A multichannel monophasic action potential electrode array for simultaneous epicardial and endocardial repolarization mapping

The authors developed an electrode array capable of recording four pairs of opposing epicardial and endocardial monophasic action potentials (MAPs) in the in vivo heart. The array was tested on three anesthetized, open chested pigs. The authors recorded simultaneous, dual surface MAPs from all eight sites in the right and left atria and in both ventricles. Atrial recordings exhibited triangular MAP morphologies, amplitudes ranging from 5 to 10 mV, smooth repolarization phases and stable baselines for up to 90 minutes. Ventricular recordings exhibited MAP waveforms with well defined plateau phases, amplitudes ranging from 15 to 40 mV smooth repolarization and stable baselines. These characteristics were comparable on both the epicardial and endocardial recordings. This multichannel electrode array was capable of recording stable, long-term simultaneous mirror image epicardial and endocardial MAPs that will facilitate the study of atrial and ventricular repolarization