An Adaptive Complex Algorithm for Shockable Heart Rhythm Detection and Its Use in Automated External Defibrillators

Purpose: Automated external defibrillators (AED) prompt the rescuer to stop cardiopulmonary resuscitation (CPR) for ECG analysis. Any interruption of CPR has a negative impact on outcome. We prospectively evaluated a new algorithm (cprINSIGHT) which can analyse the ECG while rescuers continue CPR. Methods: We analysed data from patients with attempted resuscitation from OHCA who were connected to an AED with cprINSIGHT (Stryker Physio-Control LIFEPAK CR2) between June 2017 and June 2018 in the Amsterdam Resuscitation Study region. The first analysis in the CR2 is a conventional analysis; subsequent analyses use the cprINSIGHT algorithm. This algorithm classifies the rhythm as shockable (S), non-shockable (NS), or no decision. If no decision, the AED prompts for a pause in CPR and uses its conventional algorithm. The characteristics of the first 3 cprINSIGHT analyses (analyses 2-4) were analysed. Ventricular fibrillation (VF) cases were both coarse and fine VF with a lower threshold of 0.08 mV. Results: Data from 132 consecutive OHCA cases were analysed. The initial recorded rhythm was VF or pulseless ventricular tachycardia (VT) in 35 cases (27%), pulseless electrical activity in 34 cases (25%) and asystole in 63 cases (48%). In 114 cases (86%), 1 or more cprINSIGHT analyses were done. Analyses 2-4 covered 90% of all cprINSIGHT analyses. The analyzed rhythm was VF/VT in 12-17%, organised QRS rhythm in 29-35% and asystole in 51-56% (see table). cprINSIGHT reached a S or NS decision in 65-74% of cases, with a sensitivity of 90-100% and a specificity of 100%. When it reached no decision, the rhythm was asystole in 65-79% of analyses, VF/VT in 0-9% and QRS rhythm in 18-27%; conventional analysis followed. Chest compression fraction was 85-88%, CPR fraction was 99%. Conclusion: This new algorithm analysed the ECG without need for a pause in chest compressions 65-74% of the time and had 90-100% sensitivity and 100% specificity when it made a shock or a no shock decision.

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Shock Advisory System for Heart Rhythm Analysis During Cardiopulmonary Resuscitation Using a Single ECG Input of Automated External Defibrillators

Annals of Biomedical Engineering ◽

10.1007/s10439-009-9885-9 ◽

2010 ◽

Vol 38 (4) ◽

pp. 1326-1336 ◽

Cited By ~ 16

Author(s):

Vessela Krasteva ◽

Irena Jekova ◽

Ivan Dotsinsky ◽

Jean-Philippe Didon

Keyword(s):

Cardiopulmonary Resuscitation ◽

Heart Rhythm ◽

Automated External Defibrillators ◽

Advisory System ◽

Rhythm Analysis

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Abstract 32: Chest Compression Fraction Increased When Police Used AED That Analyses Heart Rhythm During CPR

Circulation ◽

10.1161/circ.140.suppl_2.32 ◽

2019 ◽

Vol 140 (Suppl_2) ◽

Author(s):

Corina de Graaf ◽

Stefanie G Beesems ◽

Ronald E Stickney ◽

Fred W Chapman ◽

Rudolph W Koster

Keyword(s):

Cardiac Arrest ◽

Cardiopulmonary Resuscitation ◽

Chest Compression ◽

Heart Rhythm ◽

Chest Compressions ◽

Automated External Defibrillators ◽

Ecg Analysis ◽

Conventional Analysis

Introduction: Conventional automated external defibrillators (AED) prompt rescuers to stop cardiopulmonary resuscitation (CPR) for ECG analysis during cardiac arrest (CA), but pauses in CPR are associated with worse outcome. A new AED algorithm, cprINSIGHT™ Analysis Technology, analyses the ECG while rescuers continue chest compressions. Hypothesis: Compared to conventional AEDs, AEDs with the cprINSIGHT algorithm will lead to fewer and shorter interruptions of chest compressions for ECG analysis and, thereby, a higher chest compression fraction (CCF). Methods: Amsterdam Police used conventional AEDs in 2016 (LIFEPAK® 1000 defibrillator) and AEDs with cprINSIGHT in 2018 (LIFEPAK CR2 AED); in the CR2 AED, cprINSIGHT is activated after the first conventional analysis. We analysed AED data from control CA cases in 2016 and intervention CA cases in 2018, comparing pre-shock pause, median CCF and CCF categories. CCF was defined as the proportion of time with chest compressions in the period from the start of CPR after analysis 1 to the start of CPR after analysis 2. The CCF analysis included only cases where CPR was provided with a ratio of 30 compressions to 2 ventilations. Results: Data from 111 control and 87 intervention cases were analysed. The initial recorded rhythm was shockable in 42 control cases (38%) and 36 intervention cases (41%). Rhythm during analysis 2 was shockable in 28/103 (27%) control and 19/80 (24%) intervention cases; 15 cases had no second analysis. In 67/80 (84%) intervention cases, analysis 2 reached a decision without prompting for a CPR pause. Intervention cases had a significantly shorter pre-shock pause than control cases (7 sec vs 22 sec, p < 0.001) and significantly higher median CCF (87% vs 77%, P<0.001). CCF was ≥90% in 38% of intervention cases and 10% of control cases (figure). Conclusion: The use of the cprINSIGHT algorithm in AEDs leads to a shorter pre-shock pause, fewer analysis pauses and an increase in CCF compared to conventional AEDs.

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Mobile Versus Fixed Deployment of Automated External Defibrillators in Rural EMS

Prehospital and Disaster Medicine ◽

10.1017/s1049023x1500014x ◽

2015 ◽

Vol 30 (2) ◽

pp. 152-154 ◽

Cited By ~ 7

Author(s):

R. Darrell Nelson ◽

William Bozeman ◽

Greg Collins ◽

Brian Booe ◽

Todd Baker ◽

...

Keyword(s):

Cardiac Arrest ◽

Public Schools ◽

Rural Communities ◽

Rural Community ◽

Heart Rhythm ◽

Public Access ◽

Publication Type ◽

Automated External Defibrillators ◽

Institutional Review ◽

Impact On Survival

AbstractIntroductionThere is no consensus on where automated external defibrillators (AEDs) should be placed in rural communities to maximize impact on survival from cardiac arrest. In the community of Stokes County, North Carolina (USA) the Emergency Medical Services (EMS) system promotes cardiopulmonary resuscitation (CPR) public education and AED use with public access defibrillators (PADs) placed mainly in public schools, churches, and government buildings.Hypothesis/ProblemThis study tested the utilization of AEDs assigned to first responders (FRs) in their private-owned-vehicle (POV) compared to AEDs in fixed locations.MethodsThe authors performed a prospective, observational study measuring utilization of AEDs carried by FRs in their POV compared to utilization of AEDs in fixed locations. Automated external defibrillator utilization is activation with pads placed on the patient and analysis of heart rhythm to determine if shock/no-shock is indicated. The Institutional Review Board of Wake Forest University Baptist Health System approved the study and written informed consent was waived. The study began on December 01, 2012 at midnight and ended on December 01, 2013 at midnight.ResultsDuring the 12-month study period, 81 community AEDs were in place, 66 in fixed locations and 15 assigned to FRs in their POVs. No utilizations of the 66 fixed location AEDs were reported (0.0 utilizations/AED/year) while 19 utilizations occurred in the FR POV AED study group (1.27 utilizations/AED/year; P<.0001). Odds ratio of using a FR POV located AED was 172 times more likely than using a community fixed-location AED in this rural community.DiscussionPlacing AEDs in a rural community poses many challenges for optimal utilization in terms of cardiac arrest occurrences. Few studies exist to direct rural community efforts in placing AEDs where they can be most effective, and it has been postulated that placing them directly with FRs may be advantageous.ConclusionsIn this rural community, the authors found that placing AED devices with FRs in their POVs resulted in a statistically significant increase in utilizations over AED fixed locations.NelsonRD, BozemanW, CollinsG, BooeB, BakerT, AlsonR. Mobile versus fixed deployment of automated external defibrillators in rural EMS. Prehosp Disaster Med. 2015;30(2):1-3.

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