FAST COMPUTING METHOD FOR ONE-DIMENSIONAL VENTRICULAR ACTION-POTENTIAL PROPAGATION

In computer simulations of propagating ventricular action potentials, most mathematical models based on the Hodgkin-Huxley-type model are de scribed by partial differential equations. At present, a computer anal ysis utilizing these models is not applicable to cardiology because co nventional calculating methods require large amounts of computing time to solve them. In this study, a new method is presented for calculati ng computer simulations of a one-dimensional (1-D) cardiac fiber model . A feature of the method is to control the number of calculated segme nts according to partial derivative(2)V/partial derivative x(2) (where V is membrane potential). For segments where partial derivative(2)V/p artial derivative X(2) is large, V is certain to be calculated. On the other hand, for segments where partial derivative(2)V/partial derivat ive x(2) is sufficiently small, that is, where V is in a resting or pl ateau phase, it is not necessarily calculated. For the non-calculated segments, variables of the model are interpolated if necessary. The re sults of simulations showed that the computing time was reduced to one -ninth in comparison with conventional differential calculus. The rela tive error in electrophysiological indexes (action potential duration, time constant of the foot of V, and maximum rising rate of V upstroke ) was less than 3%. Therefore, the proposed method has the merits of h igh efficiency and accuracy.