High-resolution entrainment mapping of gastric pacing: A new analytical tool

Gregory O'Grady, Peng Du, Wim J.E.P. Lammers, John U. Egbuji, Pulasthi Mithraratne, Jiande D.Z. Chen, Leo K. Cheng, John A. Windsor, Andrew J. Pullan

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65 Citations (Scopus)


Gastric pacing has been investigated as a potential treatment for gastroparesis. New pacing protocols are required to improve symptom and motility outcomes; however, research progress has been constrained by a limited understanding of the effects of electrical stimulation on slow-wave activity. This study introduces high-resolution (HR) "entrainment mapping" for the analysis of gastric pacing and presents four demonstrations. Gastric pacing was initiated in a porcine model (typical amplitude 4 mA, pulse width 400 ms, period 17 s). Entrainment mapping was performed using flexible multielectrode arrays (≤192 electrodes; 92 cm2) and was analyzed using novel software methods. In the first demonstration, entrainment onset was quantified over successive waves in spatio-temporal detail. In the second demonstration, slow-wave velocity was accurately determined with HR field analysis, and paced propagation was found to be anisotropic (longitudinal 2.6 ± 1.7 vs. circumferential 4.5 ± 0.6 mm/s; P < 0.001). In the third demonstration, a dysrhythmic episode that occurred during pacing was mapped in HR, revealing an ectopic slow-wave focus and uncoupled propagations. In the fourth demonstration, differences were observed between paced and native slow-wave amplitudes (0.24 ± 0.08 vs. 0.38 ± 0.14 mV; P < 0.001), velocities (6.2 ± 2.8 vs. 11.5 ± 4.7 mm/s; P < 0.001), and activated areas (20.6 ± 1.9 vs. 32.8 ± 2.6 cm2; P < 0.001). Entrainment mapping enables an accurate quantification of the effects of gastric pacing on slow-wave activity, offering an improved method to assess whether pacing protocols are likely to achieve physiologically and clinically useful outcomes.

Original languageEnglish
Pages (from-to)G314-G321
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Issue number2
Publication statusPublished - Feb 2010
Externally publishedYes


  • Electrophysiology
  • Gastric electrical stimulation
  • Gastrointestinal
  • Slow wave

ASJC Scopus subject areas

  • Physiology
  • Hepatology
  • Gastroenterology
  • Physiology (medical)


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