Central command to control the instability of cardiac rhythm at running

Abstract

It is known that a phenomenon in which a cardiac rhythm synchronizes with a locomotor rhythm occurs during running. At this synchronization, the cardiac rhythm rate increases in proportion to the locomotor rhythm intensity, and when it approaches the limit locomotor rhythm intensity, an unstable phenomenon of the cardiac rhythm increases becomes sometimes observed. This instability of the cardiac rhythm causes lower exercise efficiency, so it is necessary to keep the stable cardiac rhythm up to the faster locomotor rhythm as far as possible. Therefore, we obtain a model with a locomotor rhythm added to the FitzHugh-Nagumo equation that expresses the cardiac rhythm, and propose a method of a central command to suppress the instability of the cardiac rhythm for this model. By simulation, we show the central command to suppress this instability.