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Mindfulness and Meditation Practices
Published in Gia Merlo, Kathy Berra, Lifestyle Nursing, 2023
Polyvagal theory, developed by Stephen Porges, is one of the most clinically relevant models of the nervous system. Porges delineates the evolution of the nervous system for one’s safety and protection. The dorsal vagal (DV) system, the unmyelinated branch of the 10th cranial vagus nerve, is the most primitive system. It is responsible for the freeze response when one is threatened with little chance for escape. The next evolutionary step is the sympathetic nervous system (SNS), the fight/flight approach to danger. The newest development in the nervous system is the ventral vagal system (VV), the myelinated ventral branch of our vagus nerve, which allows one to be calm and connected. Interestingly, the ventral vagus is only found in mammals and serves the purpose of helping find safety in alliance with others. The ventral vagal system is neuroprotective and energy efficient, acting as a neural brake by inhibiting the nervous system from going into fight, flight, or freeze states unless it is necessary. The vagus nerve mediates a brain–heart connection, which provides information about the autonomic nervous system, stress levels, and health through heart rate variability (Evans et al., 2013). Respiratory sinus arrhythmia tracks changes in heart rate associated with breath patterns (Sahar et al., 2001).
Two minds greater than one: an intersubjective approach to research
Published in Anthony Korner, Communicative Exchange, Psychotherapy and the Resonant Self, 2020
The main findings of the study were of decreasing HRV with increased respiratory rate, suggesting decreased vagal tone consistent with other studies (e.g. Hirsch & Bishop, 1981). The data also demonstrated that HRV shows dominant frequencies corresponding to the respiratory rate, consistent with the phenomenon of Respiratory Sinus Arrhythmia. At lower breathing rates there is a strong relationship between RSA and breathing rates (5; 10 breaths per minute). This relationship is much weaker at 15 bpm and there is virtually no relationship evident at 30 bpm.
Developmental Aspects of Reflex Control of the Circulation
Published in Irving H. Zucker, Joseph P. Gilmore, Reflex Control of the Circulation, 2020
Another possible factor in the etiology of SIDS could be innervation of the heart, particularly the sympathetic innervation. Certainly, it is now well documented that both cardiac vagal and sympathetic discharge show respiratory modulation in the adult (cf. Gootman, 1983 for references; Gootman et al., 1987b). There is now evidence for such modulation in spontaneous autonomic activity (Fig. 8) in neonates (Gootman et al., 1984, 1987b, 1988). Thus respiratory sinus arrhythmia is probably a reflection of periodic changes in autonomic discharge to the heart. The role of cardiac sympathetic innervation in the cardiac theory of SIDS has been discussed in detail by Schwartz (1987; Schwartz and Segantini, 1988) and reviewed by Gootman et al. (1987a). In summary, an imbalance of autonomic innervation of the heart is considered as one probable mechanism involved in the etiology of SIDS. The work of Kralois and Millar (1978) showed developmental changes in the pattern of sympathetic innervation in puppies. On the other hand, Hageman et al. (1986) did not find differences in cardiac autonomic activity between puppies and adult dogs. However, this latter finding may reflect the narrow range of postnatal ages examined by these investigators. The recent findings, albeit controversial, of diminished sinus arrhythmias in children subsequently diagnosed as succumbing to SIDS would not support a respiratory component but rather a cardiac etiology involving autonomic regulation of cardiac activity.
Effectiveness of game-based meditation therapy on neurobiological stress systems in adolescents with posttraumatic symptoms: a randomized controlled trial
Published in Stress, 2021
Angela A. T. Schuurmans, Karin S. Nijhof, Ron Scholte, Arne Popma, Roy Otten
ANS measures were performed using electrocardiogram (ECG) and impedance cardiography (ICG) registration by the VU University Monitoring System (VU-AMS) (De Geus et al., 1995; Willemsen et al., 1996). Five electrodes were placed on the participants’ chest and two on the back. Recordings were manually inspected and analyzed with the Data Analysis and Management Software (VU-DAMS) program version 4.0 (VU University, Amsterdam, the Netherlands). SNS activity was measured with a pre-ejection period (PEP). PEP expressed in ms was derived from combined ICG and ECG recordings (Van Lien et al., 2013). PNS activity was measured with respiratory sinus arrhythmia (RSA). RSA can be influenced by respiration rate (RR) independently from PNS activity (Grossman & Taylor, 2007), so respiration rate (RR) (derived from the thorax impedance) was included as a covariate for RSA. To obtain basal ANS measures during rest, we conducted VU-AMS recordings during a 5-min aquatic video (Piferi et al., 2000) that participants watched before the start of the stress task.
Heart rate as cardiovascular risk factor
Published in Postgraduate Medicine, 2020
The heart rate is modulated by branches of the autonomic system that through informations obtained by peripheral receptors activate responses to maintain cardiovascular homeostasis and to adapt the cardiovascular system to the needs of daily life activities. The most important system is that of arterial baroreceptors. The baroreceptors activation induced by increase in blood pressure induces a sympathetic inhibition and an increase in vagal activity with consequent reduction in heart rate, vasodilation, and contractility reduction. On the contrary, the baroreceptor deactivation induces a sympathetic activation and a vagal inhibition [6]. The cardiorespiratory interaction, through different receptors located in the lungs and atria, is also able to induce changes in heart rate related with respiratory activity [7]. The central factors, however, appear to be more important and the respiratory sinus arrhythmia mainly reflects changes in vagal efferent activity [8]. As regards to the neuroendocrine systems that are activated through the increased sympathetic tone is necessary to mention the renin-angiotensin-aldosterone system, inflammation, endothelial dysfunction, and oxidative stress [6,9]
Psychopathic Traits and Empathic Functioning in Detained Juveniles: Withdrawal Response to Empathic Sadness
Published in International Journal of Forensic Mental Health, 2019
Esther L. de Ruigh, Lucres M. C. Jansen, Robert Vermeiren, Arne Popma
Activation of the SNS results in an increased HR, and promotes activation such as flight and fight responses. The PNS on the other hand is activated during resting periods and decreases HR. Respiratory sinus arrhythmia (RSA; a measure of PNS activity) is considered a biomarker for emotion regulation (Beauchaine, 2015). Problems with emotion regulation and the severity of externalizing symptoms have been associated with lower responses in the PNS (Blandon, Calkins, Keane, & O'Brien, 2008; Calkins, Graziano, & Keane, 2007; Fortunato, Gatzke-Kopp, & Ram, 2013; Willemen, Schuengel, & Koot, 2009). A greater decrease in RSA, a sign of more adaptive parasympathetic activity, predicts more adaptive emotion regulation (Gentzler, Santucci, Kovacs, & Fox, 2009). This could make RSA an interesting measure when it comes to empathic responding. Results regarding PNS responses to empathy elicitation in clinical subjects are however rather inconsistent, involving both increases and decreases in PNS responses, or no differences between DBD groups and controls (Beauchaine, Gatzke-Kopp, & Mead, 2007; Marsh et al., 2008; Pang & Beauchaine, 2013; Zahn-Waxler, Cole, Welsh, & Fox, 1995). Only Marsh et al. (2008) studied SNS reactivity in relation to empathy and found no differences between a DBD group and controls.