Clinical Associations of Functional Dyspepsia with Gastric Dysrhythmia on Electrogastrography: A Comprehensive Systematic Review and Meta-Analysis

BackgroundFunctional dyspepsia (FD) is a common gastroduodenal disorder, yet its pathophysiology remains poorly understood. Bioelectrical gastric slow wave abnormalities are thought to contribute to its multifactorial pathophysiology. Electrogastrography (EGG) has been used to record gastric electrical activity, however the clinical associations require further evaluation.AimsThis study aimed to systematically assess the clinical associations of EGG in FD.MethodsMEDLINE, EMBASE, and CENTRAL databases were systematically searched for articles using EGG in adults with FD. Primary outcomes were percentage normal vs abnormal rhythm (bradygastria, normogastria, tachygastria). Secondary outcomes were dominant power, dominant frequency, percentage coupling and the meal responses.Results1751 FD patients and 555 controls from 47 studies were included. FD patients spent less time in normogastria while fasted (SMD −0.74; 95%CI −1.22 - −0.25) and postprandially (−0.86; 95%CI −1.35 - −0.37) compared to controls. FD patients also spent more fasted time in bradygastria (0.63; 95%CI 0.33 – 0.93) and tachygastria (0.45; 95%CI 0.12 – 0.78%). The power ratio (−0.17; 95%CI −0.83 - 0.48), and dominant frequency meal-response ratio (0.06; 95%CI −0.08 - 0.21) were not significantly different to controls. Correlations between EGG metrics and the presence and timing of FD symptoms were inconsistent. EGG methodologies were diverse and variably applied.ConclusionAbnormal gastric slow wave rhythms are a consistent abnormality present in FD, as defined by EGG, and therefore likely play a role in pathophysiology. The aberrant electrophysiology identified in FD warrants further investigation, including into underlying mechanisms, associated spatial patterns, and symptom correlations.

System and methodology to study and stimulate gastric electrical activity in small freely behaving animals

Aim: To develop and validate a system that can wirelessly acquire gastric slow waves and deliver electrical pulses to the stomach. Materials & methods: The system is composed of a front-end and a back-end unit connected to a computer, which runs a custom-made graphical user interface. The system was validated on benchtop and in vivo studies. Results: Benchtop validation showed an appropriate frequency response to acquire slow waves. Moreover, the system was able to deliver electrical pulses at amplitudes up to ±10 mA. Slow wave activity recorded from the stomach of rats was in the range of approximately five cycles per minute (cpm). Pulses delivered to the stomach of a rat every 15 s and reduced the activity to 4 cpm during the stimulation period. Conclusion: This study reports the first wireless system and methodology that can be used to acquire slow waves and deliver electrical stimulation to the stomach of small freely behaving animals.