Title :
Time-frequency mapping of the magnitude squared-coherence for intra-QRS potentials detection
Author :
Barbosa, P.R.B. ; Bernardino, L.C., Jr. ; Barbosa-Filho, J. ; Cordovil, I. ; Nadal, J.
Author_Institution :
Biomed. Eng. Program, Fed. Univ. of Rio de Janeiro, Brazil
Abstract :
Intra-QRS potentials detected in the presence of heart disease represents unstable electrical conduction in damaged myocardium, probably due to dispersion in propagation time-constants. A one-dimensional linear model of continuous velocity waveform transmission is proposed, and a time-frequency magnitude squared-coherence (MSC) mapping of the ventricular activation (VA) of patients with ventricular tachycardia (VT) and normal volunteers was studied. Normal subjects shows high MSC estimates, mainly at the beginning and end of VA. Reduction of MSC estimate throughout VA was observed in VT, which reflects variation in the content of successive spectral estimates. This finding is indicative of fluctuation in propagation velocity of the ventricular activation in damaged myocardium.
Keywords :
bioelectric potentials; diseases; electrocardiography; medical signal detection; patient diagnosis; physiological models; time-frequency analysis; damaged myocardium; heart disease; intra-QRS potentials detection; magnitude squared-coherence; one-dimensional linear model; time-frequency mapping; unstable electrical conduction; velocity waveform transmission; ventricular activation; ventricular tachycardia; Biomedical engineering; Cardiac disease; Cardiology; Electrocardiography; Filtering; Fluctuations; Frequency domain analysis; Myocardium; Surface waves; Time frequency analysis;
Conference_Titel :
Engineering in Medicine and Biology Society, 2003. Proceedings of the 25th Annual International Conference of the IEEE
Print_ISBN :
0-7803-7789-3
DOI :
10.1109/IEMBS.2003.1279582
