The effect of visceral reception activation (water load test) on autonomic activity and gastric myoelectric activity in gastrointestinal malignancies

Abstract

The aim of this study was to analyze the effect of water load test (WLT) on heart rate variability (HRV), blood pressure variability (BPV), hemodynamic parameters and gastric myoelectric activity in gastrointestinal (GI) cancer patients. BACKGROUND: WLT activates gastrointestinal mechanoreception and osmoreception, and hence, can indirectly modulate autonomic activity. METHODS: Eighty patients (mean age 61.2 years) were enrolled, along with the group of healthy controls. HRV, BPV and electrogastrography (EGG) were recorded at rest (in a fasted state) and after water uptake at 100 ml/min. RESULTS: WLT contributed to an increase in the percentages of normogastria time, from 37.3 % to 50.0 % (p=0.02) and from 42.3 % to 47.7 % (p=0.01), respectively in colon and rectal cancer. Cancer patients presented lower values of HRV indices determined on linear analysis at rest and after WLT. CONCLUSIONS: A slight predominance of the sympathetic component was observed in response to WLT, which was refl ected by changes in hemodynamic parameters. The response to WLT is a consequence of GI mechanoreception and osmoreception activation and resultant pressure reaction. This effect was disrupted by the neoplastic process within the GI tract, especially in gastric and colon malignancies, but not in rectal cancer (Tab. 2, Fig. 3, Ref. 40).