Ling, Feng; Shen, Yun; Yang, Jun; Xu, Hai-ying; Tong, Xiao-shan

2013-04-01

We investigated the efficacy and safety of nitroglycerin for preventing venous spasm during contrast-guided axillary vein puncture for pacemaker or defibrillator leads implantation. A total of 40 consecutive patients referred for contrast-guided axillary vein puncture for pacemaker or defibrillator implantations were included in the study. Patients were randomly assigned to control group and nitroglycerin group. Patients in the nitroglycerin group were given 200 µg (2 mL) nitroglycerin via ipsilateral peripheral vein about 3 min before puncture. The degree of venous spasm was evaluated by the reduction in lumen calibre of the axillary vein after puncture. Mild venous spasm and severe venous spasm were defined as a reduction in lumen calibre of 50-90% and ≥ 90%, respectively. The mean degree of venous spasm of axillary vein was lower in the nitroglycerin group than in the control group (23.0 ± 22.3 vs. 45.5 ± 33.6%, P = 0.018). The incidence of mild or severe venous spasm was lower in the nitroglycerin group than in the control group (3/20 vs. 11/20, P = 0.019). In the nitroglycerin group, the systolic blood pressure had a significant decrease after puncture (129.5 ± 23.7 vs. 143.0 ± 24.1 mmHg, P = 0.003). There was no hypotension and other adverse reaction of nitroglycerin in the nitroglycerin group. Intravenous nitroglycerin is effective and safe for preventing venous spasm during contrast-guided axillary vein puncture for pacemaker or defibrillator leads implantation.

The oral cavity is not a primary source for implantable pacemaker or cardioverter defibrillator infections

PubMed Central

2013-01-01

Background To test the hypothesis that the oral cavity is a potential source for implantable pacemaker and cardioverter defibrillators infections, the bacterial diversity on explanted rhythm heart management devices was investigated and compared to the oral microbiome. Methods A metagenomic approach was used to analyze the bacterial diversity on the surfaces of non-infected and infected pacemakers. The DNA from surfaces swaps of 24 non-infected and 23 infected pacemaker were isolated and subjected to bacterial-specific DNA amplification, single strand conformation polymorphism- (SSCP) and sequencing analysis. Species-specific primer sets were used to analyze for any correlation between bacterial diversity on pacemakers and in the oral cavity. Results DNA of bacterial origin was detected in 21 cases on infected pacemakers and assigned to the bacterial phylotypes Staphylococcus epidermidis, Propionibacterium acnes, Staphylococcus aureus, Staphylococcus schleiferi and Stapyhlococcus. In 17 cases bacterial DNA was found on pacemakers with no clinical signs of infections. On the basis of the obtained sequence data, the phylotypes Propionibacterium acnes, Staphylococcus and an uncultured bacterium were identified. Propionibacterium acnes and Staphylococcus epidermidis were the only bacteria detected in pacemeaker (n = 25) and oral samples (n = 11). Conclusions The frequency of the coincidental detection of bacteria on infected devices and in the oral cavity is low and the detected bacteria are highly abundant colonizers of non-oral human niches. The transmission of oral bacteria to the lead or device of implantable pacemaker or cardioverter defibrillators is unlikely relevant for the pathogenesis of pacemaker or cardioverter defibrillators infections. PMID:23575037

Poor chest compression quality with mechanical compressions in simulated cardiopulmonary resuscitation: a randomized, cross-over manikin study.

PubMed

Blomberg, Hans; Gedeborg, Rolf; Berglund, Lars; Karlsten, Rolf; Johansson, Jakob

2011-10-01

Mechanical chest compression devices are being implemented as an aid in cardiopulmonary resuscitation (CPR), despite lack of evidence of improved outcome. This manikin study evaluates the CPR-performance of ambulance crews, who had a mechanical chest compression device implemented in their routine clinical practice 8 months previously. The objectives were to evaluate time to first defibrillation, no-flow time, and estimate the quality of compressions. The performance of 21 ambulance crews (ambulance nurse and emergency medical technician) with the authorization to perform advanced life support was studied in an experimental, randomized cross-over study in a manikin setup. Each crew performed two identical CPR scenarios, with and without the aid of the mechanical compression device LUCAS. A computerized manikin was used for data sampling. There were no substantial differences in time to first defibrillation or no-flow time until first defibrillation. However, the fraction of adequate compressions in relation to total compressions was remarkably low in LUCAS-CPR (58%) compared to manual CPR (88%) (95% confidence interval for the difference: 13-50%). Only 12 out of the 21 ambulance crews (57%) applied the mandatory stabilization strap on the LUCAS device. The use of a mechanical compression aid was not associated with substantial differences in time to first defibrillation or no-flow time in the early phase of CPR. However, constant but poor chest compressions due to failure in recognizing and correcting a malposition of the device may counteract a potential benefit of mechanical chest compressions. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Overcoming Spatial and Temporal Barriers to Public Access Defibrillators Via Optimization.

PubMed

Sun, Christopher L F; Demirtas, Derya; Brooks, Steven C; Morrison, Laurie J; Chan, Timothy C Y

2016-08-23

Immediate access to an automated external defibrillator (AED) increases the chance of survival for out-of-hospital cardiac arrest (OHCA). Current deployment usually considers spatial AED access, assuming AEDs are available 24 h a day. The goal of this study was to develop an optimization model for AED deployment, accounting for spatial and temporal accessibility, to evaluate if OHCA coverage would improve compared with deployment based on spatial accessibility alone. This study was a retrospective population-based cohort trial using data from the Toronto Regional RescuNET Epistry cardiac arrest database. We identified all nontraumatic public location OHCAs in Toronto, Ontario, Canada (January 2006 through August 2014) and obtained a list of registered AEDs (March 2015) from Toronto Paramedic Services. Coverage loss due to limited temporal access was quantified by comparing the number of OHCAs that occurred within 100 meters of a registered AED (assumed coverage 24 h per day, 7 days per week) with the number that occurred both within 100 meters of a registered AED and when the AED was available (actual coverage). A spatiotemporal optimization model was then developed that determined AED locations to maximize OHCA actual coverage and overcome the reported coverage loss. The coverage gain between the spatiotemporal model and a spatial-only model was computed by using 10-fold cross-validation. A total of 2,440 nontraumatic public OHCAs and 737 registered AED locations were identified. A total of 451 OHCAs were covered by registered AEDs under assumed coverage 24 h per day, 7 days per week, and 354 OHCAs under actual coverage, representing a coverage loss of 21.5% (p < 0.001). Using the spatiotemporal model to optimize AED deployment, a 25.3% relative increase in actual coverage was achieved compared with the spatial-only approach (p < 0.001). One in 5 OHCAs occurred near an inaccessible AED at the time of the OHCA. Potential AED use was significantly improved with a spatiotemporal optimization model guiding deployment. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Rise and Shock: Optimal Defibrillator Placement in a High-rise Building.

PubMed

Chan, Timothy C Y

2017-01-01

Out-of-hospital cardiac arrests (OHCA) in high-rise buildings experience lower survival and longer delays until paramedic arrival. Use of publicly accessible automated external defibrillators (AED) can improve survival, but "vertical" placement has not been studied. We aim to determine whether elevator-based or lobby-based AED placement results in shorter vertical distance travelled ("response distance") to OHCAs in a high-rise building. We developed a model of a single-elevator, n-floor high-rise building. We calculated and compared the average distance from AED to floor of arrest for the two AED locations. We modeled OHCA occurrences using floor-specific Poisson processes, the risk of OHCA on the ground floor (λ 1 ) and the risk on any above-ground floor (λ). The elevator was modeled with an override function enabling direct travel to the target floor. The elevator location upon override was modeled as a discrete uniform random variable. Calculations used the laws of probability. Elevator-based AED placement had shorter average response distance if the number of floors (n) in the building exceeded three quarters of the ratio of ground-floor OHCA risk to above-ground floor risk (λ 1 /λ) plus one half (n ≥ 3λ 1 /4λ + 0.5). Otherwise, a lobby-based AED had shorter average response distance. If OHCA risk on each floor was equal, an elevator-based AED had shorter average response distance. Elevator-based AEDs travel less vertical distance to OHCAs in tall buildings or those with uniform vertical risk, while lobby-based AEDs travel less vertical distance in buildings with substantial lobby, underground, and nearby street-level traffic and OHCA risk.

Improving Defibrillation Efficiency in Area Schools.

PubMed

Thomas, Vincent C; Shen, Jay J; Stanley, Ramona; Dahlke, Jeffrey; McPartlin, Sheri; Row, Lynn

2016-07-01

Sudden cardiac arrest (SCA) in the young is a rare event but the effects can be devastating. We sought to identify variables that would lead to an improvement in time to defibrillation (TDFB), a previously noted factor significantly influencing survival from cardiac arrest. During the 2013-2014 academic year, the Clark county school district performed quarterly drills to practice the coordinated automated external defibrillator (AED) response. Variables including school, AED carrier, and drill characteristics were measured to determine influence on TDFB. Schools were grouped by TDFB at a cutoff of three minutes. Characteristics were sought for schools with TDFB below three minutes. A mixed regression model taking into account repeated measures was created to determine which variables influenced TDFB. Time to overhead announcement, distance of AED from drill site, and time to setup AED were the variables influencing TDFB with statistical significance (P <.01). This study supports the notion of early recognition, announcement, and close proximity to an AED during a SCA to ensure an early TDFB. These results are consistent with basic life support and the chain of survival tenets of the American Heart Association. © 2016 Wiley Periodicals, Inc.

Capacity of dental equipment to interfere with cardiac implantable electrical devices.

PubMed

Lahor-Soler, Eduard; Miranda-Rius, Jaume; Brunet-Llobet, Lluís; Sabaté de la Cruz, Xavier

2015-06-01

Patients with cardiac implantable electrical devices should take precautions when exposed to electromagnetic fields. Possible interference as a result of proximity to electromagnets or electricity flow from electronic tools employed in clinical odontology remains controversial. The objective of this study was to examine in vitro the capacity of dental equipment to provoke electromagnetic interference in pacemakers and implantable cardioverter defibrillators. Six electronic dental instruments were tested on three implantable cardioverter defibrillators and three pacemakers from different manufacturers. A simulator model, submerged in physiological saline, with elements that reproduced life-size anatomic structures was used. The instruments were analyzed at differing distances and for different time periods of application. The dental instruments studied displayed significant differences in their capacity to trigger electromagnetic interference. Significant differences in the quantity of registered interference were observed with respect to the variables manufacturer, type of cardiac implant, and application distance but not with the variable time of application. The electronic dental equipment tested at a clinical application distance (20 cm) provoked only slight interference in the pacemakers and implantable cardioverter defibrillators employed, irrespective of manufacturer. © 2015 Eur J Oral Sci.

Response interval comparison between urban fire departments and ambulance services.

PubMed

Jermyn, B D

1999-01-01

To measure the response intervals of fire departments compared with ambulance services in three urban centers to determine whether defibrillators should be added to fire vehicles. A prospective sample of 1,882 code 4 (life-threatening) tiered calls were collected over a six-month period from March 1, 1994, to August 31, 1994. A matched pairs experimental design compared the response interval of the fire department with that of the ambulance service for each call. This emergency medical services (EMS) system encompasses three urban centers with populations of 80,000, 95,000, and 170,000. In two of three of the urban centers, the fire department arrived on scene more than a minute sooner than the ambulance service: Cambridge (n = 571, mean = 2.22 min, p < 0.0001); Kitchener (n = 1,011, mean = 1.24 min, p < 0.003); and Waterloo (n = 300, mean = 0.69 min, p < 0.98). The shorter response interval of fire departments suggests placing defibrillators on fire response vehicles in an effort to decrease the time to defibrillation for cardiac arrest victims in this EMS system.

Surviving out-of-hospital cardiac arrest: just a matter of defibrillators?

PubMed

Zorzi, Alessandro; Gasparetto, Nicola; Stella, Federica; Bortoluzzi, Andrea; Cacciavillani, Luisa; Basso, Cristina

2014-08-01

Out-of-hospital sudden cardiac arrest (OHCA) is a leading cause of death all over the world. Although the outcome of OHCA resulting from 'nonshockable' rhythms (asystole and pulseless electrical activity) is poor regardless of resuscitation efforts, 'shockable' rhythms such as ventricular tachycardia or fibrillation may carry a good prognosis if early defibrillation is performed. At present, simplified cardiopulmonary resuscitation techniques (hands-only cardiopulmonary resuscitation) and automated external defibrillators (AEDs) offer lay people the possibility to provide lifesaving treatment to OHCA victims in the critical minutes before the arrival of the emergency medical system. Programs aimed at increasing provision of cardiopulmonary resuscitation and use of AEDs by lay people have been set up in different countries, including Italy, and have contributed to improve survival rates. However, success of these programs critically depends on appropriate planning and design, and on cultural predisposition of witnesses to undertake immediate measures of resuscitation in the case of OHCA. Placement of a large number of AEDs may carry high costs and little benefits if it is uncoordinated and not preceded by educational campaigns to spread widely the 'culture of resuscitation' in the population.

Classic conditioning and dysfunctional cognitions in patients with panic disorder and agoraphobia treated with an implantable cardioverter/defibrillator.

PubMed

Godemann, F; Ahrens, B; Behrens, S; Berthold, R; Gandor, C; Lampe, F; Linden, M

2001-01-01

A model for the development of anxiety disorders (panic disorder with or without agoraphobia) is needed. Patients with an implantable cardioverter/defibrillator (ICD) are exposed to repeated electric shocks. If the theory of anxiety development by aversive classic conditioning processes is valid, these repeated shocks should lead to an increased risk of anxiety disorders. To study this hypothesis, we retrospectively studied 72 patients after implantation of an automatic ICD. Patients were assessed with the semistructured Diagnostic Interview of Psychiatric Disease 1 to 6 years after implantation of an automatic ICD. Panic disorder and/or agoraphobia was diagnosed in patients who fulfilled all DSM-III-R criteria for those conditions. Anxiety disorder developed in 15.9% of patients after ICD implantation. This was significantly related to the frequency of repeated defibrillation (shocks) to stop malignant ventricular arrhythmias. Dysfunctional cognitions are an additional vulnerability factor. The data support both the conditioning hypothesis and the cognitive model of anxiety development. These findings suggest that ICD patients are an appropriate risk population for a prospective study of the development of anxiety disorders.

Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?

PubMed

De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

2017-02-16

Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator (ICD) leads. Conductor externalization is a "unique" failure mechanism: Cables externalize through the insulation ("inside-out" abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction (not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a non-prospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries (GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads.

Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?

PubMed Central

De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

2017-01-01

Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator (ICD) leads. Conductor externalization is a “unique” failure mechanism: Cables externalize through the insulation (“inside-out” abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction (not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a non-prospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries (GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads. PMID:28255544

Cardioversion

MedlinePlus

Abnormal heart rhythms - cardioversion; Bradycardia - cardioversion; Tachycardia - cardioversion; Fibrillation - cardioversion; Arrhythmia - cardioversion; Cardiac arrest - cardioversion; Defibrillator - cardioversion; Pharmacologic cardioversion

Inadvertent transarterial insertion of atrial and ventricular defibrillator leads.

PubMed

Issa, Ziad F; Rumman, Syeda S; Mullin, James C

2009-01-01

Inadvertent placement of pacemaker and implantable cardioverter-defibrillator (ICD) leads in the left ventricle (LV) is a rare but well-recognized complication of device implantation [1]. We report a case of inadvertent transarterial implantation of dual-chamber ICD leads; the ventricular lead positioned in the LV and the atrial lead positioned in the aortic root. The tip of the atrial lead migrated across the aortic wall and captured the epicardial surface of the left atrium. The diagnosis was made 5 years after the implantation procedure with no apparent adverse events directly related to left heart lead placement.

Risk Stratification in Arrhythmic Right Ventricular Cardiomyopathy Without Implantable Cardioverter-Defibrillators

PubMed Central

Brun, Francesca; Groeneweg, Judith A.; Gear, Kathleen; Sinagra, Gianfranco; van der Heijden, Jeroen; Mestroni, Luisa; Hauer, Richard N.; Borgstrom, Mark; Marcus, Frank I.; Hughes, Trina

2016-01-01

Objectives The primary objective of this study is risk stratification of patients with arrhythmic right ventricular cardiomyopathy (ARVC). Background There is a need to identify those who need an automatic implantable defibrillator (ICD) to prevent sudden death. Methods This is an analysis of 88 patients with ARVC from three centers who were not treated with an ICD. Results Risk factors for subsequent arrhythmic deaths were pre-enrollment sustained or nonsustained ventricular tachycardia (VT) and decreased left ventricular function. Conclusion These factors serve as proposed guidelines for implantation of an ICD in patients with ARVC to prevent sudden death. PMID:27790640

Double valve replacement in a patient with implantable cardioverter defibrillator with severe left ventricular dysfunction.

PubMed

Manjunath, Girish; Rao, Prakash; Prakash, Nagendra; Shivaram, B K

2016-01-01

Recent data from landmark trials suggest that the indications for cardiac pacing and implantable cardioverter defibrillators (ICDs) are set to expand to include heart failure, sleep-disordered breathing, and possibly routine implantation in patients with myocardial infarction and poor ventricular function.[1] This will inevitably result in more patients with cardiac devices undergoing surgeries. Perioperative electromagnetic interference and their potential effects on ICDs pose considerable challenges to the anesthesiologists.[2] We present a case of a patient with automatic ICD with severe left ventricular dysfunction posted for double valve replacement.

Expenditure and value for money: the challenge of implantable cardioverter defibrillators.

PubMed

Boriani, G; Biffi, M; Martignani, C; Diemberger, I; Valzania, C; Bertini, M; Branzi, A

2009-05-01

Many technology-driven interventions entail considerable financial cost, raising affordability issues. The implantable cardioverter defibrillator (ICD) is a case of an effective primary prevention intervention with high initial costs that is capable of delivering long-term population benefits. At first glance, such interventions may provoke diffidence, if not active resistance, due to the financial burdens which inevitably accompany their widespread adoption. In this article, we review the available economic tools that can help address the ICD cost issue. We think awareness of such knowledge may facilitate dialogues between physicians, administrators and policymakers, and help foster rational decision-making.

Sudden cardiac death: epidemiology and risk factors

PubMed Central

Adabag, A. Selcuk; Luepker, Russell V.; Roger, Véronique L.; Gersh, Bernard J.

2016-01-01

Sudden cardiac death (SCD) is an important public-health problem with multiple etiologies, risk factors, and changing temporal trends. Substantial progress has been made over the past few decades in identifying markers that confer increased SCD risk at the population level. However, the quest for predicting the high-risk individual who could be a candidate for an implantable cardioverter-defibrillator, or other therapy, continues. In this article, we review the incidence, temporal trends, and triggers of SCD, and its demographic, clinical, and genetic risk factors. We also discuss the available evidence supporting the use of public-access defibrillators. PMID:20142817

Infection of Retained Defibrillator Lead Fragment after Heart Transplant

PubMed Central

Durante-Mangoni, Emanuele; Vitrone, Martina; Mattucci, Irene; Caprioli, Vincenzo; Maiello, Ciro

2017-01-01

A 59-year old heart transplant recipient was admitted due to continuous pain in her left axilla. A purulent collection was found at the site of prior defibrillator placement, where a remnant proximal segment of an electric lead was found. Two years before, the patient had had pocket infection treated with revision, but without device extraction. The remnant lead was eventually removed transvenously without complications. This is the first description of infection complicating retention of lead fragments after heart transplant. The role of biofilm and net immune state on the persistence and late recurrence of infection is discussed. PMID:28458812

In-flight automated external defibrillator use and consultation patterns.

PubMed

Brown, Aaron Michael; Rittenberger, Jon C; Ammon, Charles M; Harrington, Scott; Guyette, Francis X

2010-01-01

Limited information exists about the in-flight use and outcomes associated with automated external defibrillators (AEDs) on commercial airlines. To describe the characteristics and outcomes of AED use during in-flight emergencies including in-flight cardiac arrest and the associated ground medical consultation patterns. We collected cases of AED use that were self-reported to an airline consultation service from three U.S. airlines between May 2004 and March 2009. We reviewed all available data files, related consultation forms, and recordings. For each case, demographics, initial rhythm, shock delivery/success, survival to admission, and ground medical consultation use were obtained. Success was defined as the return of a perfusing rhythm. Initial rhythms were classified as sinus, heart block, supraventricular tachycardia (SVT), atrial fibrillation/flutter, asystole, pulseless electrical activity (PEA), and ventricular fibrillation (VF)/ventricular tachycardia (VT). There were a total of 169 AED applications with 40 cardiac arrests. The mean patient ages were 58 years (standard deviation [SD] 15) and 63 years (SD 12), respectively; both populations were 64% male. AEDs were applied for monitoring in 129 (76%) cases with the following initial rhythms: sinus, 114 (88%); atrial fibrillation/flutter, seven (5%); complete heart block, four (3%); and SVT, four (3%). Presenting rhythms among the cardiac arrest population were as follows: asystole, 16 (40%); VF/VT, 10 (25%); and PEA, 14 (35%). Fourteen patients were defibrillated, including nine of the 10 patients with initial VF/VT and five for the presence of VF/VT after resuscitation for initial PEA/asystole. Defibrillation was advised but not performed in the remaining case of initial VF/VT, and no medical consultation was obtained. All five successful defibrillations occurred in patients with initial VF/VT. There were six (15%; 95% confidence interval [CI] 3-27%) survivors, with five survivals occurring after successful defibrillation for initial VF/VT and one with return of a perfusing rhythm after cardiopulmonary resuscitation (CPR) for a junctional rhythm. Survival in those with VF/VT was five of 10 (50%; 95% CI 14-86%). Medications were delivered in two cases. The median time to first shock was 19 seconds (interquartile range [IQR] 12-24 seconds) after AED application. Medical consultation was obtained in 42 (33%) of the 129 AED monitoring cases and 14 (35%) of the 40 cardiac arrest cases. Use of AEDs resulted in 50% survival among those with VF/VT in flight and 15% overall survival for cardiac arrest. Survival is poor among patients presenting with nonshockable rhythms. AEDs are used extensively for in-flight monitoring, with significant rhythms identified. Ground medical consultation is sought in only one-third of AED uses and cardiac arrests.

Cardiac e-learning: Development of a web-based implantable cardioverter defibrillator educational system.

PubMed

Hickey, Kathleen T; Johnson, Mary P; Biviano, Angelo; Aboelela, Sally; Thomas, Tami; Bakken, Suzanne; Garan, Hasan; Zimmerman, John L; Whang, William

2011-04-01

The objective of this study was to design a Web-based implantable cardioverter defibrillator (ICD) module that would allow greater access to learning which could occur at an individual's convenience outside the fast-paced clinical environment. A Web-based ICD software educational program was developed to provide general knowledge of the function of the ICD and the interpretation of the stored electrocardiograms. This learning tool could be accessed at any time via the Columbia University Internet server, using a unique, password protected login. A series of basic and advanced ICD terms were presented using actual ICD screenshots and videos that simulated scenarios the practitioner would most commonly encounter in the fast-paced clinical setting. To determine the usefulness of the site and improve the module, practitioners were asked to complete a brief (less than 5 min) online survey at the end of the module. Twenty-six practitioners have logged into our Web site: 20 nurses/nurse practitioners, four cardiac fellows, and two other practitioners. The majority of respondents rated the program as easy to use and useful. The success of this module has led to it becoming part of the training for student nurse practitioners before a clinical electrophysiology rotation, and the module is accessed by our cardiac entry level fellows before a rotation in the intensive care unit or electrophysiology service. Remote electronic arrhythmia learning is a successful example of the melding of technology and education to enhance clinical learning.

Feedback to providers improves evidence-based implantable cardioverter-defibrillator programming and reduces shocks.

PubMed

Silver, Marc T; Sterns, Laurence D; Piccini, Jonathan P; Joung, Boyoung; Ching, Chi-Keong; Pickett, Robert A; Rabinovich, Rafael; Liu, Shufeng; Peterson, Brett J; Lexcen, Daniel R

2015-03-01

Implantable cardioverter-defibrillator (ICD) shocks are associated with increased anxiety, health care utilization, and potentially mortality. The purpose of the Shock-Less Study was to determine if providing feedback reports to physicians on their adherence to evidence-based shock reduction programming could improve their programming behavior and reduce shocks. Shock-Less enrolled primary prevention (PP) and secondary prevention (SP) ICD patients between 2009 and 2012 at 118 study centers worldwide and followed patients longitudinally after their ICD implant. Center-specific therapy programming reports (TPRs) were delivered to each center 9 to 12 months after their first enrollment. The reports detailed adherence to evidence-based programming targets: number of intervals to detect ventricular fibrillation (VF NID), longest treatment interval (LTI), supraventricular tachycardia (SVT) discriminators (Wavelet, PR Logic), SVT limit, Lead Integrity Alert (LIA), and antitachycardia pacing (ATP). Clinicians programmed ICDs at their discretion. The primary outcome measure was the change in utilization of evidence-based shock reduction programming before (phase I, n = 2694 patients) and after initiation of the TPR (phase II, n = 1438 patients). Patients implanted after feedback reports (phase II) were up to 20% more likely to have their ICDs programmed in line with evidence-based shock reduction programming (eg, VF NID in PP patients 30/40 in 33.5% vs 18.6%, P < .0001). Patients implanted in phase II had a lower risk of all-cause shock (adjusted hazard ratio 0.72, 95% confidence interval 0.58-0.90, P = .003). Providing programming feedback reports improves adherence to evidence-based shock reduction programming and is associated with lower risk of ICD shocks. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Ranking businesses and municipal locations by spatiotemporal cardiac arrest risk to guide public defibrillator placement

PubMed Central

Sun, Christopher L. F.; Brooks, Steven C.; Morrison, Laurie J.; Chan, Timothy C.Y.

2017-01-01

Background Efforts to guide automated external defibrillator (AED) placement for out-of-hospital cardiac arrest (OHCA) treatment have focused on identifying broadly defined location categories without considering hours of operation. Broad location categories may be composed of many businesses with varying accessibility. Identifying specific locations for AED deployment incorporating operating hours and time of OHCA occurrence may improve AED accessibility. We aim to identify specific businesses and municipal locations that maximize OHCA coverage based on spatiotemporal assessment of OHCA risk in the immediate vicinity of franchise locations. Methods This study was a retrospective population-based cohort study using data from the Toronto Regional RescuNET Epistry cardiac arrest database. We identified all non-traumatic public OHCAs occurring in Toronto, Canada from Jan. 2007–Dec. 2015. We identified 41 unique businesses and municipal location types with 20 or more locations in Toronto from the YellowPages, Canadian Franchise Association, and the City of Toronto Open Data Portal. We obtained their geographic coordinates and hours of operation from websites, phone, or in-person. We determined the number of OHCAs that occurred within 100 m of each location when it was open (spatiotemporal coverage) for Toronto overall and downtown. The businesses and municipal locations were then ranked by spatiotemporal OHCA coverage. To evaluate temporal stability of the rankings, we calculated intra-class correlation (ICC) of the annual coverage values. Results There were 2,654 non-traumatic public OHCAs. Tim Hortons ranked first in Toronto covering 286 OHCAs. Starbucks ranked first in downtown covering 110 OHCAs. Coffee shops and bank machines from the five largest Canadian banks occupied eight of the top 10 spots in both Toronto and downtown. The rankings exhibited high temporal stability with ICC values of 0.88 (95% CI, 0.83–0.93) in Toronto and 0.79 (95% CI, 0.71–0.86) in downtown. Conclusions We identified and ranked businesses and municipal locations by spatiotemporal OHCA risk in their immediate vicinity. This approach may help policy makers and funders to identify and prioritize potential partnerships for AED deployment in public access defibrillator programs. PMID:28320803

Use of a geographic information system to identify differences in automated external defibrillator installation in urban areas with similar incidence of public out-of-hospital cardiac arrest: a retrospective registry-based study

PubMed Central

Haas, Jan; Ban, Yifang; Jonsson, Martin; Svensson, Leif; Djarv, Therese; Hollenberg, Jacob; Nordberg, Per; Ringh, Mattias; Claesson, Andreas

2017-01-01

Objectives Early defibrillation in out-of-hospital cardiac arrest (OHCA) is of importance to improve survival. In many countries the number of automated external defibrillators (AEDs) is increasing, but the use is low. Guidelines suggest that AEDs should be installed in densely populated areas and in locations with many visitors. Attempts have been made to identify optimal AED locations based on the incidence of OHCA using geographical information systems (GIS), but often on small datasets and the studies are seldom reproduced. The aim of this paper is to investigate if the distribution of public AEDs follows the incident locations of public OHCAs in urban areas of Stockholm County, Sweden. Method OHCA data were obtained from the Swedish Register for Cardiopulmonary Resuscitation and AED data were obtained from the Swedish AED Register. Urban areas in Stockholm County were objectively classified according to the pan-European digital mapping tool, Urban Atlas (UA). Furthermore, we reclassified and divided the UA land cover data into three classes (residential, non-residential and other areas). GIS software was used to spatially join and relate public AED and OHCA data and perform computations on relations and distance. Results Between 1 January 2012 and 31 December 2014 a total of 804 OHCAs occurred in public locations in Stockholm County and by December 2013 there were 1828 AEDs available. The incidence of public OHCAs was similar in residential (47.3%) and non-residential areas (43.4%). Fewer AEDs were present in residential areas than in non-residential areas (29.4% vs 68.8%). In residential areas the median distance between OHCAs and AEDs was significantly greater than in non-residential areas (288 m vs 188 m, p<0.001). Conclusion The majority of public OHCAs occurred in areas classified in UA as ‘residential areas‘ with limited AED accessibility. These areas need to be targeted for AED installation and international guidelines need to take geographical location into account when suggesting locations for AED installation. PMID:28576894

Implant and clinical characteristics for pediatric and congenital heart patients in the national cardiovascular data registry implantable cardioverter defibrillator registry.

PubMed

Jordan, Christopher P; Freedenberg, Vicki; Wang, Yongfei; Curtis, Jeptha P; Gleva, Marye J; Berul, Charles I

2014-12-01

In 2010, the National Cardiovascular Data Registry enhanced pediatric, nonatherosclerotic structural heart disease and congenital heart disease (CHD) data collection. This report characterizes CHD and pediatric patients undergoing implantable cardioverter defibrillator implantation. In this article, we report implantable cardioverter defibrillator procedures (April 2010 to December 2012) in the registry for 2 cohorts: (1) all patients with CHD (atrial septal defect, ventricular septal defect, tetralogy of Fallot, Ebstein anomaly, transposition of the great vessels, and common ventricle) and (2) patients <21 years. We evaluated indications and characteristics to include transvenous and nontransvenous lead implants, CHD type, and New York Heart Association class. There were 3139 CHD procedures, 1601 for patients <21 years and 126 for CHD <21 years. Implantable cardioverter defibrillator indications for patients with CHD were primary prevention in 1943 (61.9%) and secondary prevention in 1107 (35.2%). Pediatric patients had 935 (58.4%) primary prevention and 588 (36.7%) secondary prevention devices. Primary prevention had higher New York Heart Association class. Nontransvenous age (35.9 ± 23.2 versus 40.1 ± 24.6 years; P=0.05) and nontransvenous height (167.1 ± 18.9 cm; range, 53-193 cm versus 170.4 ± 13.1 cm; range, 61-203 cm; P<0.01) were lower than for transvenous patients. CHD and pediatrics had similar rates of transvenous (97%) and nontransvenous (3%) leads and did not differ from the overall registry. Transposition of the great vessels and common ventricle had higher rates of nontransvenous leads. Primary prevention exceeds secondary prevention for CHD and pediatrics. Nontransvenous lead patients were younger, with higher rates of transposition of the great vessels and common ventricle patients compared with transvenous lead patients. © 2014 American Heart Association, Inc.

Wearable defibrillator use in heart failure (WIF): results of a prospective registry

PubMed Central

2012-01-01

Background Heart failure (HF) patients have a high risk of death, and implantable cardioverter defibrillators (ICDs) are effective in preventing sudden cardiac death (SCD). However, a certain percentage of patients may not be immediate candidates for ICDs, particularly those having a short duration of risk or an uncertain amount of risk. This includes the newly diagnosed patients, as well as those on the cardiac transplant list or NYHA class IV heart failure patients who do not already have an ICD. In these patients, a wearable cardioverter defibrillator (WCD) may be used until long term risk of SCD is defined. The purpose of this study was to determine the incidence of SCD in this population, and the efficacy of early defibrillation by a WCD. Methods Ten enrolling centers identified 89 eligible HF patients who were either listed for cardiac transplantation, diagnosed with dilated cardiomyopathy, or receiving inotropic medications. Data collected included medical history, device records, and outcomes (including 90 day mortality). Results Out of 89 patients, final data on 82 patients has been collected. Patients wore the device for 75±58 days. Mean age was 56.8±13.2, and 72% were male. Most patients (98.8%) were diagnosed with dilated cardiomyopathy with a low ejection fraction (<40%) and twelve were listed for cardiac transplantation. Four patients were on inotropes. There were no sudden cardiac arrests or deaths during the study. Interestingly, 41.5% of patients were much improved after WCD use, while 34.1% went on to receive an ICD. Conclusions In conclusion, the WCD monitored HF patients until further assessment of risk. The leading reasons for end of WCD use were improvement in left ventricular ejection fraction (LVEF) or ICD implantation if there was no significant improvement in LVEF. PMID:23234574

Subcutaneous Implantable Cardioverter Defibrillator in Patients With Hypertrophic Cardiomyopathy: An Initial Experience.

PubMed

Weinstock, Jonathan; Bader, Yousef H; Maron, Martin S; Rowin, Ethan J; Link, Mark S

2016-02-12

The subcutaneous implantable cardioverter defibrillator (S-ICD) has been developed to avert risks associated with transvenous defibrillator leads. The technology is attractive for younger patients, such as those with hypertrophic cardiomyopathy (HCM). However, there are limited data on S-ICD use in HCM. HCM patients identified at risk for sudden death were considered for S-ICD implantation. Patients were screened for potential oversensing by surface electrocardiography (ECG). At implant, defibrillation threshold (DFT) testing was performed at 65, 50, and 35 joules (J). Twenty-seven patients were considered for S-ICD implantation, and after screening, 23 (85%) remained eligible. The presence of a bundle branch block was associated with screening failure, whereas elevated body mass index (BMI) showed a trend toward association. One patient passed screening at rest, but failed with an ECG obtained after exercise. At implant, the S-ICD terminated ventricular fibrillation (VF) with a 65J shock in all 15 implanted patients and a 50J shock was successful in 12 of 15. A 35J shock terminated VF in 10 of 12 patients. DFT failure at 50 J was associated with a higher BMI. There were no appropriate shocks after a median follow-up of 17.5 (3-35) months, and 1 patient received an inappropriate shock attributable to a temporary reduction in QRS amplitude while bending forward, resulting in oversensing, despite successful screening. In a high-risk HCM cohort without a pacing indication referred for consideration of an ICD, the majority were eligible for S-ICD. The S-ICD is effective at recognizing and terminating VF at implant with a wide safety margin. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

The effect of time on CPR and automated external defibrillator skills in the Public Access Defibrillation Trial

PubMed Central

Christenson, Jim; Nafziger, Sarah; Compton, Scott; Vijayaraghavan, Kris; Slater, Brian; Ledingham, Robert; Powell, Judy; McBurnie, Mary Ann

2009-01-01

Background The time to skill deterioration between primary training/retraining and further retraining in Cardiopulmonary resuscitation (CPR) and automated external defibrillation (AED) for lay-persons is unclear. The Public Access Defibrillation (PAD) Trial was a multi-center randomized controlled trial evaluating survival after CPR-only vs. CPR+AED delivered by onsite non-medical volunteer responders in out-of-hospital cardiac arrest. Aims This sub-study evaluated the relationship of time between primary training/retraining and further retraining on volunteer performance during pretest AED and CPR skill evaluation. Methods Volunteers at 1260 facilities in 24 North American regions underwent training/retraining according to facility randomization, which included an initial session and a refresher session at approximately 6 months. Before the next retraining, a CPR and AED skill test was completed for 2729 volunteers. Primary outcome for the study was assessment of global competence of CPR or AED performance (adequate vs not adequate) using Chi-square tests for trends by time interval (3, 6, 9, and 12 months). Confirmatory (GEE) logistic regression analysis, adjusted for site and potential confounders. Results The proportion of volunteers judged to be competent did not diminish by interval (3,6,9,12 months) for either CPR or AED skills. After adjusting for site and potential confounders, longer intervals before to further retraining was associated with a slightly lower likelihood of performing adequate CPR but not with AED scores. Conclusions After primary training/retraining, the CPR skills of targeted lay responders deteriorate nominally but 80% remain competent up to one year. AED skills do not significantly deteriorate and 90% of volunteers remain competent up to one year. PMID:17303309

Rotor Stability Separates Sustained Ventricular Fibrillation From Self-Terminating Episodes in Humans

PubMed Central

Krummen, David E.; Hayase, Justin; Morris, David J.; Ho, Jeffrey; Smetak, Miriam R.; Clopton, Paul; Rappel, Wouter-Jan; Narayan, Sanjiv M.

2014-01-01

Objective We mapped human ventricular fibrillation (VF) to define mechanistic differences between episodes requiring defibrillation versus those that spontaneously terminate. Background VF is a leading cause of mortality, yet episodes may also self-terminate. We hypothesized that the initial maintenance of human VF is dependent upon the formation and stability of VF rotors. Methods We enrolled 26 consecutive patients (age 64±10 years, n=13 with LV dysfunction) during ablation procedures for ventricular arrhythmias, using 64-electrode basket catheters in both ventricles to map VF prior to prompt defibrillation per IRB-approved protocol. Fifty-two inductions were attempted and 36 VF episodes were observed. Phase analysis was applied to identify bi-ventricular rotors in the first 10 seconds or until VF terminated, whichever came first (11.4±2.9 seconds to defibrillator charging). Results Rotors were present in 16 of 19 patients with VF, and in all patients with sustained VF. Sustained, but not self-limiting VF, was characterized by greater rotor stability: (1) rotors were present in 68±17% of cycles in sustained versus 11±18% of cycles in self-limiting VF (p<0.001); with (2) maximum continuous rotations greater in sustained (17±11, range 7–48) versus self-limiting VF (1.1±1.4, range 0–4, p<0.001). Additionally, biventricular rotor locations in sustained VF were conserved across multiple inductions (7/7 patients, p=0.025). Conclusions In patients with and without structural heart disease, the formation of stable rotors identifies individuals whose VF requires defibrillation from those in whom VF spontaneously self-terminates. Future work should define the mechanisms that stabilize rotors and evaluate whether rotor modulation may reduce subsequent VF risk. PMID:24794115

Treatment and outcome of out-of-hospital cardiac arrest in outpatient health care facilities.

PubMed

Kudenchuk, Peter J; Stuart, Russell; Husain, Sofia; Fahrenbruch, Carol; Eisenberg, Mickey

2015-12-01

We evaluated the frequency and effectiveness of basic and advanced life support (ALS) interventions by medical professionals when out-of-hospital cardiac arrest (OHCA) occurred in ambulatory healthcare clinics before emergency medical services (EMS) arrival. Non-traumatic OHCAs in adults were systematically characterized over a 15 year period by their occurrence in clinics, at home, or in non-medical public locations, and outcomes compared between matched cohorts from each group. Among 7784 patients, 6098 OHCA occurred at home, 1612 in non-medical public locations and 74 in clinics. Compared to non-medical public locations, clinic patients with OHCA were older, more often women and more frequently shocked; clinic arrests were more often witnessed, less likely to be of cardiac cause and to occur before EMS arrival. Compared to home, more clinic arrests were witnessed, occurred after EMS arrival, had bystander CPR, shockable rhythms and were defibrillated. When OHCA occurred before EMS arrival, 51 of 56 clinic patients (91%) received CPR, a defibrillator applied to 23 (41%), 17 (30%) were shocked, 4 (7%) intubated, and 7 (13%) received intravenous medications from facility personnel. Of these, only pre-EMS defibrillator use was associated with improved outcome. Among matched patients, OHCA survival was higher in clinics than at home (42% vs 26%, p=0.029), but comparable to other public locations. Survival from OHCA in clinics was comparable to non-medical public locations, and higher than at home. Alongside CPR, use of defibrillators was associated with improved survival and worth prioritizing over other interventions before EMS arrival regardless of OHCA location. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.