Conditions For The Genesis Of Early Afterdepolarization In A Model Of Aventricular Myocyte

As a complex nonlinear system,the heart is an important organ for most organisms to maintain life activities,so heart diseases are naturally an important research topic in the fields of physics and biology;as a rising discipline,nonlinear dynamics is widely used in the fields of physics,biology,and finance,so nonlinear dynamics methods are employed to research the complex system of the heart.Long QT syndrome is a kind of disease with a high risk of causing arrhythmia.It is characterized by an extraordinary prolongationof the QT interval in an electrocardiogram.Along with the AP prolongation,a type of triggered activity called early afterdepolarization may occur,which appears as a secondary membrane voltage oscillation during the repolarization phase of an AP.It may trigger abnormal excitations in cardiac tissue and,thus,is regarded as one of the major arrhythmogenic factors in LQTS.Current research points out that the Hopf bifurcation is a necessary condition for the occurrence of EAD,but the sufficient conditions for EAD have not been explained.In this paper,through the analysis of the physical mechanism of EAD,the sufficient conditions for the occurrence of EAD are studied by using non-linear dynamics related theories,and further research is made on the inherent requirements of different parameters for the occurrence of EAD.In addition,the amplitude equation of EAD is obtained,through which the conductance parameters of ion channel and how the time parameters affect the period and amplitude of EAD are studied.The research in the paper not only enriches the research work related to EAD,but also puts forward a complete set of research processes related to EAD,which paves the way for further study of more complex models,helping to explore the pathological basis of arrhythmia occurring in actual animal,so as to assist the treatment of arrhythmia.