Spatiotemporal control to eliminate cardiac alternans using isostable reduction

• Published in: Physica. D Vol. 342; pp. 32 - 44
• Main Authors: Wilson, Dan, Moehlis, Jeff
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-2017
• Subjects: Alternans; Cardiac arrhythmia; Isostable reduction; Isostables; Optimal control; Cardiac arrhythmia; Alternans; Isostables; Optimal control; Isostable reduction
• ISSN: 0167-2789; 1872-8022
• DOI: 10.1016/j.physd.2016.11.001

Cardiac alternans, an arrhythmia characterized by a beat-to-beat alternation of cardiac action potential durations, is widely believed to facilitate the transition from normal cardiac function to ventricular fibrillation and sudden cardiac death. Alternans arises due to an instability of a healthy period-1 rhythm, and most dynamical control strategies either require extensive knowledge of the cardiac system, making experimental validation difficult, or are model independent and sacrifice important information about the specific system under study. Isostable reduction provides an alternative approach, in which the response of a system to external perturbations can be used to reduce the complexity of a cardiac system, making it easier to work with from an analytical perspective while retaining many of its important features. Here, we use isostable reduction strategies to reduce the complexity of partial differential equation models of cardiac systems in order to develop energy optimal strategies for the elimination of alternans. Resulting control strategies require significantly less energy to terminate alternans than comparable strategies and do not require continuous state feedback.
•Isostable reduction (an analog of phase reduction) is applied to PDE models of cardiac dynamics.•The reduced systems are analyzed to develop an efficient control strategy for eliminating alternans.•The resulting control strategy suppresses alternans using significantly less energy than other control strategies.•The feasibility of this control strategy is investigated when the full dynamical equations are unknown.