A comparison of the output characteristics of several implantable cardioverter-defibrillators

Thammanomai, Apiradee; Sweeney, Michael O.; Eisenberg, S.R.

doi:10.1016/j.hrthm.2006.05.006

Cited by 11 publications

(4 citation statements)

References 29 publications

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“…134 ICDs sold by different manufacturers have substantive differences in shock voltage, duration, and energy. 135 However, no clinical study compares defibrillation efficacy of modern ICD waveforms, comparable to one performed a decade ago. 137…”

Section: Shock Waveformmentioning

confidence: 99%

The Dilemma of ICD Implant Testing

Swerdlow

Russo

DeGroot

2007

Pacing Clinical Electrophis

130

112

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Ventricular fibrillation (VF) has been induced at implantable cardioverter defibrillator (ICD) implant to ensure reliable sensing, detection, and defibrillation. Despite its risks, the value was self-evident for early ICDs: failure of defibrillation was common, recipients had a high risk of ventricular tachycardia (VT) or VF, and the only therapy for rapid VT or VF was a shock. Today, failure of defibrillation is rare, the risk of VT/VF is lower in some recipients, antitachycardia pacing is applied for fast VT, and vulnerability testing permits assessment of defibrillation efficacy without inducing VF in most patients. This review reappraises ICD implant testing. At implant, defibrillation success is influenced by both predictable and unpredictable factors, including those related to the patient, ICD system, drugs, and complications. For left pectoral implants of high-output ICDs, the probability of passing a 10 J safety margin is approximately 95%, the probability that a maximum output shock will defibrillate is approximately 99%, and the incidence of system revision based on testing is < or = 5%. Bayes' Theorem predicts that implant testing identifies < or = 50% of patients at high risk for unsuccessful defibrillation. Most patients who fail implant criteria have false negative tests and may undergo unnecessary revision of their ICD systems. The first-shock success rate for spontaneous VT/VF ranges from 83% to 93%, lower than that for induced VF. Thus, shocks for spontaneous VT/VF fail for reasons that are not evaluated at implant. Whether system revision based on implant testing improves this success rate is unknown. The risks of implant testing include those related to VF and those related to shocks alone. The former may be due to circulatory arrest alone or the combination of circulatory arrest and shocks. Vulnerability testing reduces risks related to VF, but not those related to shocks. Mortality from implant testing probably is 0.1-0.2%. Overall, VF should be induced to assess sensing in approximately 5% of ICD recipients. Defibrillation or vulnerability testing is indicated in 20-40% of recipients who can be identified as having a higher-than-usual probability of an inadequate defibrillation safety margin based on patient-specific factors. However, implant testing is too risky in approximately 5% of recipients and may not be worth the risks in 10-30%. In 25-50% of ICD recipients, testing cannot be identified as either critical or contraindicated.

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Section: Shock Waveformmentioning

confidence: 99%

The Dilemma of ICD Implant Testing

Swerdlow

Russo

DeGroot

2007

Pacing Clinical Electrophis

130

112

View full text Add to dashboard Cite

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“…The implanting physician has several options for dealing with the high DFT patient. These include the use of high energy and higher voltage devices, 26 changing the current path vector and impedance by the use (or disconnection of) an SVC coil, and the repositioning of the RV coil. The reversal of the shock polarity is frequently done although this practice has been recently called into question for devices shipped with a positive RV coil polarity 27 .…”

Section: Discussionmentioning

confidence: 99%

Achieving Sufficient Safety Margins with Fixed Duration Waveforms and the Use of Multiple Time Constants

Keane

Aweh

Hynes

et al. 2007

Pacing Clinical Electrophis

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“…VTs and SVTs can share similar heart rates and other characteristics, so an SVT can be mis-diagnosed as a VT. This is problematic because shock therapy used to stop a VT can deliver between 30-60 Joules of energy at around 700 Volts in under 15ms [19], directly to the heart, which is very painful to the patient 2 , and 2 Patients compare the shock to a "horse kicking you in the chest".…”

Section: B Implantable Devicesmentioning

confidence: 99%

Real-Time Decision Policies With Predictable Performance

et al. 2018

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As methods and tools for Cyber-Physical Systems grow in capabilities and use, one-size-fits-all solutions start to show their limitations. In particular, tools and languages for programming an algorithm or modeling a CPS that are specific to the application domain are typically more usable, and yield better performance, than general-purpose languages and tools. In the domain of cardiac arrhythmia monitoring, a small, implantable medical device continuously monitors the patient's cardiac rhythm and delivers electrical therapy when needed. The algorithms executed by these devices are streaming algorithms, so they are best programmed in a streaming language that allows the programmer to reason about the incoming data stream as the basic object, rather than force her to think about lower-level details like state maintenance and minimization. Because these devices are resource-constrained, it is useful if the programming language allowed predictable performance in terms of processing runtime and energy consumption, or more general costs. StreamQRE is a declarative streaming programming language, with an efficient and portable implementation and strong theoretical guarantees. In particular, its evaluation algorithm guarantees constant cost (runtime, memory, energy) per data item, and also calculates upper bounds on the per-item cost. Such an estimate of the cost allows early exploration of the algorithmic possibilities, while maintaining a handle on worst-case performance, on the basis of which hardware can be designed and algorithms can be tuned. Abstract-As methods and tools for Cyber-Physical Systems grow in capabilities and use, one-size-fits-all solutions start to show their limitations. In particular, tools and languages for programming an algorithm or modeling a CPS that are specific to the application domain are typically more usable, and yield better performance, than general-purpose languages and tools. In the domain of cardiac arrhythmia monitoring, a small, implantable medical device continuously monitors the patient's cardiac rhythm and delivers electrical therapy when needed. The algorithms executed by these devices are streaming algorithms, so they are best programmed in a streaming language that allows the programmer to reason about the incoming data stream as the basic object, rather than force her to think about lower-level details like state maintenance and minimization. Because these devices are resource-constrained, it is useful if the programming language allowed predictable performance in terms of processing runtime and energy consumption, or more general costs. StreamQRE is a declarative streaming programming language, with an efficient and portable implementation and strong theoretical guarantees. In particular, its evaluation algorithm guarantees constant cost (runtime, memory, energy) per data item, and also calculates upper bounds on the per-item cost. Such an estimate of the cost allows early exploration of the algorithmic possibilities, while maintaining a handle on worst-case per...

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A comparison of the output characteristics of several implantable cardioverter-defibrillators

Cited by 11 publications

References 29 publications

The Dilemma of ICD Implant Testing

The Dilemma of ICD Implant Testing

Achieving Sufficient Safety Margins with Fixed Duration Waveforms and the Use of Multiple Time Constants

Real-Time Decision Policies With Predictable Performance

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