Reduced motion external defibrillation: Reduced subject motion with equivalent defibrillation efficiency validated in swine

Ehud J. Schmidt, Hassan Elahi, Eric S. Meyer, Ryan Baumgaertner, Luca Neri, Ronald D. Berger, Harikrishna Tandri, David W. Hunter, Steven P. Cohen, Matt T. Oberdier, Henry R. Halperin

Research output: Contribution to journalArticlepeer-review

Abstract

Background: External defibrillators are used for arrhythmia cardioversion and for defibrillating during cardiac arrest. During defibrillation, short-duration biphasic pulses cause intense motion due to rapid chest-wall muscle contraction. A reduced motion external defibrillator (RMD) was constructed by integrating a commercial defibrillator with a Tetanizing-waveform generator. A long-duration, low-amplitude, tetanizing waveform slowly stimulated the chest musculature before the biphasic pulse, reducing muscle contraction during the shock. Objective: The purpose of this study was to evaluate RMD defibrillation in swine for subject motion during defibrillation pulses and for defibrillation effectiveness. RMD defibrillation can reduce the duration of arrhythmia ablation therapy or simplify cardioversion procedures. Methods: The tetanizing unit delivered a triangular 1-kHz pulse of 0.25- to 2.0-second duration and 10- to 100-V peak amplitude, subsequently triggering the conventional defibrillator to output standard 1- to 200-J energy biphasic pulses at the next R wave. Forward limb motion was evaluated by measuring peak acceleration and limb work during RMD (tetanizing + biphasic) or biphasic pulse–only waveforms at 10–3-second sampling rate. Seven swine were arrested electrically and subsequently defibrillated. Biphasic pulse–only and RMD defibrillations were repeated 25–35 times per swine, varying tetanizing parameters and biphasic pulse energy. Defibrillation thresholds (DFTs) were established by measuring the minimum energy required to restore sinus rhythm with biphasic pulse–only or RMD defibrillations. Results: Two forward-limb acceleration peaks occurred during both the tetanizing waveform and biphasic pulse, indicating rapid and slower nociceptic (pain sensation) nerve fiber activation. Optimal RMD tetanizing parameters (25–35 V, 0.25- to 0.75-second duration), relative to biphasic pulse–only defibrillations, resulted in 74% ± 10% smaller peak accelerations and 85% ± 10% reduced limb work. DFT energies were identical when comparing RMD to biphasic pulse–only defibrillations. Conclusion: Relative to conventional defibrillations, RMD defibrillations maintain rhythm restoration efficiency with drastically reduced subject motion.

Original languageEnglish (US)
Pages (from-to)1165-1173
Number of pages9
JournalHeart Rhythm
Volume19
Issue number7
DOIs
StatePublished - Jul 2022

Keywords

  • Cardioversion
  • Defibrillation effectiveness
  • Defibrillation motion
  • Sudden cardiac arrest
  • Ventricular tachycardia

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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