Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Nov:241:107780.
doi: 10.1016/j.cmpb.2023.107780. Epub 2023 Aug 25.

Ventricular fibrillation waveform properties influenced by thoracic impedance guided chest compressions in a porcine model

Olibhéar McAlister  1 , Adam Harvey  2 , Ben McCartney  3 , Paul Crawford  4 , Raymond R Bond  5 , Dewar D Finlay  5 , David McEneaney  6
Affiliations
Free article

Ventricular fibrillation waveform properties influenced by thoracic impedance guided chest compressions in a porcine model

Olibhéar McAlister et al. Comput Methods Programs Biomed. 2023 Nov.
Free article

Abstract

Background and objective: Quantitative measures extracted from ventricular fibrillation (VF) waveform reflect the metabolic state of the myocardium and are associated with survival outcome. The quality of delivered chest compressions during cardiopulmonary resuscitation are also linked with survival. The aim of this research is to explore the viability and effectiveness of a thoracic impedance (TI) based chest compression (CC) guidance system to control CC depth within individual subjects and influence VF waveform properties.

Methods: This porcine investigation includes an analysis of two protocols. CC were delivered in 2 min episodes at a constant rate of 110 CC min-1. Subject-specific CC depth was controlled using a TI-thresholding system where CC were performed according to the amplitude (ZRMS, 0.125 to 1.250 Ω) of a band-passed TI signal (ZCC). Protocol A was a retrospective analysis of a 12-porcine study to characterise the response of two VF waveform metrics: amplitude spectrum area (AMSA) and mean slope (MS), to varying CC quality. Protocol B was a prospective 12-porcine study to determine if changes in VF waveform metrics, due to CC quality, were associated with defibrillation outcome.

Results: Protocol A: A directly proportional relationship was observed between ZRMS and CC depth applied within each subject (r = 0.90; p <0.001). A positive relationship was observed between ZRMS and both AMSA (p <0.001) and MS (p <0.001), where greater TI thresholds were associated with greater waveform metrics.

Protocol b: MS was associated with return of circulation following defibrillation (odds ratio = 2.657; p = 0.043).

Conclusion: TI-thresholding was an effective way to control CC depth within-subjects. Compressions applied according to higher TI thresholds evoked an increase in AMSA and MS. The response in MS due to deeper CC resulted in a greater incidence of ROSC compared to shallow chest compressions.

Keywords: Amplitude spectrum area; Chest compressions; Mean slope; Quantitative waveform measures; Thoracic impedance; Ventricular fibrillation.

PubMed Disclaimer

Conflict of interest statement

Declaration of Competing Interest O. McAlister, A. Harvey and B. McCartney are employees of HeartSine Technologies Ltd. D. McEneaney is a medical advisor for HeartSine Technologies Ltd. The presented research was fully funded by HeartSine Technologies Ltd. within the scope of an industrially sponsored PhD program.

LinkOut - more resources