ReviewHeart rate variability explored in the frequency domain: A tool to investigate the link between heart and behavior☆
Section snippets
Conceptual background
The neural regulation of cardiac function is mainly determined, in its efferent side, by the interaction of sympathetic and vagal mechanisms (Fig. 1). In most physiological conditions, the activation of either sympathetic or vagal outflow is accompanied by the inhibition of the other suggesting the concept of sympathovagal balance, as a horizontal beam pivoted at its center (Malliani, 2000). This reciprocal organization, alluding to a synergistic design, seems instrumental to the fact that
Methodology
Variable phenomena such as heart period or arterial blood pressure can be described not only as a function of time (i.e. in the time domain), but also the sum of elementary oscillatory components, defined by their frequency and amplitude (i.e. in the frequency domain).
The analysis of HRV is usually performed off-line with computerized techniques. It is impossible, in this context, to address the various approaches for which we refer to previous articles (Pagani et al., 1986, Malliani et al.,
Practical aspects
In principle, spectral analysis, used to detect possible rhythmicities hidden in the signal, necessitates stationary conditions that, in strict terms, are unknown to biology.
A crucial procedure to be simultaneously performed is to obtain some measurement of respiratory rate in order to assess its synchronization with HF component (Malliani et al., 1991, Montano et al., 1994) (Fig. 2). Conversely, when the frequency of respiration decreases enough to approach the LF rhythm in such a way that HF
Physiological studies
The core hypothesis of the proposed approach was that the sympathovagal balance can, on the whole, be explored in the frequency domain. Quite numerous data support the assumptions that (1) the respiratory rhythm of heart period variability, defined as HF spectral component, is a marker o vagal modulation (Akselrod et al., 1981, Pagani et al., 1986, Malliani et al., 1991, Montano et al., 1994); (2) the rhythm defined as LF, present in RR and SAP variabilities and corresponding to vasomotor waves
Physical exercise: the complex simplicity of cardiovascular neural control
Spectral analysis of short-term HRV has been shown to be capable to detect and track the complex adaptational changes in sympatho-vagal balance attending regular physical training, a core component of primary and secondary cardiovascular prevention and of an optimal care management in cardiovascular diseases. This has been demonstrated from patients to high-performance world class athletes, implying relevant clinical information and practical applications.
In hypertensive patients who feature
General considerations
In spite of an always more diffuse use of spectral methodology and of a Task Force attempt (1996), true standard values (Fagard et al., 1999) corresponding to normal or abnormal conditions are not yet available. This is not surprising and, in a sense, is only partly detrimental. Indeed, what is to be measured is the dynamic equilibrium of the sympathovagal balance and the range of its excursions that can be extremely wide. Quite obviously this complex ensemble of properties is affected by a
Future perspectives
Linear analysis of HRV can therefore furnish non-invasive indexes of cardiac autonomic modulation in the presence of rhythmic variability. On the other hand, in settings characterized by rapid and non-repetitive changes, like the periods preceding cardiac events, or in conditions characterized by co-activation of the two branches of the ANS, non-invasive standard measurements of these control systems give less reliable information than during more stable periods (Porta et al., 2000).
We have
Conclusions
Frequency domain analysis of heart rate variability is a physiological and clinical tool having the merit of being totally non-invasive and of providing a global, although indirect, evaluation of autonomic modulation of heart period. In several instances the assessment of sympathovagal balance obtained with this procedure seems to reflect an even more general equilibrium ranging from quiet to excitation.
This approach, together with other methods based on non-linear dynamics, pertains to the
Acknowledgments
N.M. was partly supported by Italian Space Agency DCMC Grant; F.I. was supported by Italian Space Agency DCMC grant I/006/06/0.
References (102)
- et al.
Autonomic nervous system activity in idiopathic dilated cardiomyopathy and in hypertrophic cardiomyopathy
Am. J. Cardiol.
(1993) - et al.
Effects of controlled breathing, mental activity and mental stress with or without verbalization on heart rate variability
J. Am. Coll. Cardiol.
(2000) - et al.
Alterations in heart rate variability and its circadian rhythm in hypertensive patients with left ventricular hypertrophy free of coronary artery disease
Am. Heart J.
(1993) - et al.
Cardiovascular risk and adrenergic overdrive in the metabolic syndrome
Nutr. Metab. Cardiovasc. Dis.
(2007) - et al.
Impaired heart rate variability in patients with chronic Chagas’ disease
Am. Heart J.
(1991) - et al.
Accuracy of assessment of cardiac vagal tone by heart rate variability in normal subjects
Am. J. Cardiol.
(1991) - et al.
Cardiac sympathetic denervation modulated the sympathoexcitatory response to acute myocardial ischemia
J. Am. Coll. Cardiol.
(2002) - et al.
Decreased heart rate variability and its association with increased mortality after acute myocardial infarction
Am. J. Cardiol.
(1987) - et al.
Autonomic changes associated with spontaneous coronary spasm in patients with variant angina
J. Am. Coll. Cardiol.
(1996) - et al.
Heart rate variability and early recurrence of atrial fibrillation after electrical cardioversion
J. Am. Coll. Cardiol.
(2001)
Heart rate variability as an index of sympathovagal interaction after acute myocardial infarction
Am. J. Cardiol.
Heart rate variability in the early hours of an acute myocardial infarction
Am. J. Cardiol.
Effects of cardiac rehabilitation and exercise training on autonomic regulation in patients with coronary artery disease
Am. Heart J.
Heart rate dynamics before spontaneous onset of ventricular fibrillation in patients with healed myocardial infarcts
Am. J. Cardiol.
Effects of cardiac rehabilitation and beta-blocker therapy on heart rate variability after first acute myocardial infarction
Am. J. Cardiol.
Presence of vasomotor and respiratory rhythms in the discharge of single medullary neurons involved in the regulation of cardiovascular system
J. Auton. Nerv. Syst.
Spectral analysis of heart rate variability in the assessment of autonomic diabetic neuropathy
J. Auton. Nerv. Syst.
Arrhythmias in the first hours of acute myocardial infarction
Prog. Cardiovasc. Dis.
The yin and yang of cardiac autonomic control: vago-sympathetic interactions revisited
Brain Res. Rev.
Power spectrum analysis of heart rate fluctuation: a quantitative probe of beat-to-beat cardiovascular control
Science
Early abnormalities of vascular and cardiac autonomic control in Parkinson's disease without orthostatic hypotension
Hypertension
Respiratory sinus arrhythmia in the denervated human heart
J. Appl. Physiol.
Impaired circadian modulation of sympathovagal activity in diabetes. A possible explanation for altered temporal onset of cardiovascular disease
Circulation
Frequency domain measures of heart period variability and mortality after myocardial infarction
Circulation
Controlled trial of physical training in chronic heart failure. Exercise performance, hemodynamics, ventilation, and autonomic function
Circulation
Acute beta-blockade increases muscle sympathetic activity and modifies its frequency distribution
Circulation
Regular heartbeat dynamics are associated with cardiac health
Am. J. Physiol.
Improvement of left ventricular function and cardiovascular neural control after endoventriculoplasty and myocardial revascularization
Cardiovasc Res.
Sympathovagal balance: a critical appraisal
Circulation
Clinical application of noradrenaline spillover methodology: delineation of regional human sympathetic nervous responses
Pharmacol. Toxicol.
Mechanisms of sympathetic activation in obesity-related hypertension
Hypertension
Power spectral analysis of heart rate variability by autoregressive modelling and fast Fourier transform: a comparative study
Acta Cardiol.
Continuous 24-hour assessment of the neural regulation of systemic arterial pressure and RR variabilities in ambulant subjects
Circulation
Early and late effects of exercise and athletic training on neural mechanisms controlling heart rate
Cardiovasc. Res.
Cardiac autonomic patterns preceding occasional vasovagal reactions in healthy humans
Circulation
Oscillatory patterns in sympathetic neural discharge and cardiovascular variables during orthostatic stimulus
Circulation
Abnormalities of cardiovascular neural control and reduced orthostatic tolerance in patients with primary fibromyalgia
J. Rheumatol.
Depressed low frequency power of heart rate variability as an independent predictor of sudden death in chronic heart failure
Eur. Heart J.
Beneficial effect of the central nervous system beta-adrenoceptor blockade on the failing
Heart Circ. Res.
Sympathetic predominance in essential hypertension: a study employing spectral analysis of heart rate variability
J. Hypertens.
Altered pattern of circadian neural control of heart period in mild hypertension
J. Hypertens.
Influences of neural mechanisms on heart period and arterial pressure variabilities in quadriplegic patients
Am. J. Physiol.
Altered dynamics of the circadian relationship between systemic arterial pressure and cardiac sympathetic drive early on in mild hypertension
Clin. Sci.
Sympathetic predominance followed by functional denervation in the progression of chronic heart failure
Eur. Heart J.
Non-linear dynamics and chaotic indices in heart rate variability of normal subjects and heart-transplanted patients
Cardiovasc. Res.
Symbolic dynamics of heart rate variability A probe to investigate cardiac autonomic modulation
Circulation
Sex-related differences in autonomic modulation of heart rate in middle-aged subjects
Circulation
Prediction of sudden cardiac death: appraisal of the studies and methods assessing the risk of sudden arrhythmic death
Circulation
Spontaneous rhythms in physiological control systems
Nature
Novel spectral indexes of heart rate variability as predictors of sudden and non-sudden cardiac death after an acute myocardial infarction
Ann. Med.
Cited by (357)
Lower heart rate variability is associated with loss of muscle mass and sarcopenia in community-dwelling older Chinese adults
2023, Journal of the Formosan Medical AssociationNoncontact Cardiac Parameters Estimation Using Radar Acoustics for Healthcare IoT
2024, IEEE Internet of Things JournalFetal heart rate spectral analysis in raw signals and PRSA-derived curve: normal and pathological fetuses discrimination
2024, Medical and Biological Engineering and ComputingTelic-Paratelic Dominance and Heart Rate Variability in Athletes Engaged in Power and Endurance Training
2024, Perceptual and Motor Skills
- ☆
To the memory of Alberto Malliani, an extraordinary mentor, physician, scientist and friend.