Gastric Electrical Rhythm Research Articles

Analysis of gastric electrical rhythm in patients with type 2 diabetes mellitus

AimTo analysis the change of electrogastrogram (EGG) in patients with type 2 diabetes mellitus (T2DM), and evaluate the prevalence of abnormal gastric electrical rhythm (AGER) and its relative influencing factors.MethodsA total of 65 patients with T2DM hospitalized at the Second Affiliated Hospital of Soochow University from Dec. 2020 to Dec. 2021 were included in the cross-sectional study. General information, clinical data, and medical history data of all study subjects, including name, gender, body mass index (BMI), duration of diabetes, anti-diabetic therapies, high blood pressure (HBP) history, smoking history, and medication history, were completely collected. The results of laboratory tests, including biochemical parameters, glycosylated hemoglobin (HbA1c), fasting C-peptide, 2 h postprandial C-peptide, 24 h urine total protein (24 hUTP), urine microalbumin creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) were recorded. EGG, Gastroparesis Cardinal Symptom Index (GCSI), gastric emptying ultrasound, fundus examination, carotid artery ultrasonography, cardiac autonomic function test, heart rate variability (HRV) were all examined and recorded as well. According to the results of EGG, the subjects were divided into normal gastric electrical rhythm (NGER) group and abnormal gastric electrical rhythm (AGER) group.Results(1) Fasting blood glucose (FBG), HbA1c, the presence of diabetic peripheral neuropathy (DPN) and diabetic cardiac autonomic neuropathy (DCAN) were significantly higher in the AGER group (p < 0.05). Low frequency (LF) and high frequency (HF), the indicators of HRV, were significantly lower in the AGER group (p < 0.05). In addition, the prevalence of feeling excessively full after meals, loss of appetite, and stomach or belly visibly larger after meals of gastrointestinal symptoms of gastroparesis were significantly higher in the AGER group (p < 0.05). Multiple logistic regression analysis showed that FBG and the prevalence of DCAN were the independent risk factors.ConclusionAGER was associated with high FBG and the presence of DCAN. EGG examination is recommended for patients with gastrointestinal symptoms and clues of DCAN.

Clinical Efficacy and Mechanism of Transcutaneous Neuromodulation on Functional Dyspepsia.

Prokinetics and proton pump inhibitors are first-line drugs for functional dyspepsia (FD) patients. However, no available treatment is effective for most FD patients, and the pathogenesis is still unclear. The purpose of this study was to investigate the therapeutic effect of transcutaneous neuromodulation (TN) on FD and its potential mechanisms. Fifty-seven FD patients were enrolled in the study and randomly divided into 3 groups (TN Neiguan (PC6) group, TN Zusanli (ST36) group, and sham TN group) that received corresponding treatment respectively for 4 weeks. Then, all the patients enrolled received TN PC6 combined with ST36 treatment for another 4 weeks. Dyspepsia symptom questionnaire, Medical outcomes study item short form health survey (SF-36), Hospital Anxiety and Depression Scale were used to assess the severity of symptoms. Gastric accommodation, gastric emptying rate, and related parameters of electrogastrogram were used to assess the pathophysiological mechanism of FD. The possible gastrointestinal hormonal mechanism involved was assessed by detecting serum ghrelin, neuropeptide Y, and vasoactive intestinal peptide. The possible duodenal inflammation mechanism involved was assessed by detecting duodenal mucosa. TN treatment reduced the dyspepsia symptom score ( P <0.05) and improved the quality of life. After TN treatment, the gastric accommodation ( P <0.01), the gastric emptying rate ( P <0.01), and the percentages of preprandial ( P <0.05) and postprandial ( P <0.05) gastric slow waves (GSW) were increased. The proportions of preprandial ( P <0.05) and postprandial ( P <0.05) gastric electrical rhythm disorder were reduced. The double acupoint combination therapy further enhanced the therapeutic effect of single acupoint. In addition, the levels of ghrelin ( P <0.001) and neuropeptide Y ( P <0.001) were significantly increased, the level of vasoactive intestinal peptide ( P <0.001) was significantly decreased, and the total number of mast cells ( P <0.001) in the duodenal bulb was significantly decreased after double acupoints combination therapy. TN treatment significantly improves the dyspepsia symptoms of FD patients and their quality of life. TN treatment increases the percentage of normal GSW, reduces the proportion of gastric electrical rhythm disorder, and improves the gastric accommodation and gastric emptying rate. The therapeutic effect of TN may be caused by regulating gastrointestinal hormone secretion and alleviating local inflammatory responses in duodenum. In addition, the improvement of TN on GSW was closely related to the decrease of bradygastria.

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.

Effects of Zuojin pill on depressive behavior and gastrointestinal function in rats with chronic unpredictable mild stress: Role of the brain–gut axis

Ethnopharmacological relevanceZoujin pill (ZJP), a medication used to treat gastrointestinal disorders since the 15th Century in China, have been reported to exert anti-depressant effects in various models. Study aimTo assess the effects of ZJP on gastrointestinal function and depressive behavior in rats under chronic unpredictable mild stress (CUMS), and to examine the underlying mechanisms related to brain–gut axis. MethodsThe rats suffered the stressor once daily for 5 weeks. ZJP (0.6 and 1.2 g/kg) and fluoxetine (15 mg/kg) as positive control were administered to the rats through gastric intubation once daily for 5 consecutive weeks. The anti-depression effects were compared by performing sucrose preference tests and open field tests. Gastrointestinal motility was investigated by determining the gastrointestinal transit rate and by electrogastrogram. The serum levels of the gastrointestinal hormone (GAS, MOT, VIP, SP), inflammatory cytokine (IL-1β, IL-6; , TNFα) and glucagon-like peptide-1 (GLP-1) were assayed by enzyme-linked immunosorbent assay. For monoamine neurotransmitters (NE, 5-HT, DA), the levels were determined by high-performance liquid chromatography and electrochemical detection in conjunction, which was applied on the samples taken from the hypothalamus, hippocampus, and striatum. ResultsThe depression-like symptoms among rats under CUMS were significantly relieved by ZJP administration (0.6 and 1.2 g/kg). Gastrointestinal motility was also improved by restoring gastric electrical rhythm and promoting gastrointestinal propulsion. The ZJP at 0.6 g/kg dosage obviously up-regulated 5-HT and DA levels in hippocampus. The ZJP at 1.2 g/kg dosage could increase 5-HT and DA levels in hypothalamus, striatum, and hippocampus, while down-regulated the NE level in hypothalamus and hippocampus. ZJP also reversed the alterations in serum gastrointestinal hormones. Furthermore, treatment with ZJP significantly reduced levels of IL-1β, IL-6 and TNF-α and increased serum GLP-1 compared with the CUMS group. Fluoxetine also exerted similar anti-depressant effects in the absence of effects on gastrointestinal motility and the levels of serum hormone, inflammatory cytokine and GLP-1. ConclusionZJP imposed anti-depressant and gastrointestinal regulating functions in rats under CUMS, suggesting potential clinical application. .

Evaluation of gastric motility through surface electrogastrography in critically ill septic patients. Comparison of metoclopramide and domperidone effects: A pilot randomized clinical trial

Introduction and aimsCritically ill patients present with a broad spectrum of gastrointestinal motility disorders that affect the digestive tract. Our aim was to compare the effect of two prokinetic drugs on gastric electrical rhythm in critically ill septic patients, measured through surface electrogastrography (EGG). Material and methodsA prospective triple-blinded randomized study was conducted on 36 patients admitted to the intensive care unit (ICU) with the diagnosis of septic shock. They were randomized to receive metoclopramide or domperidone. We assessed dominant frequency (DF), percentage distribution over time, and dominant power (DP), which represents the strength of contraction, before and after administration of the study drugs. ResultsReliable electrogastrograms were achieved in all patients. In relation to the distribution of DF over time, 64% of patients had dysrhythmia, the mean baseline DF was 2.9 cpm, and the mean DP was 56.5μv After drug administration, 58% of the patients had dysrhythmia, the mean DF increased to 5.7 cpm (P<.05), and the DP did not change (57.4μv2). There were no significant differences between drugs. In the metoclopramide group, the baseline DF was 2.1 cpm and the baseline DP was 26.1μv2. The post-drug values increased to 5.4 cpm and 34.1μv2, respectively. In the domperidone group, the baseline DF was 3.7 cpm and the baseline DP was 86.9μv2. After drug administration, the DF increased to 6.1 cpm and the DP decreased to 83.5μv2. ConclusionsBoth metoclopramide and domperidone similarly increased the DF of gastric pacemaker activity and improved gastric motility by restoring a normogastric pattern. Gastric dysmotility is frequent in septic patients.

Functional Imaging of Evaluation of Diabetic Gastroparesis.

Gastroparesis (a complication of both type 1 and type 2 diabetes mellitus) is delayed gastric emptying in the absence of a mechanical obstruction. Overall prevalence of Gastroparesis is close to 5 % in type 1 diabetes and 1 % in type 2 diabetes. It is unclear if good glycemic control leads to the delay of development and progression of gastroparesis. Gastric enteric neurons as well as Interstitial Cells of Cajal (ICC) are depleted, truncated and are surrounded by immune infiltrates composed of macrophages. There are associated vagal nerve innervation abnormalities, smooth muscle and Fibroblast Like Cell (FLC) dysfunctions. There is s decrease in HO-1 macrophages and increase in proinflammatory macrophages. Gastric electrical rhythm abnormalities and channelopathies have been implicated in the pathology of gastrointestinal diseases. In patients with diabetes, the most common clinical symptoms include abdominal bloating and pain. Nuclear Medicine Gastric Emptying Scintigraphy (NMGES) is considered the gold standard for evaluation of gastroparesis. Conventional imaging techniques such as fluoroscopic evaluation of gastric emptying can only evaluate the presence or absence of an obstruction. Historically, solid gastric emptying has been the method for evaluation although recent data suggests that liquid gastric emptying may be altered without solid gastric emptying abnormality. It is paramount that a radiotracer for evaluating gastric emptying be tightly bound to ingested food (solid). The most frequent radiotracer used is Tc99msulfur colloid bound to egg whites. In an effort to standardize normal values across institutions, a consensus recommendation published in 2008 called for a 4- hour study utilizing a standardized meal. Nuclear Medicine Gastric Emptying Scintigraphy (NMGES) is the test of choice for evaluation of diabetic gastroparesis. Standard guidelines have been established for the performance and interpretation of the test.

Dyspepsia

Dyspepsia is the medical term for difficult digestion. It consists of various symptoms in the upper abdomen, such as fullness, discomfort, early satiation, bloating, heartburn, belching, nausea, vomiting, or pain. The prevalence of dyspepsia in the western world is approximately 20% to 25%. Dyspepsia can be divided into 2 main categories: "organic" and "functional dyspepsia" (FD). Organic causes of dyspepsia are peptic ulcer, gastroesophageal reflux disease, gastric or esophageal cancer, pancreatic or biliary disorders, intolerance to food or drugs, and other infectious or systemic diseases. Pathophysiological mechanisms underlying FD are delayed gastric emptying, impaired gastric accommodation to a meal, hypersensitivity to gastric distension, altered duodenal sensitivity to lipids or acids, altered antroduodenojenunal motility and gastric electrical rhythm, unsuppressed postprandial phasic contractility in the proximal stomach, and autonomic nervous system-central nervous system dysregulation. Pathogenetic factors in FD are genetic predisposition, infection from Helicobacter pylori or other organisms, inflammation, and psychosocial factors. Diagnostic evaluation of dyspepsia includes upper gastrointestinal endoscopy, abdominal ultrasonography, gastric emptying testing (scintigraphy, breath test, ultrasonography, or magnetic resonance imaging), and gastric accommodation evaluation (magnetic resonance imaging, ultrasound, single-photon emission computed tomography, and barostat). Antroduodenal manometry can be used for the assessment of the myoelectrical activity of the stomach, whereas sensory function can be evaluated with the barostat, tensostat, and satiety test. Management of FD includes general measures, acid-suppressive drugs, eradication of H. pylori, prokinetic agents, fundus-relaxing drugs, antidepressants, and psychological interventions. This review presents an update on the diagnosis of patients presenting with dyspepsia, with an emphasis on the pathophysiological and pathogenetic mechanisms of FD and the differential diagnosis with organic causes of dyspepsia. The management of uninvestigated and FD, as well as the established and new pharmaceutical agents, is also discussed.

Effects of Enteral and Parenteral Nutrition on Gastroenteric Hormones and Gastric Motility After Subtotal Gastrectomy

To investigate the effects of enteral nutrition (EN) and parenteral nutrition (PN) on gastric motility and gastroenteric hormones after subtotal gastrectomy. Forty-one patients underwent gastrectomy were randomly divided into EN group (n = 20) and PN group (n = 21). From the first postoperative day to the seventh day, patients received either EN (EN group) or PN (PN group) with isocaloric (84.9 kJ x kg(-1) x d(-1)) and isonitrogenous (0.11 g x kg(-1) x d(-1)) intake. Serum gastrin (GAS), plasma motilin (MTL), and plasma cholecystokinin (CCK) were measured on preoperative day, the first and seventh postoperative day. Electrogastrography (EGG) was measured on preoperative day and the seventh postoperative day. Compared with preoperation, blood GAS, MTL, and CCK levels of 41 patients decreased significantly on the first day after subtotal gastrectomy (P < 0.001), but returned to the preoperative levels one week later. EGG after gastrectomy showed that gastric basal electrical rhythm was significantly restrained (P < 0. 001). On the seventh day after subtotal gastrectomy, plasma MTL and CCK levels in EN group were higher than those in PN group (P < 0.05). There was no difference in GAS level between two groups. EGG in EN group was better than that in PN group postoperatively. The levels of gastroenteritic hormones and the gastric motility decrease significantly after subtotal gastrectomy. In contrast with PN, EN can accelerate the recovery of MTL, CCK, and gastric motility after subtotal gastrectomy.

Effect of Lying on Gastric Electrical Rhythm

Purpose: The gastrointestinal tract is uniquely sensitive to mental stress, reflecting the communication between the central nervous system and the enteric nervous system. We hypothesized that this relationship could be exploited to provide insight into the psychological state of an individual when lying by analyzing changes in gastric physiology. Current lie detection methods (using standard polygraph) rely on non- GI physiological changes (ie. heart rate and sweating), but are only about 90% accurate and often unreliable. Methods: Sixteen healthy volunteers (13F, 3M) were recruited. Simultaneous electrogastrogram “EGG” and electrocardiogram “EKG” recordings were done for 3 periods, Baseline “BsL”, “Lying” and “Truth”; the later 2 being randomized. Autonomic activity was assessed via spectral analysis of heart rate variability (HRV) data derived from EKG. Gastric slow waves were assessed via spectral analysis of EGG signal. Statistical analysis was done using Student t-test and ANOVA as appropriate. Results: The 2nd channel of EGG, located on stomach proximal antral area, showed a significant decrease in% normal slow wave in Lying vs. BsL (75.39 ± 5.5 vs. 82.29 ± 4.47; P = 0.04). This may be attributed to significant increase in% arrhythmia in Lying vs. BsL (11.13 ± 3.87 vs. 6.35 ± 2.86; P = 0.02). HRV analysis showed a significant increase in average heart rate in Lying and Truth vs. BsL (75.76 ± 1.73; 74.4 ± 1.69 vs. 72.19 ± 1.43); (p = 0.05, 0.002, 0.001 respectively). There was a significant increase in sympathovagal balance in Lying vs. BsL (1.67 ± 0.33 vs. 1.35 ± 0.32; P = 0.045), which might be attributed to significant decrease in vagal activity in both Lying and Truth periods vs. BsL (0.32 ± 0.04 and 0.33 ± 0.04 vs. 0.4 ± 0.04; P = 0.026 and 0.003 respectively). Conclusions: Lying and truth telling are both associated with an increase in heart rate and sympathovagal balance. However, the act of lying is associated with a significant increase in gastric arrhythmia. Thus standard polygraph methods to assess heart rate variability may not perform as well as the EGG in distinguishing between lying and telling the truth. The addition of the EGG to standard polygraph methods has clear value in improving the accuracy of current lie detectors. In addition to a new, potentially breakthrough method for a variety of security applications, the results also provide understanding of the complex communication between the big brain and the little brain in the stomach. Further research in real-life situations and using larger numbers is necessary to validate these results.

Estimating Gastric Rhythm Differences Using a Wavelet Method from the Electrogastrograms of Normal and Diabetic Subjects

Electrogastrogram (EGG) is the cutaneous recording of gastric electrical activity. Some patients with nausea, vomiting, early satiety, and patients with long term insulin‐dependent diabetes exhibit gastric electrical rhythm disturbances. We are interested in investigating the EGG to determine if abnormalities of the EGG occur in association with those gastric complaints. The aim of this document is to investigate long term diabetics with a history of such gastric dysrhythmia complaints in an effort to further characterize the frequency of abnormalities of the EGG in real clinical diabetic gastroparesis patients. For feature extraction purposes, we have performed Wavelet‐Packet analysis of EGG signals and have obtained power spectral density of wavelet‐packet details and approximation coefficients in diabetic patients suffering from gastric dysrhythmia (tachygastria, bradygastria) and healthy volunteers. Wavelet‐Packet analysis provides details of changes in frequency components at any time point, and enhanced interpretation of cutaneous EGG recordings. In conclusion, this paper has shown that the Wavelet‐Packet analysis method is very useful in the analysis of cutaneous EGG recordings, especially in detecting dysrhythmic events.

Cytotoxic chemotherapy has minimal direct effect on gastric myoelectric activity in children with 5HT(3) antagonist prophylaxis.

Cancer patients receiving cytotoxic chemotherapy frequently develop nausea and vomiting. The direct effect of chemotherapy on gastric pacemaker is not clear. The objective of this study was to assess the direct interference of gastric electrical activity by chemotherapeutic agents as a possible cause of vomiting using electrogastrography (EGG). Fasting surface EGGs were recorded in 24 children with malignancy and 24 age-matched controls. All oncology patients received the intravenous prophylatic ondansetron. According to the known emetic potential of the medications they received, the children were divided into mild, moderate, and severe groups. The EGG recordings of oncology patients were segmented into prechemotherapy period, chemotherapy period, and emetic period. The EGG data from each period were collected and analyzed (paired t-test and Mann-Whitney U test). There were 24 children (M:F ratio: 14:10), with a mean age of 9.6 years. Eight children vomited during the course of recording (0/3 from the mild group, 2/6 from the moderate group, and 6/15 from the severe group). The average duration of intravenous medication infusion was 7.8 hr (range 2 min to 24 hr). There was no difference between the EGG of normal control and the prechemotherapy EGG of the oncology patients. No difference was detected between the EGG data from the prechemotherapy period and the chemotherapy period. A statistically significant increase in tachygastria was detected in emetic periods (28 episodes, mean duration 5 min; P = 0.01). Insignificant EGG changes during chemotherapy suggest that chemotherapy has a minimal direct effect on gastric pacemaker. Tachygastria seemed to be a secondary effect of vomiting rather than the cause of it. These preliminary findings suggest that efforts to modify gastric electrical rhythm as a means of management of chemotherapy-induced vomiting may be futile. Further studies to identify factors responsible for vomiting are warranted.

Electrogastrography in healthy children: evaluation of normal values, influence of age, gender, and obesity.

Electrogastrography (EGG) is a reliable technique to record gastric electrical activity. However, the normal values of electrical activity in children and the effects of age, gender, and body mass index (BMI) are not well defined. To evaluate these items, EGG signal was picked up before and after a meal in 114 healthy children (age range: 6-12 years) by means of a pair of cutaneous electrodes sonographically placed on the abdominal surface. The dominant frequency was prevalently found in the 2.0-4.0 cpm range (P < 0.001). A significant difference was found comparing the pre- and postprandial instability coefficient of dominant frequency (P < 0.05). The EGG power increased postprandially (power ratio = 3.6), and the power ratio was not correlated to the approach of the wall of the gastric antrum to the abdominal surface (Spearman r = 0.0045, NS). In obese children, the postprandial pattern in response to a mixed test meal containing carbohydrate as the major caloric source was similar to that recorded in normal-weight children. EGG parameters were not affected by age and gender apart from a significant difference in the postprandial instability coefficient obtained from the "girls > or = 9 years" group compared to the "girls <9 years" and "boys > or = 9 years" groups (P < 0.05). In conclusion, in children 6-12 years old, EGG parameters are not affected by BMI in response to a mixed test meal. Gastric electrical rhythm and rate, and gastric power are not influenced by age and gender, whereas the instability coefficient seems to be influenced by these factors. The normal values of the EGG parameters evaluated in this study should be introduced in the analysis of gastric electrical activity for an effective interpretation of the EGG signal from children with functional or organic diseases.

Electrogastrography in non-ulcer dyspepsia.

Fasting and fed gastric electrical activity was recorded by cutaneous electrodes (electrogastrography) in 14 children with unexplained recurrent symptoms of upper intestinal dysfunction, and in 10 controls. The unexplained symptoms included vomiting, epigastric pain, fullness, and early satiety. Mean (SD) age was 7.0 (3) and 7.5 (2) years, respectively. Gastric emptying time of a solid-liquid meal was also measured by real time ultrasonography in all subjects (patients and controls). In all patients radiography and endoscopy excluded structural and focal abnormalities of the gastrointestinal tract. Gastric emptying time was significantly more prolonged in patients than in controls. It was also found that there were appreciable irregularities of gastric electrical rhythm (tachygastria, bradygastria, flat line pattern, and mixed arrhythmia) in 12 fasting and 10 fed patients, whereas controls showed short and rare episodes of arrhythmia during both fasting and fed recording periods. The percentage distribution of the total electrogastrographic energy power across three frequency bands of electrical activity (low, normal, and high) showed that patients were different from controls both for reduced activity of normal frequency and for increased incidence of high and low abnormal frequencies. It is concluded that gastric electrical abnormalities are found in a high proportion of children with recurrent unexplained upper gastrointestinal symptoms. Electrogastrography can be a valuable tool in the assessment of these patients.

Effects of Age and Obesity on Fasting Gastric Electrical Activity in Man: A Cutaneous Electrogastrographic Study

We investigated the effects of age and obesity on the fasting cutaneous electrogastrogram (EGGc) by studying both young and aged, healthy men. All subjects underwent an electrogastrographic recording lasting 1 h, and frequency and power data were obtained by means of spectral analysis. In order to make a precise comparison of the data, each subject's body mass index (BMI) was calculated and each age group was subdivided into nonobese subjects, those with a BMI of less than 24.9 kg/m2, and obese subjects, those with a BMI of more than 25 kg/m2. Comparison of the mean frequency values of the gastric spectral peak did not reveal statistically significant differences among the groups (young vs. old, nonobese vs. obese). Comparison of the mean power values of the gastric spectral peak, on the other hand, showed that there was a statistically significant reduction in spectral power in the aged subjects compared with the young (p = 0.017 in the aged vs. young nonobese subjects and p = 0.009 in the aged vs. young obese subjects), and in the obese subjects compared with the nonobese (p = 0.00021 in the young and p = 0.00029 in the aged). Frequency, therefore, is the parameter of gastric electrical activity which may best be studied by means of EGGc as it is only very slightly affected by physiological parameters, such as age and the adiposity of subjects. EGGc, therefore, could be useful in the study of those gastric diseases associated with disorders in gastric electrical rhythm and rate.

Gastric Electrical Dysrhythmia following Cholecystectomy in Humans

In order to observe the incidence of dysrhythmia in 20 patients who had undergone cholecystectomy, we recorded gastric electrical activity by means of serosal electrodes from the day of surgery to the 6th postoperative day. The difference between the incidence of dysrhythmia on the day of the operation and the other days is statistically significant (t test: p less than 0.001). Bradygastria was the most frequently observed dysrhythmia, both on the day of surgery and on the following days. It had a frequency of around 1.0-1.5 cpm and the episodes lasted for a minimum of 10 min to a maximum of 105 min (mean duration 32.6 min). Episodes of tachygastria were of varying duration, ranging from a minimum of 3 min to a maximum of 60 min (mean duration 18.5 min), whereas episodes of gastric tachyarrhythmia lasted between 2 min and 21 min (mean duration 5.4 min). Only 1 patient had an episode of nausea and biliary vomiting, associated with an episode of gastric tachyarrhythmia on the 1st postoperative day. None of the other patients had symptoms of impaired gastric function, such as nausea, vomiting, bloating and epigastric pain, at any time during the recording sessions. These findings suggest that in most cases, gastric electrical rhythm returns to normal within 24 h of cholecystectomy and further that gastric dysrhythmia is not related to symptoms of impaired gastric function. The etiological mechanism and clinical significance of gastric dysrhythmia, therefore, are still unclear.

Effects of various operations on the electrical activity of the human stomach recorded during the postoperative recovery period.

This study attempts to characterize any changes occurring in the human gastric control electrical rhythm (CER), following a variety of gastric surgical procedures. Pairs of electrodes were implanted in selected specific sites on the stomachs of 57 patients undergoing either antrectomy and vagotomy, proximal gastric vagotomy (PGV), vagotomy and drainage, gastric resection without vagotomy, or fundoplication. Five patients undergoing nongastric operations served as controls. After operation recordings were obtained with differential preamplifiers, an oscilloscope, and a dual-channel tape recorder. An electrical signal compatible with a CER was found almost always in the distal body or antrum, regardless of whether vagotomy was performed. In contrast, a CER was found only occasionally in the fundus, and was never found following PGV. Although there was a difference in the frequency of occurrence of fundic CER in patients with and without vagotomy, it was not statistically significant (p = 0.0668). Patients with prolonged postoperative convalescence because of gastric atony were compared with patients with normal postoperative courses regarding the presence or absence of CER in the gastric antrum or fundus. A statistically significant relationship between abnormal gastric motility and absence of CER was not established.

Quantitative effect of oral feeding on gastrointestinal myoelectric activity in the conscious dog

Gastrointestinal myoelectric activity was recorded in seven studies in five dogs during two hours of fasting immediately followed by feeding and subsequent recording for four hours. In four studies serial plasma samples were taken for radioimmunoassay of insulin and gastrin. In all animals there was a significant reduction (P less than 0.01) in gastric basic electrical rhythm (BER) frequency on feeding which was sustained throughout the postprandial period. There was no change in the duodenal BER. Feeding induced a significant (P less than 0.01) increase in overall jejunal and ileal (but not duodenal) spike activity. Ileal (but not jejunal) spike activity again increased significantly (P less than 0.05) after the first two post-prandial hours. The changes in serum gastrin or in serum insulin did not appear to account for most of the observed changes in myoelectric activity, suggesting that other humoral and/or neural factors mediate the response to food.

Electromyographic study on the propagation mechanism of canine gastric electrical activity (author's transl)

In order to clarify the propagation mechanism of the canine gastric basic electrical rhythm (BER), a complete transection-reanastomosis was done in the lower corpus, corpus-antrum junction or middle pyloric antrum in each group of 3 dogs which had been equipped with 4 bipolar electrodes. At the time of the transection-reanastomosis, 4 pacing electrodes were also implanted. The BER frequency in the preanastomosis, 4 pacing electrodes were also implanted. The BER frequency in the preanastomosis remained unchanged regardless of the site of transection-reanastomosis, while that in the postanastomosis was markedly reduced, but gradually recovered to show the synchronization with the BER in the preanastomosis. Pacing of the gastric BER in the early stage (about 10 days post op.) when the synchronization was noted, was not established through anastomosis. However, pacing in the late stage (about 30 days post op.) was established through an astomosis. Dysrhythmia in the postanastomosis were observed to occur in high incidence in the early postoperative period, but subsequently declined to the same incidence as in the controls. Therefore, the synchronized phenomenon is due partly to the recovery of the inherent automatism of the gastric wall and due to subsequent propagation of the BER through anastomosis. Dysrhythmia in the postanastomosis were of temporal occurrence.

Myoelectrical activity of the canine stomach and duodenum after gastric resection

Distal gastric resection has long-lasting effects on the basal electrical rhythm of the canine stomach and duodenum. After Billroth I resection, duodenal fast activity is no longer controlled by the gastric basal electrical rhythm and is excessive and uncoordinated. Segmental resection of the stomach is followed by a high incidence of retrograde conduction of the basal electrical rhythm of the stomach and duodenum. Pylorus-preserving gastrectomy reduces this retrograde activity to a minimum.