Termination of pinned vortices by high-frequency wave trains in heartlike excitable media with anisotropic fiber orientation
Physical Review E, 86, 031912, 2012 - doi : 10.1103/PhysRevE.86.031912
Brief Summary: ''... The basic dependence of the conduction velocities of planar waves and waves around curved obstacles as a function of anisotropy through numerical simulations of excitable media that mimic the fiber orientation in a real heart is investigated. This knowledge is used to explain the unpinning of anchored spiral waves by high-frequency wave trains in an anisotropic excitable medium. A nonmonotonic relationship between the maximum unpinning period and the obstacle radius depending on the fiber orientation is observed, where the formation of unwanted secondary pinned vortices or chaotic waves is seen over a wide range of parameters.. ...''
Controlling activation site density by low-energy far-field stimulation in cardiac tissue
M. Hörning*, S. Takagi and K. Yoshikawa
Physical Review E, 85, 061906, 2012 - doi : 10.1103/PhysRevE.85.061906
Brief Summary: ''... The activation site density depending on the applied electric field through in vitro experiments carried out on neonatal rat cardiac tissue cultures and numerical bidomain simulations is investigated. The results indicate that the activation site density increases exponentially as a function of the intracellular conductivity and the level of cell isotropy. Additionally an intuitive analytical framework that describes the activation site density is derived that provides useful information for determining the ratio of longitudinal to transverse conductivity in a cardiac tissue culture. ...''