This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Schumacher, A. M. Articles by Piano, M. R. Search for Related Content PubMed PubMed Citation Articles by Schumacher, A. M. Articles by Piano, M. R. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB ATENOLOL ATROPINE PHENTOLAMINE Social Bookmarking                         What's this?

Detection of Cardiac Variability in the Isolated Rat Heart

Department of Physiological and Technological Nursing, School of Nursing at the Medical College of Georgia, aschumacher{at}mcg.edu

Joseph P. Zbilut, PhD, DNSc

Department of Adult Health Nursing and Department of Molecular Biophysics and Physiology at the Rush University Medical Center

Charles L. Webber, Jr., PhD

Department of Physiology at the Loyola University Medical Center

Dorie W. Schwertz, PhD, RN, FAAN

Department of Medical-Surgical Nursing, College of Nursing (MC 802) at the University of Illinois at Chicago

Mariann R. Piano, PhD, RN

Department of Medical-Surgical Nursing, College of Nursing (MC 802), at the University of Illinois at Chicago

Cardiac variability can be assessed from two perspectives: beat-to-beat performance and continuous performance during the cardiac cycle. Linear analysis techniques assess cardiac variability by measuring the physical attributes of a signal, whereas nonlinear techniques evaluate signal dynamics. This study sought to determine if recurrence quantification analysis (RQA), a nonlinear technique, could detect pharmacologically induced autonomic changes in the continuous left ventricular pressure (LVP) and electrographic (EC) signals from an isolated rat heart—a model that theoretically contains no inherent variability. LVP and EC signal data were acquired simultaneously during Langendorff perfusion of isolated rat hearts before and after the addition of acetylcholine (n = 11), norepinephrine (n = 12), or no drug (n = 12). Two-minute segments of the continuous LVP and EC signal data were analyzed by RQA. Findings showed that%recurrence,%determinism, entropy, maxline, and trend from the continuous LVP signal significantly increased in the presence of both acetylcholine and norepinephrine, although systolic LVP significantly increased only with norepinephrine. In the continuous EC signal, the RQA trend variable significantly increased in the presence of norepinephrine. These results suggest that when either the sympathetic or parasympathetic division of the autonomic nervous system overwhelms the other, the dynamics underlying cardiac variability become stationary. This study also shows that information concerning inherent variability in the isolated rat heart can be gained via RQA of the continuous cardiac signal. Although speculative, RQA may be a tool for detecting alterations in cardiac variability and evaluating signal dynamics as a nonlinear indicator of cardiac pathology.

Key Words: cardiac variability • recurrence quantification analysis • isolated rat heart model

Biological Research For Nursing, Vol. 8, No. 1, 55-66 (2006)
DOI: 10.1177/1099800406289775


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?