Cardiac Purkinje cells are responsible for transmitting electrical signals (action potentials) from the pacemaker cells, down the centre of the heart to the apex, and out to the ventricular endocardium, where they trigger the contraction of myocardial cells.
In recent years, research has been focused on determining how Purkinje cells function to fulfill their role, with many questions yet unanswered. Notably, a more complete understanding of the mechanisms of calcium regulation in Purkinje cells is required to understand, and possibly prevent, ventricular arrhythmias that are thought to originate in abnormal Ca2+ handling of Purkinje cells. A mathematical model consisting of a system of PDEs that describe calcium dynamics in Purkinje cells will be presented. This model includes: calcium release (from the sarcoplasmic reticulum (SR) - the main calcium storage organelle); calcium diffusion; calcium uptake (into the SR); calcium leak into the cytosol; as well as the interaction of calcium with various buffers (both mobile and stationary) within the cell. Numerical results show that the model is able to reproduce both spontaneous and evoked calcium events that have been observed experimentally.