Cardiac sympathovagal balance during endoscopic retrograde cholangiopancreatography

Background and Study Aims: Cardiopulmonary complications have been reported during upper gastrointestinal endoscopy and endoscopic retrograde cholangi opancreatography (ERCP), The aim of this study was to evaluate the sympatho vagal response to the stretching of the common bile duct caused by contrast medium injection during ERCP, Patients and Methods: The 16 patients included in the study were assigned t o two groups according to the size of common bile duct. Group A consisted o f patients with normal-sized bile ducts, while Group B patients had dilated common bile ducts, The heart rate variability (HRV) technique was used to assess the sympathovagal balance. The HRV data were gathered using the Holt er technique, and frequency domain analysis revealed two main spectral comp onents of HRV: low frequency (LF) and high frequency (HF). Results: In patients with normal-sized bile ducts, contrast injection initi ated a rapid increase in the po vver spectra (ms(2)) of both the HF and LF components, In patients with dilated common bile ducts, this phenomenon was not observed. Conclusions: During ERCP, contrast injection into a dilated common bile duc t does not stimulate the autonomic nervous system in the same way as it doe s when the common bile duct is of normal size.