Assessment of autonomic nervous activity during gastrointestinal endoscopy: Analysis of blood pressure variability by tonometry

Abstract

We continuously measured blood pressure by tonometry in 30 patients during endoscopy to determine the influence of upper gastrointestinal endoscopy on cardiac events. Patients were divided into two groups: one group treated with scopolamine butylbromide as premedication (SB group) and another group without premedication (C group). Time- and frequency domain analyses of beat-to-beat systolic blood pressure variability were performed for 128 consecutive beats. For time-domain analysis, we calculated the coefficient of variation of systolic blood pressure (CV(BP)). For the frequency domain analysis, we determined the low-frequency (LF(BP); 0.04-0.15 Hz) and high-frequency (HF(BP); 0.15-0.40 Hz) powers of the variation in systolic blood pressure and the ratio of LF(BP) to HF(BP) (LF(BP)/HF(BP)) during endoscopy. The CV(BP) and HF(BP), indicators of parasympathetic tone, increased in the early phase of endoscopy but decreased significantly in the middle and late phases compared with the pre-endoscopy value. The ratio of LF(BP)/HF(BP), an indicator of indirect sympathetic tone, increased throughout the endoscopic procedure. Moreover, premedication with scopolamine butylbromide prevents the excessive parasympathetic nervous reflex when an endoscope passes through the upper digestive tract and also brings both decreased parasympathetic tone and increased sympathetic tone at the late phase of endoscopic procedure. Our results indicate that gastrointestinal endoscopy induced an autonomic nervous abnormality, which may contribute to the occurrence of cardiac events during endoscopic procedures.

Heart Rate and Blood Pressure Changes during Gastroscopy in Healthy Older Subjects

“…We have shown that older subjects tend to have a sustained increase in blood pressure throughout the procedure whilst younger patients have an increase at intubation but return to baseline within 1 min. These findings of two different types of response are in keeping with the results of the one previous study of blood pressure during gastroscopy [10]. However, our study suggests that these differences are related to advancing age and not premedication as previously suggested.…”

“…In approximately two thirds of subjects there was an initial increase in blood pressure at intubation, after which the blood pressure returned to baseline within 1 min. In the remaining one third, the blood pressure elevation was sustained throughout the procedure [10]. The authors of this study attributed these different blood pressure responses to the use of premedication and resting the patient prior to the procedure.…”

Autonomic nervous function in upper gastrointestinal endoscopy: A prospective randomized comparison between transnasal and oral procedures

“…[11][12][13][14]16,17 The ratio of LF power to HF power (LF power/HF power) has been reported to correlate with the level of sympathetic nervous activity. [11][12][13][14]16,18 We converted HF power data to a logarithmic scale to make it possible to analyze with linear regression. Changes in the parameters (∆LF power/HF power and ∆log HF power) were calculated using the following equation: (values during the endoscopy or at the completion)-(values before the endoscopy).…”

“…Recently, quantitative evaluation of autonomic nervous functions has become possible by PSA of heart-rate variability during endoscopic procedures. [11][12][13][14] Patients and methods…”

Clinical Efficacy of Efonidipine Hydrochloride, a T-type Calcium Channel Inhibitor, on Sympathetic Activities. Examination Using Spectral Analysis of Heart Rate/Blood Pressure Variabilities and 123I-Metaiodobenzylguanidine Myocardial Scintigraphy.

“…To measure BP, a tonometric pulse pressure wave sensor was placed on the radial artery, and the beat-to-beat BP was noninvasively monitored. [9][10][11] The pulse pressure sensor consists of 30 elements; it facilitates measurement of BP per beat by automatically correcting the element pulse pressure in each position and the BP measured by the oscillometric method.…”