Heart on a chip - Extracellular multielectrode recordings from cardiac myocytes in vitro

Abstract

Analyses of cardiac electrical potentials in vivo, such as in the electrocardiogram, are well known to reveal information about system properties of the heart, arrhythmia, indications of conduction failures etc., as has been described in Section I of this book. While such recordings are absolutely indispensable, the spatial resolution and the opportunities for manipulation with this approach are limited. In vitro investigations of isolated organs (see Section II), e.g. Purkinje fibers, papillary muscle, the Langendorff heart or patches of cardiac muscle (Yamamoto et al. 1998), have long been used to study the mechanisms of the generation and propagation of cardiac potentials at higher spatial resolution with either intra- or extra-cellular recording, or optical recording (Hirota et al. 1987). Cultures of cardiac myocytes, e.g. harvested after enzymatic digestion from cardiac tissue, on the other hand, offer the possibility of single cell or aggregate analyses, e.g. for developmental (Banach et al. 2003), pharmacological and biophysical studies (see also Section 5). Although these cultures do not maintain the structure of cardiac tissue, the functional properties of action potential generation and propagation, contractility and, depending to some extent on the culture system, the ion channel composition of the original cells are conserved or reestablished. The ease of production and the simple structure of these cell and tissue culture systems thus allow the researcher to address questions not easily accessible in organs or animal preparations. The motion of the cells in most of these preparations, however, hinders studies with conventional electrodes, in particular intracellular or patch-clamp recording, and in optical recordings with voltage sensitive dyes. © Springer-Verlag Berlin Heidelberg 2005.