Decrease In Parasympathetic Nervous Activity Research Articles

Difference in the Effects of Lidocaine With Epinephrine and Prilocaine With Felypressin on the Autonomic Nervous System During Extraction of the Impacted Mandibular Third Molar: A Randomized Controlled Trial

Complications during local anesthesia include increased blood pressure and vasovagal reflex, which are caused by changes in the autonomic nervous system. The commonly used local anesthetic preparations are lidocaine to which the vasoconstrictor epinephrine is added (lidocaine-epinephrine) and prilocaine to which the vasoconstrictor felypressin is added (prilocaine-felypressin); however, their effects during dental treatment are unclear. We examined the effects of these 2 different local anesthetic preparations on the autonomic nervous system and circulation during extraction of the impacted mandibular third molar. In this randomized controlled trial, 40 female patients scheduled for extraction of an impacted mandibular third molar were randomized to the lidocaine-epinephrine group or prilocaine-felypressin group. Heart rate variability, heart rate, and systolic blood pressure were recorded during the experiment. Descriptive and bivariate statistics were computed, and the P value was set at .05. The low frequency-high frequency ratio was significantly increased in the prilocaine-felypressin group during extraction compared with that in the lidocaine-epinephrine group (P<.05). In the lidocaine-epinephrine group, a significant decrease in the high-frequency component was observed during bone removal and extraction compared with that at rest (P<.05). In both groups, a significant increase in systolic blood pressure was observed during local anesthesia, incision and reflection of the flap, bone removal, separation of the tooth crown, extraction, and suturing compared with that at rest (P<.01). This study is the first to investigate the differences in the influence of 2 different local anesthetic preparations on the autonomic nervous system during extraction of the mandibular third molar. Changes in circulatory dynamics during tooth extraction with the 2 different local anesthetic preparations were the result of a decrease in parasympathetic nervous activity with lidocaine-epinephrine and an increase in sympathetic nervous activity with prilocaine-felypressin.

Evaluation of heat stress response in crossbred dairy cows under tropical climate by analysis of heart rate variability.

The present study aims to examine the effect of tropical temperatures on autonomic nervous activity in Cambodian dairy cattle by analyzing heart rate variability (HRV). Holter-type electrocardiograms were recorded in adult crossbred cows (Cambodian native × Holstein) either in a sheltered area or under direct sunlight. Rectal temperatures and heart rates increased in animals under direct sunlight as compared to those in the shelter. The power spectral analysis of HRV revealed that three out of the five cows studied underwent a decrease in parasympathetic nervous activity under direct sunlight with the remaining two cows showing no apparent change. The HRV analysis would prove to be a useful tool to reveal information about heat tolerance in dairy cows.

Loss of Postprandial Insulin Sensitization During Aging

With aging, there is a decrease in parasympathetic nervous activity. Since the hepatic parasympathetic nerves (HPNs) are essential to the disposal of nutrients, through the hepatic insulin sensitizing substance (HISS), we tested the hypothesis that aging leads to a lowering of postprandial glucose disposal by a decrease of the HISS-dependent component of insulin action. Insulin sensitivity was quantified in fed or fasted, male and female Wistar rats (from 6 to 52 weeks), using a euglycemic clamp. The HISS-dependent component was quantified by administration of the muscarinic antagonist atropine. Total insulin action decreased gradually up to 52 weeks of age: The HISS-independent component of insulin action decreased until 9 weeks of age and remained unchanged thereafter; the HISS-dependent component decreased from 9 weeks of age throughout aging. The continuous decrease of HISS action, uncovered by blocking the HPN, is the key phenomenon for the gradual decrease of insulin sensitivity with aging.

RELATIONSHIP BETWEEN PULSE WAVE VELOCITY AND CIRCULATORY HEMODYNAMICS DURING UPPER GASTROINTESTINAL ENDOSCOPY

Background: Arterial stiffness has recently been proposed as a powerful independent predictor of cardiovascular disease. The aim of the present study was to establish the relationship between aortic stiffness and circulatory complications during gastrointestinal endoscopy using pulse wave velocity (PWV) as a parameter.Methods: We serially monitored standard 12‐lead ECGs, blood pressure, and percutaneous arterial oxygen saturation during gastrointestinal endoscopy, and performed a spectral analysis of heart rate variability and an analysis of QT dispersion. We also performed a logistic multivariate analysis of the severity of atherosclerosis and changes in the circulatory kinetics using PWV.Results: In the elderly group (older than 65 years), the rate of decrease in parasympathetic nervous activity and rate of change in blood pressure and QT dispersion were significantly larger than those in the non‐elderly group (younger than 65 years) (P &lt; 0.05). However, a multivariate analysis showed that the relative risk for the grade of atherosclerosis was greater in an evaluation by PWV than by age.Conclusions: We conclude that the grade of atherosclerosis, as evaluated from PWV, is a stronger predictive factor for changes in circulatory kinetics during gastrointestinal endoscopy than age. PWV screening may facilitate the prevention of cardiac accidents during gastrointestinal endoscopy to some degree.

Autonomic nervous system activity during myocardial ischemia in man estimated by power spectral analysis of heart period variability

Ambulatory patients with coronary artery disease exhibit a nearly universal increase in heart rate during episodes of ST depression. 1 The cause of the increase in heart rate presumably represents an increase in sympathetic nervous activity, a decrease in parasympathetic nervous activity, or both. The purpose of this investigation was to determine the cause of increased heart rate during ambulatory ischemic episodes using power spectral analysis of normal RR intervals. An increase in sympathetic nervous activity causes an increase in low frequency power and an increase in the low to high frequency ratio. A decrease in parasympathetic nervous activity causes a decrease in both low and high frequency power, that is, no change or a decrease in the low to high frequency ratio.