High-Energy Pacing Inhibits Slow Wave Dysrhythmias in the Small Intestine

Abstract

The motility of the gastrointestinal tract is coordinated in part by rhythmic slow waves, and disrupted slow wave patterns are linked to functional motility disorders. At present, there are no treatment strategies that primarily target slow wave activity. This study assessed the use of pacing to suppress glucagon-induced slow wave dysrhythmias in the small intestine. Slow waves in the jejunum were mapped in vivo using a high-resolution surface-contact electrode array in pigs (n=7). Glucagon was intravenously administered to induce hyperglycemia. Slow wave propagation patterns were categorized into antegrade, retrograde, collision, pacemaker and uncoupled activity. Slow wave characteristics such as period, amplitude and speed were also quantified. Post-glucagon infusion, pacing was applied at 4 mA and 8 mA and the resulting slow waves were quantified spatiotemporally. Antegrade propagation was dominant throughout all stages with a prevalence of 55 ± 38% at baseline. However, glucagon infusion resulted in a substantial and significant increase in uncoupled slow waves from 10 ± 8% to 30 ± 12% (p=0.004) without significantly altering the prevalence of other slow wave patterns. Slow wave frequency, amplitude and speed remained unchanged. Pacing, particularly at 8 mA, significantly suppressed dysrhythmic slow wave patterns and achieved more effective spatial entrainment (85%) compared to 4 mA (46%, p=0.039).This study defined the effect of glucagon on jejunal slow waves and identified uncoupling as a key dysrhythmia signature. Pacing effectively entrained rhythmic activity and suppressed dysrhythmias, highlighting the potential of pacing for gastrointestinal disorders associated with slow wave abnormalities.