Review articleSympathetic rhythms and cardiovascular oscillations
Section snippets
LF and HF oscillations in motor and premotor sympathetic neurons
In an earlier study (Montano et al., 1992) performed on decerebrate, artificially ventilated cats, we observed the presence of the two main rhythms, LF and HF, in the variability of the discharge of cardiac sympathetic efferent fibers. Both these oscillatory components were highly coherent with the similar spectral components detectable in the variability of RR interval and systolic arterial pressure (SAP), and underwent parallel changes during hemodynamic maneuvers. Briefly, increases in
LF and HF oscillations and sympathetic spinal network
Since the neural regulation of cardiovascular function is integrated not only at supraspinal but also at spinal level, thereby including sympatho-sympathetic reflexes Malliani et al., 1975, Coote, 1988, we wondered whether LF and HF rhythmicities could be found also in sympathetic spinal outflow. Indeed, it has long been known that spinal structures provide a tonic sympathetic discharge compatible with resting blood pressure within a physiological range Sherrington, 1906, Beacham and Perl, 1964
Independence of LF of HRV from hemodynamic oscillations
The capability of central structures generating an LF rhythm is strongly suggested also by a study (Cooley et al., 1998) performed on two patients with severe congestive heart failure (CHF), who underwent the implantation of a left ventricular assist device (LVAD). This device, used as a bridge to cardiac transplantation in intractable heart failure, obtains oxygenated blood from the native left ventricle and sends it to the arterial circulation. Thus, these patients represent a unique model in
LF and HF oscillations in muscle sympathetic nerve activity
The advent in recent years of direct intraneural microneurographic recordings of efferent sympathetic nerve traffic, to both muscle blood vessels (MSNA) and skin blood vessels (SSNA), has allowed us to address this issue also in human beings Wallin, 1983, Mark et al., 1985.
Previous studies in human healthy volunteers reported the presence of both LF and HF oscillations in spectral profile of MSNA Eckberg et al., 1985, Saul et al., 1990. However, they did not investigate the correlation between
Conclusions
In numerous circumstances, the increase in sympathetic activity seems to be associated with a simultaneous enhancement of its LF rhythm and, conversely, with a decrease of its HF component. The reciprocal organization seems to be a fundamental characteristic of central autonomic cardiovascular control.
The relative distribution of power between these two oscillatory frequencies is tightly linked to changes in the strength of the signal, so that one oscillatory frequency is a marker of excitation
References (29)
- et al.
Spinal cardiovascular reflexes
Brain Res.
(1975) - et al.
Presence of vasomotor and respiratory rhythms in the discharge of single medullary neurons involved in the regulation of cardiovascular system
J. Auton. Nerv. Syst.
(1996) - et al.
Emergence of lung-inflation-related sympathetic nerve activity in spinal cord transected neonatal swine
Brain Res.
(1997) - et al.
Power spectrum analysis of heart rate fluctuations: a quantitative probe of beat to beat cardiovascular control
Science
(1981) - et al.
Background and reflex discharge of sympathetic preganglionic neurons in the spinal cat
J. Physiol.
(1964) - et al.
Circulation
(1995) - et al.
Evidence for a central origin of the low-frequency oscillation in RR interval variability
Circulation
(1998) The organization of cardiovascular neurons in the spinal cord
Rev. Physiol., Biochem. Pharmacol.
(1988)- de Boer, W., Karemaker, J.M., Strackee, J., 1987. Hemodinamic fluctuations and baroreflex sensitivity in humans: a...
- et al.
Respiratory modulation of muscle sympathetic and vagal cardiac outflow in man
J. Physiol. (London)
(1985)
Sympathetic activity and the systemic circulation in the spinal cat
J. Physiol. (London)
Oscillatory patterns in sympathetic neural discharge and cardiovascular variables during orthostatic stimulus
Circulation
Influences of neural mechanisms on heart period and arterial pressure variabilities in quadriplegic patients
Am. J. Physiol.
Sympathetic unit activity associated with Mayer waves in the spinal dog
Am. J. Physiol.
Cited by (29)
Respiratory training in older women: Unravelling central and peripheral hemodynamic slow oscillatory patterns
2023, Experimental GerontologyCitation Excerpt :The baroreflex buffering in arterial pressure oscillations and the cerebral autoregulation play a fundamental role in the CBF control (Levine et al., 1994; Ogoh et al., 2010; Koep et al., 2022). The central generated sympathetic rhythms and the peripheral reflex mechanisms within the closed-loop model seem to explain the low-frequency (0.1 Hz) oscillations from blood pressure and R-R intervals (Montano et al., 2001; Malliani et al., 1991), while in the high-frequency band respiration modulates the vagal activity to the heart (Montano et al., 1994). The CBF is under tonic autonomic neural control and autoregulated in the very-low-frequency (Zhang et al., 2002a).
Midcingulate somatomotor and autonomic functions
2019, Handbook of Clinical NeurologyCitation Excerpt :It corresponds to the heart rate beat-to-beat variability and it can be appreciated by studying the interval between R-waves on electrocardiogram (ECG). Two oscillatory patterns in R-R intervals can be dissociated: (1) the low-frequency (LF) pattern (0.05 ± 0.15 Hz) which is supposed to reflect the influence of the sympathetic network on the heart (Pagani et al., 1986; Eckberg, 1997; Montano et al., 2001) and (2) the high-frequency (HF) pattern (0.15 ± 0.50 Hz), which is known to reflect the influence of the parasympathetic network on the heart (Montano et al., 2001). Blood pressure is known to be controlled by both the sympathetic and the parasympathetic networks.
Exercise training improves hypertension-induced autonomic dysfunction without influencing properties of peripheral cardiac vagus nerve
2017, Autonomic Neuroscience: Basic and ClinicalCitation Excerpt :Moreover, our results showed that the training-induced BP reduction, observed in SHR with improved baroreceptor function, was associated with a marked reduction of sympathetic variability (significantly elevated in sedentary SHR versus normotensive control animals), as indicated by the marked decrease of the normalized LF component of systolic pressure. Evidences from experimental data suggest that the LF component of SBP is modulated by sympathetic activity and that an increased BPV represents disturbance in BP control and is usually associated to arterial hypertension (Montano et al., 2001). The training-induced BP reduction observed in our study was associated with LF power reductions in SHR group, with no significant effect in the WKY rats.
Nonlinear dynamics of cardiovascular ageing
2010, Physics ReportsCitation Excerpt :The duration of the synchronization observed increases as the average RF increases, and is inversely correlated with the variability in the respiratory rate. There are many studies of HRV, its links to autonomic control and its potential use as a diagnostic tool (see for example, [92,192]). We conclude, however, that RF and RFV are also critical indicators of the cardio-respiratory interaction, and that future studies should consider them in more detail.
Effect of aerobic training on heart rate variability at rest
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