Optimization of pacing parameters to entrain slow wave activity in the pig jejunum.

Abstract

Pacing has been proposed as a therapy to restore function in motility disorders associated with electrical dysrhythmias. The spatial response of bioelectrical activity in the small intestine to pacing is poorly understood due to a lack of high-resolution investigations. This study systematically varied pacing parameters to determine the optimal settings for the spatial entrainment of slowwave activity in the jejunum. An electrode array was developed to allow simultaneous pacing and high-resolution mapping of the small intestine. Pacing parameters including pulse-width (50, 100ms), pulse-amplitude (2, 4, 8mA) and pacing electrode orientation (antegrade, retrograde, circumferential) were systematically varied and applied to the jejunum (n = 15 pigs). Pulse-amplitudes of 4mA (p = 0.012) and 8mA (p = 0.002) were more effective than 2mA in achieving spatial entrainment while pulse-widths of 50ms and 100ms had comparable effects (p = 0.125). A pulse-width of 100ms and a pulse-amplitude of 4mA were determined to be most effective for slowwave entrainment when paced in the antegrade or circumferential direction with a success rate of greater than 75%. These settings can be applied in chronic studies to evaluate the long-term efficacy of pacing, a critical aspect in determining its therapeutic potential.