Parasympathetic withdrawal is an integral component of autonomic imbalance in congestive heart failure: Demonstration in human subjects and verification in a paced canine model of ventricular failure

Abstract

Although enhanced sympathetic tone is a well recognized component of the autonomic profile characteristic of congestive heart failure, the contribution of parasympathetic withdrawal to this autonomic imbalance is less well described. The technique of spectral analysis of heart rate variability provides a dynamic map of sympathetic and parasympathetic tone and was thus used to define the nature of sympathetic-parasympathetic interactions in humans with idiopathic dilated cardiomyopathy and in a paced canine model of congestive heart failure. Humans with cardiomyopathy were found to have an augmentation of the sympathetically mediated low frequency area of the power density spectrum. Parasympathetic withdrawal was demonstrated by significant reductions in the parasympathetically mediated high frequency area (p less than 0.05) and the ratio of high to low frequency areas (p less than 0.01). Administration of atropine to normal subjects resulted in a significant reduction in the high frequency area (p less than 0.05) and the high/low frequency area ratio, both of which decreased within the range noted in patients with congestive heart failure. Administration of isoproterenol in normal subjects led to an augmentation of the low frequency area but to only a small decrease in the high/low frequency area ratio. Induction of congestive heart failure in a paced canine model resulted in alterations in the autonomic profile that resembled those seen in humans with ventricular failure. The prominent high frequency region of the spectrum at baseline, indicating a predominance of parasympathetic tone, was absent after the evolution of congestive heart failure, and there was a marked augmentation of the low frequency region of the spectrum.(ABSTRACT TRUNCATED AT 250 WORDS)

Heart rate variability (HRV) analysis in radio and TV broadcasting stations workers

“…For the purpose of this study, the heart rate variability analysis has been performed as it allows for monitoring of the sympathetic and parasympathetic activity of the autonomic nervous system [7]. The method has become commonly applied in the diagnostics of diabetic neuropathy and the risk assessment of a sudden cardiac death in post-infarction patients as well as for screening other cardiovascular and neurological disorders [8][9][10][11]. It is also used in experimental physiological studies [12,13], but is rarely applied to individual examinations of people occupationally exposed to various occupational factors [14].…”

Heart rate changes during the Valsalva maneuver in patients with isolated aortic insufficiency

“…Since the two additional tests of cardiac parasympathetic function were also normal in our asymptomatic patients with ventricular dilatation and no segmental wall motion abnormalities, we are tempted to hypothesize that, in order to impair parasympathetic heart rate control, ventricular dilatation should be associated with segmental wall motion abnormalities and/or congestive heart failure (40).…”

Heart rate variability: Linear and non-linear analysis of pre-awake period for normal and intrauterine growth restricted children at 10 year

“…The other measures that show statistically significant differences are LF, HF and LF/HF. Low HF is a marker of sudden death [25], and high ratio LF/HF is associated with CHB and ischemia/dilated cardiomyopathy [26]. SD2 which is related to the long term variability, gives (p<0.05).…”