Gastric Dysrhythmias and Transient Sleep Impairment in Healthy Subjects

Studies have shown that impaired sleep quality is associated with exacerbation of gastrointestinal problems. The aim of this study was to measure gastric myoelectrical activity and visceral perception to fullness before and after a water load in healthy volunteers with or without transient sleep impairment. Twenty-eight male subjects (mean age, 39.3 years; range, 14-58 years) were studied. The subjective sleep quality was measured by visual analogue scale (bad [0] to very good [100]. Gastric myoelectrical activity was recorded and analyzed before and after the subjects ingested water until full. Subjects were stratified into two groups, i.e., with impaired sleep quality (Group A [Gr-A]; n = 15; mean age, 35.1 years) and with fine sleep quality (Group B [Gr-B]; n = 13; mean age, 40.7 years). Gr-A subjects ingested less water (514 +/- 21 ml) compared to the Gr-B subjects (621 +/- 50 ml: P < 0.05). After ingestion of the water load, Gr-A had significantly less 2.5- to 3.75-cpm activity (28.0 +/- 4%) by 21-30 min and more tachygastric activity (28 +/- 2 and 30 +/- 4%) by 11-30 min compared with Gr-B (43 +/- 5, 20 +/- 2, and 18 +/- 2%, respectively; P < 0.05). There was a significant positive correlation between sleep quality and the percentage of power in the normal range by 21-30 min after the water load (r = 0.5, P < 0.01). In contrast, a negative correlation was observed between sleep quality and tachygastric activity by 11-20 min (r = -0.4, P < 0.05) and 21-30 min (r = -0.4, P < 0.05) after ingestion of water. Transient sleep impairment is associated with increases in gastric dysrhythmia and altered perception to gastric distension in response to the water load. The study provides a potential clue that transient sleep impairment might influence gastric myoelectrical functioning in healthy individuals.     

窒息对新生儿胃电活动的影响

目的:研究窒息对新生儿胃电活动的影响。方法:研究对象来自我院1998年9月～2000年5月以窒息收住新生儿病房的足月新生儿32例,其中重度窒息20例,轻度窒息12例。对照组:系同期以新生儿生理性黄疸收住院的足月新生儿10例,无消化道症状,吃奶好,二便正常。采用瑞典Synectics公司生产的便携式Digitrapper双电极EGG记录仪进行胃电图检查,用计算机运行频谱分析数据。结果:窒息组与对照组比较,餐前胃动过缓显著增加,正常节律百分比、胃动过速明显降低,差别有显著意义(P<0.01和P<0.05)。餐后胃动过缓也有增加,差别有显著意义(P<0.01)。餐后正常节律百分比、胃动过速也有降低但差别无显著性意义。重度窒息组与轻度窒息组比较,前者餐前胃动过缓明显增加,正常节律百分比明显降低,差别有显著意义(P<0.01)。两者餐前胃动过速及餐后各项指标比较均无显著差异(P>0.05)。结论:(1)窒息新生儿存在明显胃电节律紊乱。临床多表现为拒奶、喂养不耐受。呕吐和腹胀等消化道症状;(2)体表胃电图与胃肌电活动的相关性较好,可用来研究窒息新生儿的胃电活动,进而研究新生儿消化道动力;(3)窒息组胃电提示异常者,曾试用普瑞博思0.2mg/(kg·次)治疗能改善临床症状,但尚缺乏胃电图观察,有待进一步胃电图研究。     

Effect of laparoscopic Nissen fundoplication on symptoms and gastric myoelectric activity in gastroesophageal reflux disease

BACKGROUND: Laparoscopic Nissen fundoplication is an effective treatment for gastroesophageal reflux disease (GERD). The aim of this study was to determine whether laparoscopic fundoplication alters gastric myoelectric activity. Change of digestive symptoms was also assessed. METHODS: Sixteen patients with GERD (2 males, 14 females, mean age: 53 years) undergoing a laparoscopic fundoplication participated. Electrogastrography (EGG) was assessed before and after the subject ingested water until full (water load). Symptoms of upper abdominal discomfort, early satiety, postprandial abdominal distension, nausea, vomiting, and anorexia were recorded. At a 2-month postoperative follow-up, preoperative tests were repeated. RESULTS: The EGG was abnormal in 11 of 16 patients (69%) preoperatively and 6 of 16 patients (38%) postoperatively. The EGG changed from abnormal to normal in 5 of 16 patients (31%). The percentage of power at 3 cpm increased significantly during the fasting state postoperatively (29.9% vs. 21.2%, P < 0.05). There was a significant improvement in epigastric pain (P < 0.001), early satiety (P < 0.01), and postprandial fullness (P < 0.001). CONCLUSIONS: Increased presence of normal 3 cpm activity is the predominant effect of fundoplication on gastric myoelectric activity. Dyspeptic symptoms are also significantly improved postoperatively.     

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

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

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.     

Prevalence of Gastric Myoelectrical Abnormalities in Patients with Nonulcer Dyspepsia and H. pylori Infection

The aims of this study were to investigate the effects of H. pylori eradication on gastric myoelectrical activity and dyspeptic symptoms. Sixty-two subjects with H. pylori infection and no active peptic ulcer participated in this study, which involved three sessions. Anti-H. pylori therapy consisting of clarithromycin and omeprazole was given for two weeks. Gastric myoelectrical activity was measured using surface electrogastrography and dyspeptic symptoms were scored at each session. A [¹⁴C] urea breath test was performed at baseline and one month after treatment. In comparison with baseline, the percentage of normal slow waves was significantly increased and the mean total symptom score was significantly reduced one and three months after therapy (P < 0.05). Approximately 40% of patients with nonulcer dyspepsia symptoms and H. pylori infection have abnormal gastric myoelectrical activity, which may be normalized following the eradication of H. pylori infection. The normalization of gastric myoelectrical activity may be one explanation for the significant symptom improvement in this subset of the dyspepsia population after H. pylori eradication.     

Impaired Gastric Myoelectrical Activity in Patients with Chronic Renal Failure

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

Motor and sensory function of the proximal stomach in reflux disease and after laparoscopic Nissen fundoplication

OBJECTIVE: After Nissen fundoplication, dyspeptic symptoms such as fullness and early satiety develop in >30% of patients. These symptoms may result from alterations in proximal gastric motor and sensory function. METHODS: We have evaluated proximal gastric motor and sensory function using an electronic barostat in 12 patients after successful laparoscopic Nissen fundoplications (median follow-up; 12 months). Twelve age- and gender-matched patients with severe gastroesophageal reflux disease (GERD) and 12 healthy volunteers served as controls. Studies were performed in the fasting state and after meal ingestion. Gastric emptying tests were performed in all patients. Vagus nerve integrity was measured by the response of pancreatic polypeptide (PP) to insulin hypoglycemia. RESULTS: Minimal distending pressure and proximal gastric compliance were not significantly different between post-Nissen patients, GERD patients, and healthy controls. Postprandial relaxation of the stomach, however, was significantly (p < 0.05) reduced post-Nissen (267 +/- 34 ml), compared with controls (400 +/- 30 ml) and GERD (448 +/- 30 ml). Postprandial relaxation was significantly (p < 0.01) prolonged in GERD patients. Postprandial relaxation of the stomach correlated with gastric emptying of solids (r = 0.62; p = 0.01). Gastric emptying of solids became significantly (p < 0.05) faster after fundoplication. Postprandial fullness was significantly (p < 0.05) increased in the operated patients. CONCLUSIONS: Post-Nissen patients have a significantly reduced postprandial gastric relaxation and significantly accelerated gastric emptying, which may explain postoperative dyspeptic symptoms. The abnormalities result from fundoplication and not from vagus nerve injury or reflux per se, because in reflux patients gastric relaxation and gastric emptying are prolonged.     

The role of transsphincteric pressure and proximal gastric volume in acid reflux before and after fundoplication

BACKGROUND & AIMS: This study was conducted to explore the role of proximal gastric volume and transsphincteric pressure on acid reflux during transient lower esophageal sphincter relaxation (TLESR) in patients with gastroesophageal reflux disease (GERD) both before and after laparoscopic fundoplication. METHODS: Twenty GERD patients were studied before and after fundoplication along with 20 healthy controls. High-resolution manometry and pH recording was performed for 1 hour before and 2 hours following meal ingestion (500 mL/300 kcal). Three-dimensional ultrasonographic images of the stomach were acquired before and every 15 minutes after meal ingestion. RESULTS: Postprandial proximal to total gastric volume distribution ratios were significantly larger in GERD patients before fundoplication (0.57 +/- 0.01; P < .05) and smaller following fundoplication (0.37 +/- 0.01; P < .001) compared with controls (0.46 +/- 0.01). The percentage of TLESRs associated with acid reflux did not relate to proximal gastric volume in any subject group. The transsphincteric pressure profile was different for TLESRs with and without reflux in GERD patients as well as in healthy controls. The pressure gradient across the esophagogastric junction (EGJ) (DeltaEGJp) was greater for TLESRs with acid reflux compared with TLESRs without acid reflux in both GERD patients (11.4 +/- 0.8 vs 8.0 +/- 0.5 mm Hg, respectively; P < .01) and controls (10.6 +/- 0.7 vs 7.1 +/- 0.8 mm Hg, respectively; P < .05). After fundoplication, DeltaEGJp during TLESRs was 7.9 +/- 0.9 mm Hg, and the transsphincteric pressure profile markedly changed. CONCLUSIONS: Although proximal gastric volume plays a key role in eliciting TLESRs, it is not related to the incidence of acid reflux during TLESRs. The transsphincteric pressure gradient is greater in TLESRs associated with acid gastroesophageal reflux.     

Gastric myoelectrical activity, gastric emptying, and correlations with symptoms and fasting blood glucose levels in diabetic patients

BACKGROUND: The aims of this study were to determine the electrogastrogram (EGG) changes and gastric emptying rates in diabetic patients and to investigate the correlation between upper gastrointestinal symptoms, fasting blood glucose, and gastric myoelectrical abnormalities. METHODS: Fourteen patients with long-standing type 1 diabetes mellitus and dyspepsia symptoms participated in the study. EGG recordings were obtained 30 minutes before and during a 2-hour radionuclide gastric emptying test for a solid meal. Fasting blood glucose was determined immediately before the gastric emptying study. Symptoms of nausea, vomiting, early satiety, abdominal bloating, and pain were rated from 0 to 3. RESULTS: Nine patients (64%) had delayed gastric emptying with 84.6 +/- 4.5% retention at 2 hours. Seven patients (50%) had abnormal EGG findings. The postprandial power change in the EGG of the patients with delayed gastric emptying (-0.48 +/- 0.16 dB) was decreased compared with patients with normal gastric emptying (4.7 +/- 2.6 dB) (P = 0.079). In patients with abnormal EGGs, the mean symptom score was significantly higher than patients with normal EGGs (2.42 +/- 0.13 versus 2.0 +/- 0.16; P < 0.05). Compared with normal gastric emptying patients, patients with delayed gastric emptying had higher but not significantly different symptom scores (2.31 +/- 0.11 versus 2.08 +/- 0.30; P = 0.225). There was no significant difference in fasting glucose levels in delayed (252 +/- 61.2 mg/dl) versus normal (378 +/- 82 mg/dl) gastric emptying or abnormal (288 +/- 86.4 mg/dl) EGGs versus patients with normal (304 +/- 57.6 mg/dl) EGGs. CONCLUSIONS: Overall, 78% (11 of 14) of patients with diabetes had either gastric motility or myoelectrical abnormalities. Patients with abnormal EGGs had more severe symptom scores. In diabetic patients with symptoms of gastropathy, an EGG may provide an important screening test for diagnosing abnormal gastric motility.     

Impaired Gastric Myoelectrical Activity in Patients with Parkinson's Disease and Effect of Levodopa Treatment

The aim of this study was to evaluate gastric myoelectrical activity in patients with Parkinson's disease during and after levodopa treatment. Thirteen Parkinson's patients and 13 age-matched Parkinson's-free controls were enrolled. Electrogastrography was used to record gastric myoelectrical activity in all subjects for 30 min before and 30 min after a standard meal. In the group with Parkinson's disease, gastric myoelectrical activity was recorded during both the "on" (with levodopa treatment) and the "wearing-off" (without levodopa for at least 12 hr) periods. Results were as follows. (1) The patients without treatment showed a significantly lower percentage of regular slow waves and a significantly higher instability coefficient of the dominant frequency; (2) the patients showed an absence of the normal postprandial increase in gastric slow wave frequency which was seen in the controls: and (3) treatment with levodopa resulted in an improvement in the fed state, including a marginal increase in the percentage of regular slow waves (P = 0.1), a significant decrease in the instability coefficient, and an enhanced postprandial power increase. In conclusion, patients with Parkinson's disease have reduced slow wave rhythmicity and an impaired postprandial response in gastric myoelectrical activity. These abnormalities may be partially corrected with levodopa treatment in the fed state.     

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.     

Impaired gastric slow waves induced by spatial disorientation and effect of domperidone

OBJECTIVES: Our aims were to investigate the dominant frequency and regularity of gastric myoelectrical activity during motion sickness induced with the advanced spatial disorientation demonstrator (ASDD) and to evaluate the effect of domperidone on gastric myoelectrical activity and gastrointestinal symptoms during motion sickness. METHODS: Thirteen healthy volunteers participated in this study. This study was executed using the ASDD, which could duplicate several spatial disorientation phenomena in a safe, controlled environment. Each subject participated in two sessions and received oral administration of 10 mg domperidone before the study in one of the sessions. In each session, three 15-min EGG recordings were made before, during, and after rotation. The symptoms were scored by Graybiel's scale of motion sickness before and after rotation. All EGG data were subjected to computerized spectral analysis to obtain the percentage of normal 2-4 cycles/min (cpm) slow waves, percentage of tachygastria, EGG dominant frequency and power, and instability coefficient of the dominant frequency. RESULTS: We have found that the percentage of normal gastric slow wave was decreased (control session: 86.2 +/- 4.0% vs 70.0 +/- 5.4%, p < 0.01; domperidone session: 82.7 +/- 4.6% vs 69.8 +/- 5.6%, p < 0.03) and the percentage of tachygastria was increased (control session: 8.7 +/- 3.2% vs 17.8 +/- 5.6%, p < 0.01; domperidone session: 9.2 +/- 3.3% vs 18.1 +/- 3.5%, p < 0.01) after rotation in both sessions. The minute-by-minute variation of the gastric slow wave frequency was significantly increased during rotation in both sessions (control: 0.74 +/- 0.16 vs 1.35 +/- 0.19, p < 0.01; domperidone: 0.90 +/- 0.20 vs 1.47 +/- 0.17, p < 0.01). Domperidone did not prevent dysrhythmia or the symptoms of motion sickness. CONCLUSIONS: The percentage of normal gastric slow waves is decreased and the percentage of tachygastria is increased with spatial disorientation. Domperidone does not prevent gastric dysrhythmia or the symptoms of motion sickness induced with spatial disorientation.     

Utility of electrogastrography in differentiating Parkinson's disease with or without gastrointestinal symptoms: a prospective controlled study

BACKGROUND/AIMS: Parkinson's disease (PD) may be associated with various gastrointestinal symptoms. This study was designed to assess the gastric myoelectrical functioning in patients with PD and in healthy controls by using electrogastrography (EGG) with the water load test and to determine the clinical utility of EGG in differentiating PD patients with or without upper gastrointestinal symptoms. METHODS: Twenty patients (13 men, mean age 63 years) with PD and 11 healthy controls (5 men, mean age 55 years) were studied. The PD patients were stratified into two subgroups: 9 were assessed as PD without upper gastrointestinal symptoms (group A) and 11 as PD with upper gastrointestinal symptoms (group B). The gastric myoelectrical activity was assessed using cutaneous electrodes to record EGG before and after the subjects ingested water until full. RESULTS: The PD patients drank significantly less water until full as compared with the controls (303 +/- 45 vs. 627 +/- 67 ml, p < 0.05). At baseline, the PD patients had a significantly higher 1.0- to 2.5-cpm activity as compared with the controls (44 +/- 3 vs. 33 +/- 3%, p < 0.05). These differences persisted after ingestion of the water load. The PD patients had a significantly lower 2.5- to 3.75-cpm activity late after ingestion of the water load as compared with the controls (33 +/- 4 vs. 49 +/- 5%, p < 0.05). No statistically significant differences were found in any EGG variables or the water load between the two groups of PD patients. CONCLUSIONS: This study has shown that the gastric myoelectrical activity is impaired in both groups of PD patients. EGG appears to have a limited, if any, clinical utility in the differentiation of PD patients with or without upper gastrointestinal symptoms.     

Effect of hypo- and hyperthyroidism on gastric myoelectrical activity

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

Is There a One-to-One Correlation Between Gastric Emptying of Liquids and Gastric Myoelectrical or Motor Activity in Dogs?

The aim of this study was to investigate the correlation of gastric emptying with gastric myoelectrical activity recorded from internal serosal electrodes and with gastric motility measured from strain gauges. The study was performed in eight healthy dogs chronically implanted with four pairs of electrodes and two strain gauges on the gastric serosa and equipped with a duodenal fistula for the assessment of gastric emptying. Each dog was fed four liquid test meals on four separate days with identical calories (320 kcal) and volume (473 ml). A correlation was found between gastric emptying and the energy of contraction in the frequency band of 3.75–7.50 cycles/min during the first 30 min after the meal (r = 0.46, P < 0.05). While none of the parameters of gastric myoelectrical activity was correlated with gastric emptying, two major parameters, percentage of regular gastric slow waves and percentage of slow-wave coupling, were found to be associated with delayed gastric emptying. A significant correlation was found between the frequency of gastric slow waves and that of the contractions in both fasting (r = 0.83, P < 0.001) and fed state (r = 0.70, P < 0.001 at 30 min, r = 0.86, P < 0.001 at 60 min). It was concluded that gastric emptying is correlated with the strength of gastric contractions in a frequency range identical to that of the gastric slow waves, and there is no one-to-one correlation between gastric emptying of liquids and any parameters of gastric myoelectrical activity. However, major parameters of gastric myoelectrical activity are associated with gastric emptying.     

Effects of acupressure on gastric myoelectrical activity in healthy humans

OBJECTIVE: Acupressure at Neiguan point (P6) has been used as an antiemetic in Eastern countries and many studies have reported its effectiveness on gastrointestinal symptoms. The aim of the present study was to investigate the effects of acupressure on gastric myoelectrical activity in healthy humans. MATERIAL AND METHODS: Fifteen healthy volunteers (9 M, 6 F) served as subjects. Acupressure at P6 was applied for 1 min followed by 1 min of rest, and this alternating sequence was continued for a total of 30 min. Electrogastrogram (EGG) was recorded for 30 min before ("baseline"), during ("acupressure") and after ("recovery") the application of acupressure. Heart rate variability (HRV) was also recorded to analyze autonomic nervous activities. RESULTS: The percentage of normal 3 cycles per minute slow wave (%NSW) was changed significantly by the application of acupressure (86.5+/-2.4, 92.3+/-1.2, 92.8+/-1.9% in the baseline, acupressure and recovery periods, respectively, p = 0.0424). The %NSW was significantly larger in the acupressure and the recovery periods than in the baseline period (p <0.03). The changes in %NSW from the baseline to the acupressure (r = -0.8598, p < 0.001) and to the recovery (r = -0.6422, p <0.01) periods were negatively correlated with the baseline %NSW. There was no change in HRV. CONCLUSIONS: Acupressure at P6 increased %NSW of gastric myoelectrical activity. The negative correlation between the baseline value and the change in %NSW may extrapolate a possible normalizing effect of acupressure on impaired gastric myoelectrical activity in symptomatic patients.     

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.     

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

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

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.