Steady-state solutions of cell volume in a cardiac myocyte model elaborated for membrane excitation, ion homeostasis and Ca2+ dynamics

► Cell volume change was described by general formulations with Ca2+ dynamics in modeling study. ► Explicit formulas of charge conservation and steady-state volume in cytosol and ER are derived. ► Volume changes in cardiac myocytes were simulated with release or uptake of Ca2+ across SR membrane. ► Influences of ionic currents on the steady-state volume were examined with bifurcation analysis.