Universal bifurcations and the classification of cardiac arrhythmias.

An appreciation of the extraordinarily rich dynamics of cardiac arrhythmias can be obtained from examination of any text in electrocardiography. Typically, there are a large number (100 or more) of rhythms that are identified on the basis of changes outside of normal limits of rhythm and wave morphology in the electrocardiogram.’*’ The point of this paper is to show that mathematics can provide a framework for studying several cardiac arrhythmias. It is possible to theoretically predict dynamics in some biological models and clinical situations using appropriate mathematical models. The main theoretical technique used is to represent cardiac systems by a finitedifference equation of the form,