Figure 3: In vivo epicardial recordings from canine atria showing bipolar EGMs using a multielectrode atria with varying electrode pairings as depicted by box on left image. Upper panels use horizontal pairing, middle panels utilise vertical pairing and lower panels use clique of 4 electrodes to generate omnipolar direction-independent EGM. Panel A shows EGMs during sinus rhythm with marked direction dependence as evident from difference in peak-to-peak voltage (Vpp) between horizontal and vertical electrode pairings. In contrast omnipolar Vpp is larger and more similar to the maximal measured voltage. Panel B shows similar measurements in AF averaged over 2.5 seconds with maximal Vpp using omnipolar EGMs higher than either horizontally or vertically paired electrodes. (Adapted with permission from (144)).