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PubMed1996

Effect of progressive systemic sclerosis on antral myoelectrical activity and gastric emptying.

In patients with progressive systemic sclerosis (PSS) suffering from chronic dyspepsia the stomach may be affected by this disease. The objective of this study was to investigate both antral myoelectrical activity and gastric emptying in PSS patients. Electrogastrography (EGG) was performed in 17 PSS patients (16 female, one male, median age 58 years, range 32-74 years) with chronic dyspepsia. After an overnight fast during one hour in the fasting and one hour in the fed state after ingestion of a liquid-solid test meal (370 kcal; liquid phase labeled with 0.5 mCi 99mTc-colloid) antral electrical activity was measured by one pair of electrodes sonographically placed on the skin overlying the gastric antrum. Several EGG parameters including dominant frequency (DF), percentages of DF in the normal range (2-4 cycles per minute [cpm]), bradygastria (< 2 cpm) and tachygastria (4-10 cpm), dominant frequency instability coefficient (DFIC), and postprandial to preprandial power ratio (PR) were calculated. The data were correlated to results obtained in 20 age- and gender-matched healthy subjects. In addition, the data were compared to gastric retention of the radionuclide at 60 min measured by simultaneous scintigraphy. The PSS patients did not reveal electrical disturbances. They even exhibited a significant postprandial decrease in DFIC, bradygastria, and tachygastria (ns) compared to healthy subjects. Over 50% of the PSS patients showed a delayed gastric emptying. However, EGG did not correlate to radioscintigraphy significantly. Our results reflect an absent relationship between antral myoelectrical activity in EGG and gastric emptying. Therefore, electrogastrography is unsuitable to assess gastric involvement in PSS.

Adult↗
PubMed1997

Median arcuate ligament syndrome: a possible cause of idiopathic gastroparesis.

The median arcuate ligament syndrome (MALS) is characterized by abdominal pain, nausea, and vomiting attributed to compression of the celiac axis by a fibrous band (the median arcuate ligament) connecting the diaphragmatic crura. The pathophysiologic origin of these symptoms is not clearly understood. Theories invoking either a neurogenic or vascular origin for the clinical features associated with MALS have been proposed, but objective evidence to support these theories is lacking. We describe the clinical course and gastric myoelectrical features of a patient with postprandial epigastric pain, weight loss, gastroparesis, and gastric dysrhythmias in whom a diagnosis of MALS was established. Surgical decompression of the celiac axis in our patient resulted in resolution of abdominal pain, return to a full diet within 4 weeks without nausea or vomiting, improvement in radionuclide gastric emptying, and restoration of the gastric electrical rhythm to a normal 3 cycle/min conduction rate. This is the first demonstration of altered gastric myoelectrical activity in a patient with MALS. The regularization of the gastric electrical rhythm in our patient after surgical decompression of the celiac axis would support a neurogenic basis for the symptoms associated with MALS. MALS should be excluded in patients with idiopathic gastroparesis and unexplained epigastric pain.

Abdominal Pain↗
PubMed1996

[The involvement of prostaglandins in the inhibiting effect of endotoxin on the myoelectric activity of the gastrointestinal system in pigs].

The probable involvement of prostaglandins in the myoelectrical response of the antrum pylori and small intestine to endotoxin (LPS) was studied in the piglet. In these experiments the influence of I.V. infusion of PGF2 alpha and PGE2 and of I.V. injection of LPS, without and with indomethacin (INDO) pretreatment, on myoelectrical activity of the antrum pylori, duodenum, jejunum and ileum as well as on some clinical and haematological parameters was studied. Infusion of the 2 PG's, especially PGE2, inhibited myoelectrical activity of the antrum pylori. PGE2 also reduced duodenal activity. PGF2 alpha was without effect on duodenal and jejunal activity, but stimulated ileal activity. Both PG's induced fever, nausea, vomiting and sedation or excitation. With the higher dose of PGE2 diarrhoea was also observed. Injection of LPS induced identical myoelectrical and clinical changes, as described for PGE2. However, endotoxin did not induce diarrhoea. Depending on the dose, administration of LPS resulted in a leukocytosis or a leukopenia together with an increase in band neutrophils. Following pretreatment with INDO the effects of LPS on gastrointestinal electrical activity were reduced and its clinical symptoms were nearly completely inhibited. The haematological changes induced by LPS, however, were not influenced by INDO. These experiments suggest a possible involvement of the PG's in the clinical symptoms and in the initial inhibitory effect of LPS on myoelectrical activity especially of the antrum. However, the induced haematological changes are probably not mediated by the arachidonic acid pathway.

Animals↗
PubMed1997

Myoelectric activity of the cecum and proximal loop of the ascending colon in cows after spontaneous cecal dilatation/dislocation.

OBJECTIVE: To analyze myoelectric activity of the cecum and proximal loop of the ascending colon (PLAC) in cows after spontaneous cecal dilatation/dislocation (CDD) and compare it with that in healthy cows after surgical evacuation of the cecum. ANIMALS: 12 cows with spontaneous CDD and 6 healthy cows (group C). Cows with spontaneous CDD were retrospectively assigned to 2 groups: delayed recovery from surgery or recurrence (group A; n = 3), and normal recovery (group B; n = 9). PROCEDURE: After surgical evacuation of the cecum, 8 pairs of bipolar, retrievable electrodes were implanted in the ileum, cecum, and PLAC. Cows were evaluated daily from postoperative day 1 to 7, using routine clinical methods and computer-based analysis of myoelectric activity of the cecum, and PLAC. Parameters of myoelectric activity included rate of spike bursts, duration of individual spike bursts, duration of overall spike burst activity per electrode, rate of propagated spike burst sequences, and ratio of orally propagated spike burst sequences. RESULTS: Rate of spike bursts, duration of cecocolic spike burst activity, and ratio of orally to aborally propagated spike burst sequences did not vary among groups during the 7-day recording period. However, cows with delayed recovery had a typical, uniform pattern of myoelectric activity of the cecum and PLAC at days 1 and 2 after surgery that consisted of repeated, propagated spike burst sequences, made up of spike bursts of significantly (P < 0.05) increased duration at postsurgical day 1 and substantially prolonged duration at postsurgical day 2, interrupted by periods of little or no activity. CONCLUSION: Delayed recovery and recurrence of CDD in cows after spontaneous CDD is not caused by hypomotility of the cecum and PLAC. CLINICAL RELEVANCE: Postoperative treatment, intended to reduce recurrence of CDD or delayed recovery after surgical evacuation of the cecum, should address propagation of digesta in the spiral colon.

Animals↗
PubMed1997

Electrical stimulation of acupuncture points enhances gastric myoelectrical activity in humans.

OBJECTIVE: Acupuncture is known to enhance gastric motility. Electrical acustimulation has been shown to reduce gastric tachyarrhymia in vection-induced motion sickness. The aim of this study was to investigate the effect of electrical stimulation of acupuncture points on gastric myoelectrical activity in healthy humans. METHODS: Nine healthy native Chinese were studied. Gastric myoelectrical activity was recorded using surface electrogastrography (EGG). The EGG recording was made in the fasting state, in a study period during which acupuncture points were electrically stimulated continuously, and in a recovery period after stimulation. The percentage of regular slow waves was assessed by computing the percentage of 2 to 4 cycles per minute slow waves in the EGG. RESULTS: Electrical stimulation significantly increased the percentage of regular slow waves, which was sustained in the recovery period. The increase of the regular slow wave activity resulted from the normalization of arrhythmia. CONCLUSION: Electrical stimulation of acupuncture points may enhance the regularity of gastric myoelectrical activity and may be an option for treatment of gastric dysrhythmia.

Acupuncture Points↗
PubMedDate not supplied

Effect of hyperthyroidism on antral myoelectrical activity, gastric emptying and dyspepsia in man.

BACKGROUND/AIMS: The objective of the present study was to investigate the effect of hyperthyroidism on antral myoelectrical activity, gastric emptying and dyspepsia in man. METHODOLOGY: Twenty-three patients with manifest hyperthyroidism and dyspepsia confirmed by a standardized protocol were studied by electrogastrography (EGG). The following EGG parameters were determined: dominant frequency (DF cycles per minute (cpm), DF (%) in the normal range (2-4 cpm)), bradygastria (< 2 cpm), tachygastria (4-10 cpm), dominant frequency instability coefficient (DFIC), and postprandial to fasting power ratio. Data were correlated to results obtained in 18 age- and gender-matched controls. In 10 patients, a control measurement was performed after antithyroid therapy. In addition, in 15 consecutive patients, EGG data were compared to gastric emptying of radionuclides recorded simultaneously (gamma camera). RESULTS: Hyperthyroid patients revealed a significant increase in preprandial DF, and in pre- and post-prandial tachygastrias compared to controls (3.3 cpm vs 3.1 cpm; 8.8% vs 3.5%; 12.3% vs 3.5%; p < 0.05). After antithyroid therapy, postprandial tachygastrias were reduced significantly. About 50% of the patients exhibited delayed gastric emptying compared to previously evaluated normal values (t 60 nuclide retention: > 68%). However, these patients did not differ in tachygastria and the other EGG parameters from those with normal gastric emptying (p > 0.05). Both EGG and radioscintigraphy did not correlate significantly with dyspepsia. CONCLUSIONS: Dyspeptic patients with hyperthyroidism frequently display tachygastria and delayed gastric emptying. However, tachygastria has no important effect on gastric motor activity in hyperthyroidism.

Aged↗
PubMed1997

Factors responsible for computed electrogastrographic parameters in humans.

OBJECTIVES: Clinical knowledge about myoelectrical frequency is well known, but the factors responsible for recorded myoelectrical amplitude remain less clear. METHODS: We assembled an electrogastrographic system that could automatically compute the dominant myoelectrical frequency and power and power ratio. We enrolled 50 healthy volunteers (25 men and 25 women) to study their myoelectrical characteristics. Three surface electrodes were placed in the fundic, stomach body, and antral positions for two 30-min recordings in the fasting and postprandial states. RESULTS: The three different electrodes recorded similar dominant frequencies of about 3 cpm before and after a meal. The fasting dominant powers from these electrodes were 52.9 +/- 14.7, 44.6 +/- 11.5, and 50.1 +/- 15.1 dB, respectively (p < 0.01), whereas the postprandial dominant powers were 61.6 +/- 28.8, 54.3 +/- 26.6, and 61.9 +/- 27.8 dB, respectively (p < 0.01). Meal ingestion did increase the power (p < 0.05). Women had a lower dominant power than men (p < 0.001). Moreover, the dominant powers of each electrode were significantly correlated with body mass index (r = 0.3-0.36, p < 0.05) regardless of meal ingestion. The postprandial power ratio was not influenced by electrode position, gender, or body mass index. CONCLUSIONS: Myoelectrical dominant frequencies and power ratios are similar throughout the whole stomach area, whereas a lower power area exists on the stomach body. Gender-related variation in dominant power seems to be an effect of body size. The power ratio is the only reliable parameter for expressing myoelectrical amplitude.

Adult↗
PubMed1996

[Effect of atropine on the enhancing action of Fructus Aurantii Immaturus on the myoelectric activity of small intestine in dogs].

Effect of Fructus Aurantii Immaturus (FAI) was observed by using the computerized electrophysiologic method with the interdigestive myoelectric complex (IDMEC) as criterion. 100% FAI was given to the healthy, awakened and fasting dogs by gastrogavage and as soon as the effect on electric activity of small intestine appeared, atropine was injected. Results showed that the enhancing effect of FAI could be inhibited significantly by atropine, an antagonist of cholinergic receptor. It revealed that although the duration of phase II and general cycle were prolonged, but the spike burst per cluster in the duration between phase II and phase III as well as that per minute were decreased. It suggested the effect of FAI might be relevant with muscarinic receptor.

Animals↗
PubMed1996

[Inhibitory effect of substance P of caudate nucleus on gastric motility via substantia nigra and dorsal vagal nucleus mediated by vagus nerve].

Effects of lesion of bilateral hypothalamus (LH), substantia nigra and dorsal vagal nucleus as well as their efferent pathway on the inhibition of gastric myoelectric fast wave and gastric motility due to injection of substance P (SP) to caudate nucleus were studied in rats. The experimental results showed that this induced inhibition was independent of the presence of intact LH but abolished by lesioning substantia nigra, dorsal vagal nucleus or vagus nerve. Depletion of sympathetic transmitter by reserpine did not affect the occurrence of the inhibition. Thus, it appears that the gastric inhibitory effect of caudate nucleus SP is mediated via substantia nigra and dorsal vagal nucleus to vagus nerve.

Animals↗
PubMed1992

Intestinal myoelectric activity and contractile motility in dogs with a reversed jejunal segment after extensive small bowel resection.

To evaluate the functioning and effectiveness of a reversed jejunal segment after extensive small bowel resection, we continuously measured the postoperative bowel motility (using bipolar electrodes and/or contractile strain gage force transducers) in interdigestive and postprandial conscious dogs at 2 to 5 weeks after surgery. The fasting duodenal migrating myoelectric (or motor) complex (MMC) occurred at markedly longer intervals in dogs with a 20-cm reversed jejunal segment created after 75% to 80% extensive small bowel resection (group 3) than in dogs that received extensive resection alone (group 2) or dogs that underwent construction of a reversed jejunal segment without bowel resection (group 1). The MMC arising from the duodenum was often interrupted at the jejunum above the proximal anastomosis and did not migrate smoothly to the reversed segment or terminal ileum in group 3. In addition, brief small discordant contractions were frequent in the reversed segment and the jejunum above the proximal anastomosis in group 3. The duration of the postprandial period without duodenal MMC activity was significantly prolonged in groups 2 and 3. These results suggest that the transit time and passage of intestinal contents were delayed and that the periodical MMC was disturbed in group 3. The delay of transit time was due to prolongation of the interval between duodenal MMCs, the interruption of MMC propagation at the jejunum above the proximal anastomosis, the dominance of MMCs that followed the inherent anatomical continuity of the bowel, and discordant movements across the proximal anastomosis. Functional obstruction could be a potential problem in a 20-cm reversed jejunal segment inserted after extensive small bowel resection.

Anastomosis, Surgical↗
PubMed1996

Intestinal motility after massive small bowel resection in conscious canines: comparison of acute and chronic phases.

To evaluate intestinal function after 80% massive distal small bowel resection (MSBR), we continuously monitored interdigestive and postprandial bowel motility using bipolar electrodes and/or contractile strain gauge force transducers in conscious beagle dogs before and at 2-4 weeks (acute postoperative phase; acute phase) and 8-13 months (chronic postoperative phase; chronic phase) after the surgery. Fasting duodenal migrating myoelectric (or motor) complexes (MMC) occurred at longer intervals in the acute phase after 80% MSBR than in control beagles. Intervals between duodenal MMC in the chronic phase were similar to those found in control beagles. MMC arising from the duodenum were often interrupted before the jejunum above the anastomosis in the acute phase, and a slight recovery of propagation frequency to the jejunum above the anastomosis was observed in the chronic phase. However, duodenal MMC did not migrate smoothly to the terminal ileum in both groups. In the acute phase, the velocity of duodenal MMC propagation was slowed in every intestinal segment, including the duodenum and the jejunum above the anastomosis, and had not recovered even long after the operation. The duration of the postprandial period without duodenal MMC was prolonged significantly in the acute phase postoperatively. Although it shortened in the chronic phase, it still remained significantly longer than in controls. These findings suggest that changes in gut motility after MSBR tend to compensate for the shorter intestine and maintain small bowel absorption early postoperatively. However, these compensatory changes decrease over the long term, and their adaptive contributions to increased intestinal absorption may decrease as well.

Anastomosis, Surgical↗
PubMed1986

Electrogastrographic characteristics of interdigestive migrating complex in humans.

Interdigestive myoelectric activity and mechanical activity were studied simultaneously by means of cutaneous electrodes (electrogastrography) and intraluminal pressure recording, respectively, in 10 healthy male volunteers. The aims of the present study were 1) to describe the characteristics of the electrogastrogram during the different phases of the interdigestive migrating complex (IMC) in healthy subjects and 2) to determine to what extent these characteristics can be used to identify the different phases of the IMC. The electrogastrograms were analyzed visually and by running-spectrum analysis. It was concluded that in humans the gastric frequency present in the electrogastrogram appears to be less stable during motor activity than during motor quiescence, in particular during phase III, but far more stable than its canine counterpart. A small but consistent drop in gastric frequency was observed in the changeover from motor quiescence to phase II motor activity. The power of the gastric frequency increased with increasing motor activity, except during phase III. A characteristic frequency and power behavior during phase III could only be recognized in a minority of the IMCs. In general, electrogastrography cannot, given the present state of the art, be used to precisely identify the different phases of the IMC.

Adult↗