Irina V. Biktasheva, Vadim N. Biktashev, Arun V. Holden
Submitted to Lecture Notes in Computer Science: 2004/11/24. Accepted subject to minor revisions: 2005/02/15. Submitted in revised form: 2005/02/27
We describe numerical simulations of spiral waves dynamics in the computational model of human atrial tissue with the Courtemanche-Ramirez-Nattel local kinetics. The spiral wave was initiated by cross-field stimulation protocol, with and without preliminary ``fatigue'' by rapid stimulation of the model tissue for a long time. In all cases the spiral wave has finite lifetime and self-terminates. However the mechanism of self-termination appears to depend on the initiation procedure. Spiral waves in the ``fresh'' tissue typically terminate after a few rotations via dissipation of the excitation front along the whole of its length. The dynamics of spiral waves in ``tired'' tissue is characterized by breakups and hypermeander, which also typically leads to self-termination but only after a much longer interval of time. Some features of the observed behaviour can not be explained using existing simplified theories of dynamic instabilities and alternanses.
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