Biochaos in cardiac rhythms

Biological rhythm is an essential characteristic of natural systems that can present regular or irregular dynamics, which can be associated with normal or pathological functioning. In this regard, nonlinear dynamics perspective is able to connect biorhythm with functioning characteristics. This paper investigates the heart dynamics by considering a mathematical model that is built from three coupled nonlinear oscillators. The main strategy is to investigate natural pacemaker behavior, establishing its influence on the electrical activity of the heart represented by electrocardiograms (ECGs). Different kinds of pacemaker behaviors are treated, dedicating special attention to chaotic rhythms.