Gastric Rhythm Research Articles

Data augmentation for generating synthetic electrogastrogram time series

To address an emerging need for large number of diverse datasets for rigor evaluation of signal processing techniques, we developed and evaluated a new method for generating synthetic electrogastrogram time series. We used electrogastrography (EGG) data from an open database to set model parameters and statistical tests to evaluate synthesized data. Additionally, we illustrated method customization for generating artificial EGG time series alterations caused by the simulator sickness. Proposed data augmentation method generates synthetic EGG data with specified duration, sampling frequency, recording state (postprandial or fasting state), overall noise and breathing artifact injection, and pauses in the gastric rhythm (arrhythmia occurrence) with statistically significant difference between postprandial and fasting states in > 70% cases while not accounting for individual differences. Features obtained from the synthetic EGG signal resembling simulator sickness occurrence displayed expected trends. The code for generation of synthetic EGG time series is not only freely available and can be further customized to assess signal processing algorithms but also may be used to increase data diversity for training artificial intelligence (AI) algorithms. The proposed approach is customized for EGG data synthesis but can be easily utilized for other biosignals with similar nature such as electroencephalogram.Graphical abstract

Children aged 5-13 years show adult-like disgust avoidance, but not proto-nausea.

Disgust is a vital emotion in the avoidance of illness. Human adults across cultures show disgust towards sources of potential contamination or pathogens, and elect to avoid their ingestion or even to look at them. Stomach rhythms appear to play an important role: disgust reduces normogastric power, and the pharmacological normalisation of gastric state reduces disgust avoidance. Human children are remarkably slow to develop disgust as measured by self-report and facial expressions. Here, we investigate whether disgust-induced avoidance (measured using eye tracking) and changes in gastric rhythm (measured using electrogastrography) exist in children aged 5 to 13 years (N = 45). We found that children in this bracket showed oculomotor avoidance of disgusting stimuli in a preferential-looking task, similar to adult samples in previous research. However, in contrast to adult samples in previous research, children did not show an attenuation in normogastric power. These findings could suggest that avoidance behaviour precedes gastric involvement during disgust. This would support the idea that children initially respond to parental modelling: parents set (and enforce) the social norm of disgust avoidance, and children initially conform and only later do they internalise disgust as an interoceptive signal. Alternatively, the employed stimuli could have been potent enough to induce oculomotor avoidance, but not a gastric response. Research is slim in this area, and future work should focus on elucidating the role of the stomach in disgust, and on longitudinal studies of disgust development from childhood to adolescence.

Interoceptive rhythms in the brain.

Sensing internal bodily signals, or interoception, is fundamental to maintain life. However, interoception should not be viewed as an isolated domain, as it interacts with exteroception, cognition and action to ensure the integrity of the organism. Focusing on cardiac, respiratory and gastric rhythms, we review evidence that interoception is anatomically and functionally intertwined with the processing of signals from the external environment. Interactions arise at all stages, from the peripheral transduction of interoceptive signals to sensory processing and cortical integration, in a network that extends beyond core interoceptive regions. Interoceptive rhythms contribute to functions ranging from perceptual detection up to sense of self, or conversely compete with external inputs. Renewed interest in interoception revives long-standing issues on how the brain integrates and coordinates information in distributed regions, by means of oscillatory synchrony, predictive coding or multisensory integration. Considering interoception and exteroception in the same framework paves the way for biological modes of information processing specific to living organisms.

The psychophysiology of guilt in healthy adults

Guilt is a negative emotion, elicited by realizing one has caused actual or perceived harm to another person. Anecdotally, guilt often is described as a visceral and physical experience. However, while the way that the body responds to and contributes to emotions is well known in basic emotions, little is known about the characteristics of guilt as generated by the autonomic nervous system. This study investigated the physiologic signature associated with guilt in adults with no history of psychological or autonomic disorder. Healthy adults completed a novel task, including an initial questionnaire about their habits and attitudes, followed by videos designed to elicit guilt, as well as the comparison emotions of amusement, disgust, sadness, pride, and neutral. During the video task, participants’ swallowing rate, electrodermal activity, heart rate, respiration rate, and gastric activity rate were continuously recorded. Guilt was associated with alterations in gastric rhythms, electrodermal activity, and swallowing rate relative to some or all the comparison emotions. These findings suggest that there is a mixed pattern of sympathetic and parasympathetic activation during the experience of guilt. These results highlight potential therapeutic targets for modulation of guilt in neurologic and psychiatric disorders with deficient or elevated levels of guilt, such as frontotemporal dementia, posttraumatic stress disorder, and Obsessive-compulsive disorder.

Endoscopic mucosal electrodes: New directions for recording and regulating gastric myoelectric activity.

With the gradual deepening of the study of gastric motility disorders, people increasingly realize that gastric myoelectric activity plays an important role in coordinating gastric function. This article introduces the advantages of endoscopic mucosal electrodes compared with traditional electrodes. Several different types of mucosal electrodes and how to fix the electrodes by endoscope are introduced. Endoscopic mucosal electrodes can record and regulate gastric myoelectric activity, which has great value in the study of gastric motility. Endoscopic mucosal electrode technique refers to the fixation of the electrode in the designated part of the gastric mucosa by endoscope. Through endoscopic mucosal electrodes, on the one hand, we can record gastric myoelectric activity, on the other hand, we can carry out gastric electrical stimulation to interfere with gastric rhythm. Endoscopic mucosal electrodes have higher accuracy than traditional cutaneous electrodes, less trauma and lower cost than serosal electrodes. Endoscopic mucosal electrodes have a good application prospect for diseases such as gastroparesis and obesity.

Defining and Phenotyping Gastric Abnormalities in Long-Term Type 1 Diabetes Using a Novel Body Surface Gastric Mapping Device

Diabetic gastroenteropathy is associated with poor glycemic control and morbidity in people with type 1 diabetes (T1D). There is a lack of noninvasive techniques to assess and monitor gastric abnormalities. We aimed to define phenotypes of gastric myoelectrical abnormalities in people with longstanding T1D with and without symptoms using a novel noninvasive body surface gastric mapping (BSGM) device. BSGM was performed on people with T1D of >10 years duration and matched controls, employing Gastric Alimetry (Alimetry, New Zealand), comprising of a high-resolution 64-channel array, validated symptom-logging App, and wearable reader. Thirty-two people with T1D were recruited (15 with a high symptom burden), and 32 controls. Those with symptoms showed more unstable gastric myoelectrical activity (Gastric Alimetry Rhythm Index 0.39 vs 0.51, P= .017; and lower average spatial covariance 0.48 vs 0.51, P= .009) compared with controls. Symptomatic patients also had a higher prevalence of peripheral neuropathy (67% vs 6%, P= .001), anxiety/depression diagnoses (27% vs 0%, P= .001), and higher mean hemoglobin A1C levels (76 vs 56 mmol/mol, P < .001). BSGM defined distinct phenotypes in T1D participants including those with markedly unstable gastric rhythms (4/32, 12.5%) and abnormally high gastric frequencies (9/32, 28%). Deviation in gastric frequency was positively correlated with symptoms of bloating, upper gut pain, nausea and vomiting, and fullness (R > 0.35, P < .05). Gastric symptoms in people with longstanding T1D correlate with myoelectrical abnormalities on BSGM evaluation, in addition to glycemic control, psychological comorbidities, and peripheral neuropathy. BSGM using Gastric Alimetry identified a range of myoelectrical phenotypes, presenting targets for diagnosis, monitoring, and therapy.

Frequency-specific electrogastrography as a non-invasive tool to measure gastrointestinal maturity in preterm infants

Enteral feeding is challenging in preterm infants because of gastrointestinal (GI) immaturity. Electrogastrography (EGG) is a non-invasive technology that measures gastric myoelectrical activity and can be utilized to measure changes that occur with maturation at different gestational ages (GA). Three gastric rhythms (GR) exist between 0.5–9 cycles per minute (cpm), namely, bradygastria (0.5 ≤ GR < 2 cpm), normogastria (2 ≤ GR < 4 cpm), and tachygastria (4 ≤ GR < 9 cpm). We aimed to characterize EGG-derived parameters for different GA by quantifying (1) power spectral density (PSD) and its spectral means at three GR bands (i.e., mPSDGR) and (2) the percent (%) time spent in each band. Data analyzed was from a longitudinal cohort of preterm infants (n = 51) born at early, mid, and term GA of < 29, 29–33, and ≥ 37 weeks, respectively. Weekly EGG monitoring was performed until 40 weeks’ postmenstrual age or discharge. Pre-, during, and post-feed data were analyzed for mPSDGR at each GR band. Also, % bradygastria, % normogastria, and % tachygastria were calculated by continuous wavelet transform analysis. Results showed (1) mPSD values in normogastria and tachygastria during feeding increased with advancing GA, and (2) % normogastria increased with advancing GA regardless of GR ranges, suggesting EGG may measure GI maturity in preterm infants.

The Sensory and Motor Components of the Cortical Hierarchy Are Coupled to the Rhythm of the Stomach during Rest

Bodily rhythms appear as novel scaffolding mechanisms orchestrating the spatiotemporal organization of spontaneous brain activity. Here, we follow-up on the discovery of the gastric resting-state network (Rebollo et al., 2018), composed of brain regions in which the fMRI signal is phase-synchronized to the slow (0.05 Hz) electrical rhythm of the stomach. Using a larger sample size (n = 63 human participants, both genders), we further characterize the anatomy and effect sizes of gastric-brain coupling across resting-state networks, a fine grained cortical parcellation, as well as along the main gradients of cortical organization. Most (67%) of the gastric network is included in the somato-motor-auditory (38%) and visual (29%) resting state networks (RSNs). Gastric brain coupling also occurs in the granular insula and, to a lesser extent, in the piriform cortex. Thus, all sensory and motor cortices corresponding to both exteroceptive and interoceptive modalities are coupled to the gastric rhythm during rest. Conversely, little gastric-brain coupling occurs in cognitive networks and transmodal regions. These results suggest not only that gastric rhythm and sensory-motor processes are likely to interact, but also that gastric-brain coupling might be a mechanism of sensory and motor integration that mostly bypasses cognition, complementing the classical hierarchical organization of the human brain.SIGNIFICANCE STATEMENT While there is growing interest for brain-body communication in general and brain-viscera communication in particular, little is known about how the brain interacts with the gastric rhythm, the slow electrical rhythm continuously produced in the stomach. Here, we show in human participants at rest that the gastric network, composed of brain regions synchronized with delays to the gastric rhythm, includes all motor and sensory (vision, audition, touch and interoception, olfaction) regions, but only few of the transmodal regions associated with higher-level cognition. Such results prompt for a reconsideration of the classical view of cortical organization, where the different sensory modalities are considered as relatively independent modules.

Influence of visual food cues on autonomic activity and craving

In this study, we tested the hypothesis that autonomic control of the stomach is related to craving and is modulated by visual food cues. Twenty-nine healthy human participants were shown pictures of either high- or low-appeal food, as well as non-food pictures, and were asked to rate how much they wanted to eat each item using a 7-point Likert scale. Simultaneously, the electrogastrogram, electrocardiogram, electrodermal activity, respiration rate, and pupil diameter were recorded. After the ingestion of a 500-kcal liquid meal, participants were asked to perform the task a second time. Despite changes in craving ratings, we did not find changes in the amplitude of the gastric rhythm, but we found increases in pupil diameter for the high appeal food pictures. Moreover, craving ratings were mostly related to increases in pupil and tonic electrodermal activity, compatible with an increase in arousal and a heightened motivational response to food.

Phase-locking of resting-state brain networks with the gastric basal electrical rhythm

A network of myenteric interstitial cells of Cajal in the corpus of the stomach serves as its “pacemaker”, continuously generating a ca 0.05 Hz electrical slow wave, which is transmitted to the brain chiefly by vagal afferents. A recent study combining resting-state functional MRI (rsfMRI) with concurrent surface electrogastrography (EGG), with cutaneous electrodes placed on the epigastrium, found 12 brain regions with activity that was significantly phase-locked with this gastric basal electrical rhythm. Therefore, we asked whether fluctuations in brain resting state networks (RSNs), estimated using a spatial independent component analysis (ICA) approach, might be synchronized with the stomach. In the present study, in order to determine whether any RSNs are phase-locked with the gastric rhythm, an individual participant underwent 22 scanning sessions; in each, two 15-minute runs of concurrent EGG and rsfMRI data were acquired. EGG data from three sessions had weak gastric signals and were excluded; the other 19 sessions yielded a total of 9.5 hours of data. The rsfMRI data were analyzed using group ICA; RSN time courses were estimated; for each run, the phase-locking value (PLV) was computed between each RSN and the gastric signal. To assess statistical significance, PLVs from all pairs of “mismatched” data (EGG and rsfMRI data acquired on different days) were used as surrogate data to generate a null distribution for each RSN. Of a total of 18 RSNs, three were found to be significantly phase-locked with the basal gastric rhythm, namely, a cerebellar network, a dorsal somatosensory-motor network, and a default mode network. Disruptions to the gut-brain axis, which sustains interoceptive feedback between the central nervous system and the viscera, are thought to be involved in various disorders; manifestation of the infra-slow rhythm of the stomach in brain rsfMRI data could be useful for studies in clinical populations.

A Causal Role for Gastric Rhythm in Human Disgust Avoidance

SummaryRotten food, maggots, bodily waste—all elicit disgust in humans. Disgust promotes survival by encouraging avoidance of disease vectors1 but is also implicated in prejudice toward minority groups; avoidance of environmentally beneficial foods, such as insect protein; and maladaptive avoidance behavior in neuropsychiatric conditions.2, 3, 4, 5 Unlike fear, pathological disgust is not improved substantially by exposure therapy clinically,6 nor in experimental work does behavioral avoidance of disgusting images habituate following prolonged exposure.7,8 Under normal physiological conditions, perception of disgusting stimuli disrupts myoelectrical rhythms in the stomach,9, 10, 11, 12, 13 inducing gastric dysrhythmias that correlate with neural signatures of disgust.11 However, the causal role of gastric rhythm in disgust avoidance is unknown. We manipulated gastric rhythm using domperidone, a peripheral dopamine D2/D3 antagonist and common anti-emetic, at a dose (10 mg) that acts to convert gastric dysrhythmias to normal rhythms.9 In a preregistered, randomized, double-blind, placebo-controlled crossover design in 25 healthy volunteers (aged 18–25), we measured the effects of domperidone on core disgust avoidance, using eye tracking to measure implicit (oculomotor) avoidance of disgusting images (feces) before and after an “exposure” intervention (monetary reinforcement for looking at disgusting images).7,8 We find that domperidone significantly reduces oculomotor disgust avoidance following incentivized exposure. This suggests that domperidone may weaken the “immunity” of disgust to habituation, putatively by reducing gastric dysrhythmias during incentivized engagement with disgusting stimuli. This indicates a causal role for disgust-related visceral changes in disgust avoidance, supporting the hypothesis that physiological homeostasis contributes to emotional experience.

Electrogastrography for psychophysiological research: Practical considerations, analysis pipeline, and normative data in a large sample.

Electrogastrography (EGG) is the noninvasive electrophysiological technique used to record gastric electrical activity by means of cutaneous electrodes placed on the abdomen. EGG has been so far mostly used in clinical studies in gastroenterology, but it represents an attractive method to study brain‐viscera interactions in psychophysiology. Compared to the literature on electrocardiography for instance, where practical recommendations and normative data are abundant, the literature on EGG in humans remains scarce. The aim of this article is threefold. First, we review the existing literature on the physiological basis of the EGG, pathways of brain‐stomach interactions, and experimental findings in the cognitive neuroscience and psychophysiology literature. We then describe practical issues faced when recording the EGG in young healthy participants, from data acquisition to data analysis, and propose a semi‐automated analysis pipeline together with associated MATLAB code. The analysis pipeline aims at identifying a regular rhythm that can be safely attributed to the stomach, through multiple steps. Finally, we apply these recording and analysis procedures in a large sample (N = 117) of healthy young adult male and female participants in a moderate (<5 hr) to prolonged (>10 hr) fasting state to establish the normative distribution of several EGG parameters. Our results are overall congruent with the clinical gastroenterology literature, but suggest using an electrode coverage extending to lower abdominal locations than current clinical guidelines. Our results indicate a marginal difference in EGG peak frequency between male and female participants, and that the gastric rhythm becomes more irregular after prolonged fasting.

Clinical efficacy of Huxiang-Yangwei powder combined with conventional western medicine on gastric motility and gastrointestinal hormones in patients with chronic atrophic gastritis

Objective To observe clinical effect of Huxiang-Yangwei powder combined with conventional western medicine on gastric motility and gastrointestinal hormones in patients with chronic atrophic gastritis. Methods A total of 100 patients with chronic atrophic gastritis according to the inclusion criteria were randomly divided into the observation group and the control group, with 50 cases in each group. The control group was given routine symptomatic treatment. Based on the treatment of control group, the observation group was given Huxiang-Yangwei powder therapy. After 1 month, the gastroscope score, pathological tissue score, gastric motility index (gastric motility rhythm, gastroelectric rhythm and gastric antrum motility), and the improvement of plasma gastrointestinal hormone (MTL, GAS, SS) were compared. Results The total effective rate of the observation group was 92.0% (42/50), and the total effective rate of the control group was 78.0% (39/50), with statistically significant (Z=-2.978, P=0.003). After treatment, the under gastroscope score (0.59 ± 0.06 vs. 1.23 ± 0.17, t=4.877) and the pathological organization score (0.65 ± 0.08 vs. 1.33 ± 0.19, t=5.096) of the observation group were significantly lower than those of the control group (P<0.05). After treatment, the gastric motility rhythm (76.15% ± 8.77% vs. 62.35% ± 7.31%, t=5.301), gastroelectric rhythm (81.02% ± 9.23% vs. 73.02% ± 8.43%, t=5.286), gastric antral motility (0.012 ± 0.002 Ω vs. 0.008 ± 0.001 Ω, t=4.160) of the observation group were significantly higher than those of the control group (P<0.05). After treatment, the plasma MTL (246.73 ± 31.82 pg/ml vs. 203.86 ± 27.91 pg/ml, t=5.832), GAS (49.55 ± 6.25 pg/ml vs. 35.81 ± 4.63 pg/ml, t=5.126), SS (17.35 ± 2.76 pg/ml vs. 15.01 ± 2.60 pg/ml, t=4.970) of the observation group were significantly higher than those of the control group (P<0.05). Conclusions The application of Huxiang-Yangwei powder in the treatment of chronic atrophic gastritis patients can repair gastric mucosa, regulate gastrointestinal hormone levels and increase gastric motility. Key words: Gastritis, atrophic; Huxiang-Yangwei powder; Gastric emptying; Prokinetic drugs (TCD); Motilin; Plastering therapy

Cellular switches orchestrate rhythmic circuits.

Small inhibitory neuronal circuits have long been identified as key neuronal motifs to generate and modulate the coexisting rhythms of various motor functions. Our paper highlights the role of a cellular switching mechanism to orchestrate such circuits. The cellular switch makes the circuits reconfigurable, robust, adaptable, and externally controllable. Without this cellular mechanism, the circuit rhythms entirely rely on specific tunings of the synaptic connectivity, which makes them rigid, fragile, and difficult to control externally. We illustrate those properties on the much studied architecture of a small network controlling both the pyloric and gastric rhythms of crabs. The cellular switch is provided by a slow negative conductance often neglected in mathematical modeling of central pattern generators. We propose that this conductance is simple to model and key to computational studies of rhythmic circuit neuromodulation.

Consequences of acute and long-term removal of neuromodulatory input on the episodic gastric rhythm of the crab Cancer borealis.

For decades, the episodic gastric rhythm of the crustacean stomatogastric nervous system (STNS) has served as an important model system for understanding the generation of rhythmic motor behaviors. Here we quantitatively describe many features of the gastric rhythm of the crab Cancer borealis under several conditions. First, we analyzed spontaneous gastric rhythms produced by freshly dissected preparations of the STNS, including the cycle frequency and phase relationships among gastric units. We find that phase is relatively conserved across frequency, similar to the pyloric rhythm. We also describe relationships between these two rhythms, including a significant gastric/pyloric frequency correlation. We then performed continuous, days-long extracellular recordings of gastric activity from preparations of the STNS in which neuromodulatory inputs to the stomatogastric ganglion were left intact and also from preparations in which these modulatory inputs were cut (decentralization). This allowed us to provide quantitative descriptions of variability and phase conservation within preparations across time. For intact preparations, gastric activity was more variable than pyloric activity but remained relatively stable across 4-6 days, and many significant correlations were found between phase and frequency within animals. Decentralized preparations displayed fewer episodes of gastric activity, with altered phase relationships, lower frequencies, and reduced coordination both among gastric units and between the gastric and pyloric rhythms. Together, these results provide insight into the role of neuromodulation in episodic pattern generation and the extent of animal-to-animal variability in features of spontaneously occurring gastric rhythms.

Gastric dysrhythmias: a potential objective measure of nausea

Nausea is a noxious, uncomfortable feeling usually located in the epigastrium. The pathophysiology of nausea encompasses brain-gut and gut-brain interaction. Nausea is associated with myoelectrical dysrhythmias of the stomach, an objective marker in the periphery. The aims of this review were to describe (1) the physiology of normal 3cycle per minute (cpm) gastric myoelectrical activity and (2) conditions where shifts from normal 3cpm gastric rhythms to gastric dysrhythmias are associated with the onset of nausea. Illusory self-motion, infusion of drugs such as morphine and glucagon, and ingestion of water or nutrient loads are several of the multitude of stimuli that induce acute nausea and a variety of gastric dysrhythmias such as tachygastrias (3.75-10cpm) and bradygastrias (1.0-2.5cpm). In nausea of motion sickness, increased nausea severity correlates with increased plasma vasopressin and epinephrine levels. Gastric dysrhythmias are also present in chronic gastrointestinal neuromuscular disorders such as gastroparesis. When gastric dysrhythmias resolve after drug or device therapies, nausea resolves. The shift in state from comfort in the epigastrium area and normal 3cpm gastric rhythm to symptoms of nausea and gastric dysrhythmias represents dynamic gut-brain and brain-gut interactions that can be tracked by changes in gastric rhythm. (1) gastric dysrhythmias represent at least one peripheral mechanism underlying the symptom of nausea, and (2) gastric dysrhythmias are an objective biomarker for nausea and potential therapeutic targets for anti-nauseant therapies.

Effect of electroacupuncture at Zusanli on gastric electric rhythm in functional dyspepsia rats

Effect of electroacupuncture at Zusanli on gastric electric rhythm in functional dyspepsia rats

Diet induced obesity disrupts gastric vagal afferent circadian rhythm

Diet induced obesity disrupts gastric vagal afferent circadian rhythm

Abnormal gastric myoelectrical activity in postural tachycardia syndrome

Postural tachycardia syndrome (PoTS) is an important cause of orthostatic intolerance resulting from cardiovascular autonomic dysfunction. In addition to postural symptoms, PoTS patients may have allied features, including gastrointestinal (GI) symptoms, which have not yet been thoroughly investigated. We evaluated gastric myoelectrical activity in PoTS patients. Using cutaneous electrogastrography (EGG), we recorded gastric myoelectrical activity before and after standard liquid meal ingestion in 15 PoTS patients (age 27 ± 4 years); including 7 with and 8 without GI symptoms, and in 11 healthy individuals (age 23 ± 7 years). We performed spectral analysis of EGG recordings to obtain the dominant frequency of gastric pacemaker rhythm (DF), instability coefficient of DF (ICDF), and low (LFR%), normal (NFR%), and high (HFR%) range power percentages of the total power. Instability coefficient of DF, an index of variability of gastric pacemaker rhythm, was significantly elevated both pre- and post-prandially (30-45 min after the meal) in the PoTS group (8.8 ± 6, 10.0 ± 8 %) compared with controls (4.0 ± 3, 4.0 ± 3 %; both p < 0.05). Patients with GI symptoms had significantly higher post-prandial ICDF (15.0 ± 5 %) than those without GI symptoms (5.6 ± 4 %; p < 0.05). There were no significant differences in DF, LFR%, NFR% and HFR% before and after the meal between the PoTS and control groups, or between PoTS patients with and without GI symptoms. Our study revealed increased variability of gastric pacemaker rhythm in PoTS, and these findings might be related to pathophysiology of functional GI symptoms in PoTS.

The study on gastric electrical activity and gastric emptying in patients with primary pathological duodenogastric reflux

Objective To explore the etiological factors of primary pathological duodenogastric reflux (DGR) through investigating the relationship between severity of bile refulx,the changes of surface gastric electric rhythm and gastric emptying movement in primary pathological DGR patients.Methods From January 2007 to April 2008 in Qingdao Municipal Hospital,58 cases of outpatients diagnosed as primary pathological DGR and 21 healthy individuals (control group) were collected and underwent 24-hour gastric bilirubin monitoring,gastric endoscopy,gastric electric rhythm,and gastric emptying test.The relationship between gastric electric parameters and gastric emptying,bilirubin reflux,Hp infection was analyzed.Results 1.The main frequency in fasting and postprandial of primary pathological DGR patients [(1.94±0.04) cpm vs (2.93±0.07) cpm; (2.12±0.03) cpm vs (3.35 ±0.05) cpm],the percentage of normal gastric slow wave in fasting and postprandial (74.46± 0.56 vs 85.55 ± 1.06 ; 63.97 ± 0.64 vs 86.13 ± 1.49),and fasting/postprandial power ratio (PR) (1.68±0.02 vs 2.75±0.09) were all lower than those of control group (P＜0.05).The percentage of bradygastria in fasting and postprandial of DGR patients (18.04±0.36 vs 7.76±0.78;23.73±0.91 vs 8.47±0.55),the percentage of tachygastria in fasting and postprandial (8.93±0.26 vs 5.75±0.66;13.02±0.40 vs 7.66±0.27) were higher than that of control group (P＜0.05).2.The main frequency of severe reflux patients in fasting and postprandial [( 1.68 ± 0.07) cpm vs (2.13 ± 0.07)cpm; (2.18±0.09) cpm vs (2.76±0.06) cpm],the percentage of normal gastric slow wave in fasting and postprandial (69.71±0.43 vs 80.35±0.68; 56.36 ±0.85 vs 72.34±0.80),fasting /postprandial PR (1.47±0.04 vs 2.02±0.04) were lower than those of mild-reflux group (P＜0.05).The percentage of bradygastria in fasting and postprandial of severe reflux patients (22.94 ± 0.68 vs 13.47 ± 0.61; 29.61 ± 1.14 vs 17.55 ± 0.51) and the percentage of tachygastria in fasting and postprandial (9.94 ± 0.54 vs 7.02 ± 0.42 ; 17.04 ± 0.70 vs 10.71 ± 0.20) were higher than that of mild-reflux group (P＜0.05).3.There was no significant difference of gastric electrical parameters in fasting and postprandial between Hp-positive and Hp-negative groups (P＞0.05).4.The ratio of gastric emptying in DGR group was significantly lower than that of control group (37.9％ vs 90.5 ％,P＜0.05).The gastric emptying delay in DGR group significantly increased compared with control group (60.3％ vs 9.5％,P＜0.05).There was no significant difference in gastric emptying delay between severe-reflux group and light-reflux group (69.0％ vs 51.7％,P ＞ 0.05).Conclusions There is dysfuntion of gastric myoelectrical activity and gastric motility in primary pathological DGR patients,which may be an important mechanism in pathological DGR. Key words: Duodenogastric reflux; Electrogastrography; Gastric emptying