Autonomic function in patients with functional dyspepsia assessed by 24-hour heart rate variability

The function of the autonomic nervous system was assessed in 23 patients with dysmotility-like functional dyspepsia and 12 healthy volunteers by analysis of 24-hr heart rate variability and a battery of five standardized sympathetic and parasympathetic cardiovascular reflex tests. Measures of heart rate variability were obtained by analysis of ambulatory electrocardiographic recordings using both the time and the frequency domain methods. The values of parameters reflecting vagal activity (HF, rMSSD) were significantly lower in patients with functional dyspepsia. Individual analysis of heart rate variability data identified at least one abnormal parameter of vagal function in seven (30.4%) patients, and in five of these the results of parasympathetic cardiovascular reflex tests were also abnormal. Our results suggest impaired efferent vagal function in a subgroup of patients with functional dyspepsia. This abnormality may play a role in the pathogenesis of the disease in these patients.