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.     

Mediation of transcatheter arterial chemoembolization induced gastric slow-wave dysrhythmia by endogenous prostaglandin

BACKGROUND AND AIMS: In recent years, gastric slow-wave dysrhythmias induced by transcatheter arterial chemoembolization (TACE) have been observed. Enhanced endogenous prostaglandin may be a possible mechanism for the myoelectrical changes. The aim of this study was to evaluate whether the gastric slow-wave dysrhythmias induced by TACE may be mediated by ketoprofen, a prostaglandin synthesis inhibitor. METHODS: Twenty-three patients with hepatocellular carcinoma (HCC) admitted for TACE were enrolled. A follow-up TACE was scheduled to take place 2 months later. During the next admission for TACE, 50 mg of ketoprofen was given intramuscularly 12 h for 3 days, beginning 48 h before TACE, as premedication. Cutaneous electrogastrography (EGG) was performed before and within 24 h after TACE. RESULTS: The results showed that the change in the fasting EGG parameters after TACE without premedication was not statistically significant. However, the postprandial EGG parameters, including the dominant frequency (DF); the percentages of DF in the normal, bradygastric and tachygastric range; along with the dominant frequency instability coefficient, deteriorated significantly after the procedure (P < 0.01). After the follow-up TACE with ketoprofen premedication, neither the fasting nor postprandial EGG parameters in the control group changed significantly. CONCLUSIONS: Gastric slow-wave dysrhythmias induced by TACE may be mediated by ketoprofen, a prostaglandin synthesis inhibitor, in HCC patients. However, the improvement in the gastric myoelectrical activity does not eliminate the degree of nausea/vomiting after TACE.     

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.     

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.     

甲状腺机能亢进和减退患者的胃电图改变初探

目的通过胃电图(EGG)检查,观察32例甲状腺机能亢进(甲亢)病人,29名甲状腺机能减退(甲减)病人及30名正常健康人餐前和餐后30min的体表胃电频谱变化。结果3组内餐后胃电图主频(DF)、平均幅值(AP)、正常慢波百分比(N%)与餐前相比均有显著增加(P<0.01)。甲亢组主频和平均幅值与对照组相比,无显著差异(P>0.05),甲减组平均幅值与正常慢波百分比较对照组差异显著(P<0.01)。结论甲亢组食欲亢进在胃电图上无特殊反映,表现为主频正常,胃电节律正常,振幅亦无明显升高。甲减组食欲减退可能与胃动过缓,胃电节律紊乱增多有关。     

Electrogastrography in healthy subjects

Electrogastrography (EGG) permits measurements of the gastric electrical activity. However, normal values of electrical activity are poorly defined. In addition, limited data are available on the effect of age and gender. Therefore, in 40 healthy subjects (age range: 19–90 years) normal values for several EGG parameters were assessed after an overnight fast for 1 hr in the fasting and fed state after ingestion of a standardized solid-liquid meal. The electrical signals were capture by a pair of surface electrodes sonographically placed on the skin overlying the gastric antrum. The dominant electrical frequency was predominantly in the defined normal frequency range between 2 and 4 cycles per minute (cpm) (P<0.001) and was higher in the postprandial than in the preprandial period (3.1 cpm vs 2.8 cpm,P=0.02). The instability of the electrical rhythm calculated by a dominant frequency instability coefficient (DFIC) was postprandially lower than in the fasting state (P=0.04). The electrical power (amplitude) increased postprandially (postprandial to fasting power ratio =2.4). To evaluate the influence of age and gender on normal values the subjects were divided into four groups (median age: male, 28 and 69 years; female, 25 and 67 years). The most parameters did not differ significantly between the groups. However, DFIC was different between the groups (P<0.05), with elderly women revealing lowest DFIC. In conclusion, normal values for several EGG parameters evaluated in this study should be included in the analysis of gastric electrical activity. The magnitude of electrical frequency and power are not influenced by age and gender, whereas the instability of the electrical frequency is influenced by these factors.     

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 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.     

慢性肝衰竭患者体表胃电图表现

对18例慢性肝衰竭患者行体表胃电图检查,20例健康志愿者作为正常对照。结果 显示慢性肝衰竭组餐后主频降低,正常胃电慢波百分比减少,胃动过缓百分比增加,与正常对照组相比差异均有统计学意义（P〈0.05）。     

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.     

Inhibitory effects of cholecystokinin on postprandial gastric myoelectrical activity

While a number of studies have investigated the effects of cholecystokinin (CCK) on gastrointestinal motility, little is known on the effects of CCK on gastric myoelectrical activity, which regulates gastric motility. The aim of this study was to investigate the effects of intravenous infusion of CCK-8 on gastric myoelectrical activity in normal humans. Gastric myoelectrical activity was measured in 10 healthy subjects with a noninvasive electrogastrographic technique by placing abdominal electrodes on the epigastric area. Two study sessions were performed in each subject on two separate days with double-blinded infusion of either saline or CCK (24 pmol/kg/hr). The procedure for each session was as follows: (A) 30-min baseline fasting electrogastrogram (EGG); (B) start infusion, another 30-min EGG; (C) give meal, 60-min EGG; and (D) stop infusion, another 60-min EGG. The dominant frequency and peak power (amplitude) of the EGG, and the percentage of normal 2–4 cycles/min slow waves during each recording session were computed and compared between placebo and CCK. It was found that normal 3 cpm slow waves were recorded in all EGGs. Infusion of CCK had no effect on the frequency of the gastric slow wave and did not induce gastric dysrhythmias. It was also found that intravenous infusion of CCK significantly decreased the EGG peak power (amplitude) during the first hour after the meal (the infusion was given during this period) in comparison with placebo (P<0.05). This inhibitory effect on EGG peak power was sustained but not significant during the second postprandial hour (the infusion was not given during this period). It was concluded that intravenous infusion of CCK at a physiological concentration significantly decreased the postprandial EGG amplitude in normal humans, suggesting an inhibitory effect on postprandial gastric motility, but did not change the frequency and regularity of the gastric slow wave.     

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.     

胃食管反流病胃肌电活动的变化

目的 分析描述胃食管反流病(GERD)患者的胃肌电活动特点,探讨胃肌电活动的变化在GERD发病中的作用,以期有助于临床诊疗.方法 对65例GERD患者和30例健康志愿者进行餐前、餐后体表胃电图监测.根据内镜检查结果,把GERD患者分为反流性食管炎(RE)组、非糜烂性反流病(NERD)组,行组间胃电参数比较,随访19例胃电节律异常的GERD患者,观察治疗前后胃电参数的变化.结果 GERD组的主频(DF)正常慢波节律百分比(N%)、餐前餐后功率比(PR)与对照组相比明显降低(P<0.05或0.01).胃电节律紊乱,以胃动过缓为主.经1周治疗后,GERD异常胃电参数明显正常化(P<0.05或0.01).餐前RE组胃电节律异常的发生率(37.5%)显著高于NERD组(12.1%).餐后胃电节律异常的发生率RE组和NERD组分别为71.9%和60.6%,两者没有统计学意义(P>0.05).结论 GERD患者存在餐前、餐后胃肌电活动异常,异常胃电节律以胃动过缓节律为主,胃电图能为GERD诊断提供依据.     

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.     

An Evaluation of Adult Electrogastrography Criteria in Healthy Children

The current study examined whether electrogastrogram (EGG) recordings obtained from healthy children would be considered normal by standards established for adults and whether EGG patterns differ between children/adolescents and adults. Twenty-eight healthy children (54% females; ages 8–17 years; mean = 12.4 years) were evaluated and compared to 15 healthy adults evaluated previously. EGGs were recorded for 30 min in the fasting state and for 1 hr following a standard meal. For both pediatric and adult participants, there was a significant increase in both the dominant frequency and the dominant power from the pre- to the postprandial period (P < 0.001 for each). Using adult standards, the percentage normal slow waves was ≥70% of the recording time in 96% of children in the fasting state and in 100% in the postprandial period. A postprandial power increase was seen in 89% of the children. In conclusion, our data indicate that American Motility Society (AMS) consensus adult criteria for a normal EGG are appropriate to apply to children and adolescents when utilizing methodology and meal challenge similar to those used to establish the adult norms.     

功能性消化不良患者胃肌电紊乱的发生率

背景：功能性消化不良（FD）的病理生理机制尚未完全阐明，消化道运动功能异常可能是主要发病机制之一。目的：通过胃电图检查探讨FD患者胃肌电紊乱的发生率，证实胃动力异常在FD发生中的作用。方法：368例FD患者行餐前和餐后体表胃电图榆查，对正常胃慢波百分比和胃电主功率两项参数进行分析。结果：根据正常胃慢波百分比，本组FD患者可分为胃电节律正常组（43．2％）、胃动过缓组（33．2％）、胃动过速组（6．2％）和混合性胃电节律紊乱组（17．4％）。在胃电节律正常的FD患者中，34．0％（54例）存在餐后／餐前胃电主功率比异常。结论：本组71．5％的FD患者存在胃肌电紊乱，证实胃动力异常在FD的发病机制中起有重要作用。     

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.     

Electrogastrography associated with symptomatic changes after prokinetic drug treatment for functional dyspepsia

AIM:To evaluate the effect of prokinetic drugs on electrogastrography(EGG) parameters according to symptomatic changes in patients with functional dyspepsia(FD).METHODS:Seventy-four patients with FD were prospectively enrolled in this study between December 2006 and December 2010.We surveyed the patients using a questionnaire on dyspeptic symptoms before and after an 8-wk course of prokinetic drug treatment.We also measured cutaneous pre-prandial and postprandial EGG recordings including percentage of gastric waves(normogastria,bradygastria,tachygastria),dominant frequency(DF),dominant power(DP),dominant frequency instability coefficient(DFIC),dominant power instability coefficient(DPIC),and the ratio of post-prandial to fasting in DP before and after the 8-wk course of prokinetic drug treatment.RESULTS:Fifty-two patients(70%) achieved symptomatic improvement after prokinetic drug treatment.Patients who had normal gastric slow waves showed symptom improvement group after treatment.Postprandial DF showed a downward trend in the symptom improvement group,especially in the itopride group.Post-prandial DP was increased regardless of symptom improvement,especially in the itopride group and mosapride group.Post-prandial DFIC and DPIC in the symptom improvement group were significantly increased after the treatment.The EGG power ratio was increased after treatment in the symptom improvement group(0.50 ± 0.70 vs 0.93 ± 1.77,P = 0.002),especially in the itopride and levosulpiride groups.CONCLUSION:Prokinetics could improve the symptoms of FD by regulating gastric myoelectrical activity,and EGG could be a useful tool in evaluating the effects of various prokinetics.     

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.     

Identification of Gastric Contractions from Cutaneous Electrogastrogram

Objective : The objective of this study was to investigate whether gastric contractions in the fasting and fed state can be identifled from the cutaneous electrogastro-gram. Methods : Simultaneous measurements of gastric myoelectrical and manometric activities were made in 10 healthy female volunteers from 1:00 AM to 9:45 AM. For manometric recording, a catheter incorporating solid state transducers was used. Cutaneous electro-gastrography (EGG) was used for myoelectrical recording. All EGG data from 1:00 AM to 7:30 AM that occurred during motor quiescence, all EGG data that occurred during antral contractions, and 2-h EGG data after breakfast given at 7:30 AM were quantitatively analyzed and compared with each other. The EGG in three specific periods (fasting without antral contractions, fasting with contractions, and postprandial) was characterized by four parameters that include frequency, power, and stabilities of the frequency and power. Results: 1 ) the peak power of the postprandial EGG was, respectively, 12.5 dB (about 2-fold increase n i amplitude) and 6.8 dB (ahout 1-fold increase in amplitude) higher than that during motor quiescence (p < 0.05) and motor activity in the fasting state; 2) the dominant frequency of the postprandial EGG was, respectively, 6% and 13% higher than that during motor quiescence and motor activity (p < 0.05) in the fasting state; 3) the peak power of the fasting EGG was 48% more unstable during motor activity than motor quiescence (p < 0.05); 4) the stability of the EGG frequency was not significantly different during the three different periods. Conclusion : The EGG provides important and useful information for the assessment of gastric motility. An unstable EGG peak power is indicative of gastric contractions in the fasting state. An increase in EGG peak power and/or dominant frequency after a solid test meal suggests a normal postprandial gastric motility.