Acceleration Spectrum Analysis: A Novel Quantitative Method for Frequenc y-Domain Analysis of the Signal-Averaged Electrocardiogram

Autor: Eric K.Y. Chan
Rok vydání: 1996
Předmět:
Zdroj: Annals of Noninvasive Electrocardiology. 1:306-315
ISSN: 1542-474X
1082-720X
DOI: 10.1111/j.1542-474x.1996.tb00284.x
Popis: Background: Frequency-domain techniques presently used for micropotential analysis in the signal averaged ECG (SAECC) have several inherent shortcomings. For example, they depend on sensitive determination of the I-point, which becomes inaccurate in the presence of noise, or derivation of multiple, complicated statistical parameters to quantify spectral characteristics in a three-dimensional “spectral temporal map.” While these techniques are not as well accepted clinically as the conventional time-domain Simson method, the latter is not without limitations either. Although time-domain SAECG analysis has a very high negative predictive value, it has low positive predictive accuracy. Furthermore, it cannot be used to analyze SAECC data in patients with conduction delay problems, such as bundle branch block. Hence, the goal of this new frequency-domain technique is to address and solve some of these shortcomings. Methods: The Fourier transform of the second derivative signal, or “acceleration spectrum,” extracts the frequency-domain “signature” of damaged myocardium throughout the entire QRS complex, rather than from only the late potential region. The technique i s not dependent on precise endpoint or other fiducial point determination. A “spectral change index” (SCI) for quantifying variation from 50-300 Hz in the acceleration spectrum i s calculated. The characterization of the cut-off values for the SCI was based on results from a study including 50 postmyocardial infarction (post-MI) patients (25 of whom were inducible to sustained ventricular tachycardia), and 10 normal controls. Results: An SCI
Databáze: OpenAIRE
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