title: Evaluation of ischemic injury of the cardiac tissue by using the principal component analysis of an epicardial electrogram.
abstract: Monitoring and control of the heart tissue viability is of crucial importance during heart surgery operations. In most cases the heart tissue suffers from an ischemic injury that causes a decrease in the velocity of electrical excitation propagation in it and influences the shape of the excitation wave front that spreads over the injured area. It is reflected in a more complex shape of the registered epicardial electrogram as compared to normal. A method for quantitative evaluation of the complexity of the shape of the epicardial electrogram based on the principal component analysis is here proposed for evaluation of the ischemic injury of the cardiac tissue. A minimal, yet sufficient, number of the principal components (the optimal basis functions) for truncated expansion of the epicardial electrogram signals could be used as an estimate of signal complexity. The method for determination of such a minimal, yet sufficient, number of principal components were developed by using epicardial electrograms registered during in situ experiments on dogs in which local ischemia was evoked by ligation of a coronary vessel.
authors.affiliation: Institute for Biomedical Research of Kaunas University of Medicine, Eiveniu 4, LT-50009 Kaunas, Lithuania. akri@kmu.lt
authors.forename: Algimantas
authors.initials: A
authors.lastname: Krisciukaitis
authors.forename: Mindaugas
authors.initials: M
authors.lastname: Tamosiunas
authors.forename: Povilas
authors.initials: P
authors.lastname: Jakuska
authors.forename: Romualdas
authors.initials: R
authors.lastname: Veteikis
authors.forename: Raimundas
authors.initials: R
authors.lastname: Lekas
authors.forename: Viktoras
authors.initials: V
authors.lastname: Saferis
authors.forename: Rimantas
authors.initials: R
authors.lastname: Benetis
mesh_terms: D000818:Animals; D004285:Dogs; D004562:Electrocardiography / Q000379:methods*; D017202:Myocardial Ischemia / Q000503:physiopathology*