title: Amplitude spectrum area to guide defibrillation: a validation on 1617 patients with ventricular fibrillation.
abstract: BACKGROUND
  This study sought to validate the ability of amplitude spectrum area (AMSA) to predict defibrillation success and long-term survival in a large population of out-of-hospital cardiac arrests.
  
  
  RESULTS
  ECGs recorded by automated external defibrillators from different manufacturers were obtained from patients with cardiac arrests occurring in 8 city areas. A database, including 2447 defibrillations from 1050 patients, was used as the derivation group, and an additional database, including 1381 defibrillations from 567 patients, served as validation. A 2-second ECG window before defibrillation was analyzed, and AMSA was calculated. Univariable and multivariable regression analyses and area under the receiver operating characteristic curve were used for associations between AMSA and study end points: defibrillation success, sustained return of spontaneous circulation, and long-term survival. Among the 2447 defibrillations of the derivation database, 26.2% were successful. AMSA was significantly higher before a successful defibrillation than a failing one (13 ± 5 versus 6.8 ± 3.5 mV-Hz) and was an independent predictor of defibrillation success (odds ratio, 1.33; 95% confidence interval, 1.20-1.37) and sustained return of spontaneous circulation (odds ratio, 1.22; 95% confidence interval, 1.17-1.26). Area under the receiver operating characteristic curve for defibrillation success prediction was 0.86 (95% confidence interval, 0.85-0.88). AMSA was also significantly associated with long-term survival. The following AMSA thresholds were identified: 15.5 mV-Hz for defibrillation success and 6.5 mV-Hz for defibrillation failure. In the validation database, AMSA ≥ 15.5 mV-Hz had a positive predictive value of 84%, whereas AMSA ≤ 6.5 mV-Hz had a negative predictive value of 98%.
  
  
  CONCLUSIONS
  In this large derivation-validation study, AMSA was validated as an accurate predictor of defibrillation success. AMSA also appeared as a predictor of long-term survival.
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.). gristag@gmail.com.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ristagno
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Tommaso
authors.initials: T
authors.lastname: Mauri
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Cesana
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Yongqin
authors.initials: Y
authors.lastname: Li
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Andrea
authors.initials: A
authors.lastname: Finzi
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Francesca
authors.initials: F
authors.lastname: Fumagalli
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Gianpiera
authors.initials: G
authors.lastname: Rossi
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Niccolò
authors.initials: N
authors.lastname: Grieco
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Maurizio
authors.initials: M
authors.lastname: Migliori
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Aida
authors.initials: A
authors.lastname: Andreassi
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Roberto
authors.initials: R
authors.lastname: Latini
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Carla
authors.initials: C
authors.lastname: Fornari
authors.affiliation: From the IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy (G.R., A.F., F.F., R.L.); Department of Anesthesia and Intensive Care, San Gerardo Hospital, Monza, and University of Milano-Bicocca, Milan, Italy (T.M., G.R., A.P.); Research Center on Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy (G.C., C.F.); School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China (Y.L.); and Azienda Regionale Emergenza Urgenza (AREU), Milan, Italy (G.R., N.G., M.M., A.A., A.P.).
authors.forename: Antonio
authors.initials: A
authors.lastname: Pesenti
mesh_terms: D000368:Aged; D047548:Defibrillators / Q000592:standards*; D004554:Electric Countershock / Q000379:methods / Q000592:standards*; D004562:Electrocardiography / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014693:Ventricular Fibrillation / Q000503:physiopathology* / Q000628:therapy*
keywords: cardiac arrest; defibrillation, electric; survival; ventricular fibrillation