Changes in gastric electrical activity in patients with severe post-operative nausea and vomiting

Gastric electrical activity in a group of patients with severe nausea and repeated vomiting in the post-operative phase following major abdominal surgery (Group A, n = 21), was compared to that in a control group of patients without symptoms after colonic surgery (Group B, n = 14). Physical signs related to the digestive tract were assessed and electrical activity of the stomach was measured non-invasively by means of electrogastrography (EGG) and impedance gastrography (IGG). Two EGG/IGG recordings were performed in each patient. In group A the first recording was carried out after the onset of nausea and/or vomiting and a second control recording after disappearance of these symptoms and resumption of a normal diet. In group B the post-operative recording was performed on the second post-operative day, the control EGG/IGG signals were recorded pre-operatively. EGG and IGG could be successfully recorded in the post-operative phase, even in nauseated and vomiting patients. During post-operative nausea and vomiting power and frequency of the normal gastric myoelectrical activity (0.04–0.06 Hz) were not significantly lower than in the control recordings. In the first post-operative recordings (in Group A during nausea and vomiting and in Group B on the second post-operative day) an increased incidence of abnormal gastric frequencies (tachygastrias, 0.10–0.18 Hz) was observed in both groups. No significant difference between the groups was found. After nausea and vomiting had subsided in Group A, the incidence of tachygastrias was persistently high.     

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.     

脊柱手术对胃功能的影响及相关治疗的疗效研究

目的：研究脊柱手术对胃功能的影响及相关治疗的疗效。方法：６０例脊柱手术患者，２０例四肢手术患者，２０名健康者，脊柱手术组术前及术后的均行胃电图检查，其中２０例行Ｘ线钡餐造影动态胃蠕动波记录，脊柱手术组术后随机分为３组，分别予中药香砂养胃丸、艾灸、吗丁啉治疗，同时观察比较治疗前后胃电图变化，结果：脊柱手术组术后胃电节律有明显异常，频率和振幅与其他两组差异有显著性（Ｐ〈０．０５，Ｐ〈０．０１），胃蠕动     

用计算机技术研究大鼠胃电和胃运动信号

利用体表电极、体内胃肠电极和压力传感器,通过计算机分别同时记录正常对照组和急性应激组 Ｗｉｓｔａｒ 大鼠体表胃电、体内平滑肌慢波和胃平滑肌运动信号,并进行数据处理和统计学分析。结果表明,正常对照组和急性应激组的体表胃电、体内平滑肌慢波和胃平滑肌运动存在差别。这种差别提示：①体表胃电在一定程度能够反映胃的活动,揭示胃的生理和病理规律,有可能应用于临床,作为胃病的诊断和疗效判定的客观标准;②体表胃电不仅反映体内胃平滑肌慢波的电活动,还与胃平滑肌运动有关,反映了有关胃平滑肌运动的一些信息。     

Recent progress in gastric arrhythmia: Pathophysiology,clinical significance and future horizons

Gastric arrhythmia continues to be of uncertain diagnostic and therapeutic significance. However, recent progress has been substantial, with technical advances, theoretical insights and experimental discoveries offering new translational opportunities. The discoveries that interstitial cells of Cajal (ICC) generate slow waves and that ICC defects are associated with dysmotility have reinvigorated gastric arrhythmia research. Increasing evidence now suggests that ICC depletion and damage, network disruption and channelopathies may lead to aberrant slow wave initiation and conduction. Histological and high‐resolution (HR) electrical mapping studies have now redefined the human ‘gastric conduction system’, providing an improved baseline for arrhythmia research. The application of HR mapping to arrhythmia has also generated important new insights into the spatiotemporal dynamics of arrhythmia onset and maintenance, resulting in the emergence of new provisional classification schemes. Meanwhile, the strong associations between gastric functional disorders and electrogastrography (EGG) abnormalities (e.g. in gastroparesis, unexplained nausea and vomiting and functional dyspepsia) continue to motivate deeper inquiries into the nature and causes of gastrointestinal arrhythmias. In future, technical progress in EGG methods, new HR mapping devices and software, wireless slow wave acquisition systems and improved gastric pacing devices may achieve validated applications in clinical practice. Neurohormonal factors in arrhythmogenesis also continue to be elucidated and a deepening understanding of these mechanisms may open opportunities for drug design for treating arrhythmias. However, for all translational goals, it remains to be seen whether arrhythmia can be corrected in a way that meaningfully improves organ function and symptoms in patients.     

Nissen fundoplication improves gastric myoelectrical activity characteristics and symptoms in gastroesophageal reflux patients: evaluation in transcutaneous electrogastrography

Background Gastric myoelectrical activity disorders play an essential role in the pathophysiology of gastroesophageal reflux disease (GERD), although little is known about gastric motility following surgical treatment of the disease. The aim of present study was to analyze the impact of Nissen fundoplication on both gastric myoelectrical activity, measured using the transcutaneous electrogastrography technique (EGG), and change in digestive symptoms. Methods In 43 patients with GERD, EGG was recorded before and after the Nissen procedure and compared with the EGG obtained in eight healthy volunteers. Symptoms of epigastric pain, belching, regurgitation, heartburn, postprandial abdominal distension, and early satiety were recorded. At a three-week and a one-year postoperative follow-up, these tests were repeated. Results In fasted patients before the operation, the slow-wave frequency distribution (normogastria, 53.7%; bradygastria, 44.2%; dysrhythmia, 47.1%) was significantly different compared with that of controls (89.2%, 7.0%, and 10.4%, respectively). No major changes in slow-wave frequency distribution were observed after a meal in examined patients, besides a significant rise in tachygastria (12.4%). Three weeks following the Nissen fundoplication, the fasting slow-wave frequency distribution did not change significantly compared with the preoperative period, being 58.1% for normogastria, 43.2% for bradygastria, and 12.0% for tachygastria. The abnormal distribution of slow waves (bradygastria + tachygastria) was not significantly affected by Nissen fundoplication, being 47.1% before and 44.9% after the operation, respectively. At the same time and still one year after operation there was a significant improvement in all clinical symptoms measured. Conclusion EGG showed that Nissen fundoplication influenced and might improve the slow-wave generation in gastric pacemaker. Dyspeptic symptoms were also improved up to one year postoperatively.     

Effect of a muscarinic M3 receptor agonist on gastric motility

Muscarinic M3 receptors exist in the gastrointestinal wall in humans and the muscarinic M3 agonist cevimeline hydrochloride (Evoxac) is a candidate therapeutic agent for the treatment of xerostomia in Sjögren’s syndrome. However, M3 receptor agonists are not known to show efficacy for diseases associated with abnormal gastrointestinal motility. Herein the effects are reported of cevimeline on gastric motility in two patients with non‐ulcer dyspepsia. The patients both received long‐term proton pump inhibitor therapy for 6 months, but their symptoms persisted. Then cevimeline was administered orally for 8 weeks at 30 mg three times daily (90 mg/day) and their dyspepsia symptoms improved. Electrogastrography was performed to examine gastric motility before and after administration of the M3 agonist. The fasting or nocturnal wave rate was significantly increased after administration compared with before administration, but no significant postprandial changes were seen. No adverse effects of cevimeline were observed. This drug might be a candidate therapeutic agent for non‐ulcer dyspepsia. Because its postprandial effects on gastrointestinal motility are unclear, a dose‐finding clinical study should be performed in the future.     

Stimulation of gastric slow waves with manual acupuncture at acupuncture points ST36 and PC6--a randomized single blind controlled trial

Background To investigate the effects of stimulated and non‐stimulated manual acupuncture at ST36 and PC6 on gastric myoelectrical activity and autonomic function. Methods A total of 65 healthy volunteers were randomly assigned to a 1: 1: 2 ratio to receive either 15 min of verum acupuncture (VA) with stimulation followed by 15 min of VA without stimulation (nsVA), or 15 min of nsVA followed by 15 min of VA with stimulation (sVA), or 30 min of sham acupuncture (SA). Measures of autonomic function included electrogastrogram, electrocardiogram, impedance cardiography and assessment of blood pressure, breathing frequency, and electrodermal activity. Outcome parameters were compared between VA and SA, and between sVA and nsVA. The percentage of regular gastric slow waves (normogastria) was defined as the primary outcome. Key Results The percentage of normogastria was not significantly different between VA and SA. Differences in secondary outcomes such as power spectrum of gastric slow waves and heart rate variability parameters were pronounced in the comparison of sVA and nsVA. During sVA, the percentage of normogastria was lower (P = 0.005), the percentage of bradygastria was higher (P = 0.003) and power ratio was higher (P < 0.001), systolic blood pressure was lower (P = 0.039) and RMSSD was higher (P < 0.001) as compared with nsVA. Conclusions & Inferences Our study suggests that manual stimulation of acupuncture needles at ST36 and PC6 affects gastric myoelectrical as well as cardiac activities in healthy volunteers. The effect of stimulation in acupuncture deserves further investigation.