A model of cardiac tissue as a conductive system with interacting   pacemakers and refractory time
  A model of the heart tissue as a conductive system with two interacting pacemakers and a refractory time, is proposed. In the parametric space of the model the phase locking areas are investigated in detail. Obtained results allow us to predict the behaviour of excitable systems with two pacemakers depending on the type and intensity of their interaction and the initial phase. Comparison of the described phenomena with intrinsic pathologies of cardiac rhythms is presented. 
Alexander Loskutov, Sergei Rybalko and Ekaterina Zhuchkova