Arrhythmias in the gut

Abstract

In recent years, it has become possible to record, from a large number of extracellular electrodes, the electrical activities of smooth muscle organs. These recordings, after proper processing and analysis, may reveal origin and propagation of normal and abnormal electrical activities in these organs. Several publications have appeared in the past 5 years describing origin and propagation of slow waves in the stomach of experimental animals and in humans. Furthermore, publications are now starting to appear that describe pathophysiological patterns of propagation and these studies provide us with novel concepts regarding potential mechanisms of arrhythmias in the gut, crucial information if we are ever going to successfully treat patients suffering from such arrhythmias. In this issue of Neurogastroenterology & Motility, Angeli et al. have mapped the slow wave propagation in the porcine small intestine and discovered two types of reentry; functional reentry and circumferential reentry. Next to the descriptions of arrhythmias in the stomach, the fact that reentrant arrhythmias may also occur in the small intestine further extends this new emerging field of gastrointestinal (GI) arrhythmias. In this viewpoint, the relevance of these arrhythmias is further discussed and a few ideas for future research in this field, not necessarily constrained to the GI system, proposed.

Loss of Interstitial Cells of Cajal and Patterns of Gastric Dysrhythmia in Patients With Chronic Unexplained Nausea and Vomiting

“…Originally described by Lammers et al in 2008 in a canine model, 37 and subsequently in several other invitro and in-vivo animal models, 34,35,38 re-entry is now a focus of considerable recent interest as a mechanism of sustained gastrointestinal dysrhythmias. 39 Based on our findings, re-entry is a relatively uncommon dysrhythmia in the human stomach, likely because there is a narrow excitable gap, or window, in which an aberrant stimulus can successfully invoke a re-entry, based on the relative timing of the leading depolarizing edge and refractory tail. 34,35,39 Re-entry is also an important finding because it is a potentially treatable form of dysrhythmia, for example, by gastric pacing guided by mapping, 40 as is routinely achieved in cardiology.…”

“…39 Based on our findings, re-entry is a relatively uncommon dysrhythmia in the human stomach, likely because there is a narrow excitable gap, or window, in which an aberrant stimulus can successfully invoke a re-entry, based on the relative timing of the leading depolarizing edge and refractory tail. 34,35,39 Re-entry is also an important finding because it is a potentially treatable form of dysrhythmia, for example, by gastric pacing guided by mapping, 40 as is routinely achieved in cardiology.…”

Gastric Arrhythmias in Gastroparesis

“…43 These techniques are well established in the clinical management of modern cardiac arrhythmias, and are now showing similar potential in the GI field. 44 …”

“…44 A surprising complexity to gastric arrhythmias is being revealed, necessitating new terms and classification schemes adapted from cardiology, including focal events and re-entry as mechanisms of tachygastria, and conduction block and retrograde escape rhythms as mechanism of bradygastria. 19,46 It has also been possible to assess the dynamic evolution of arrhythmic patterns through time, including defining wavefront interactions and collisions.…”

Visco-hyperelasticity of Electro-active Soft Tissues

“…Slow waves are fundamental to regulate GI contractility. The anatomical entities responsible for the slow wave generation and propagation are the so called interstitial cells of Cajal (ICC) 23 . ICC are specialized smooth muscle cells, organized in a homogeneous network within the intestine wall, between the longitudinal and circumferential muscularis.…”