SKM 2021 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 10: Focus session: Nonlinear Dynamics of the Heart I (organized by Markus Bär, Stefan Luther and Ulrich Parlitz)

DY 10.3: Vortrag

Mittwoch, 29. September 2021, 15:45–16:00, H6

The mechanism of defibrillation of cardiac tissue by time-periodic low-energy shocks II: Subsequent shortening of refractory boundary length enables low energy antifibrillatory pacing (LEAP) — •Pavel Buran, Thomas Niedermayer, and Markus Bär — Physikalisch-Technische Bundesanstalt, Abbestr. 2 - 12, 10587 Berlin

We present a generic mechanism for the success of LEAP protocols, which covers termination of multiple stable rotors as well as of states of spatiotemporal chaos. Previously, we found that knowledge of the refractory boundary length is sufficient to estimate the success probability of an individual LEAP pulse which is found to decay exponentially with this length in a medium with stable spirals. This result is also found in simulations of cardiac models exhibiting spatiotemporal chaos. Whereas single shock defibrillation requires instantaneous annihilation of all existing vortices, during LEAP the defibrillation process is more gradual and is based on a subsequent shortening of the total refractory boundary length. The average shortening factor, i. e. the ratio between the refractory boundary lengths just before subsequent pulses during periodic pacing can be determined numerically both for media with spatiotemporal chaos and multiple stable spirals and provides a good indicator for the efficiency of a given LEAP protocol.