Electrical activity recorded from abdominal surface after gastrectomy or colectomy in humans

The visceral electrical activity recorded from the abdominal surface was studied before and after either total gastrectomy or colectomy. The patterns obtained from fast Fourier transform analysis demonstrated the disappearance of the power peak of approximately 3 cpm after gastrectomy, whereas colectomy did not result in the disappearance of the power peak of approximately 3 and 8-12 cpm. Only the frequencies of approximately 3.5-7.5 cpm were not present after colon surgery. These data demonstrate that the spectral power peaks at frequencies of approximately 3 cpm are entirely related to the stomach because they disappear after gastrectomy; the power peaks between 3.5 and 7.5 cpm are related to the colon because they are present after gastrectomy but not after colectomy; the power peaks between 7.5 and 11 cpm are related to the small intestine because they are present after either gastrectomy or colectomy. The authors conclude that the electrical activity recorded from the abdominal surface and analyzed by fast Fourier transform gives reliable information concerning the electrical activity of the stomach and small intestine, although it is less reliable concerning the electrical activity of the colon.     

Effects of highly selective vagotomy on gastric myoelectrical activity

Changes in gastric myoelectrical activity following highly selective vagotomy were studied in 12 patients by means of electrogastrography (EGG) using cutaneous electrodes. Measurements were made before, 10 days after, and six months after operation. Eight patients undergoing cholecystectomy served as controls. Preoperatively all controls and patients had normal recordings. In the cholecystectomized patients no significant changes were found postoperatively. Ten days after highly selective vagotomy the normal initial postprandial dip in gastric ECA frequency and the subsequent increase in frequency and power were not seen. Tachygastrias were observed in three patients. Six months after operation the normal frequency and power responses to a test meal had returned, but both the fasting and postprandial ECA frequencies were raised significantly. It is concluded that highly selective vagotomy is associated with abnormalities in myoelectrical activity, in particular in the postprandial state, most of which are reversible with time.     

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.     

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.     

Pre- and postoperative electrogastrography in patients with gastric cancer

BACKGROUND/AIMS: To investigate the changes of electrogastrography (EGG) after stomach resection, fasting and postprandial EGG were recorded in 10 volunteers and 23 gastric cancer patients who had undergone total or subtotal gastrectomy. METHODOLOGY: EGG signals in patients were recorded before and after surgery and were analyzed by power spectrum. RESULTS: The power spectrum components at three cycles/minute (cpm) as normal subject, had completely disappeared in all patients after total gastrectomy, and irregular powers, especially under 9 cpm, had increased. These results suggest that the activity of the 3-cpm component is specific for the stomach. In subtotal gastrectomy patients, 3-cpm power peaks were clearly observed in seven of twelve patients, but it was not recorded in the remaining five patients, who showed irregular powers similar to that in patients after total gastrectomy. Therefore, it was speculated that the area containing the "pacemaker" of gastric electric potentials was removed during gastrectomy in these five patients. The postprandial dip, which is considered to reflect autonomic nervous function, was not observed in six of seven subtotal gastrectomy patients who demonstrated the 3-cpm component in their EGG, and it was speculated that the gastric branch of the vagus nerve in these six patients might have been partially removed by surgery. CONCLUSIONS: These findings suggest that EGG is available as a non-invasive method to evaluate the motility and autonomic function of the remnant stomach after gastrectomy.     

Analysis of Canine Model of Gastric Electrical Uncoupling Using Recurrence Quantification Analysis

This study reports the results of recurrence quantification analysis (RQA) applied to internal gastric electrical activity (GEA) and cutaneous electrogastrographic (EGG) digital recordings obtained from acute canine models. The purpose of this chaos analysis is to differentiate three states—normal, mild, and severe induced electrical uncoupling—utilizing five quantities associated with RQA: percent recurrence, percent determinism, maximum deterministic line, entropy, and trend. The results indicate that percent recurrence and trend are the only quantities that relate the three states of gastric electrical uncoupling in any meaningful way. The ability of EGG to detect mild electrical uncoupling in the stomach appears to be limited due to the impact of numerous external factors on the signals, even if multichannel recordings are utilized.     

Dynamics of the Level of Randomness in Gastric Electrical Activity

This study was undertaken to investigate thedynamics of the level of randomness in gastricelectrical signals. Combined recordings of internalgastric electrical activity (GEA) and electrogastrograms(EGG) were obtained from 16 unconscious dogs and twopostoperative patients. The signals were amplified usingspecially designed amplifiers with flexible frequencyrange and were digitized with 10-Hz sampling frequency. The 4.27-min portions of the digitalsignals were subjected to a previously described turningpoint test for randomness. The distributions of thenumber of turning points (NTP) in successive time intervals calculated from all GEA signalswere compared to the estimated NTP distribution of arandom signal. NTP dynamics of internal GEA signals wasalso correlated to the NTP dynamics of cutaneous EGG. In five of 16 recordings from the dogs andin two of the 14 recordings from the patients, NTPvalues calculated from some internal GEA channelsexceeded the 1% probability level for entering thenormal NTP distribution of a random signal (P >0.01). In all measurements the distributions of the NTPvalues recorded from cutaneous EGG channels weresignificantly different (P < 0.01) from the NTPdistribution of a random signal. There was significantcorrelation (P < 0.01) between the NTP dynamics ofinternal GEA and EGG. The level of randomness ininternal GEA recorded with the short-distance bipolartechnique is substantially higher than that in cutaneousEGG, probably due to the occurrence of spike activity.Although the level of randomness in EGG is affected bymany external factors, its dynamics correlated significantly with the level of randomness ininternal GEA.     

Electrogastrography can recognize gastric electrical uncoupling in dogs

BACKGROUND & AIMS: Electrical uncoupling is the lack of electrical synchronization in different parts of the stomach. The ability of electrogastrography (EGG) to recognize gastric electrical uncoupling has not been adequately studied. The aim of this study was to determine the impact on EGG of surgically introduced gastric uncoupling in anesthesized dogs. METHODS: Six pairs of bipolar electrodes were inserted into the antral gastric wall of 16 anesthetized dogs at laparotomy. Eight-channel bipolar cutaneous EGGs were simultaneously recorded. Three separate half-hour recordings were made from each dog in the basal state and after each of two circumferential cuts of all gastric muscle. The stomach was divided into three equally sized areas, each with an electrode pair in its anterior and posterior walls. Gastric electrical activity was assessed visually. EGG was digitized and processed by computer. RESULTS: Criteria for EGG normality were defined from 9 dogs with normal gastric electrical activity. After the first antral cut, internal recordings from the area below the division were at a lower frequency and often irregular. The second cut produced three different frequencies. Suggested criteria for normality allowed correct recognition of 93% of all severely abnormal records. Records with mild gastric electrical abnormalities were recognized with a sensitivity of 74%. CONCLUSIONS: EGG can recognize severe electrical uncoupling. (Gastroenterology 1997 Jun;112(6):2006-11)     

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.     

Postprandial Response of Gastric Slow Waves: Correlation of Serosal Recordings with the Electrogastrogram

Controversial interpretations have been given to the postprandial increase in the dominant power (amplitude) of the electrogastrogram (EGG). The aim of this study was to find an appropriate interpretation of the postprandial EGG power changes. Simultaneous serosal and cutaneous recordings of gastric myoelectrical activity were made in 11 patients with gastroparesis in the fasting state and after the ingestion of 8 oz of water. The dominant frequency and corresponding power of the recording before and after water were computed using the power spectral analysis method. It was found that the dominant frequency of the EGG was the same as that of the serosal recording in 10 patients. One patient showed a substantial amount of dysrhythmia and no obvious dominant frequency was noted. A decrease in the dominant frequency was found in these 10 patients after the ingestion of water. Tachygastria of higher than 4 cycles/min was observed in one of 11 patients both in the prewater and postwater states. Consistent changes in amplitude after a drink of water were noted in both serosal recording and EGG. Statistical analysis demonstrated that the dominant power change after water computed from the EGG was correlated with that observed in the serosal recording (r = 0.757, P = 0.007). In conclusion, exogenous stimulation, such as ingestion of water, may change the amplitude of the gastric slow wave and this change is reflected in the EGG, suggesting that the change of the slow-wave amplitude is an important contributing factor to the postprandial change in the EGG dominant power.     

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.     

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.     

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 Slow Wave Abnormalities in Patients with Gastroparesis

The aim of this study was to determine whether cutaneous electrogastrograms (EGGs) could be used to differentiate gastroparetic patients from asymptomatic healthy controls. Pre- and postprandial cutaneous EGGs were obtained from 24 asymptomatic healthy volunteers and 27 patients with gastroparesis documented by a delayed gastric emptying of a solid test meal. A definition of slow wave abnormality was introduced. For the fasted condition, all 24 controls showed highly regular, predominant peaks in the 2-4 cycles/min (cpm) range, in contrast to the patient group in which 11 subjects showed an absence of normal slow wave activity (p less than 0.001). For the postprandial condition, again, all 24 controls showed slow wave normality consisting of increased amplitude and regularity of the 2-4 cpm frequency component. This was in sharp contrast to the patient group in which 13 subjects showed abnormalities (p less than 0.0001). Approximately 75% of the patients had an abnormal pre- or postprandial EGG: four patients had abnormal EGGs both during fasting and after eating, seven patients had abnormal EGGs during fasting but normal EGGs after eating, and nine patients had normal EGGs during fasting but abnormal EGGs after eating. We conclude that the cutaneous EGG may be used to differentiate gastroparetic patients from asymptomatic normals.     

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.     

Spontaneous contractions and some electrophysiologic properties of circular muscle from normal sigmoid colon and ulcerative colitis

Spontaneous contractions, inhibitory responses produced by electrical field stimulation, and some electrophysiologic properties of circular smooth muscle from normal sigmoid colon and from sigmoid colon of ulcerative colitis patients were compared in vitro using simultaneous recordings of mechanical and intracellular electrical activity. In normal colonic circular muscle obtained from 21 patients, the frequency of spontaneous summation contractions ranged from 3 to 7 per 4 min, whereas in circular muscle from 13 patients with ulcerative colitis, the frequency of these contractions ranged from 1 to 9 per 4 min. Nonadrenergic, noncholinergic relaxation produced by electrical field stimulation was recorded in the majority of circular smooth muscle strips from both normal colon and colon from patients with ulcerative colitis. There were no significant differences in mean resting membrane potential, mean slow-wave frequency, mean maximum slow-wave amplitude, or inhibitory-junction potential amplitudes recorded using circular smooth muscle from both normal colon and colon from patients with ulcerative colitis. There appeared to be a weak association in patients with ulcerative colitis between increasing duration of symptoms and decreasing frequency of spontaneous summation contractions, but there were no associations between the frequency of these contractions and the severity of colonic inflammation, patient age, or the frequency of stools. The mechanism accounting for a wider range in the frequency of summation contractions recorded from colonic circular smooth muscle in ulcerative colitis remains to be determined.     

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.     

Gastric involvement in systemic sclerosis: a prospective study

OBJECTIVES: This study aims to assess the prevalence of gastric electrical activity dysfunction with cutaneous electrogastrography (EGG), disturbances of gastric emptying function using radiopaque pellets, and gastric endoscopic abnormalities in patients with systemic sclerosis (SSc). We also investigate for an association between EGG and gastric-emptying data with clinical manifestations and esophageal motor disturbances. METHODS: Fasting and postprandial gastric electrical activity was studied in 22 consecutive patients with SSc (17 with and 5 without clinical gastric manifestations) and 22 age- and sex-matched healthy subjects. Gastric emptying of radiopaque pellets and gastroscopy were also performed in SSc patients. RESULTS: The prevalence of EGG disturbances was as high as 81.82% in SSc patients. SSc patients exhibited, compared with controls, higher median percentage of dominant frequency in bradygastria during the fasting period and lower median values for postprandial electrical power and postprandial to fasting ratio for electrical power. Gastric emptying of radiopaque pellets was delayed in 11 SSc patients, and gastroscopy demonstrated "watermelon stomach" in 3 SSc patients. No correlation was found between the severity of gastric impairment and clinical presentation, SSc duration and subsets, and esophageal manometric impairment. CONCLUSIONS: Our study underlines the high frequency of gastric dysfunction in SSc patients. It suggests the usefulness of EGG in SSc in noninvasively detecting disorders of gastric electrical activity at an early stage and symptomatic patients with gastroparesis (because there was a correlation between values of postprandial to fasting ratio for electrical power of < 1 on EGG and delayed gastric emptying). Gastric-emptying evaluation of radiopaque pellets may further be a helpful method to depict symptomatic SSc patients with gastroparesis. Finally, our series confirms that watermelon stomach diagnosis should be excluded in SSc patients presenting with gastrointestinal hemorrhage or with anemia related to iron deficiency.