Impaired Postprandial Gastric Myoelectrical Activity in Chinese Patients with Nonulcer Dyspepsia

Using a homemade electrogastrography (EGG) system, we studied the characteristics of the myoelectrical rhythm in Chinese patients with nonulcer dyspepsia (NUD). Based on short-term Fourier transformation, recorded slow waves could be automatically analyzed to obtain the following parameters: dominant frequency/power, percent of normal frequency (2–4 cpm), power ratio, etc. EGG parameters, Helicobacter pylori status, histological examination of gastric mucosa, and dyspeptic symptoms were recorded in 27 NUD patients. Compared to 32 healthy controls, the Chinese NUD patients had abnormal postprandial EGG parameters including a lower percentage of regular 2–4 cpm slow waves (70.10 ± 2.97% vs 79.08 ± 2.95%, P < 0.05), a lower level of increment of dominant power (0.62, ± 0.91 vs 3.76 ± 0.58 dB, P < 0.05), lower power ratio (1.42 ± 0.28 vs 2.79 ± 0.39, P < 0.05) and a higher instability coefficient (0.36 ± 0.03 vs 0.26 ± 0.03, P < 0.05). However, Helicobacter pylori infection and its associated gastritis did not influence any EGG parameters in NUD patients. Six main dyspeptic symptoms and total symptom score had no correlation with any EGG parameters. In conclusion, Chinese NUD patients may have abnormal postprandial stomach myoelectrical activity, but these EGG abnormalities are not a direct result of Helicobacter pylori infection and its related gastritis and do not contribution to the dyspeptic symptoms.     

Gastric Myoelectrical Activity in Healthy Children and Children with Functional Dyspepsia

The aim of this study was to investigateabnormalities in pediatric patients with functionaldyspepsia. Fifteen symptomatic pediatric patientsdiagnosed with functional dyspepsia and 17 aged-matchedhealthy controls were studied. Gastric myoelectricalactivity was recorded using surface electrogastrographyfor 1 hr in the fasting state and 1 hr after a testmeal. It was found that, in comparison with thecontrols, the children with functional dyspepsia had alower percentage of 2- to 4-cpm slow waves in bothfasting state (66.0 ± 4.7% vs 79.7 ± 3.1%,P < 0.07) and fed state (72.4 ± 5.4% vs 85.0± 2.9%, P < 0.04), and a significantly higherinstability of the dominant frequency in both fastingstate (0.50 ± 0.05 vs 0.31 ± 0.04, P <0.01) and fed state (0.39 ± 0.05 vs 0.25 ±0.03, P < 0.05). It was also found the postprandial increase inEGG dominant power in the patients was inverselycorrelated with the total symptom score (r = 0.63, P =0.03). It was concluded that abnormal gastricmyoelectrical activity may play a role in the pathogenesis ofpediatric functional dyspepsia.     

Inhibitory effect of white wine on gastric myoelectrical activity and the role of vagal tone

Although extensively investigated throughout the gastrointestinal tract, the influence of alcohol on gastric motility is still unclear. Our aim was to investigate the effect of wine on gastric myoelectrical activity and vagal activity. Ten healthy subjects were studied in two sessions with the electrogastrogram (EGG) for 30 min at baseline, 30 min after ingesting the test liquid [white wine (12.5% alcohol) or matched juice], and 60 min after a standard test meal. Spectral analysis was performed to compute EGG parameters and their postprandial changes. The vagal activity was assessed based on spectral analysis of the heart rate variability (HRV) signal derived from the ECG recording. White wine preload significantly diminished the postprandial increase in EGG dominant power compared to juice preload (1.16 ± 1.57 vs 5.48 ± 1.01 dB, P < 0.001). A significant decrease in vagal activity was observed after wine (23.40 ± 4.30 vs 17.43 ± 3.40%, P < 0.005), which remained unchanged after the test meal (23.40 ± 4.30 vs 16.77 ± 4.40%, P < 0.05). This decrease was not noted in the juice session. A correlation was established between changes after wine consumption in EGG dominant power and in the percentage of the vagal activity (r = 0.89, P < 0.05). In conclusion, white wine preload inhibits the postprandial EGG dominant power, suggesting a possible inhibition of postprandial gastric contractions. This effect may be associated with diminished vagal activity.     

Impaired gastric slow wave rhythmicity in patients after bone marrow or stem cell transplant

Patients after bone marrow or stem cell transplant often develop gastrointestinal symptoms. The aim of this study was to investigate possible impairment of gastric myoelectrical activity in these patients. The study was performed in 15 patients who had had bone marrow or stem cell transplant and 13 healthy subjects. Gastric myoelectrical activity was assessed using electrogastrography. The electrogastrogram (EGG) was made for 30 min in the fasting state and 60 min after a test meal (475 kcal; turkey sandwich). Overall and minute-by-minute spectral analyses were performed to derive various parameters of the EGG. Compared with the healthy controls, the patients showed a significantly higher percentage of arrhythmia (no obvious rhythmicity observed in the EGG) in both fasting (17.6 ± 3.8% vs 7.1 ± 2.17%, P < 0.02) and fed (11.4 ± 2.65% vs 4.19 ± 1.04%, P < 0.02) state. The patients showed a significantly higher instability coefficient of the dominant frequency in the fasting state than in the controls (0.51 ± 0.06 vs 0.29 ± 0.18, P < 0.008). The total average symptom score was 3.93 ± 0.84 in the patients and 0 in the controls, and a relatively weak but significant correlation was found between the symptom scores and the percentage of arrhythmia in the patients in fed state (r = 0.69, P < 0.02). It was concluded that patients with bone marrow or stem cell transplant have excessive arrhythmia that is correlated with their dyspeptic symptoms.     

Gastric Myoelectrical Activity in Patients with Parkinson's Disease (Evidence of a Primary Gastric Abnormality)

Parkinson's disease patients may experiencevarious gastrointestinal symptoms; however, the exactpathophysiology of these symptoms is not fullyunderstood. Therefore, the aim of this study was toinvestigate the pattern of gastric myoelectrical activityin patients with Parkinson's disease. Eleven patientswith Parkinson's disease and 10 healthy subjectsparticipated in the study. Patients were stratified as receiving dopaminergic therapy (N= 5) and off therapy (N = 6). Gastricmyoelectrical activity was measured by means of surfaceelectrogastrography (EGG) for 30 min before and for 90 min after a standardized meal. The dominantfrequency, postprandial EGG power change, and thepercentage of normal 2-4 cycles/min (cpm) slow-waveactivity in the three groups were calculated andcompared. The mean postprandial EGG power increase in theuntreated patients was smaller than in the treatedpatients (–3.11 ± 1.01 and 1.17 ±1.96 dB; P = 0.072). Moreover, both of these values weresignificantly decreased when compared to the control group(untreated vs control: d–3.11 ± 1.01 vs8.01 ± 1.86 dB; P = 0.04 and treated vs control:1.17 ± 1.96 vs 8.01 ± 1.86 dB; P = 0.02).The percentage of normal 2-4 cpm slow waves in untreated patients wasnot different from the treated patients (82.6 ±6.6% vs 75.8 ± 13.6%, P = NS) or from the controlgroup (88.2 ± 5.4%, P = NS). The dominantfrequency after the meal was similar to that in thefasting state both in the untreated (3.3 ± 0.1 vs3.2 ± 0.2 cpm; P = NS) and treated patients (3.2± 0.1 vs 3.1 ± 0.1 cpm, P = NS), whereasthe dominant frequency significantly increasedpostprandially in the control group (2.88 ± 0.12vs 3.05 ± 0.16; P < 0.05). Abnormalities ingastric myoelectrical activity in untreated Parkinson'sdisease patients reflect direct involvement of thegastrointestinal tract by the primary disease process.EGG can be regarded as a useful diagnostic tool inevaluating gastrointestinal involvement inneurodegenerative diseases.     

Effect of Peritoneal Dialysis on Gastric Myoelectrical Activity in Patients with Chronic Renal Failure

Impaired gastric myoelectrical activity has been reported in patients with chronic renal failure (CRF). The effect of peritoneal dialysis on this function has not previously been described. The aim here was to investigate the effect of peritoneal dialysis on gastric myoelectrical activity. Gastric myoelectrical activity was recorded by electrogastrography (EGG) in 23 patients with CRF (18 with dyspepsia) during peritoneal dialysis and with the peritoneal cavity empty of dialysis fluid (14 patients), and in 20 healthy controls. Two 30-min EGG recordings before and after a solid test meal were analyzed using spectral analysis methods. No significant difference in the percentage of normal 2- to 4-cpm slow waves was found in patients on peritoneal dialysis compared to those with the peritoneal cavity empty of dialysis fluid or to controls (in fasting state 83 ± 3%, 80 ± 5% and 89 ± 4%, in fed state 91 ± 3%, 86 ± 4% and 83 ± 4%, respectively). It was found that the power ratio (change in power of normal slow waves in fed state) was significantly higher in the 14 patients on peritoneal dialysis compared to the same patients with the peritoneal cavity empty of dialysis fluid (27.2 ± 10.7 vs 8.6 ± 4.8, P < 0.05). There was no significant difference in the power ratio between patients with the peritoneal cavity empty of dialysis fluid and controls (8.6 ± 4.8 vs 7.5 ± 2.2). The subgroup of patients with no dyspepsia had a significantly higher power ratio compared to those with dyspepsia both on dialysis and with the peritoneal cavity empty of dialysis fluid (39.4 ± 13.7 vs 12.4 ± 5.2 and 29.2 ± 21.5 vs 2.8 ± 0.4 respectively, P < 0.05). In conclusion, there was no significant difference in gastric myoelectrical activity between patients with the peritoneal cavity empty of dialysis fluid and controls. Dialysis fluid in the peritoneal cavity seems to enforce the gastric myoelectrical signal.     

Edrophonium Provocative Testing During Electrogastrography (EGG) (Effects on Dyspeptic Symptoms and the EGG)

The aim of this study was to determine whetheredrophonium induces dyspeptic symptoms and/or gastricmyoelectric changes in normal subjects and patients withfunctional dyspepsia. Eighteen normal controls and 28 patients with functional dyspepsiaunderwent electrogastrography (EGG) with edrophoniumadministration. After EGG recording with 1-hr fastingand 2-hr postprandial periods, subjects received anintravenous infusion of saline (placebo) followed byedrophonium 10 mg. After each injection, the EGG wasrecorded for 15 min and symptoms scored. Patients withfunctional dyspepsia had significantly more frequent gastrointestinal symptoms in response toedrophonium than normal controls. Edrophonium had noeffect on EGG dominant frequency, but increased thepower of the dominant frequency in both controls anddyspeptic patients. In the dyspeptic patients,reproduction of the patient's symptoms was associatedwith an increase in the power of the dominant frequency,whereas when no symptoms were produced, there was nochange in power. Overall, 21 of 28 dyspeptic patients(75%) had either an abnormal baseline EGG (N = 10) or anormal EGG and positive edrophonium test (N = 11). Inconclusion, edrophonium administration can reproduce symptoms in some dyspeptic patients.Symptoms after edrophonium administration may be relatedto either more vigorous gastric contractions and/orincreased visceral perception of normal gastric contractions.     

Impaired Gastric Myoelectrical Activity in Patients with Chronic Renal Failure

Dysmotility and delayed emptying of the stomachhave been reported in patients with chronic renalfailure (CRF). The aim of this study was to investigatewhether gastric myoelectrical activity was impaired in patients with CRF using electrogastrography.The electrogastrogram (EGG) was recorded in 24symptomatic patients with CRF (15 with diabetes) and 12normal subjects. Two 30-min EGG recordings before and after a test meal were analyzed using spectralanalysis methods. It was found that patients with CRFshowed a significantly lower percentage of normal 2-4cpm slow waves in both fasting and fed states in comparison with healthy controls (in fastingstate: 88.9 ± 2.5% vs 67.4 ± 6.6%/63.27.0%, P < 0.01; in fed state: 89.6 ± 1.8% vs64.6 ± 6.2%/62.0 ± 8.3%, P < 0.01;controls vs diabetic patients/nondiabetic patients). Both patient groups showed a significantlyhigher prevalence of the abnormal EGG, which was definedas the percentage of 2-4 cpm slow waves lower than 70%(fasting state: 8% vs 60%/56%, P < 0.01/0.05; fed state: 0% vs 53%/56%, P < 0.005/0.002;controls vs diabetic patients/nondiabetic patients). Nosignificant difference was observed in the regularity ofthe gastric slow waves between the two patient groups. The healthy controls showed a significantincrease in the dominant power and frequency of the EGGafter the test meal. However, this increase was absentin the two patient groups. It was concluded that patients with chronic renal failure haveabnormal gastric myoelectrical activity, includingimpaired regularity of the gastric slow wave and afailed increase in the power of the EGG at 3 cpm.Electrogastrography is an attractive noninvasive method for thestudy of gastric motility in patients with severechronic renal failure.     

Effects of Octreotide and Erythromycin on Gastric Myoelectrical and Motor Activities in Patients with Gastroparesis

Simultaneous recordings of gastric manometry andmyoelectrical activity were made in 10 patients withgastroparesis. Intravenous erythromycin (100 mg) wasadministered in the fasting state for a period of 30 min. Subcutaneous injection of octreotide(100 g) was administered before one of the fouridentical test meals. It was found that octreotidesignificantly decreased the antral motility index(30-min fasting: 4.51 ± 1.04 vs 1.75 ±0.97, P < 0.02; 60-min fed: 5.16 ± 1.44 vs 3.4± 1.41, P < 0.05) and the dominant power ofthe EGG (fasting power: 35.19 ± 1.54 vs 30.84± 1.57 dB, P < 0.004; postprandial powerincrease: 5.52 ± 1.06 vs 0.27 ± 0.87, P< 0.001). Erythromycin significantly increased theantral motility index (3.16 ± 0.96 vs 9.5± 0.61, P < 0.001) and the dominant power ofthe EGG (28.86 ± 1.57 dB vs 33.55 ± 1.59dB, P < 0.005) in the fasting state. An improvement in theregularity of the gastric slow wave was also noted witherythromycin. It was concluded that: (1) the inhibitoryeffect of octreotide on postprandial gastric motility and myoelectrical activity suggests thatcaution should be exercised when octreotide is used inpatients with gastroparesis; and (2) the stimulatoryeffect of erythromycin on gastric myoelectrical activity may enhance gastric motility and gastricemptying in patients with gastroparesis.     

Electrogastrographic characteristics in patients of stomach cancer

Using a homemade electrogastrography (EGG) system, we studied the characteristics of myoelectrical rhythm in gastric cancer (GC) patients. Based on a short-term Fourier transform, recorded slow waves could be automatically analyzed to obtain the following parameters: dominant frequency/power, percent of normal rhythm (2.4–3.7 cpm), power ratio, etc. Fifty histologically confirmed GC patients (34 men, 16 women) were enrolled before surgical intervention to measure their fasting and postprandial EGG parameters for 30 min. The cancerous parameters of GC patients were then obtained postoperatively. In addition, 46 healthy subjects were enrolled for comparison. When compared to controls, GC patients had the following characteristics: absence of postprandial increase in dominant frequency (GC: 3.04 ± 0.47 vs 3.07 ± 0.44 cpm, NS; controls: 3.02 ± 0.31 vs 3.21 ± 0.25 cpm, P < 0.001), marked power response after meal (P < 0.05), and obvious power ratio (4.58 ± 7.38 vs 2.27 ± 2.05, P < 0.05). Multivariate analysis indicated that advanced GC was the factor responsible for the obvious dominant power enhancement after meal (P < 0.05). Other demographic, clinical, and cancerous factors did not influence EGG parameters. We conclude that apparent arrhythmia is not encountered in GC patients, although they mainly exhibit obvious postprandial power response. Advanced GC is likely responsible for this power enhancement on EGG recording.     

Is Electrogastrography a Substitute for Manometric Studies in Children with Functional Gastrointestinal Disorders?

We performed simultaneous fasting and fedantroduodenal manometry and EGG in 25 children withfunctional bowel disorders. Three patients (12%) had anuninterpretable EGG. The manometric studies showedsevere neuropathy in six patients; milder neuropathicchanges in five patients; postprandial hypomotility inone patient; myopathy in four patients, and normalmotility in the remaining six patients. The percentage of tachygastria time (frequency >3.5cycles/min) was higher in the patients with mild (44.1± 15.8%) and severe (48 ± 19.1%)neuropathy than in the patients with myopathy (20± 16.2%, P < 0.05) or with normal motility (23 ± 13.3%, P< 0.05). There was a considerable overlap in thepercentage of tachygastria and total arrhythmia timeamong the different study groups. The ratio of post- to preprandial power was significantly higher (2.5± 0.07) in children with normal motility than inthe other patients groups. Every child with totalarrhythmia time <35% and a ratio of post-topreprandial power >2.4 had normal manometry. In summary,EGG differentiated groups of children with normalmanometry from others with neuropathic or myopathicchanges, but in a minority of patients the study was not interpretable and there was overlap in EGGresults between children with normal and abnormalmanometry.     

Gastric myoelectrical activity and gastric emptying in patients with functional dyspepsia

OBJECTIVES: The aims of this study were to investigate gastric myoelectrical activity and gastric emptying (GE) and their relationship in patients with functional dyspepsia. METHODS: The study was conducted in 15 healthy volunteers (six women, nine men, mean age: 42 yr) and 15 patients (13 women, two men, mean age: 43 yr) with functional dyspepsia. Gastric myoelectrical activity was recorded using cutaneous electrogastrography (EGG) for 30 min in the fasting state and for 120 min simultaneously with GE monitoring after an isotope-labeled solid meal. The anterior/posterior images of the stomach were taken using a technetium scanner immediately after eating, and then at 1, 2, and 4 h to determine the percentage of gastric retention. The dominant frequency of the EGG, the change of the postprandial EGG peak power (deltaP), and the percentage of normal 2-4 cycles/min (cpm) slow waves during each recording session were calculated and compared between the patients and healthy subjects. RESULTS: The patients had a significantly lower mean percentage of 2-4 cpm slow waves, both in the fed state and in the fasting state, than did healthy subjects. Compared to the EGG in the fasting state, a significant increase of the EGG dominant frequency in the fed state was observed in healthy subjects but not in the patients. The mean postprandial EGG power increase in the patients was substantially less than in the healthy subjects during the first postprandial hour but similar during the second postprandial hour. The mean percentage of gastric retention in patients is substantially higher than in the healthy subjects, both at 2 h after eating and at 4 h after eating. Of 15 patients, nine (60%) had delayed GE (gastric retention at 2 h >50%) and 10 (66%) had abnormal EGGs (percentage of 2-4 cpm <70% and/or deltaP < 0). Eight of these 10 patients (80%) with abnormal EGGs had delayed GE. CONCLUSIONS: A high proportion of adult patients (60%) with functional dyspepsia have abnormally slow GE and abnormalities in gastric myoelectrical activity.     

Impaired gastric myoelectricity in patients with chronic pancreatitis： Role of maldigestion

AIM: To investigate whether gastric myoelectrical activity was impaired in patients with chronic pancreatitis (CP) and to explore the role of pancreatic enzyme in regulating gastric myoelectrical activity. METHODS: Twenty CP patients and 20 controls participated in the study. Gastric myoelectrical activity was recorded by a homemade electrogastrography (EGG) device. Two experiments were carried out. In experiment one, EGG was recorded in both controls and CP patients. While in experiment two, either pancreatic enzymes or placebo was given together with test meals. Spectral analysis was used to generate various EGG parameters. RESULTS: The control subjects, but not the CP patients, showed typically increased postprandial dominant frequency. The postprandial dominant power (DP) increment (2.24±1.13 vs 5.35±0.96 dB, P= 0.04) and the percentage of normal 2-4 cpm slow waves (63.0±3.8% vs 77.4±3.1%, P<0.05) were lower in CP patients when compared with the control. In the 20 CP patients, the DP increment (4.76±1.02 vs 2.53±1.20 dB, P<0.05) and the postprandial percentage of normal 2-4 cpm (74.4±2.8% vs 64.8±5.7%, P<0.05) were significantly higher with pancreatic enzyme replacement than the placebo. CONCLUSION: CP patients have an abnormal postprandial stomach myoelectricity showing poor response in dominant frequency/power and regularity, whereas these abnormalities are corrected after pancreatic enzyme replacement. Maldigestion is likely to be the factor leading to abnormal postprandial gastric myoelectricity of CP patients.     

Electrogastrography Before and After a High-Caloric,Liquid Test Meal in Healthy Volunteers and Patients with Severe Functional Dyspepsia

Background: The cutaneous recording of gastric electric rhythm, so-called electrogastrography (EGG), has been purported as a non-invasive method for studying patients with functional dyspepsia and unexplained nausea and vomiting. The aims of this study were to determine normal values for EGG characteristics before and after a liquid, high-caloric test meal and to investigate whether EGG could discriminate between patients with functional dyspepsia and normal controls. Methods: In studying 20 healthy volunteers and 10 patients with functional dyspepsia, we recorded gastric electrical activity during the 30 min before and after a liquid 1.0-1.5 kcal/ml test meal. Satiety before and after the meal was estimated on a 10-point scale. EGG was analysed regarding dominant frequency, instability of the dominant frequency, power ratio and percentage activity in the normal frequency range. Results: The mean ( ± s ) caloric intake in patients with functional dyspepsia (286 ± 160 kcal) was significantly lower ( P < 0.001) than in healthy volunteers (610 ± 211 kcal). The patients reported a more pronounced feeling of satiety before the test meal (5.6 ± 3.2) compared to healthy volunteers (3.6 ± 1.2, P < 0.05), but at the end of the test meal there was no difference in satiety (7.9 ± 2.5 versus 7.7 ± 1.0). However, none of the EGG parameters showed any difference between patients and healthy volunteers. Conclusions: EGG before and after a high-caloric test meal showed large variation in healthy subjects and seemed to be of little value for differentiating between healthy individuals and patients with functional dyspepsia.     

Effect of hypo- and hyperthyroidism on gastric myoelectrical activity

Although hypo- and hyperthyroid patients have different symptoms in the gastrointestinal tract, the mechanism of thyroid action on the gut remains poorly understood. Thus the aim of this study was to investigate the effect of hypo- and hyperthyroidism on gastric myoelectrical activity, gastric emptying, dyspeptic symptoms. Twenty-two hyperthyroid (median age 45, 15 females) and 11 hypothyroid (median age 42, 10 females) patients were included into the study. Dyspepsia score, hypo- and hyperthyroid symptom scale, abdominal ultrasonography and upper gastrointestinal endoscopy were performed. Gastric myoelectrical activity was measured by electrogastrograpy (EGG) before and after therapy both preprandially and postprandially and compared with age, gender, and body-matched controls (12 for hypothyroid, 15 for hyperthyroid patients). Radionuclide gastric emptying studies were performed with a solid meal. Hypothyroid patients revealed a significant increase in preprandial tachygastria as compared with controls (12.3% vs 4.8%). The percentage of preprandial normal slow waves (2.4–3.7 cpm) was below 70% (dysmotility) in 7 of 11 hypothyroid patients versus 2 of 12 controls (P < 0.05). Hyperthyroid patients revealed a significantly higher preprandial (3.1 vs 2.8) and postprandial (3.4 vs 3) DF when compared with the controls (P < 0.05). A higher percentage of postprandial taschygastria (7.9 vs 0) was present in hyperthyroid patients than in the controls (P < 0.05). The decrease on postprandial EGG power (power ratio < 1) was observed in 7 patients the in hyperthyroid group and 1 in controls (P < 0.05). The percentage of postprandial normal slow waves was below 70% in 10 of 20 hyperthyroid patients vs 1 of 15 controls (P < 0.05). After therapy these differences disappeared in the euthyroid state. The hypo- and hyperthyroid symptom scale correlated to dyspepsia score. Dyspepsia score in hyperthyroidism correlated to power ratios in hyperthyroid patients. We detected some correlations between serum levels of fT3 or fT4 and some EGG parameters in hypo- and hyperthyroidism. Dyspepsia score and hypo- and hyperthyroid symptom scale were improved significantly after therapy in the euthyroid state. In conclusions, we showed gastric dysrhythmia by EGG in both hypo- and hyperthyroid patients. Dyspeptic symptoms correlated to the activity of thyroid disease. After therapy, these findings and dyspeptic symptoms improved in the euthyroid state. Abnormalities of power ratios may be responsible of dyspeptic symptoms in hyperthyroid patients. EGG may be a useful and noninvasive tool for detecting gastric disturbances during hypo- and hyperthyroidism.     

Electrogastrography before and after a high-caloric,liquid test meal in healthy volunteers and patients with severe functional dyspepsia

BACKGROUND: The cutaneous recording of gastric electric rhythm, so-called electrogastrography (EGG), has been purported as a non-invasive method for studying patients with functional dyspepsia and unexplained nausea and vomiting. The aims of this study were to determine normal values for EGG characteristics before and after a liquid, high-caloric test meal and to investigate whether EGG could discriminate between patients with functional dyspepsia and normal controls. METHODS: In studying 20 healthy volunteers and 10 patients with functional dyspepsia, we recorded gastric electrical activity during the 30 min before and after a liquid 1.0-1.5 kcal/ml test meal. Satiety before and after the meal was estimated on a 10-point scale. EGG was analysed regarding dominant frequency, instability of the dominant frequency, power ratio and percentage activity in the normal frequency range. RESULTS: The mean (+/-s) caloric intake in patients with functional dyspepsia (286 +/- 160 kcal) was significantly lower (P < 0.001) than in healthy volunteers (610 +/- 211 kcal). The patients reported a more pronounced feeling of satiety before the test meal (5.6 +/- 3.2) compared to healthy volunteers (3.6 +/- 1.2, P < 0.05), but at the end of the test meal there was no difference in satiety (7.9 +/- 2.5 versus 7.7 +/- 1.0). However, none of the EGG parameters showed any difference between patients and healthy volunteers. CONCLUSIONS: EGG before and after a high-caloric test meal showed large variation in healthy subjects and seemed to be of little value for differentiating between healthy individuals and patients with functional dyspepsia.     

Abnormal gastric myoelectrical activity and delayed gastric emptying in patients with symptoms suggestive of gastroparesis

Gastric myoelectrical activity modulates gastric motor activity. Abnormalities in gastric myoelectrical activity may be associated with gastric motility disorders. The aim of this study was to investigate the correlation of gastric myoelectrical activity with gastric emptying in symptomatic patients with and without gastroparesis. Ninety-seven patients with symptoms suggestive of gastroparesis participated in the study. Gastric myoelectrical activity was recorded using surface electrogastrography. The electrogastrogram (EGG) was recorded for 30 min in the fasting state and for 120 min after a solid test meal. Gastric emptying of the solid meal was simultaneously monitored for 120 min. Patients with delayed gastric emptying showed a significantly lower percentage of normal gastric slow waves (P<0.03) and a significantly reduced increase of the dominant power in the postprandial EGG (P<0.02). Postprandial EGG parameters were found to be able to predict delayed emptying of the stomach. Postprandial gastric dysrhythmia predicts delayed gastric emptying with an accuracy of 78%, while the abnormality in postprandial EGG power predicts delayed gastric emptying with an accuracy of 75%. All patients with abnormalities in both the rhythmicity and the power had delayed gastric emptying. Patients with delayed gastric emptying have a lower percentage of normal gastric slow waves in the EGG and a lower postprandial increase in the dominant power. Abnormalities in the postprandial EGG seem to be able to predict delayed emptying of the stomach. However, a normal EGG does not seem to guarantee normal emptying of the stomach.     

Clonidine Inhibits Postprandial Response of Antral Myoelectrical Activity

Clonidine, an ₂-adrenergic agonist, is known to inhibit gastric motility and delay gastric emptying in both humans and animals, but its effect on gastric myoelectric activity is unclear. The aim of this study was to investigate the effect of clonidine on postprandial gastric myoelectric activity. The experiment was performed in eight hound dogs (14.5–22.6 kg) implanted with three pairs of bipolar serosal electrodes with an interval of 4 cm and the most distal pair 2 cm above the pylorus. Each dog was studied twice on two separate days after a complete recovery from surgery. Gastric myoelectrical activity was recorded for 30 min in the fasting state and 90 min after a solid test meal of 838 kcal. Two tablets of clonidine (0.4 mg) were given with the meal in one of the sessions. The dominant frequency and power of the slow waves from the most distal pair were calculated by computerized spectral analysis. All data were expressed as mean ± se. A significant postprandial increase in the dominant power of the slow wave and an increase in the percentages of gastric slow waves with spike bursts were observed in the control session, whereas the dominant frequency of gastric slow waves showed a significant postprandial decrease after the meal. The dominant power increased 8.24 ± 0.5, 8.6 ± 0.2, and 7.5 ± 0.3 dB, respectively, in the first, and second, and third 30-min period after the meal (all P < 0.01 vs baseline). Clonidine completely abolished the postprandial increase in the dominant power of the gastric slow wave and significantly inhibited spike bursts. The dominant power only increased 2.4 ± 1.1 dB (P > 0.05 vs baseline; P < 0.01 vs the first postprandial period in the control session), 0.6 ± 1.5 dB (P > 0.05 vs baseline; P < 0.05 vs the second postprandial period in the control session) and –1.5 ± 2.2 dB (P > 0.05 vs baseline; P < 0.05 vs the third postprandial period in the control session) respectively during the first, second, and third periods after the meal and clonidine. However, it did not affect the postprandial change of the dominant frequency of gastric slow waves. No significant changes in percentage of regular slow waves were noted with the meal or with clonidine (P > 0.05). In conclusion, the postprandial response of gastric myoelectrical activity in dogs to a solid meal is featured with an increase in amplitude and spike bursts, which is inhibited by clonidine.     

Stomach myoelectrical response of patients with gastroesophageal reflux disease receiving omeprazole treatment

BACKGROUND AND AIM: Proton pump inhibitor treatment is effective for gastroesophageal reflux disease (GERD). It is unknown whether these agents effect any change in the stomach myoelectricity of GERD patients. Electrogastrographic (EGG) recording was used to study the probable effect of omeprazole on GERD patients. METHODS: Nineteen endoscopically confirmed GERD patients and 38 dyspepsia-free controls were invited to receive EGG recording. After daily omeprazole treatment for 4 weeks, the symptomatic response of GERD patients was scaled, healing of erosive esophagitis was endoscopically assessed, and EGG recording was repeated for comparison. RESULTS: Before treatment, GERD patients and controls displayed similar dominant frequency, whereas the former had higher dominant power compared with controls, either in fasting (29.2 +/- 6.0 dB compared with 25.3 +/- 3.8 dB, P < 0.01) or postprandial (31.9 +/- 5.6 dB compared with 27.7 +/- 3.8 dB, P < 0.001) recording. They also had diminished percentile normal rhythm (2-4 c.p.m.), irrespective of fasting (40.2 +/- 14.5% compared with 65.8% +/- 23.5%, P < 0.001) or postprandial (47.5 +/- 23.3% compared with 77.9 +/- 16.8%, P < 0.001) recording. After omeprazole treatment, healing was achieved in 12 patients (63.2%). Among the abnormal EGG parameters, only the postprandial percentile normal rhythm was restored (47.5 +/- 23.3% compared with 65.2 +/- 20.8%, P < 0.01). CONCLUSIONS: Gastroesophageal reflux disease patients may have obvious dysrhythmia and higher myoelectrical power. Effective omeprazole treatment only improves the postprandial myoelectrical regularity, whereas abnormal EGG parameters remain impaired.     

Gastric Dysrhythmias and Delayed Gastric Emptying in Patients with Functional Dyspepsia

An association between dyspepsia, gastricmotility disorders, and myoelectrical abnormalities hasbeen noted. The objective of the present study was toinvestigate both antral myoelectrical activity and gastric emptying in patients with functionaldyspepsia (FD). Electrogastrography (EGG) was performedin 25 adult patients with FD, which had been evaluatedby score. After an overnight fast, for 1 hr in the pre- and postprandial state (370 kcalliquid-solid test meal) the following EGG parameterswere determined: dominant frequency [DF (cpm)], DF (%)in the normal range (2-4 cpm), bradygastria (<2 cpm), tachygastria (4-10 cpm), dominant frequencyinstability coefficient (DFIC), and postprandial tofasting power ratio (PR). The data were correlated toresults obtained in 20 age- and gender-matched controls. In addition, in 17 consecutive patients the EGGdata were compared to the gastric retention ofradionuclides after 60 min (liquid-solid phase labeledwith ^99mTc colloid). Patients with FDrevealed a preprandial increase in tachygastria compared to controls(P < 0.001). Of 17 FD, seven patients exhibiteddelayed gastric emptying (t60 retention >68%). Thesepatients showed significantly more pre- and postprandial tachygastrias than patients with normal gastricemptying (P < 0.05). The dyspeptic symptology and H.pylori status did not correlate with EGG andradioscintigraphy. Patients with FD frequently revealimpaired gastric emptying and increased tachygastria,which may have pathophysiological significance in someof these patients.