Dietary influence on electrogastrography and association of alterations in gastric myoelectrical activity with symptoms in patients with functional dyspepsia

Background and Aim: It is unclear which type of meal is adequate in measuring electrogastrography and which parameter of electrogastrography is of clinical relevance. The aims of the present study were to compare the influence of water and a nutrient drink on electrogastrography in patients with functional dyspepsia (FD) and in healthy volunteers, and to investigate the association of alterations of electrogastrography with symptoms. Method: In 30 patients with FD and 12 healthy volunteers, the recording of electrogastrography with symptom assessments was performed preprandially and postprandially. Subjects ingested the same volume of water and a nutrient drink at a fixed rate, which was performed in a randomized cross‐over design. Results: Unlike water, the power ratio after/before a nutrient drink was significantly lower in patients compared to controls. Patients had more severe bloating and epigastric pain after nutrient ingestion than after water intake. Absent postprandial increase of power was observed in seven of the 30 patients after nutrient intake, and in three of the 30 patients after water intake. The former patients had significantly more severe fullness and bloating. Irrespective of a test meal, the percentage rates of normogastria significantly decreased postprandially in the patient group, but not in the control group. No differences in symptom severity were observed between patients with and without abnormally low percentage rates of normogastria. Conclusions: Decreased postprandial rates of normogastria and absent postprandial increase of power are electrogastrographic abnormalities found in a subset of patients with FD. A nutrient drink is more adequate for the detection of such alterations than water. The lack of a postprandial increase of power is associated with the severity of some dyspeptic symptoms, but decreased postprandial rates of normogastria are not.     

An assembled electrogastrographic device to examine the meal effect on gastric slow wave

We have assembled an electrogastrographic device based on the main components of amplifiers, a band-pass filter, an analogue/digital converter, low band-pass digital filters and a personal computer. The analysis software uses autoregressive moving average modelling to compute the frequency of slow waves and uses fast Fourier transformation for power spectral computation. Twenty healthy young male volunteers were enrolled in the study to test meal-elicited responses of the slow wave. Subjects underwent a 15 min recording while fasting and then a standard breakfast, which included 250 mL milk and a cake with a total of 1.45 kj, was ingested within 5 min. The post-prandial 15 min recording was immediately resumed after the meal. A slight but significant increase in the frequency of slow waves was seen in post-prandial measurements (mean ± s.d., 0.0506±0.0005 vs 0.0497±0.0005 Hz; P<0.0001). Moreover, a significant enhancement of the power of slow waves was elicited following the meal (36.0±3.1 vs 27.6±3.1 dB; P<0.0001). We conclude that this assembled electrogastrographic device is a reliable means of monitoring gastric myoelectrical activity because the phenomenon of post-prandial responses of slow waves in either frequency or power is well demonstrated.     

儿童厌食症胃电图临床研究

[目的]探讨儿童厌食症胃动力与胃电图变化的关系. [方法]2007年5月～2008年2月本院门诊就诊,年龄1～7岁的50例厌食症儿童及50例健康儿童,分别接受胃肠电图仪检测,分析胃电描记数据,使用SPSS11.0统计软件处理数据. [结果]厌食症儿童胃电参数f、F、Vpp、Ra显示餐后比餐前降低,餐后胃窦导联f、F、Vpp、Ra比胃体导联降低,差异有显著性(P<0.05).健康儿童组餐后胃电参数f、F明显比餐前增高,而Vpp、Ra餐前餐后无明显变化,餐后胃窦导联f、F比胃体导联增高(P<0.05). [结论]厌食症儿童胃电异常,胃电基本节律减慢,提示胃动力异常,胃排空过缓.胃电图对评价厌食儿童胃动力异常极有帮助作用.     

Effect of fat preload on gastric myoelectrical activity in normal humans

The aim of this study was to investigate the effect of fat preload on gastric myoelectrical activity in normal humans. The study was performed in 10 normal subjects (five males, five females) fasted for 6h or more. Gastric myoelectrical activity was recorded using surface abdominal electrodes. In the study session the subjects ingested a 40-g liquid fat meal (2 oz of lipomul) after a 30-min baseline recording. A test meal (225 kcal beef stew) was then consumed 15 min after drinking the lipomul, and the recording was continued for 2 h after the test meal. The control session performed on a separate day followed the same procedure except that the lipomul was replaced by 2 oz of water. The order of the study and control sessions was randomized. The cutaneous recording of gastric myoelectrical activity (electrogastrogram or EGG) was digitized and subjected to computerized quantitative data analysis. The peak power and the corresponding frequency of the EGG during every 15-min time interval were computed using spectral analysis. Student's t-test was applied to determine the effect of fat preload on the surface recording of gastric myoelectrical activity. It was found that: (1) the power of the 15-min EGG at the dominant frequency immediately after fat preload was significantly lower than that of the baseline EGG (P = 0.01); (2) the postprandial power increase of the EGG at the dominant frequency was significantly lower with fat preload than with placebo preload (P = 0.002); (3) the dominant frequency of the EGG was not affected by fat preload. It was concluded that fat preload significantly decreases the power of the EGG but does not affect the frequency of the gastric slow wave.     

针刺对腹部手术后消化功能不良患者胃功能的影响

目的：本研究以体表胃电图描记和99mTc核素扫描胃排空实验为手段，试图揭示腹部手术后消化功能不良的发生机理，探讨针刺足三里和内庭的疗效及治疗机制。方法：对腹部手术后消化功能不良患者行针刺足三里及内庭穴，并记录针刺前后胃电图的变化。利用核素扫描胃排空测定方法观察针刺前后胃排空的改变。结果：针刺后患者消化功能不良的临床表现得到不同程度的缓解；针刺后胃电图波幅及胃电频率正常波所占的百分比显著增高，胃电图波型变规整；针刺后胃排空明显加快。结论：胃电幅度的降低、胃电正常波的减少、低频波的增多及胃排空的缓慢是腹部手术后消化功能不良的常见表现。针刺疗法可促进胃正常电节律的恢复，加速胃的排空，是治疗消化功能不良的有效方法之一．     

大腹皮对大鼠胃电节律失常的影响及其机制

为探讨大腹皮对大鼠胃电节律失常的影响及其机制，将30只健康成年Wistar大鼠随机分为3组：①正常对照组；②模型组；③大腹皮＋模型组。通过胃电记录仪记录并分析各组慢波频率、慢波频率变异系数及异常节律指数，同时对各组大鼠胃窦肌间神经从胆碱能及氮能神经进行组化染色。结果发现，模型组大鼠胃慢波频率变异系数及异常节律指数明显高于对照组（P＜0．01），应用大腹皮后模型组大鼠胃慢波频率变异系数及异常节律指数与对照组差异无显著性意义（P＞0．05）；模型组大鼠胃窦肌间神经丛胆碱能神经密度明显低于对照组（P＜0．01），氮能神经密度明显高于对照组（P＜0．05），应用大腹皮后大鼠胃窦肌间神经从胆碱能和氮能神经密度明显减少，与对照组比较差异无显性意义(P＞0．05）。提示，大腹皮对大鼠胃电节律失常具有调节作用，其机制可能与增加胃窦肌间神经丛胆碱能神经分布及减少氮能神经分布有关。     

Myo-electrical and motor activity of the stomach in the first days after abdominal surgery: Evaluation by electrogastrography and impedance gastrography

The electrical and motor activities of the stomach were studied in the early postoperative phase after abdominal surgery by means of surface recording techniques: electrogastrography (EGG) and impedance gastrography (IGG). EGG and IGG recordings were made pre-operatively and on the first and second postoperative days. Physical signs and symptoms related to gastrointestinal motility were assessed. Two patient groups were studied; a group of patients undergoing cholecystectomy (n = 9) was compared with a group with major colonic surgery (n = 14). After colonic surgery, resumption of a normal oral diet was later and nausea and vomiting were seen more frequently than after cholecystectomy. Other physical signs concerning intestinal motility did not differ between the groups. Gastric myo-electrical activity (0.04-0.06 Hz), recorded electrogastrographically, tended to decrease in the postoperative phase in both groups, and return to pre-operative values later in the colonic surgery group. However, none of the differences reached statistical significance. Abnormal gastric activity (tachyarrhythmia) was observed in one pre-operative patient but in 6 patients (2 cholecystectomy, 4 colonic surgery) after operation. IGG variables were not significantly affected by the operation and were not significantly different between the groups. No correlation between the symptoms nausea and vomiting in the postoperative phase and the incidence of tachyarrhythmias could be demonstrated in this study. It is concluded that antral myo-electrical and motor activity, measured with non-invasive techniques (EGG and IGG), are not grossly abnormal on the first and second postoperative day after abdominal surgery. It is further concluded that abnormal gastric frequencies do not appear to play a major role in the genesis of postoperative nausea and vomiting.     

Gastric myoelectrical activity in premature and term infants

Electrogastrography is a non-invasive method for recording gastric myoelectrical activity. The aims of this study were to record gastric myoelectrical activity in newborn infants using electrogastrographic methods and to compare frequency distributions of postprandial electrogastrograms (EGGs) recorded after gavage feedings. Nineteen infants with gestational ages ranging from 28 weeks to term were studied. Group I subjects were studied only after formula feedings (n = 15) and were divided by age into subgroups A, B and C: A (term, n = 4), B (33–36 weeks, n = 4), and C (28–32 weeks, n = 7). Group II infants (32–34 weeks, n = 4) were studied before and after gavage feeding. The percentage of total EGG power was calculated for four frequency ranges: 1–2.4 cpm (bradygastria); 2.5–3.6 cpm (normal range); 3.7–9.9 cpm (tachygastria); and 10–15 cpm (duodenal/respiratory). Results showed no significant differences in postprandial EGG power in these frequency ranges among the Group I infants of different gestational ages. The power in these EGG frequency ranges did not change significantly after gavage feedings in the Group II infants. In conclusion: (a) EGGs may be recorded successfully from preterm and term infants, (b) postprandial gastric myoelectrical activity in all frequency bands is similar among groups of premature and term infants, and (c) gavage feedings in premature infants did not increase 3 cpm EGG activity.     

Electrogastrographic characteristics in subjects with stomach remnant

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

Gastric electrical activity and cardiovascular risk factors in relation to autonomic nervous function, hormonal responses, and health-related lifestyles in young men

Background Electrogastrography (EGG) is the noninvasive recording of gastric myoelectrical activity. The purpose of the present study was to assess associations of EGG with risk factors for cardiovascular disease (CVD), autonomic nervous function, hormonal responses, and health-related lifestyles. Methods EGG was measured in 435 Japanese men, aged 24–39 years, who worked at the same company. In addition to anthropometric measurements and blood examinations, power spectral analysis of heart rate variability in low-frequency (LF; 0.04–0.15 Hz) and high-frequency (HF; 0.15–0.40 Hz) bands was conducted. LF/HF and HF were used as the indicators of sympathetic and parasympathetic nervous activity, respectively. Serum cortisol and catecholamine levels were measured as well. Results In univariate analyses, the EGG frequency was associated positively with the serum high-density lipoprotein (HDL) and cholesterol level (both-P < 0.0001) and negatively with age, body mass index (BMI), serum triglyceride level, fasting blood sugar, and diastolic blood pressure (all P < 0.05). The EGG frequency tended to increase with increases in the HF band (P = 0.10) and was not significantly associated with the LF/HF ratio (P = 0.45). Neither hormonal responses nor health-related lifestyle factors such as smoking and alcohol were significant (all P > 0.05). A multivariate analysis indicated that both the HDL cholesterol level and BMI were independent predictors of EGG frequency (both P < 0.05), after adjusting for the significant effects of age, HF, and other CVD factors. Conclusions Slowed EGG frequency appeared to be linked with various CVD risk factors, including obesity and low HDL cholesterol levels, in young men.