Electrogastrographic responses to the stress of a mirror drawing test in outpatients consulting a psychosomatic clinic.

The respiratory rate, LF, HF, and the LF/HF ratio from heart rate variability (HRV) were compared between outpatients (n=25) and controls (n=58) during rest and while performing a mirror drawing test (MDT). Anxiety and depression scores were obtained before the test. In addition, the power content of the electrogastrograms (EGGs) recorded during MDT were compared to those recorded during rest (c-MDT/r). The anxiety scores, depression scores, resting heart rate, resting respiratory rate and the 3 cpm resting frequency of the epigastric EGG were significantly higher in outpatients than in controls. Both the heart rate and the 3 cpm frequency in the infraumbilical EGG during the stress of the MDT were significantly higher in outpatients than in controls. Instability factors (IF, standard deviation/mean frequency) of the 3 cpm frequency in the epigastric EGG were higher in controls than in outpatients, though the spectral frequencies were similar and insignificantly different between the two groups. Interestingly, the slope of the significant linear correlation was positive in controls but was negative in outpatients between both the resting LF/HF and the power content ratio of the 3 cpm frequency in the infraumbilical EGG, c-MDT/r, which corresponds to the colonic responses to MDT stress.