Abstract 16924: Initial AMSA and Increased AMSA After CPR Predict Second Shock Success in Initially Shock-resistant VF During Out-of-hospital Cardiac Arrest

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Ulrich Herken ◽  
Weilun Quan
Keyword(s):  
Logistic Regression ◽  
Cardiac Arrest ◽  
Ventricular Fibrillation ◽  
Success Rate ◽  
Fourier Transformation ◽  
Amplitude Spectrum ◽  
Fast Fourier Transformation ◽  
Shock Delivery ◽  
Spectrum Area ◽  
Hospital Cardiac Arrest

Purpose: Amplitude spectrum area (AMSA), which is calculated from the ventricular fibrillation (VF) waveform using fast Fourier transformation, has been recognized as a predictor of successful defibrillation (DF) and as an index of myocardial perfusion and viability during resuscitation. In this study, we investigated whether a change in AMSA occurring during CPR would predict DF outcome for subsequent DF attempts after a failed DF. We hypothesized that a patient responding to CPR with an increase in AMSA would have an increased likelihood of DF success. Methods: This was a retrospective analysis of out-of-hospital cardiac arrest patients who received a second DF due to initially shock-resistant VF. A total of 193 patients with an unsuccessful first DF were identified in a manufacturer database of electrocardiographic defibrillator records. AMSA was calculated for the first DF (AMSA1) and the second DF (AMSA2) during a 2.1 sec window ending 0.5 sec prior to DF. A successful DF attempt was defined as the presence of an organized rhythm with a rate ≥ 40 / min starting within 60 sec from the DF and lasting for > 30 sec. After the failed first DF, all patients received CPR for 2 to 3 minutes before delivery of the second DF. Change in AMSA (dAMSA) was calculated as dAMSA = AMSA2 - AMSA1. Results: The overall second DF success rate was 14.5%. Multivariable logistic regression showed that both AMSA1 and dAMSA were independent predictors of second DF success with odds ratios of 1.24 (95% CI 1.12 - 1.38, p<0.001) and 1.27 (95% CI 1.16 - 1.41, p<0.001) for each mVHz change in AMSA or dAMSA, respectively. Conclusions: In initially DF-resistant VF, a high initial AMSA value predicted an increased likelihood of second shock success. An increase of AMSA in response to CPR also predicted a higher second shock success rate. Monitoring of AMSA during resuscitation therefore may be useful to guide CPR efforts, possibly including timing of second shock delivery. These findings also further support the value of AMSA as indicator of myocardial viability.

scholarly journals Insights From the Ventricular Fibrillation Waveform Into the Mechanism of Survival Benefit From Bystander Cardiopulmonary Resuscitation

2021 ◽  
Vol 10 (19) ◽  
Author(s):  
Brooke Bessen ◽  
Jason Coult ◽  
Jennifer Blackwood ◽  
Cindy H. Hsu ◽  
Peter Kudenchuk ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Ventricular Fibrillation ◽  
Cardiopulmonary Resuscitation ◽  
Survival Benefit ◽  
Amplitude Spectrum ◽  
Peak Frequency ◽  
Spectrum Area ◽  
Bystander Cardiopulmonary Resuscitation ◽  
Bystander Cpr ◽  
Hospital Cardiac Arrest

Background The mechanism by which bystander cardiopulmonary resuscitation (CPR) improves survival following out‐of‐hospital cardiac arrest is unclear. We hypothesized that ventricular fibrillation (VF) waveform measures, as surrogates of myocardial physiology, mediate the relationship between bystander CPR and survival. Methods and Results We performed a retrospective cohort study of adult, bystander‐witnessed patients with out‐of‐hospital cardiac arrest with an initial rhythm of VF who were treated by a metropolitan emergency medical services system from 2005 to 2018. Patient, resuscitation, and outcome variables were extracted from emergency medical services and hospital records. A total of 3 VF waveform measures (amplitude spectrum area, peak frequency, and median peak amplitude) were computed from a 3‐second ECG segment before the initial shock. Multivariable logistic regression estimated the association between bystander CPR and survival to hospital discharge adjusted for Utstein elements. Causal mediation analysis quantified the proportion of survival benefit that was mediated by each VF waveform measure. Of 1069 patients, survival to hospital discharge was significantly higher among the 814 patients who received bystander CPR than those who did not (0.52 versus 0.43, respectively; P <0.01). The multivariable‐adjusted odds ratio for bystander CPR and survival was 1.6 (95% CI, 1.2, 2.1), and each VF waveform measure attenuated this association. Depending on the specific waveform measure, the proportion of mediation varied: 53% for amplitude spectrum area, 31% for peak frequency, and 29% for median peak amplitude. Conclusions Bystander CPR correlated with more robust initial VF waveform measures, which in turn mediated up to one‐half of the survival benefit associated with bystander CPR. These results provide insight into the biological mechanism of bystander CPR in VF out‐of‐hospital cardiac arrest.

Prediction of Countershock Success in Patients Using the Autoregressive Spectral Estimation

2012 ◽  
Vol 51 (01) ◽  
pp. 13-20 ◽  
Author(s):  
A. Neurauter ◽  
L. Wieser ◽  
V. Wenzel ◽  
B. Abella ◽  
H. Myklebust ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Spectral Estimation ◽  
Amplitude Spectrum ◽  
Diagnostic Odds Ratio ◽  
Dominant Frequency ◽  
Fast Fourier Transformation ◽  
Optimal Timing ◽  
Spectrum Area ◽  
Life Threatening ◽  
Hospital Cardiac Arrest

SummaryObjectives: Ventricular fibrillation (VF) is a life-threatening cardiac arrhythmia and within of minutes of its occurrence, optimal timing of countershock therapy is highly warranted to improve the chance of survival. This study was designed to investigate whether the autoregressive (AR) estimation technique was capable to reliably predict countershock success in VF cardiac arrest patients.Methods: ECG data of 1077 countershocks applied to 197 cardiac arrest patients with out-of-hospital and in-hospital cardiac arrest between March 2002 and July 2004 were retrospectively analyzed. The ECG from the 2.5 s interval of the precountershock VF ECG was used for computing the AR based features Spectral Pole Power (SPP) and Spectral Pole Power with Dominant Frequency weighing (SPPDF) and Centroid Frequency (CF) and Amplitude Spectrum Area (AMSA) based on Fast Fourier Transformation (FFT).Results: With ROC AUC values up to 84.1 % and diagnostic odds ratio up to 19.12 AR based features SPP and SPPDF have better prediction power than the FFT based features CF (80.5 %; 6.56) and AMSA (82.1 %; 8.79).Conclusions: AR estimation based features are promising alternatives to FFT based features for countershock outcome when analyzing human data.

Abstract 12769: Amplitude-Spectral Area of the Ventricular Fibrillation Waveform and Chest Compression Quality in Witnessed and Unwitnessed Out-Of-Hospital Cardiac Arrest: Can We Predict Who is Unlikely to Survive?

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Julia Indik ◽  
Zacherie Conover ◽  
Meghan McGovern ◽  
Annemarie Silver ◽  
Daniel Spaite ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Cardiac Arrest ◽  
Ventricular Fibrillation ◽  
Hospital Discharge ◽  
Chest Compression ◽  
Stepwise Logistic Regression ◽  
Individual Subject ◽  
Spectral Area ◽  
Initial Rhythm ◽  
Hospital Cardiac Arrest

Background: Previous investigations in human out of hospital cardiac arrest (OHCA) due to ventricular fibrillation (VF) have shown that the frequency-based waveform characteristic, amplitude spectral area (AMSA) predicts defibrillation success and is associated with survival to hospital discharge. We evaluated the relative strength of factors associated with hospital discharge including witnessed/unwitnessed status, chest compression (CC) quality and AMSA. We then investigated if there is a threshold value for AMSA that can identify patients who are unlikely to survive. Methods: Adult OHCA patients (age ≥18), with initial rhythm of VF from an Utstein-Style database (collected from 2 EMS systems) were analyzed. AMSA was measured from the waveform immediately prior to each shock, and averaged for each individual subject (AMSA-ave). Univariate and stepwise multivariable logistic regression, and receiver-operator-characteristic (ROC) analyses were performed. Factors analyzed: age, sex, witnessed status, time from dispatch to monitor/defibrillator application, number of shocks, mean CC rate, depth, and release velocity (RV). Results: 140 subjects were analyzed, [104 M (74%), age 62 ± 14 yrs, witnessed 65%]. Survival was 38% in witnessed and 16% in unwitnessed arrest. In univariate analyses, age (P=0.001), witnessed status (P=0.009), AMSA-ave (P<0.001), mean CC depth (P=0.025), and RV (P< 0.001) were associated with survival. Stepwise logistic regression identified AMSA-ave (P<0.001), RV (P=0.001) and age (P=0.018) as independently associated with survival. The area under the curve (ROC analysis) was 0.849. The probability of survival was < 5% in witnessed arrest for AMSA-ave < 5 mV-Hz, and in unwitnessed arrest for AMSA-ave < 15 mV-Hz. Conclusion: In OHCA with an initial rhythm of VF, AMSA-ave and CC RV are highly associated with survival. Further study is needed to evaluate whether AMSA-ave may be useful to identify patients highly unlikely to survive.

Abstract 309: A Novel Method to Predict Survival From Ventricular Fibrillation Arrest During Chest Compressions

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Jason Coult ◽  
Lawrence D Sherman ◽  
Jennifer Blackwood ◽  
Heemun Kwok ◽  
Peter J Kudenchuk ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Ventricular Fibrillation ◽  
Characteristic Curve ◽  
Amplitude Spectrum ◽  
Support Vector ◽  
Chest Compressions ◽  
Time Frequency ◽  
Model Combining ◽  
Spectrum Area ◽  
Care Guidelines

Background: Quantitative measures of the ventricular fibrillation (VF) electrocardiogram (ECG) such as Amplitude Spectrum Area (AMSA) assess myocardial physiology and predict cardiac arrest outcomes, offering the potential to guide resuscitation care. Guidelines recommend minimally-interrupted chest compressions (CCs) during resuscitation, but CCs corrupt the ECG and must be paused for analysis. We therefore sought to develop a novel measure to predict survival without requiring CC pause. Methods and Results: Five-second VF ECG segments were collected with CCs and without CCs prior to 2755 defibrillation shocks in 1151 patients with out-of-hospital cardiac arrest. The cohort was divided into a training set to develop the measure and a test set to evaluate performance. Using segments from 460 training patients, we designed an adaptive filter to remove CC artifacts based on chest impedance and ECG characteristics, derived novel time-frequency and amplitude features of the filtered VF ECG, and trained a Support Vector Machine (SVM) model combining these novel features to predict survival with favorable neurologic status. In 691 test cases, area under the receiver operating characteristic curve (AUC) for predicting survival using the SVM was 0.74 (95% CI: 0.71-0.77) with CCs and 0.74 (95% CI: 0.71-0.76) without CCs (Figure 1). By comparison, AUC for predicting survival using AMSA was 0.70 (95% CI: 0.67-0.73) with CCs (p=0.001 for difference versus SVM) and 0.73 (95% CI: 0.71-0.76) without CCs (p=0.68 for difference versus SVM). Conclusions: VF waveform measures such as AMSA predict functional survival when obtained during ongoing CCs, but prognostic performance is reduced compared to CC-free analysis. However, an SVM-based measure combining novel VF waveform features enabled similar prediction with and without CCs. Machine learning combinations of features optimized for use during CCs may thus afford a means for VF prognosis during uninterrupted CCs.

Abstract 9764: Prevalence of Inappropriate Defibrillation Attempts During Pediatric In-Hospital Cardiac Arrest

Circulation ◽  
2021 ◽  
Vol 144 (Suppl_2) ◽  
Author(s):  
James M Gray ◽  
Tia T Raymond ◽  
Dianne L Atkins ◽  
Ken Tegtmeyer ◽  
Dana E Niles ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Ventricular Tachycardia ◽  
Ventricular Fibrillation ◽  
Age Groups ◽  
Inappropriate Shock ◽  
Shock Delivery ◽  
Inappropriate Shocks ◽  
Hospital Cardiac Arrest ◽  
Significant Opportunity ◽  
Age Category

Introduction: Shockable rhythms (ventricular fibrillation [VF] and ventricular tachycardia [VT]) occur in <25% of pediatric in-hospital cardiac arrest (IHCA) events, yet the prevalence of inappropriate defibrillation attempts for non-VF/VT rhythms is unknown. We aim to describe the prevalence of inappropriate shocks across a large, multi-national pediatric cardiac arrest network. Methods: We included children <18y reported to the pedi atric RES uscitation- Q uality (pediRES-Q) network from 2015-2019 with complete defibrillator files who received defibrillation attempts during IHCA (ZOLL R-Series, MA). Two pediatric cardiologists independently classified rhythms immediately prior to shock as: 1) appropriate (VF or wide complex ≥ 150/min), 2) indeterminate (narrow complex ≥150/min or wide complex 100-149/min), or 3) inappropriate (asystole, sinus, narrow complex <150/min, or wide complex <100/min). Rhythms that were undecipherable due to artifact were excluded from analysis (n=22). Disagreements were resolved by arbitration and consensus. Results: Of 896 IHCA events, 124 (14%) had defibrillation attempts. A total of 303 shocks were delivered: 87 (29%) in age <1y, 84 (28%) in 1-8y, and 132 (44%) in 9-17y. Of shocks delivered, 206 (68%) were appropriate, 12 (4%) indeterminate, and 85 (28%) inappropriate. There was no difference in inappropriate shock delivery by age category: <1y (24/87, 28%), 1-8y (26/84, 31%), 9-17y (35/132, 27%) ( p =0.4). Conclusions: Across a multi-national pediatric cardiac arrest network, a large proportion (28%) of defibrillation attempts were inappropriate, suggesting significant opportunity for improvement in rhythm identification in pediatric cardiac arrest. There was no difference in inappropriate shock delivery across age groups. Figure 1. Representation of rhythm classification and appropriateness of defibrillation attempts with exemplar rhythms.

Abstract 289: Relationship Between Myocardial Glycogen Concentrations and Amplitude Spectrum Area During Ventricular Fibrillation in a Rat Model of Cardiac Arrest and Resuscitation

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Qiaohua Hu ◽  
Xiangshao Fang ◽  
Zhengfei Yang ◽  
Wanchun Tang
Keyword(s):  
Cardiac Arrest ◽  
Energy Metabolism ◽  
Ventricular Fibrillation ◽  
Rat Model ◽  
Glycogen Content ◽  
Amplitude Spectrum ◽  
High Energy ◽  
Myocardial Energy Metabolism ◽  
Spectrum Area ◽  
The Relationship

Introduction: Myocardial high-energy phosphate (ATP) levels has been demonstrated correlating with amplitude spectrum area (AMSA) during ventricular fibrillation (VF) in previous experimental studies. In the present study, we investigated the relationship between AMSA and myocardial glycogen content (MGC),which can be used to reflect the status of myocardial energy metabolism indirectly during VF. Hypothesis: AMSA has a significantly correlation with MGC during VF in a rat model of cardiac arrest and resuscitation. Methods: Twenty male Sprague-Dawley rats weighing 350 to 450 g were utilized and randomized into two groups: VF and cardiopulmonary resuscitation (CPR) (VF/CPR group) or untreated VF (VF group). 5 mins of CPR was performed after 10 mins of untreated VF in VF/CPR animals. Amplitude spectrum area (AMSA) at VF 5, 10 and 15 mins were calculated from ECG signals. The rats’ hearts were quickly removed at the predetermined time of 15 min for determines the glycogen contents by the anthrone reagent method using a glycogen assay kit. Results: AMSA values significantly decreased during untreated VF in both VF and VF/CPR animals. However, much greater AMSA during CPR was achieved by the VF/CPR group in comparison with the VF group. There was a marked and negative relationship between AMSA at VF 15 min and MGC. (Figure). Conclusion: MGC was significantly and negatively correlated with AMSA during VF in this rat model of cardiac arrest and resuscitation. In clinical practice, we can use AMSA to reflect the state of myocardial energy metabolism indirectly. Figure The changes of AMSA and relationship between AMSA and glycogen content:(A) The change of AMSA between VF/CRP group and VF group;(B) The relationship between AMSA and glycogen content. AMSA, amplitude spectrum area; V, time of ventricular fibrillation; # p <0.05 vs. V4.

Abstract 188: Temporal Changes in Morphological Characteristics of Ventricular Fibrillation from Out-of-Hospital Cardiac Arrest in an Asian Community

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Weiting Chen ◽  
Nai-Chuan Chen ◽  
Yen-Pin Chen ◽  
Yi-Chia Lee ◽  
Hui-Chih Wang ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Ventricular Fibrillation ◽  
Amplitude Spectrum ◽  
Morphological Characteristics ◽  
Asian Community ◽  
Electrocardiographic Recordings ◽  
Hospital Cardiac Arrest ◽  
Morphology Characteristics ◽  
Over Time

Introduction: Ventricular fibrillation (VF) is the most common arrhythmia causing out-of-hospital cardiac arrest (OOHCA) and defibrillation remains the mainstay of its treatment. Successful defibrillation is linked to VF morphology characteristics, and is affected by VF duration, quality of cardiopulmonary resuscitation (CPR) and emergency medical service (EMS) responsiveness. This study aimed at comparing VF morphology characteristics and their relationships with patients and EMS characteristics, as well as outcomes, in an Asian community. Method: Electrocardiographic recordings of VF signals from automated external defibrillators (AEDs) in 2008 to 2012 were obtained from OOHCA subjects in Taipei city, a metropolitan with 2.65 million residents in 272km2. Amplitude spectrum analysis (AMSA) and DFAα2 were calculated and compared year by year in the study period. Results: A total of 612 OOHCA subjects with VF were included for analysis. Both DFA and AMSA changed significantly over time (χ 2 for trend: -0.128 for DFA, p<0.01; 0.092 for AMSA, p=0.02). There was no change in gender, age, and bystander CPR rates; however, in later years there were more witnessed arrests, shortened EMS responses, and better sustained (>2 hr) return of spontaneous circulation (ROSC) and neurological outcomes (CPC 1&2). The time trend for DFAα2 (OR 0.98, CI 0.96-0.99, p=0.003), but not for AMSA (OR 1.07, CI 0.99-1.14), remained after adjustment for confounders. Both DFAα2 and AMSA were associated with sustained ROSC (DFA OR 0.08, CI 0.04-0.18, p<0.001; AMSA OR 1.18, CI 1.01-1.38, p=0.03) and CPC 1&2 (DFA OR 0.04, CI 0.01-0.16, p<0.001; AMSA OR 1.30, CI 1.07-1.57, p=0.008) in multiple regression models. Conclusions: DFAα2 and AMSA, two important VF characteristics, changed significantly over time in an Asian community, and were associated with improved outcomes. This might reflect improvement in community chain of survival especially among EMS responses and community quality of CPR.

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