title: Time frequency power profile of QRS complex obtained with wavelet transform in spontaneously hypertensive rats.
abstract: We evaluated whether frequency analysis could detect the development of interstitial fibrosis in rats. SHR/Izm and age-matched WKY/Izm were used. Limb lead II electrocardiograms were recorded. Continuous wavelet transform (CWT) was applied for the time-frequency analysis. The integrated time-frequency power (ITFP) between QRS complexes was measured and compared between groups. The ITFP at low-frequency bands (≤125Hz) was significantly higher in SHR/Izm. The percent change of ITFP showed the different patterns between groups. Prominent interstitial fibrosis with an increase in TIMP-1 mRNA expression was also observed in SHR/Izm. These results were partly reproduced in a computer simulation.
authors.affiliation: Department of Ischemia Circulatory Physiology, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. namikubota-circ@umin.ac.jp
authors.forename: Nami K
authors.initials: NK
authors.lastname: Takano
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tsutsumi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Yoshiwo
authors.initials: Y
authors.lastname: Okamoto
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Nakajima
mesh_terms: D000818:Animals; D003198:Computer Simulation; D004562:Electrocardiography / Q000379:methods*; D005355:Fibrosis / Q000473:pathology; D006352:Heart Ventricles / Q000473:pathology; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism; D020257:Ventricular Remodeling / Q000502:physiology; D058067:Wavelet Analysis
chemical_list: D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1