Combined optically coupled transmembrane potential and transmembrane current recording arrays

The spatial and temporal complexity of activation and repolarization sequences observed during ventricular arrhythmias such as ventricular fibrillation have hampered their mechanistic elucidation. We have recently developed a technique utilizing microscopically dimensioned extracellular recording electrode arrays for estimating the cardiac transmembrane current that crosses the myocardial membrane during cardiac activation. We have combined this extracellular electrogram recording array with an immediately adjacent fiber optically coupled transmembrane potential recording array. Using these arrays in isolated blood perfused dog hearts the kinetics of both activation and repolarization can, be recorded without the need for cell disruption.