Impedance analysis applicable to cardiac muscle and smooth muscle bundles

An electrical equivalent circuit was constructed to represent a chain of five myocardial cells in a cardiac muscle bundle with various degrees of cell-to-cell coupling, and an impedance analysis was performed. The impedance across the entire network was measured at frequencies ranging from 10 ¹ to 10 ⁶ Hz. The total tissue resistivity (R _t) increased as a function R ₀. Thus, in low coupling cases, almost all of the applied current passes through the interstitial space; e.g., at 1 tunnel (10 Hz), 1.0% of the current passes through the cell pathway (R _cell). It is concluded that it is difficult to determine the degree of cell coupling from such impedance analysis, unless the same tissue can be used for its own control, i.e., before and after a large change in cell coupling is introduced.