Analysis of an experimental model of in vitro cardiac tissue using phase space reconstruction

Abstract

The in vitro cultures of cardiac cells represent valuable models to study the mechanism of the arrhythmias at the cellular level. But the dynamics of these experimental models cannot be characterized precisely, as they include a lot of parameters that depend on experimental conditions. This paper is devoted to the investigation of the dynamics of an in vitro model using a phase space reconstruction. Our model, based on the heart cells of new born rats, generates electrical field potentials acquired using a microelectrode technology, which are analyzed in normal and under external stimulation conditions. Phase space reconstructions of electrical field potential signals in normal and arrhythmic cases are performed after characterizing the nonlinearity of the model, computing the embedding dimension and the time lag. A non-parametric statistical test (Kruskal-Wallis test) shows that the time lag τ could be used as an indicator to detect arrhythmia, while the embedding dimension is not significantly different between the normal and the arrhythmia cases. The phase space reconstructions highlight attractors, whose dimension reveals that they are strange, depicting a deterministic dynamics of chaotic nature in our in vitro model.

Heart-on-a-chip based on stem cell biology

“…Next to features such as culture medium perfusion, the presence of hemoglobin via oxygen carriers in the culture medium or the acting of cyclic stretch, electrical field stimulation is the most important to mimic heart tissue. Electrical field was used for development of in vitro models of arrhythmia, investigation of cardiac phenotype or analysis of cells migration and orientation (Bian and Tung, 2006, Sathaye et al, 2006, Kong et al, 2005Xu et al, 2014, Nunes et al, 2013, Lasher et al 2012, Kujala et al 2012). Moreover, electrical stimulation can be used to enhance function of the cardiac cells and the formation of synchronously beating tissue (Radisic et al, 2004Hirt et al, 2014.…”

Quantification of Contractile Dynamic Complexities Exhibited by Human Stem Cell-Derived Cardiomyocytes Using Nonlinear Dimensional Analysis

“…Methods from chaos theory and nonlinear dynamics give us the opportunity to study these complex biological signals, including entropy 6 , complexity indexes 7 and dimensional analysis 8 . Phase space reconstruction (PSR) 9,10 and dimensional analysis has been implemented to characterize the intrinsic nonlinear complexity within the time series signals 11–13 . Specifically, the phase space consists of a set of typical trajectories of the system, in which each point corresponds to one system state.…”

Quantitatively characterizing drug‐induced arrhythmic contractile motions of human stem cell‐derived cardiomyocytes

“…PSR has previously been applied to analyze electrophysiological signals to identify arrhythmia both in vitro and in vivo. Electrical field potentials from nrCMs recorded by MEA were subjected to PSR to compute the parameters that quantified the unique dynamics of normal versus arrhythmic signals (Xu, Jacquir, Laurent, Bilbault, & Binczak, 2014). PSR was also used to analyze heart rate intervals of electrocardiograms (ECGs) (Mironyuk & Loskutov, 2006;Richter & Schreiber, 1998) and magnetic resonance image (MRI) data (Cîndea, Odille, Bosser, Felblinger, & Vuissoz, 2010) acquired from patients with different heart pathologies.…”