Extracellular potential measurements of cultured fetal rat cardiomyocytes

Hospital researchers have been developing methodologies for isolating and culturing cardiomyocytes from the ventricular myocardium. One intention is to use these cells as a base to grow replacement cardiac tissue for patients with scarred, non-conductive cardiac tissue. In addition, an in vivo model for studying cardiac tissues was also desired. Researchers were seeking a system to non-invasively monitor the electrical activity of these cardiac cells in the laboratory under normal and drug-influenced conditions. In this work, electrograms were acquired from the electrical activity generated by spontaneously contracting fetal rat cardiac cells cultured in a Petri dish. Electrograms were acquired with probes in contact with or less than 200 microns above the surface of the cells. Unipolar electrograms of Signals up to 120 /spl mu/V peak-to-peak were measured. Different waveform and contraction rates from 5 to 136 beats/min. were measured. The variety and complexity of the waveforms observed are considered to be due to the degree of heterogeneity of intercellular coupling of the underlying tissue. Temperature and drug effects on cardiac cell activity were also monitored.