Causal Scale of Rotors in a Cardiac System

Frontiers in Physics

Ashikaga, Hiroshi³  Prieto-Castrillo, Francisco⁵  Kawakatsu, Mari⁶  Dehghani, Nima⁷ 

[1] Cardiac Arrhythmia Service, Johns Hopkins University School of Medicine, United States;Harvard T. H. Chan School of Public Health, Harvard University, United States;IHU Liryc L'Media Laboratory, Massachusetts Institute of Technology, United States;institut de Rythmologie et Modélisation Cardiaque, Hôpital Xavier Arnozan, France

关键词: complex systems;    Information Theory;    Cardiac dynamics;    rotors;    Atrial Fibrillation;   

DOI  :  10.3389/fphy.2018.00030

学科分类：物理（综合）

来源: Frontiers

【 摘 要 】

Rotors of spiral waves are thought to be one of the potential mechanisms that maintain atrial fibrillation (AF). However, disappointing clinical outcomes of rotor mapping and ablation to eliminate AF raise a serious doubt on rotors as a macro-scale mechanism that causes the micro-scale behavior of individual cardiomyocytes to maintain spiral waves. In this study, we aimed to elucidate the causal relationship between rotors and spiral waves in a numerical model of cardiac excitation. To accomplish the aim, we described the system in a series of spatiotemporal scales by generating a renormalization group, and evaluated the causal architecture of the system by quantifying causal emergence. Causal emergence is an information-theoretic metric that quantifies emergence or reduction between micro- and macro-scale behaviors of a system by evaluating effective information at each scale. We found that the cardiac system with rotors has a spatiotemporal scale at which effective information peaks. A positive correlation between the number of rotors and causal emergence was observed only up to the scale of peak causation. We conclude that rotors are not the universal mechanism to maintain spiral waves at all spatiotemporal scales. This finding may account for the conflicting benefit of rotor ablation in clinical studies.

【 授权许可】

CC BY