[Usefulness of heart rate variability for evaluating cardiac autonomic nervous function]

To investigate the effect of gastric ulceration on cardiac autonomic nervous function, 24-hour ambulatory electrocardiograms were recorded in patients with artificial gastric ulcers caused by endoscopic treatment of gastric tumors. Their cardiac autonomic nervous activity was assessed by both time- and frequency-domain analyses of heart rate variability obtained from electrocardiogram recordings. The results were compared with those from patients who had undergone endoscopic treatment of esophageal varices or colorectal tumors, or gastrointestinal endoscopy alone. Parameters of time-domain analysis decreased significantly with the formation of gastric ulcers. Because parameters of frequency-domain analysis did not change in the group with gastric ulcers, this decrease in parameter of time-domain analysis suggests increased activity of cardiac sympathetic nervous system. There were no changes in the parameters of either time- or frequency-domain analysis in other groups. These results suggest that artificial gastric ulceration modifies cardiac sympathovagal balance, favoring cardiac sympathetic activity, while artificial esophageal and colon ulcers have no effect on cardiac autonomic nervous activity. Heart rate variability analysis is a useful method of evaluating possible implications between gastric ulceration and cardiac autonomic nervous function.