Abstract
We investigated the possibility of single lead DDD sensing/pacing on the basis of the results using an original double balloon bipolar lead having variable dipole spacing. In the present study, on the selective detection of atrial p-waves, it was shown that the best results came from the narrow dipole spacing, small electrode surface area, and the electrode positioning at the high right atrium. In terms of atrial stimulation, it was shown that for floating electrodes a smaller electrode surface area yielded a lower stimulation threshold and the optimal dipole spacing was dependent on the distance between the atrial wall and the stimulating electrodes. However, in all cases the stimulation threshold of the floating electrodes was higher than that of conventional non-floating electrodes. Additionally, the optimal stimulation point in the right atrium could not be determined. Based on these results, we concluded that an adequate stimulation threshold could not be obtained with the floating atrial electrodes. Further studies, including biphasic stimulation, will be necessary to realize the single lead DDD.
