Berlin 2012 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 19: Nonlinear Dynamics of the Heart: Contributed talks to focus session
DY 19.1: Vortrag
Mittwoch, 28. März 2012, 15:00–15:15, MA 001
From Vascular Structures to Cardiac Activation Dynamics — •Daniel Hornung1,2, Philip Bittihn1,2, Amgad Squires1, Flavio Fenton1,3, and Stefan Luther1,2,3 — 1Max-Panck-Institut für Dynamik und Selbstorganisation Göttingen — 2Institut für Nichtlineare Dynamik, Georg-August-Universität Göttingen — 3Department of Biomedical Sciences, Cornell University
Under externally applied electric fields, heterogeneities in cardiac muscle tissue may serve as sources of cellular activation and thus emit waves of muscular excitation. This effect is most promising on the search for new, more gentle, low energy defibrillation techniques, and quantitative methods for assessing these heterogeneities and their effects on cardiac (de)fibrillation are of the greatest importance.
We show a method to convert the measured sizes of cardiac coronary blood vessels -- one kind of the mentioned heterogeneities -- into a prediction of the heart activation under external electric fields.
By using micro X-ray computed tomography images of heart tissue, we are able to automatically reconstruct the structure of the coronary arterial vascular tree. The blood vessel diameter distribution in this tree follows a power law, which can then be transformed, using know relations between size and excitability, into a prediction of the time required to activate the whole tissue by an electric stimulus of a given strength. The relation between activation time and electric field strength also follows a power law, where the two respective exponents can be easily converted into one another.