Title :
Slow conduction within infarct scars as a source of high-frequency oscillations in the QRS signal
Author :
Kapela, A. ; Starmer, C.F. ; Bezerianos, A.
Author_Institution :
Dept. of Medical Phys., Patras Univ., Greece
Abstract :
We propose a detailed explanation of increased variability of high-frequency (> 100 Hz) components within the QRS observed in post-myocardial infarction patients, reported in recent studies of real high-resolution ECGs. Using mathematical models of single, branching and tortuous cardiac strands, based on cellular experimental data, we simulated effects of conduction slowing, characteristic for regions bordering infarcts, on spectral properties of the depolarization signal, assessed by means of wavelet transform and wavelet variance. Calculated extracellular potentials contained oscillations with frequencies related to propagation velocity and cellular dimensions by simple mathematical formulas. We conclude that slow AP propagation at 3-20 cm/s within infarct scars is a possible source of high-frequency (100-300 Hz) micropotentials and, with unstable activation wavefront and/or trigger jitter, contributes to the increased beat-to-beat variability in the QRS.
Keywords :
bioelectric potentials; electrocardiography; medical signal processing; signal resolution; wavelet transforms; 100 to 300 Hz; QRS signal; action potential propagation; beat-to-beat variability; branching cardiac strands; cellular dimensions; depolarization signal; extracellular potentials; high-frequency micropotentials; high-frequency oscillations; high-resolution ECGs; infarct scars; post-myocardial infarction patients; propagation velocity; single cardiac strands; slow conduction; spectral properties; tortuous cardiac strands; trigger jitter; unstable activation wavefront; wavelet transform; wavelet variance; Cardiology; Electrocardiography; Extracellular; Fractionation; Frequency; Mathematical model; Morphology; Physics; Signal resolution; Wavelet transforms;
Conference_Titel :
Computers in Cardiology, 2003
Print_ISBN :
0-7803-8170-X
DOI :
10.1109/CIC.2003.1291076