Nonlinear properties of vagal and sympathetic modulations of heart rate variability in ovine fetus near term.

Time scales of autonomic information flow in near-term fetal sheep

Autonomic information flow (AIF) characterizes fetal heart rate (FHR) variability (fHRV) in the time scale dependent complexity domain and discriminates sleep states [high voltage/low frequency (HV/LF) and low voltage/high frequency (LV/HF) electrocortical activity (ECoG)]. However, the physiologic relationship of AIF time scales to the underlying sympathetic and vagal rhythms is not known. Und...

اثر داروی آنتی کولینرژیک دی سیکلومین هیدروکلراید بر نوسان ضربان قلب و آزمون چمباتمه در داوطلبین سالم

Background and purpose:Squatting test and heart rate variability (HRV) are currently being used to evaluate cardiovascular autonomic nervous function. HRV indexes are able to measure vagal function, while squatting test is able to measure both sympathetic and vagal functions. Our objective in this research is to evaluate the influence of injective dicyclomine hydrochloride (DCH)-an M1 recepto...

Estimated cardiac vagal tone predicts fetal responses to mother's and stranger's voices.

Heart rate responses of 84 near-term fetuses to recorded female voices were examined in 166 trials of auditory stimulation. Each fetus was presented with a 2-min recording of their mother's voice and a 2-min recording of a female stranger's voice, in counterbalanced order, with a 10-min rest period between trials. High frequency heart rate variability during a 2-min baseline period was used to ...

Umbilical cord occlusions in near - term ovine fetus induce increased beat - to - beat heart rate 1 variability correlating to decreases in neuroinflammation : a case for the afferent cholinergic anti - 2 inflammatory pathway ?

Concurrent sympathetic activation and vagal withdrawal in hyperthyroidism: Evidence from detrended fluctuation analysis of heart rate variability

Despite many previous studies on the association between hyperthyroidism and the hyperadrenergic state, controversies still exist. Detrended fluctuation analysis (DFA) is a well recognizedmethod in the nonlinear analysis of heart rate variability (HRV), and it has physiological significance related to the autonomic nervous system. In particular, an increased short-termscaling exponentα1 calcula...