Temporary unipolar pacing using a dual cathode

Using standard biopolar, temporary pacing catheters, thresholds were measured in four configurations: (1) bipolar (distal electrode negative, proximal electrode positive); (2) distal unipolar (distal electrode negative, right arm electrode positive); (3) proximal unipolar (proximal electrode negative, right arm electrode positive); (4) dual-cathode unipolar (distal and proximal electrodes negative, right arm electrode positive). With one exception, the bipolar threshold was the lower of the distal or proximal unipolar thresholds, suggesting that bipolar temporary pacing is reliable because one of the two electrodes is in good contact with the endocardium. In both the distal and proximal unipolar configurations there were numerous instances of high threshold and failure to pace. However, with one exception, in all cases either the distal or proximal unipolar threshold was normal and thus pacing was possible and effective in the dual-cathode configuration. Dual-cathode unipolar pacing combines the excitation and sensing advantages of unipolar pacing with the reliability of bipolar stimulation.