Size matters: Effects of the size of heterogeneity on the wave re-entry and spiral wave formation in an excitable media

2021 ◽  
Vol 31 (5) ◽  
pp. 053131
Author(s):  
Karthikeyan Rajagopal ◽  
Shaobo He ◽  
Anitha Karthikeyan ◽  
Prakash Duraisamy
Keyword(s):  
Spiral Wave ◽  
Wave Formation ◽  
Excitable Media

scholarly journals Spiral Wave Formation in Three-Dimensional Excitable Media

1996 ◽  
Vol 77 (15) ◽  
pp. 3244-3247 ◽  
Author(s):  
Takashi Amemiya ◽  
Sándor Kádár ◽  
Petteri Kettunen ◽  
Kenneth Showalter
Keyword(s):  
Three Dimensional ◽  
Spiral Wave ◽  
Wave Formation ◽  
Excitable Media

Model for spiral wave formation in excitable media

1988 ◽  
Vol 60 (18) ◽  
pp. 1880-1883 ◽  
Author(s):  
Ehud Meron ◽  
Pierre Pelcé
Keyword(s):  
Spiral Wave ◽  
Wave Formation ◽  
Excitable Media

scholarly journals Positive genetic feedback governs cAMP spiral wave formation in Dictyostelium.

1996 ◽  
Vol 93 (13) ◽  
pp. 6382-6386 ◽  
Author(s):  
H. Levine ◽  
I. Aranson ◽  
L. Tsimring ◽  
T. V. Truong
Keyword(s):  
Spiral Wave ◽  
Wave Formation

Origin of Spiral Wave Formation in Excitable Optical Systems

1996 ◽  
Vol 77 (25) ◽  
pp. 5051-5054 ◽  
Author(s):  
Dejin Yu ◽  
Weiping Lu ◽  
Robert G. Harrison
Keyword(s):  
Spiral Wave ◽  
Wave Formation ◽  
Optical Systems

scholarly journals Vulnerable windows define susceptibility to alternans and spatial discordance

2010 ◽  
Vol 298 (6) ◽  
pp. H1727-H1737 ◽  
Author(s):  
Seth Weinberg ◽  
Neha Malhotra ◽  
Leslie Tung
Keyword(s):  
Cycle Length ◽  
Ventricular Myocytes ◽  
Spiral Wave ◽  
Wave Formation ◽  
Neonatal Rat ◽  
Strongly Correlated ◽  
Experimental Conditions ◽  
Lower Temperature ◽  
Neonatal Rat Ventricular Myocytes ◽  
Vulnerable Window

Electrophysiological alternans is a beat-to-beat alternation of the action potential duration and/or Ca2+ transient amplitude and is linked to ventricular arrhythmias. We investigated the significance of various rate parameters under different experimental conditions with respect to alternans incidence and the propensity for spiral wave formation. Voltage and Ca2+ were optically mapped in monolayers of neonatal rat ventricular myocytes. Alternans did not occur at physiological temperature, but its incidence increased significantly at lowered temperatures. Pacing cycle length for spatially concordant alternans onset (PCLC), PCL for spatially discordant alternans onset (PCLD), and minimum cycle length for loss of 1:1 or 2:2 capture (MCL) also significantly increased with lower temperature but in a way such that the differences between PCLC and MCL and between PCLD and MCL widened. These results provided the rationale to identify the former difference as the alternans vulnerable window (AVW; in ms) and the latter difference as the discordant alternans vulnerable window (AVWD; in ms). Computational simulations showed that interventions that widen AVW, including altered Ca2+ cycling and enhanced K+ currents, also promote alternans, regardless of whether PCLC or MCL increased or decreased. The simulation results were confirmed experimentally by addition of the ATP-sensitive K+ channel agonist pinacidil. Mathematical analysis provided a theoretical basis linking the size of AVW to the incidence of alternans. Finally, experiments showed that the size of AVWD is related to the incidence of spatially discordant alternans and, additionally, to the incidence of spiral wave formation. In conclusion, vulnerable windows can be defined that are strongly correlated with alternans incidence, spatial discordance, and spiral wave formation.

scholarly journals Spiral waves within a bistability parameter region of an excitable medium

2022 ◽  
Author(s):  
Vladimir Zykov ◽  
Eberhard Bodenschatz
Keyword(s):  
Initial Conditions ◽  
Three Dimensional ◽  
Spiral Wave ◽  
Gradient Flow ◽  
Spiral Waves ◽  
Excitable Medium ◽  
Excitable Media ◽  
Circular Trajectory ◽  
Parameter Region ◽  
Scroll Wave

Abstract Spiral waves are a well-known and intensively studied dynamic phenomenon in excitable media of various types. Most studies have considered an excitable medium with a single stable resting state. However, spiral waves can be maintained in an excitable medium with bistability. Our calculations, performed using the widely used Barkley model, clearly show that spiral waves in the bistability region exhibit unique properties. For example, a spiral wave can either rotate around a core that is in an unexcited state, or the tip of the spiral wave describes a circular trajectory located inside an excited region. The boundaries of the parameter regions with positive and "negative" cores have been defined numerically and analytically evaluated. It is also shown that the creation of a positive or "negative" core may depend on the initial conditions, which leads to hysteresis of spiral waves. In addition, the influence of gradient flow on the dynamics of the spiral wave, which is related to the tension of the scroll wave filaments in a three-dimensional medium, is studied.

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