Evaluation of autonomic nervous function during upper gastrointestinal endoscopy using heart rate variability

To investigate autonomic nervous function during upper gastrointestinal end oscopy, we analyzed R-R interval variability from electrocardiograms obtain ed during endoscopy. Holter electrocardiogram recordings were made before a nd after premedication, and during endoscopy. Time- and frequency-domain an alyses of heart rate variability were performed in 54 subjects premedicated with scopolamine butylbromide (SB group) and in GB subjects premedicated w ith glucagon (G group). To determine the effect of autonomic imbalance on a rrhythmia generation during endoscopy, subjects with arrhythmias (A group) were compared with subjects without arrhythmias (N group). In the SE group, high frequency spectral power (HF power; 0.15 to 0.40 Hz), which reflects parasympathetic activity, decreased significantly after premedication, and decreased further during endoscopy (P < 0.01). Moreover, HF power before pr emedication or during endoscopy in the A group was significantly lower than that in the N group (P < 0.01). This study suggests that the measurement o f HF power prior to endoscopy can identify subjects with reduced HF power. This should allow the prevention of cardiovascular complications related to premedication and endoscope insertion.