An inexpensive alternative bath system for electrophysiological characterization of isolated cardiac tissue

Abstract

A tissue bath system, to be used as an alternative to complex perfusion chambers, was constructed for use in cardiac electrophysiological studies. This system consists of an acrylic chamber to hold circulating physiological medium such as DMEM, suspended in a water bath warmed by a hot plate. Temperature and pH were controlled to mimic physiological conditions. Rat and porcine cardiac tissues, were used to test viability of the conditions presented in the bath system. Using a cardiac mapping system, the tissues were stimulated and responses recorded. From the recordings we were able to calculate conduction velocities and spatial dispersion of activation indices. The results are comparable to previous in-vivo work, which suggests that the tissue bath system design can maintain tissue viability. This tissue bath system is a relatively simple alternative for ex-vivo testing of cardiac tissues.

Fig. 1

Cross sectional view of the constructed bath system for electrophysiological characterization.

Fig 2

Activation time contour maps after pacing (ms) and conduction velocity vector fields for rat (a) and (b), and porcine (c) and (d) samples, respectively. Conduction velocity vector length is proportional to conduction velocity magnitude. Stimulation was delivered from the bottom edge of each map which corresponds to the base of the heart. The 14x14 electrode array is 8x8 mm.