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PubMed1999

Effect of acute gastric dilatation on gastric myoelectic and motor activity in dogs.

OBJECTIVE: To investigate the effects of experimentally induced acute gastric dilatation on electrical and mechanical activities of the stomach in dogs. ANIMALS: 7 healthy dogs. PROCEDURE: Electrodes and strain-gauge force transducers were implanted on the serosal surface of the antrum and pylorus. Eight days later, baseline gastric electrical and contractile activities were recorded. The dogs were anesthetized and mechanically ventilated to maintain normocapnia while the stomach was distended (intragastric pressure, 30 mm Hg) for 180 minutes, using a thin compliant bag. Gastric electrical and contractile activities were recorded again on days 1 and 10 after dilatation. Recordings were analyzed to determine gastric slow-wave frequency, slow-wave dysrhythmia, propagation velocity of slow-waves, coupling of contractions to slow waves, motility index on the basis of relative contractile amplitudes, and onset of contractions after a standardized meal. RESULTS: Electrical or contractile activities were not significantly different 18 hours after acute gastric dilatation (day 1). Arrhythmias were evident before and after gastric dilatation in dogs from which food was withheld and in dogs after consumption of a meal. CONCLUSIONS: Variables for assessing gastric electrical and contractile activities were unaffected 18 hours after acute gastric dilatation. CLINICAL RELEVANCE: Analysis of results of this study indicated that altered electrical and contractile activities in dogs with short-term gastric dilatation are not likely to be secondary to the process of acute gastric dilatation.

Animals↗
PubMedDate not supplied

Early effects of standard and pylorus-preserving pancreatectomy on myoelectric activity and gastric emptying.

BACKGROUND/AIMS: The main concern about pylorus preserving pancreatectomy (PPP) is delayed gastric emptying (GE). Both cancer and surgical procedures cause damage to the enteric nervous system and induce profound changes in gastric motility and emptying. The aim was to evaluate the effects of primary disease and type of surgical procedure used (standard pancreatoduodenectomy, SP vs. PPP) on myoelectric activity (MA), and solid and liquid GE in pancreatectomy patients. METHODOLOGY: Twenty-eight subjects were included, 18 after Whipple (group A) and 10 after a Traverso (group B) procedure. MA was captured by cutaneous electrodes (Synectics) and simultaneously LGE tested with ultrasonography. On separate days, the SGE of a radiolabelled meal was measured. MA and GE studies were done before and within three months after surgery. RESULTS: Before surgery LGE/SGE were delayed in 5/8 patients in group A and 2/2 in group B. Gastric dysrhythmia was observed in 6 patients in group A and 1 in group B. After PPP, the nasogastric tube was removed within 8.4+/-4.9 days and after SP within 4.6+/-4.1 days. GE studies showed accelerated LGE/SLG in 16/12 and delayed in 6/5 patients, respectively, in group A and B. Dysrhythmia was observed in 16 patients in group A and in 4 in group B. There was a strong relationship between SGE delay and dysrhythmia in patients after PPP. CONCLUSIONS: We conclude that papilla of Vater neoplasia damages mechanisms responsible for gastric emptying to a lesser extent than pancreatic cancer. In patients after PPP, post-operative MA disturbances are partially responsible for delayed GE.

Adolescent↗
PubMed1999

[Otolith-autonomic reactions in waking Macaca mulatta monkeys].

The aim was to determine a technique and parameters to test the otolith-autonomous reflex responses in conscious monkeys. The study involved 8 Macacas mulatta weighing 3 to 5 kg with subcutaneously pre-implanted electrodes to record ECG, rheopneumogram, and myoelectric activity of the stomach. The animals were seated in primate couches in which their bodies were softly restrained whereas their heads were restrained rigidly with plastic rings mounted on the cranium. Subsiding motion of a flat-parallel swing with the proper period of 3 s and starting amplitudes 20 cm (0.08 g) and 40 cm (0.16 g) exerted vestibular stimulation along the interaural axis. The monkeys responded to stimulation by altering the external breathing, myoelectric activity of the stomach, and cardiac rhythm. The highest reproducibility and individual steadiness featured cardiac reactions manifested by 2 waves of HR acceleration sequel to reflex-driven changes in the activity of the sympathetic and parasympathetic components of the autonomous nervous system. Data of the study attested the feasibility of testing the otolith-autonomous reflex responses in conscious monkeys with moderate stimulation in controlled experiments.

Animals↗
PubMed1999

Electrogastrography in cyclic vomiting syndrome.

Children with cyclic vomiting syndrome have a characteristic periodicity, and this could be due to abnormal gastric myoelectrical activity detectable by cutaneous electrogastrography (EGG). Fifteen children, aged 4-15 years, with CVS (eight symptomatic and seven asymptomatic at the time of study) underwent EGG and were compared to five normal and four disease control children. The relative tachygastria activity (RTA) or power ratio was calculated in each group. Five of the eight symptomatic CVS children showed marked episodes of tachygastria preprandially and all showed tachygastria postprandially. The asymptomatic CVS children showed tachygastria only postprandially after the test meal. RTA index and or power ratio of symptomatic children was significantly different from the asymptomatic CVS children (P = 0.001), normal (P = 0.007) and disease control children (P = 0.006). In a subsequent study, 2-hr gastric emptying 99mTc scintiscans were performed in 28 CVS children and compared to eight healthy control children. Twelve of 16 CVS children (75%) showed abnormal gastric emptying, and 7 of 28 (25%) showed abnormal EGG with significant tachygastria. The CVS children had significantly higher RTA both preprandially (P < 0.05) and postprandially (P < 0.05). Our results demonstrate that accelerated gastric rhythm was seen during the acute episodes of half of the CVS patients studied. Abnormal EGGs and higher RTA or power ratios were associated with delayed gastric emptying in the CVS children. Abnormal gastric myoelectrical activity may play a role in the pathogenesis of CVS syndrome.

Adolescent↗
PubMed1999

Relationship of Helicobacter pylori infection with gastrointestinal motility.

The interest of gastroenterologists in the relationship between Helicobacter pylori and gastrointestinal motility emerges from the observation that Helicobacter pylori may be involved in the pathogenesis of functional dyspepsia and that a relatively large percentage of patients with dyspepsia may show impaired gastrointestinal motility. A number of studies have been published on the interaction between Helicobacter pylori infection and gastrointestinal motility with controversial results, and, therefore, there are no definite conclusions, as yet, as to whether Helicobacter pylori is able, at all, or in which degree, to influence the motility of the upper gastrointestinal tract. Motility of the upper gastrointestinal tract has been studied in Helicobacter pylori positive and negative individuals by means of manometry, scintigraphy, radio-opaque markers or by other, recently developed, procedures such as breath tests, ultrasonography, and barostat. The vast majority of studies do not support the hypothesis that Helicobacter pylori may influence gastrointestinal motility. Nearly all these studies are, however, affected by methodological problems related to the small numbers of patients, different methodological approaches, and to the well-known difficulties in studying both gastrointestinal motility and functional dyspepsia.

Dyspepsia↗
PubMed2000

Gastric myoelectric activity during low frequency oscillation.

BACKGROUND: The normal 3 cycles per minute (3 c/m) resting activity of the stomach has been reported to shift into the range of 4-9 c/m (tachyarrhythmia) in subjects with symptoms of motion sickness. Previous studies have provoked motion sickness with an optokinetic stimulus and have not normally reported changes relative to a control condition. The present experiment investigated changes in the electrogastrogram (EGG) during a control condition and during exposure to 0.125 Hz off-axis yaw oscillation of the body. METHODS: There were 16 male subjects who participated in the two conditions 1 wk apart. The electrogastrogram, respiration rate and subjective ratings of sickness were monitored throughout both conditions. Spectral analysis of the EGG time histories provided measures of 3 c/m power and tachyarrhythmia power, which were also expressed as a percentages of EGG power over the total EGG frequency range (0.04 to 0.16 Hz.). The median frequency of the EGG over this bandwidth was also calculated. RESULTS: During motion exposure, the median frequency of the EGG and the percentage tachyarrhythmia power increased and the percentage 3 c/m power decreased relative to a pre-exposure baseline period and relative to the static control condition. CONCLUSIONS: Low frequency off-axis yaw oscillations disrupted the normal resting gastric myoelectric activity relative to a control condition.

Adult↗
PubMed2000

Spatio-temporal nonlinear modeling of gastric myoelectrical activity.

The accomplishment of a complete digestive process of human stomach is regulated by a spatio-temporally-coordinated electric pattern called gastric myoelectrical activity (GMA). The normal patterns of GMA present temporal evolution from endogenous rhythmic oscillation to bursting of spikes associated with contractions, and also ordered spatial propagation of the oscillating waves. The abnormal patterns of GMA have been observed in temporal dysrhythmia, such as tachygastria, bradygastria and arrhythmia, and in spatial propagation failure, such as retrograde propagation and uncoupling. Different GMA patterns are associated with different gastric symptoms and there exist some nonlinear mechanisms to govern the formation and dynamic evolution of these patterns. However, these mechanisms are so complex that few of them are known by medical observations. The aim of this study is to explore these mechanisms by spatio-temporal modeling of GMA. The single-cell model simulating the formation process of slow waves and spikes, the multi-cell model simulating the propagation process of GMA and the extracellular model simulating the formation of bipolar recordings are presented.

Computer Simulation↗
PubMed2000

Role of calcitonin gene related peptide in the modulation of intestinal circulatory, metabolic, and myoelectric activity during ischemia/reperfusion.

Calcitonin gene related peptide (CGRP) is widely distributed in the myenteric neurons along GI tract. Biological effects of CGRP on gastrointestinal tract include increase in the intestinal blood flow, relaxation of the smoth muscle and slight increase in the slow wave amplitude (SWA) with no effect on frequency (SWF) of intestinal myoelectric activity (IMA). The aim of this study was to evaluate the possible protective effects of endo- and exogenous CGRP against ischemia/reperfusion (I/R) induced bowel injury in rats. Experiments were performed on 30 fasted anesthetized Wistar rats. Systemic arterial blood pressure (AP), mesenteric blood flow (MBF) and microcirculatory intestinal blood flow (LDBF) were measured. Oxygen consumption (VO2) was estimated from MBF and mesenteric AVO2 difference. IMA was recorded by 4 monopolar electrodes in proximal jejunum and analyzed using computer program with Fourrier analysis of SWF. Control ischemia induced by 30 min total occlusion of anterior mesenteric artery (AMA) reduced SWA by 25+/-5% and SWF by 24+/-4%. At the end of 60 minute reperfusion period SWA and SWF values were restored to control values but SWF showed instability. At the 15th minute of reperfusion period MBF, LDBF and VO2 increased to 109+/-6, 119+/-11 and 120+/-7% of control values respectively. Infusion of exogenous CGRP (0,16 microg/kg/min i.a.) increased MBF, LDBF and VO2 by 26+/-6, 31+/-9 and 20+/-4% respectively in comparison to control values. In the same experimental group SWA increase of 14% was observed with not significant changes in SWF. In the group where CGRP was administrated before and during 30 min period of intestinal ischemia MBF, LDBF and VO2 values at 15th minute of reperfusion were significantly higher by 24+/-6, 32+/-7 and 17+/-5% respectively in comparison to the values observed in the control reperfusion. In that group SWA values were restored to preocclusion values at 15th minute of reperfusion yet and SWF showed much more stability. Infusion of CGRP receptor antagonist (CGRP 8-37) reduced MBF, LDBF and VO2 by 12+/-7, 14+/-8 and 11+/-6% respectively (differences not significant versus control). In I/R group when CGRP 8-37 was given hemodynamic parameters (during reperfusion) were significantly lower and IMA parameters were not restored to preocclusion values. We conclude, that endogenous and exogenous CGRP attenuate circulatory parameters of the small intestine during ischemia and reperfusion. A direct correlation exists between hemodynamic, metabolic and myoelectric effects of CGRP.

Animals↗
PubMed2001

Gastric myoelectrical and autonomic cardiac reactivity to laboratory stressors.

We evaluated the effects of two laboratory stressors (speech preparation and isometric handgrip) on gastric myoelectrical and autonomic cardiac activity, and the extent to which autonomic responses to these stressors and somatization predict reports of motion sickness during exposure to a rotating optokinetic drum. Both stressors prompted a decrease in preejection period (PEP) and respiratory sinus arrhythmia (RSA), and an increase in a dysrhythmic pattern of gastric myoelectrical activity, termed gastric tachyarrhythmia. Stressor-induced decreases in RSA and higher somatization scores predicted increased reports of motion sickness during drum rotation. These results demonstrate that laboratory stressors concurrently affect gastric myoelectrical activity and autonomic control of the heart, and that stressor-induced decreases in RSA and higher levels of somatization predict motion sickness susceptibility.

Adolescent↗
PubMed2001

[Effect of chemical sympathectomy on myoelectric activity of the small bowel].

UNLABELLED: Central and peripheral noradrenergic system modulates myoelectric activity of the small bowel. Aim of this study was to evaluate the role of peripheral noradrenergic system in modulation of slow waves activity. Recordings of slow waves were performed on 20 conscious rats chronically fitted with 2 unipolar electrodes. After controls recording the animals were injected i.p. with 6-hydroxydopamine (6-OHDA--Sigma H8523) and the recording were performed on daily basis through the period of one month. RESULTS: The increase of frequency slow waves during the first week after 6-OHDA from 0.61 (+/- 0.11) to 0.71 (+/- 0.03), (p. < 0.05), and amplitude from 14468 +/- 11196 to 19128 +/- 5282 (microV)2 (p > 0.05) were observed. Variability in control recording was higher (SD +/- 0.11) than after 6-OHDA (SD 0.03). Next day diarrhoea after 6-OHDA occurred, persisted despite return normal myoelectric activity. Slow waves frequency gradually returns to control value after the fourth week. CONCLUSION: Peripheral noradrenergic system has a significant effect on the frequency and variability of slow wave and minor role on its amplitude but no on diarrhoea pattern.

Animals↗
PubMed2001

[Percutaneous electrogastrography in the perioperative period in laparoscopic gastric banding at the First Surgical Clinic of the General Faculty Hospital in Prague].

Percutaneous electrogastrography (EGG) is a method which makes non-invasive follow-up of the myoelectric gastric activity possible. The authors present the results of assessment of the myoelectric gastric activity during the perioperative period in patients undergoing, at the First Surgical Clinic General Faculty Hospital, laparoscopic non-adjustable gastric banding. The data were recorded using a Microdigittrapper and evaluated using spectral analysis and Fourier's transformation. The authors mention also briefly conditions which must be met to ensure the study, and the physiological and pathophysiological background of the method. In 14 patients the ECG record was made 24 hours prior to surgery and then 5 hours, 24 and 48 hours after surgery on fasting and after a fluid bolus. The assembled results of the dynamics of perioperative changes on the EGG were compared with results obtained in a group of healthy volunteers. The most frequent finding during the early postoperative period was bradygastria, the return to preoperative values occurred on average 48 hours after surgery. Percutaneous electrogastrography is a non-invasive method which can provide the surgeon during the early postoperative period with information on myoelectric gastric activity.

Adult↗
PubMedDate not supplied

Pancreatic carcinoma-induced changes in gastric myoelectric activity and emptying.

BACKGROUND/AIMS: Twenty patients with histologically confirmed pancreatic carcinoma without any endoscopic evidence of gastroduodenal obstruction were included in the study. The aim was to determine changes in gastric myoelectric activity and liquid/solid gastric emptying induced by pancreatic tumor. METHODOLOGY: According to TNM/UICC classification patients were divided into two groups A (T2) and B (T3) due to extent of tumor invasion (mainly to retroperitoneum space). In all patients electrogastrography, solid and liquid gastric emptying tests were performed. RESULTS: In the majority of patients of groups A and B the most commonly reported complaints included upper abdominal pain (60% vs. 80%) and icterus (80% vs. 60%). Dyspeptic symptoms were observed in 40% patients of group A and 90% in group B. In group electrogastrography recordings showed dysrhythmia patterns, mostly bradygastria, in 50% of group A patients and in 80% of group B. Liquid/solid gastric emptying were delayed in 20/40% of group A patients and 50/80% of group B. Disorders of gastric myoelectric activity and emptying correlated with tumor stage and location across analyzed groups but not with histology and hyperbilirubinemia levels. CONCLUSIONS: It was observed that solid gastric emptying is affected earlier compared to liquid gastric emptying. Delayed gastric emptying may be attributed to gastric dysrhythmia and/or abdominal pain but not mechanical effects of tumor growth that occur during the course of disease.

Adenocarcinoma↗
PubMed2002

The influence of cholecystokinin on gastric myoelectrical activity in duodenal ulcer following Helicobacter pylori eradication--an electrogastrographic study.

Cholecystokinin (CCK) plays an important role in the regulation of postprandial gastric motor activity which was found to be abnormal in duodenal ulcer patients. This study was designed to compare the influence of CCK on gastric myoelectrical function in duodenal ulcer patients and healthy controls. Fifteen patients with active duodenal ulcer and Helicobacterpylori (H. pylori) infection and 15 healthy controls were included into this study. Electrogastrography (EGG) was performed before and 4 weeks after the eradication of H. pylori in ulcer patients and in healthy controls. We compared EGG parameters in the fasting and postprandial period and during intravenous infusion of caerulein, an analog of CCK with or without addition of loxiglumide, a specific CCK-1 receptor antagonist. The amplitude of fasting EGG in duodenal ulcer patients was similar to that in control subjects and was not affected by H. pylori eradication. In contrast, the amplitude of postprandial EGG was markedly increased in duodenal ulcer patients when compared to that in healthy controls and it was significantly reduced following the eradication of H. pylori. The blockade of CCK-1 receptors with loxiglumide in healthy controls or H. pylori eradicated ulcer patients significantly enhanced postprandial EGG amplitude almost to the level observed in the infected duodenal ulcer patients, but failed to affect this amplitude in ulcer patients. Exogenous caerulein, an analog of CCK, failed to affect EGG amplitude in duodenal ulcer patients with H. pylori infection, but it reduced significantly EGG amplitude in these patients after H. pylori eradication and in control subjects. This inhibitory effect of caerulein in H. pylori negative ulcer patients and healthy controls was abolished by the addition of loxiglumide. Ulcer patients showed significant dysrhythmia with tachygastria up to 20% of the recording time both under basal conditions and postprandially and H. pylori eradication was followed by a significant decrease in tachygastria to about 5%, the value being similar to that in healthy controls. We conclude that the amplitude and frequency of gastric myoelectrical activity are enhanced in duodenal ulcer patients and impaired in response to CCK but these changes can be normalized by successful H. pylori eradication.

Adult↗
PubMed2002

[Ganglionic blockers in abdominal surgery: facts and hypotheses. I. Benzohexonium and motor function of the gastrointestinal system in the early postoperative period].

The method of registration of the intraluminal pressure was used to study the function of the stomach, small intestine and sigmoid colon under conditions of partial ganglionic blockade in the first days after truncal vagotomy and resection of the stomach. It was found that benzohexonium in doses 0.1-0.3 mg/kg failed to substantially decrease the frequency of early functional motor-evacuation disorders of the "operated" stomach, but the results of using N-cholinolytic was better after truncal vagotomy than after resection of the stomach. Benzohexonium in doses 0.1-0.2 mg/kg failed to considerably stimulate the motor function of the small intestine while the doses of 0.3-0.4 mg/kg resulted in a decrease of its contractile activity. No reliable changes in the qualitative and quantitative parameters of the sigmoid colon motor function were found against the background of ganglionic blockade. So, for prevention and correction of early postoperative motor-evacuation disorders of the gastrointestinal tract the ganglionic blockade with N-cholinolytics should not be taken as a method of choice or a variant of monotherapy.

Animals↗
PubMedDate not supplied

Effect of fluoxetine on symptoms and gastric dysrhythmia in patients with functional dyspepsia.

BACKGROUND/AIMS: Although antidepressants have been used for decades in treating patients with functional abdominal syndromes, how they influence gastrointestinal motility remains unclear. We aimed to assess the role of depression in functional dyspepsia, and the effect of antidepressants on the functional dyspepsia patients' symptoms and gastric myoelectrical activity. METHODOLOGY: We conducted an open clinical trial with 40 functional dyspepsia patients. Zung self-rating depression scale was used in evaluating the patients' depression. Cutaneous electrogastrography and evaluation of upper gastrointestinal symptoms were performed before and after administration of a one-month course of fluoxetine. RESULTS: In the baseline study, the depressed functional dyspepsia patients had higher symptom scores than non-depressed patients (P < 0.05). The depressed functional dyspepsia patients had higher percentages of tachygastria than healthy controls (P < 0.05), but the electrogastrography parameters of depressed and non-depressed functional dyspepsia patients were not different. After one-month fluoxetine treatment, the symptom scores improved significantly in the depressed functional dyspepsia patients (P < 0.05), but not in the non-depressed patients. Electrogastrography did not improve in either group. CONCLUSIONS: Depressive functional dyspepsia patients had higher symptom scores and responded well to fluoxetine treatment. However, electrogastrography did not improve after the treatment. These findings suggest that depression is significant in the presentation of functional dyspepsia symptoms, but not correlated with gastric myoelectrical activity.

Adolescent↗
PubMed2002

Effects of carbohydrate meals of varying consistency on gastric myoelectrical activity.

BACKGROUND: There is at present no agreement on the type of test meal to be used when performing EGG. To our knowledge the response of the stomach to high carbohydrate isocaloric meals of different consistencies has not been formally assessed. AIM: To study 1) the effects of high carbohydrate meals of varying consistency on EGG activity; and 2) the effects of increasing the calorie content of a meal without changing its consistency and composition on the postprandial EGG. SUBJECTS: Eighteen healthy volunteers, six males (age: 21-35 year, weight: 45-60 kg) and 12 females in the follicular phase of the menstrual cycle (age: 24-30 years, weight: 45-55 kg). METHODS: Following an overnight fast subjects were given three high carbohydrate, low fat, isocaloric meals (165-170 kcal) of different consistencies (solid, semisolid, liquid), on three separate days in a random order. The liquid and semisolid meals were equal in volume (200 ml) while the volume of the solid meal was smaller. One hour EGG recordings were done in the fasting and fed states in each subject. As a second step, ten of the above volunteers (taken randomly) were given the solid test meal on a separate day after increasing the calorie content of the meal to 350 kcal. RESULTS: The power of the EGG at the dominant frequency significantly increased after solid (175 kcal meal: fasting 49 +/- 12 dB vs. fed 57 +/- 13 dB; p < 0.05, 375 kcal meal: fasting 48.5 +/- 12.9 dB vs fed 58.1 +/- 11.7 dB) and semisolid (fasting 50 +/- 12 dB vs. fed 55 +/- 13; P < 0.05). The increase in power was not significantly different when fed with solids and semisolids. There was no statistically significant change in EGG power during the first 15 or 60 minutes after the liquid meal. Feeding showed no significant effect on the dominant frequency and the percentage of 2-4 cpm waves of the EGG with any of the three types of test meals. CONCLUSIONS: Solid and semisolid meals high in carbohydrate and low in fat are capable of inducing a significant increase in the EGG power in normal subjects. Isocaloric solid and semisolid meals have similar effects on gastric slow wave activity. EGG appears unaffected by the liquid meal. Therefore only an increase in the power of the EGG can be regarded as normal if a high carbohydrate solid or a semisolid meal is given as the test meal when performing an EGG.

Adult↗
PubMed2002

[Percutaneous electrogastrography in the perioperative period in laparoscopic and classical cholecystectomy and in laparoscopic nonadjustable gastric banding].

Percutaneous electrogastrography (EGG) is a non-invasive measuring method of gastric myoelectrical activity. We measured myoelectrical activity patients after laparoscopic cholecystectomy (16 patients), after laparotomic cholecystectomy (9 patients) and after gastric bandage (14 patients). We used a Microdigitrapper (Medtronic) and data were analysed with a spectral analysis and Fournier's transformation. We measured 24 hours and 5 hours before operation procedure and 24 and 48 hours after operation. After operative procedure we compared results with healthy voluntaries. Bradygastria was found in most frequent cases in early postoperative period. Physiologic conditions were renewed in laparoscopic operative procedure in first day, after laparotomic operation in second day after operation.

Adult↗