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Am J Physiol Gastrointest Liver Physiol. 2016 Nov 1;311(5):G895-G902. doi: 10.1152/ajpgi.00255.2016. Epub 2016 Sep 22.

Functional physiology of the human terminal antrum defined by high-resolution electrical mapping and computational modeling.

Author information

1
Auckland Bioengineering Institute, University of Auckland, Aukland, New Zealand.
2
Department of Biomedical Engineering, Tohoku University, Sendai, Japan.
3
Department of Surgery, University of Auckland, Auckland, New Zealand.
4
School of Engineering, Tohoku University, Sendai, Japan; and.
5
Auckland Bioengineering Institute, University of Auckland, Aukland, New Zealand; l.cheng@auckland.ac.nz.
6
Department of Surgery, Vanderbilt University, Nashville, Tennessee.

Abstract

High-resolution (HR) mapping has been used to study gastric slow-wave activation; however, the specific characteristics of antral electrophysiology remain poorly defined. This study applied HR mapping and computational modeling to define functional human antral physiology. HR mapping was performed in 10 subjects using flexible electrode arrays (128-192 electrodes; 16-24 cm2) arranged from the pylorus to mid-corpus. Anatomical registration was by photographs and anatomical landmarks. Slow-wave parameters were computed, and resultant data were incorporated into a computational fluid dynamics (CFD) model of gastric flow to calculate impact on gastric mixing. In all subjects, extracellular mapping demonstrated normal aboral slow-wave propagation and a region of increased amplitude and velocity in the prepyloric antrum. On average, the high-velocity region commenced 28 mm proximal to the pylorus, and activation ceased 6 mm from the pylorus. Within this region, velocity increased 0.2 mm/s per mm of tissue, from the mean 3.3 ± 0.1 mm/s to 7.5 ± 0.6 mm/s (P < 0.001), and extracellular amplitude increased from 1.5 ± 0.1 mV to 2.5 ± 0.1 mV (P < 0.001). CFD modeling using representative parameters quantified a marked increase in antral recirculation, resulting in an enhanced gastric mixing, due to the accelerating terminal antral contraction. The extent of gastric mixing increased almost linearly with the maximal velocity of the contraction. In conclusion, the human terminal antral contraction is controlled by a short region of rapid high-amplitude slow-wave activity. Distal antral wave acceleration plays a major role in antral flow and mixing, increasing particle strain and trituration.

KEYWORDS:

computational fluid dynamics; electrophysiology; interstitial cell of Cajal; slow wave; stomach

PMID:
27659422
PMCID:
PMC5130547
DOI:
10.1152/ajpgi.00255.2016
[Indexed for MEDLINE]
Free PMC Article

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