Numerical simulation of cardiac electrophysiology is very time consuming. Reduced order method have been recently used in different fields including cardiac electro- physiology. In this paper we use a reduced order method based on the proper orthogonal decomposition (POD), and we propose to evaluate the accuracy of this method while changing different parameters in the model. To describe the propagation of the action potential in the myocardium, we use the monodomain model which is a reaction diffusion PDE system coupled to a dynamic system of ODEs representing the time evolution of the electrophysiology in the cell membrane. We build the reduced order model using a set of parameters, afterwards, we evaluate the accuracy of the reduced model while changing the parameters of the model. We numerically analyze the sensitivity of the reduced order method to the model parameters including the change of the whole ionic model.