Dresden 2017 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 43: Nonlinear Dynamics, Synchronizsation and Chaos

DY 43.5: Vortrag

Donnerstag, 23. März 2017, 10:30–10:45, ZEU 118

Wave control by cooperative excitation of cardiac tissue — •Pavel Buran¹, Sergio Alonso², Markus Bär¹, and Thomas Niedermayer¹ — ¹Physikalisch-Technische Bundesanstalt (PTB), Berlin — ²Universitat Politècnica de Catalunya, Barcelona

Rotating excitation waves and electrical turbulence in cardiac tissue have been associated with arrhythmias like the life-threatening ventricular fibrillation. The application of an electrical shock (defibrillation) is an effective therapy, as it globally excites the tissue resulting in termination of all excitation waves, but also causes severe side effects. Recent experimental studies have shown that a sequence of electrical pulses is able to terminate fibrillation more gently than a single pulse. Only tissue at major conduction heterogeneities, such as large coronary arteries, may be activated by each of these very weak pulses. Therefore, global tissue activation and wave termination originates from few localized activation sites. In order to decipher the interplay of the individual pulses, we performed extensive simulations of cardiac tissue perforated by blood vessels and tested a variety of cellular models. For models exhibiting a dominant excitation period during fibrillation, the pulses appear to be highly cooperative if the period between these pulses matches the dominant period. These findings are elucidated by the analysis of the dynamical variables, such as the fraction of excited tissue and the number of phase defects, both during the state of electrical turbulence and during cooperative excitation. Moreover, we propose a simple stochastic model which integrates our results in an intuitive way.