Gastric myoelectrical activity in patients with gastric outlet obstruction and idiopathic gastroparesis

Objective: The cause of gastroparesis may be uncertain in some patients. Mechanical obstruction of the stomach or duodenum should be excluded in patients with idiopathic gastroparesis. The objective of this study was to compare gastric myoelectrical activity in patients with idiopathic gastroparesis with that of patients with gastroparesis due to mechanical obstruction of the stomach or duodenum.
Methods: Electrogastrography techniques were used to record gastric myoelectrical activity in 20 patients with idiopathic gastroparesis and in nine patients with gastroparesis secondary to gastric outlet obstruction. Four of these nine patients initially were thought to have idiopathic gastroparesis. Electrogastrograms (EGGs) were recorded from 29 healthy subjects who served as controls. EGGs were recorded for 20–30 min 2 h after a standard 200-Kcal meal and were analyzed visually and by computer.
Results: Patients with gastroparesis due to outlet obstruction had high-amplitude and excessively regular 3–cycles-per-minute (cpm) EGG patterns, whereas patients with idiopathic gastroparesis had primarily 1- to 2-cpm patterns and little 3-cpm EGG activity. The percentage of total EGG power in the 3-cpm range was approximately 50% in patients with gastric outlet obstruction compared with 20% in patients with idiopathic gastroparesis (   p < 0.001  ). The percentage of EGG power in the normal 3-cpm range was greater in the obstructed patients (50%) than in the healthy controls (35%;   p < 0.052  ).
Conclusions: Gastric myoelectrical patterns recorded in the EGG distinguish mechanical and idiopathic causes of gastroparesis and may be useful in evaluating patients with nausea, vomiting, and gastroparesis of unknown cause.     

Effects of epalrestat,an aldose reductase inhibitor,on diabetic neuropathy and gastroparesis

OBJECTIVE: Diabetic patients with severe autonomic nervous disorder show delayed gastric emptying accompanied by diabetic gastroparesis, which decreases the electric activity of the stomach associated with gastric motility. It is reported that epalrestat, an aldose reductase inhibitor, is useful for treating diabetic neuropathy. Therefore, we evaluated whether this drug improves the decreased gastric motility in diabetic patients. METHODS: The present study evaluated the electrogastrograms (EGG) and autonomic nervous activity in 15 healthy volunteers (N group), and in 15 diabetic patients before and after the administration of epalrestat (DM group). Autonomic nervous activity was evaluated by spectral analysis of heart rate variability. The EGGs were recorded before and after oral administration of epalrestat (3 months or more) in the DM group. RESULTS: The dominant frequency of EGG was 3 cycles/min (cpm) in the N group. However, these 3 cpm waves disappeared with bradygastria, and postprandial increases in the peak powers of EGG were not observed in the DM group. Both the amplitude of 3 cpm waves and the postprandial peak powers were significantly increased after the administration of epalrestat. The parameters of autonomic nervous activities (LF power, HF power, and the LF/HF ratio) were significantly lower in the DM group before the administration of epalrestat than in the N group. However, these parameters were improved after the administration of epalrestat. CONCLUSION: Since gastroparesis is a form of diabetic dysautonomia, complication by gastroparesis may influence blood sugar control and the absorbance of oral antidiabetics. Epalrestat significantly increased the amplitude of 3 cpm waves on EGG and improved the spectral analytical parameters of heart rate variability. These findings suggest that epalrestat is useful for the treatment of diabetic gastroparesis.     

Sham feeding

The effects of sham feeding on gastric motility of human subjects have not previously been studied. The amplitude of 3-cpm electrogastrogram (EGG) waves increases after the ingestion of food. We hypothesized that sham feeding would stimulate a similar, but briefer gastric myoelectric response. Healthy human subjects chewed and expectorated a hot dog on a roll and later ate a second hot dog. EGGs were continuously recorded before, during, and after sham feeding and eating. The results of experiment I (N=27) showed that the hand-scored amplitude of the 3-cpm waves increased significantly (P<0.01) during sham feeding. Two minutes after sham feeding, the mean amplitude of 3-cpm EGG waves returned to baseline level. The increase in EGG amplitude during eating was also significant (P<0.01), and remained increased for approximately 30 min after ingestion. The procedure used in experiment II (N=20) was similar to experiment I, but EGGs were computer analyzed and power, ie, spectral intensities, at 3 cpm were obtained. The increase in power at 3 cpm during sham feeding and during eating was significant (P< 0.05 and P<0.02, respectively). Similar to experiment I, the duration of increase in power at 3 cpm was brief during sham feeding compared to the postprandial increase. Four vagotimized subjects failed to show an increase in power at 3 cpm in response to sham feeding. We conclude: (1) The cephalic—vagal stimulation of sham feeding increases briefly the amplitude and power of 3-cpm gastric myoelectric activity in healthy subjects but not vagotomized patients. (2) The increase in postprandial 3-cpm amplitude is prolonged, reflecting initial cephalic-vagal activity and subsequent gastric stimulation by luminal contents.     

Electrogastrography prior to and following total gastrectomy,subtotal gastrectomy,and gastric tube formation

On electrogastrography (EGG) spectral analysis, an activity of 3 cycles per minute (cpm) is supposed to be specific for the stomach. After total or subtotal gastrectomy, the original site of the stomach is occupied mainly by the intestine. We attempted to determine if intestinal activity could be recorded in this region with EGG. Epigastric recordings were performed in patients prior and following gastrointestinal or control surgeries. Spectral analysis, using the maximal entropy method and ensemble means was applied to data analysis from these recordings. Preoperatively, the majority of the power peaks were found around 3, 6, and 11 cpm. The postprandial-to-fasting power ratio of all of these power peaks increased significantly postprandially (P<0.05–0.01). Following total gastrectomy, the power peak around 3 cpm disappeared or was significantly diminished in amplitude (P<0.05). The postoperative-to-preoperative power ratio ranged from 0.03 to 0.10 (P<0.001–0.01). However, the power peak around 11 cpm did not significantly change prior to or following total gastrectomy, and the 11 cpm peak appeared relatively dominant. Simultaneous manometric studies in the Roux limb demonstrated a correlation between the power spectral frequency of EGG and manometry at 11 cpm. Therefore, the 11 cpm peak appeared to reflect jejunal or Roux limb electrical activity. The postoperative to preoperative power ratio for the 3 cpm also was significantly reduced following subtotal gastrectomy and gastric tube formation in patients in the postprandial state (P<0.05–0.001).     

Trans-cutaneous electrogastrographic study of gastric myoelectric activity in transposed intrathoracic stomach after esophagectomy

We examined the feasibility of trans-cutaneous electrogastrography (EGG) in recording myoelectric activity of the transposed thoracic stomach after esophagectomy. Nineteen patients who had Ivor-Lewis esophagectomy were studied. The EGG signal was recorded using cutaneous electrodes placed over the lower sternum. Eleven patients who underwent total gastrectomy served as controls. Normal rhythm pattern (2.4-3.6 cpm > or = 70%) and power ratio (PR > or = 2) was observed in five and 12 patients, respectively, after esophagectomy. The observation of normal gastric rhythm was more frequent in the postprandial period in the esophagectomy group (median 42.6%vs. 7.4%, P = 0.01), and the PR was significantly higher (median 2.27 vs. 1.38, P = 0.013) than the gastrectomy group. Feeding further increased the prevalence of normal gastric slow wave in the esophagectomy group (median 14.8% to 42.6%, P = 0.002) and improved the stability of dominant frequency (median 78% to 67%, P = 0.015). We conclude that gastric myoelectric activities of thoracic transposed stomach can be detected from cutaneous sternal electrodes. This represented a preservation of gastric motility even when the stomach is pulled up to the thorax as a substitute for the esophagus.     

Electrical activity from colon overlaps with normal gastric electrical activity in cutaneous recordings

The stability of EGG recordings is affected by a variety of artifacts. The aim of this study was to investigate possible overlapping of dominant frequencies in recorded cutaneous electrical activity arising simultaneously from the stomach and/or colon. Ten normal volunteers, eight posttotal colectomy patients, and four patients posttotal gastrectomy were studied. Fasting cutaneous recordings were obtained using four pediatric ECG electrodes attached to the abdominal surface. Electrical activity was recorded and digitally analyzed using custom-designed software. Spectral analysis after gastrectomy and colectomy showed persistence of power peaks in the gastric electrical activity range of frequency (2.5–3.75 cpm). In conclusion, noninvasively obtained colonic frequencies overlap EGG. This hypothesis is supported by the persistence of power peaks in the EGG range of frequency after gastrectomy and colectomy. Therefore, we conclude that contribution of electrical activity arising from the colon could substantially affect EGG recordings.     

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.     

Gastric emptying and gastric myoelectrical activity in patients with diabetic gastroparesis: effect of long-term domperidone treatment

We measured gastric emptying and gastric myoelectrical activity with solid-phase gastric-emptying tests and cutaneously recorded electrogastrograms (EGGs), respectively, in six insulin-dependent diabetic patients with nausea and vomiting who did not respond to standard treatments. Baseline solid phase gastric emptying was markedly delayed (78 +/- 8% retained at 120 min) and EGG recordings revealed gastric dysrhythmias; tachygastria (4-9 cpm signals) in one patient, 1- to 2-cpm waves in two patients, and flatline patterns in three patients. No patient had a normal 3-cpm EGG pattern. After 6 months of domperidone treatment, mean upper gastrointestinal symptoms scores decreased from 17.8 to 3.7 (p less than 0.01), and normal 3-cpm EGG frequencies were recorded from each of the six patients. The mean percentage of meal retained at 120 min decreased but did not improve significantly. Thus, establishment of normal 3-cpm gastric myoelectric activity and resolution of dysrhythmias, not normalization of emptying rates, was associated with improvement in upper gastrointestinal symptoms in these diabetic patients.     

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.     

Electrogastrographic characteristics in subjects with stomach remnant

Background and Aims: Slow wave (SW) is an essential component in mediating stomach motility. The purpose of the present study was to investigate the SW characteristics in subjects with stomach remnant. Methods: We consecutively enrolled 58 distal radical subtotal gastrectomy (RSG) patients (male/female: 44/14, age: 33–79 years) to receive an electrogastrographic (EGG) measurement. Their Helicobacter pylori status and dyspeptic score were simultaneously assessed. In addition, EGG data of 58 age‐ and sex‐matched healthy subjects were compared. Based on power spectral analysis, the following EGG parameters were derived: dominant frequency (DF)/power (DP), percentage of normal rhythm (2–4 cpm), power ratio (PR) referring the postprandial power change, etc. Results: Visual analysis occasionally found a short period of ～11 cpm myoelectricity‐like rhythm. Distal RSG patients had lower fasting (1.90 ± 0.69 vs 2.97 ± 0.58 cpm, P < 0.001) and postprandial (2.03 ± 0.72 vs 3.35 ± 0.27 cpm, P < 0.001) DF values, while their fasting (36.2 ± 22.3% vs 67.1 ± 23.4%, P < 0.001) and postprandial (33.4 ± 19.9% vs 82.2 ± 16.7%, P < 0.001) percentages of normal rhythms were diminished. In contrast, fasting DP, its meal response and PR (2.99 ± 2.40 vs 2.45 ± 2.63, NS) were comparable to those of controls. Neither gender, age, type of gastroenterostomy, Helicobacter pylori colonization, dyspeptic score nor elapsed time after surgery had an obvious influence on EGG parameters. Conclusions: Distal RSG patients may have decreased SW frequency and less meal ingestion changed EGG parameters in terms of SW frequency, normality and stability, whereas their EGG power remained unchanged irrespective of meal ingestion.     

Gastric dysrhythmias and nausea of pregnancy

Gastric dysrhythmias have been recorded from patients with a variety of nausea syndromes. The aim of this study was to measure gastric myoelectric activity in women with and without nausea during the first trimester of pregnancy. In 32 pregnant women gastric myoeletric activity was recorded for 30-45 min with cutaneous electrodes that yielded electrogastrograms (EGGs). Frequencies of the EGG waves were analyzed visually and by computer. Subjects rated their nausea at the time of EGG recording on a visual analog scale with 0 representing no nausea and 300 mm severe nausea. Gastric dysrhythmias were found in 26 pregnant subject: Seventeen had tachygastrias (EGG frequencies of 4-9 cpm), five had 1- to 2-cpm EGG waves, and four had flat-line patterns Mean nausea scores of the subjects with tachygastrias, 1- to 2-cpm, and flat-line patterns were 64.8 +/- 13, 93.4 +/- 23, and 77.2 +/- 36, respectively. Six pregnant subjects had normal 3-cpm EGG patterns, and their nausea scores averaged 2.8 +/- 1.1 (P less than 0.05 compared with nausea scores in subjects with tachygastrias, 1- to 2-cpm, and flat-line rhythms). Six subjects with gastric dysrhythmias during pregnancy were restudied after delivery; each of these subjects had normal 3-cpm EGG patterns and none had nausea. Thus, gastric dysrhythmias are objective pathophysiologic events associated with symptoms of nausea reported during the first trimester of pregnancy.     

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.     

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.     

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.     

Fasting and postprandial small intestinal slow waves non-invasively measured in subjects with total gastrectomy

BACKGROUND AND AIM: Slow wave is essential to initiate gastrointestinal tract motility. Subjects with total gastrectomy (TG) provide an opportunity to study small intestinal slow wave in the absence of stomach interference. The aims of this study were to determine the origin of 3 cycles per min (cpm) slow wave recorded via electrogastrogram (EGG) and the characteristics of putative small intestinal slow waves in TG subjects. METHODS: Thirty-three subjects with TG (25 male, age: 44-83 years) were consecutively enrolled. In each subject, the myoelectricity-like signals of the gastrointestinal tract were recorded using 3-channel EGG. Fourier transform-based spectral analysis was performed to derive the EGG parameters including dominant frequency/power, % normal rhythm (2-4 cpm), and power ratio. RESULTS: Neither visual nor spectral analysis of the EGG revealed any waves at a frequency of about 3 cpm. The most frequently observed peaks in the power spectra of all subjects were those at approximately 1, approximately 6 and approximately 11 cpm with occurrences of 97%, 6.1% and 90.9%, respectively. Based on visual analysis of all recorded signals, the approximately 11 cpm signal was exactly rhythmically recorded rather than the approximately 1 cpm. The recorded approximately 11 cpm wave had a frequency of 10.9 +/- 1.0 cpm in the fasting state and 10.9 +/- 1.3 cpm in the fed state (NS), and a power of 31.5 +/- 3.2 dB in the fasting state and 35.2 +/- 3.8 dB in the fed state (P < 0.0001). None of other factors, including sex, age, and body mass index, had any impact on this approximately 11 cpm wave. CONCLUSIONS: Small intestinal slow wave can be recorded non-invasively using EGG via cutaneous electrodes in TG subjects. Sex, age and body mass index have no effect on the intestinal slow waves. The power rather than frequency of intestinal slow wave is increased after a solid meal.     

Gastric myoelectrical activity in diabetics with and without diabetic autonomic neuropathy

BACKGROUND/AIMS: The effects of diabetes mellitus on gastric myoelectrical activity has not been fully investigated. The aim of the present study was to investigate the pattern of gastric myoelectrical activity in noninsulin dependent diabetics, detected by electrogastrography in an attempt to clarify the relation between diabetic autonomic neuropathy and gastric myoelectrical abnormalities, if any. METHODOLOGY: The study was carried out on 34 noninsulin dependent diabetes (7 males, 27 females). Their age ranged from 35-60 years with mean age of 51.5 +/- 3.5 years. The EGG was recorded for 30 min in both the fasting and postprandial states, using an ambulatory EGG recording device (Digitrapper EGG, Synectics Medical). The adaptive spectral analysis method was used to assess the normality of the EGG. The EGG was defined as abnormal if: the percentage of normal slow waves (2.5-3.7 cycles/min) was below 70% during either the baseline or postprandial recording or there was a decrease in EGG peak power after the meal, or both. RESULTS: EGG abnormalities were detected in 13 patients (38.2%); 1 had tachygastria, 1 had bradygastria, 7 had dysrhythmias, and 4 had decreased EGG peak power after the meal. All diabetic patients with abnormal EGG suffer autonomic neuropathy. CONCLUSIONS: These results suggest that gastric myoelectrical abnormalities occur in a high proportion of noninsulin dependent diabetics and these abnormalities predominate in those patients with autonomic neuropathy.     

Evaluation of Residual Stomach Motility After Proximal Gastrectomy for Gastric Cancer by Electrogastrography

The relationship between the motility and the size of the residual stomach after proximal gastrectomy was evaluated using electrogastrography (EGG). Based on fast Fourier transformation, recorded slow waves could be analyzed to obtain the following parameters: dominant frequency (DF), percentage normal frequency (% 3 cycles per minute [cpm]), and power ratio (PR). EGG parameters, the length of the greater curvature of the residual stomach (LGC), were recorded in 18 gastrectomized patients. Compared to 12 healthy controls, the gastrectomized patients had abdominal EGG parameters including lower %3cpm (43 ± 21% vs 83 ± 7%; P < 0.05), DF (2.2 ± 0.4 vs 3.0 ± 0.2 cpm; P < 0.05), and PR (1.5 ± 0.8 vs 2.5± 0.8; P < 0.05). In relation to LGC and parameters, there was no difference between the patients whose LGC was > 20 cm and controls in PR (2.3± 0.9 vs 2.5± 0.8; n.s.). In conclusion, the motility of the residual stomach would be equal to that of the nonresected stomach as if the volume of the residual stomach was more than half.     

Multichannel electrogastrography (EGG) in symptomatic patients: a single center study

OBJECTIVES: To determine the value of multichannel versus conventional single-channel electrogastrography (EGG) and of an additional postprandial hour recording in symptomatic patients. METHODS: Eighteen normal subjects and 47 patients with upper GI symptoms underwent multichannel EGG with four cutaneous recording electrodes placed on the antral axis. Fasting EGG was recorded for 1 h, followed by meal ingestion, followed by two 1-h postprandial EGG recordings. Variables assessed: (1) dominant frequency (DF) and its power; (2) percent time in normal (2-4) cpm frequency; (3) average percent of slow wave coupling (% SWC). RESULTS: Normal values for single-channel EGG were: (1) DF from 2.5-3.3, 2.7-3.5, and 2.6-3.5 cpm in the fasting, first, and second postprandial hours; (2) percentage of time in 2-4 cpm: >50%, >65%, and >65% in the fasting, first, and second postprandial hours. Normal values for percent SWC using multichannel EGG were >50%, >55%, >55% in the fasting, first, and second postprandial hours. In the symptomatic patients, an abnormal 2-h single-channel EGG was obtained in 16 of 47 (34%) patients. Adding an additional 1 h of postprandial recording identified another 4 abnormal patients (20/47 = 43%). With multichannel EGG, abnormal results were obtained in 24 of 47 patients (51%) with the 2-h study. An additional 1 h of postprandial recording identified another 4 patients as abnormal (28/47 = 60%). CONCLUSIONS: Multichannel EGG recording improved the detection of abnormal gastric myoelectric activity in symptomatic patients. This study also demonstrates prolonging the postprandial recording to 2 h increases the diagnostic yield for both single-channel and multichannel EGG.     

Multichannel Electrogastrography (EGG) in Normal Subjects: A Multicenter Study

The aim of this study was to record gastric myoelectric activity using multichannel electrogastrography (EGG) and to determine if there are differences due to age, gender, body mass, and study location. In 61 normal subjects from four centers, fasting multichannel EGG was recorded for 1 h, followed by two 1-h postprandial recordings after a test meal. Variables assessed included dominant frequency (DF) and its power, percentage time in 2- to 4-cpm frequency, and percentage slow-wave coupling (%SWC). There were no significant differences in EGG parameters with respect to gender or age. Subjects with a BMI >25 had a decrease in the absolute DF power but a similar increase in the postprandial DF power. Subjects with a BMI >25 had a postprandial decrease in the %SWC compared to those with a BMI <25. There was a decrease in postprandial %SWC in European/Asian centers compared to American centers. In conclusion, multichannel EGG provides assessment of electrical slow-wave coupling in addition to determining dominant frequency, power, and percentage normal rhythm. This multicenter study of normal subjects shows similar multichannel EGG values among different genders and ages. Body mass and ethnicity may impact on some of the EGG values.     

Effect of barium meals on gastric electromechanical activity in man

The relationship between the cutaneously recorded electrogastrogram (EGG) and gastric contractions in man is unclear. We investigated: (1) the relationship between the electrogastrogram (EGG) signals and gastric contractions elicited by barium meals and (2) the effects of barium meals on frequency and amplitude of EGG signals. As documented by fluoroscopy in four healthy subjects, barium meals stimulated three per minute gastric peristalsis which corresponded with simultaneously recorded three cycle per minute (cpm) EGG waves. Eighteen other healthy volunteers ingested 45% (w/v) or 60% barium suspensions. As determined by Fourier analysis, the dominant EGG frequency before barium was 3 cpm in 16 subjects; two subjects had no distinct frequency peaks. After barium ingestion, the mean amplitude or power at 3 cpm and 1 cpm increased, but the increase was significant only after 45% barium. In conclusion: (1) individual EGG waves after barium reflect gastric peristaltic sequences, which are reflected in increases in amplitude or power of 3 cpm EGG activity; (2) density or viscosity of the barium meal affects the gastric myoelectric response; and (3) mechanical correlates of 1 cpm EEG activity are unknown.