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

The application of the monophasic action potential (MAP) contact electrode technique to repolarization mapping is limited by the number of simultaneous recording sites. The authors have developed an electrode array which records epicardial MAPs from up to 16 sites. The array consists of a square 4×4 matrix of Ag/AgCl active elements spaced 5 mm apart. Four reference electrodes are used-one for each quadrant along with a single saline sponge. MAP recordings were obtained from five anesthetized open-chest pigs. Simultaneous diagnostic quality MAPs were obtained from up to 13 out of 16 ventricular sites. The ratio of MAPd90 and VERP was consistent in all but one recording. In conclusion, simultaneous multichannel mapping of diagnostic-quality MAPs can be achieved. Maintaining proper electrode pressure and contact is difficult yet essential