Analysis of the Ventricular Fibrillation ECG Signal Amplitude and Frequency Parameters as Predictors of Countershock Success in Humans

• Published in: Chest Vol. 111; no. 3; pp. 584 - 589
• Main Authors: Strohmenger, Hans-Ulrich, Lindner, Karl H., Brown, Charles G.
• Format: Journal Article
• Language: English
• Published: Northbrook, IL Elsevier Inc 01.03.1997; American College of Chest Physicians
• Subjects: Biological and medical sciences; Cardiac arrest; Cardiac arrhythmia; Cardiopulmonary resuscitation; CPR; Electric Countershock; Electrocardiography; Electrocardiography. Vectocardiography; Electrodiagnosis. Electric activity recording; fast Fourier transformation; Fourier Analysis; Fourier transforms; Heart Arrest - physiopathology; Heart Arrest - therapy; Humans; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Retrospective Studies; Sensitivity and Specificity; Software; Success; Treatment Outcome; ventricular fibrillation; Ventricular Fibrillation - diagnosis; Ventricular Fibrillation - therapy; ventricular fibrillation; cardiac arrest; fast Fourier transformation; Human; Intensive cardiocirculatory care; Cardiocirculatory arrest; Prognosis; Arrhythmia; Instrumentation therapy; Cardiovascular disease; Exploration; Excitability disorder; Ventricular fibrillation; Heart rate; Electrodiagnosis; Instrumental stimulation; Treatment; Heart disease; Electrocardiography
• ISSN: 0012-3692; 1931-3543
• DOI: 10.1378/chest.111.3.584

The purpose of this study was to assess from the ventricular fibrillation ECG signal whether certain amplitude parameters, or frequency parameters derived using fast Fourier transform analysis, are predictive of countershock success (defined as a stable supraventricular rhythm following countershock). Retrospective, descriptive study. Emergency medical service at a university hospital. Twenty-six patients with out-of-hospital cardiac arrest, whose initial ECG rhythm was identified as ventricular fibrillation. In all patients, advanced cardiac life support was performed in the out-of-hospital setting and a semiautomatic defibrillator was used for countershock therapy and simultaneous on-line ECG recording. For each patient, ECG data were stored in modules in digitized form over a period of 20 min and analyzed retrospectively. Using fast Fourier transform analysis of the ventricular fibrillation ECG signal in the frequency range of 0.3 to 30 Hz (mean±SD), median frequency, dominant frequency, edge frequency, and amplitude were as follows: 5.17 ± 1.05 Hz, 4.56 ± 0.99 Hz, 10.74 ± 3.46 Hz, and 1.33 ± 0.44 mV before successful countershock (n=20); and 4.2I±1.17 Hz (p=0.0034), 3.31 ± 1.57 Hz (p=0.0004), 9.46 ± 2.93 Hz (p=0.5390), and 1.15 ± 0.69 mV (p=0.0134) before unsuccessful countershock (n=134). Using software filters to completely eliminate interference due to manual cardiopulmonary resuscitation from the ventricular fibrillation power spectrum, only amplitude remained statistically different (p≤0.03) in predicting countershock success. We conclude that in patients, median frequency, dominant frequency, and amplitude are predictive of countershock success in humans.