Tonic blood pressure modulates the relationship between baroreceptor cardiac reflex sensitivity and cognitive performance

Symbolic dynamics of sleep heart rate variability is associated with cognitive decline in older men

We aimed to investigate the association between autonomic and cognitive functions in older men. We investigated heart rate variability (HRV) during sleep using time domain metrics and symbolic dynamics analysis of inter-beat intervals. These metrics were statistically analysed for associations with cognitive function which was elicited by administering the modified mini-mental state examination (3MS) and the Trail making test part-B in older men participating in the MrOS sleep study.Multivariable linear regression adjusted for age, body-mass-index (BMI), apnea-hypopnea index (AHI) and arousal index (A.I.) showed that symbolic dynamics of HRV especially the 0V% which is a measure of sympathetic outflow to the heart during rapid eye movement (REM) sleep is significantly associated with 3MS and Trail B scores. In conclusion, nonlinear HRV during sleep provides a unique window to probe the association between cognitive and autonomic function.Clinical Relevance- This study shows that cognitive decline is associated with altered cardiac autonomic function.

Cardiovascular reactivity during sadness induction predicts inhibitory control performance

Higher negative affectivity has an association with decreased executive function and cognitive control. Heart rate variability (HRV) serves as an index of cardiac vagal regulation differences in the autonomic nervous system for both cognition and emotion. The current study investigates this association using a classic as well as emotional antisaccade paradigm to study inhibitory control performance. Ninety participants completed affective questionnaires (Beck Depression Inventory-II, and Mood Scale), a 6-minute baseline electrocardiogram, and two different antisaccade tasks. After the baseline, subjects were presented with a video sequence with either neutral, sad, or emotionally arousing content. By subtracting the baseline from the video sequence, we computed HRV reactivity and tested whether the reactivity score could predict inhibitory control performance. We hypothesized that this would be the case in both the sadness and arousal group, but not in the neutral one. Furthermore, we awaited significant performance differences between experimental groups. Contrary to our assumption, inhibitory control performance did not differ between experimental groups. Moreover, there was no significant relation between affective measures and task performance. Nevertheless, cardiovascular reactivity in terms of HRV was predictive of error rates in both antisaccade tasks in the sadness group. We could find this effect neither in the neutral nor in the arousal group. In addition, BDI scores moderated the effect in the emotional task. Results indicate that emotional reactivity to a sad video stimulus as indexed by HRV as well as the interaction with current emotional state predict inhibitory control performance.

Baseline heart rate variability (HRV) and performance during a set-shifting visuospatial learning task: The moderating effect of trait negative affectivity (NA) on behavioral flexibility✰

Higher negative affectivity (NA) has an association with decreased executive function and cognitive control. Heart rate variability (HRV) may index cardiac vagal regulation differences in the autonomic nervous system (ANS) for both cognition and emotion. The current study investigates this association using a set-shifting variant of the Virtual Morris Water Task (VMWT) to study discrimination learning, spatial learning, reversal learning, and attentional set-shifting in a virtual environment. 73 participants completed affective questionnaires (Beck Depression Inventory-II, Beck Anxiety Inventory, Positive and Negative Affective Scale), a 5-minute baseline electrocardiogram, and the VMWT. Individuals who failed to complete the task exhibited significantly lower baseline RMSSD then those who completed the task. There was no direct effect between affective measures and task performance. Higher baseline HRV was predictive of better performance during set-shifting. Trait NA moderated the effect of baseline HRV, as well as trait positive affectivity (PA), on performance during the extradimensional shift condition. Increased behavioral flexibility performance was only predicted by higher HRV and PA in low NA individuals. High trait NA negates the positive effects of HRV and PA on behavioral flexibility.

The cardiac, vasomotor, and myocardial branches of the baroreflex in fibromyalgia: Associations with pain, affective impairments, sleep problems, and fatigue

This study investigated the cardiac, vasomotor, and myocardial branches of the baroreflex in fibromyalgia using the spontaneous sequence method. Systolic blood pressure (SBP), interbeat interval (IBI), stroke volume (SV), pre-ejection period (PEP), and total peripheral resistance (TPR) were continuously recorded in 40 fibromyalgia patients and 30 healthy individuals during a cold pressor test and a mental arithmetic task. Sequences of covariation between SBP and IBI (cardiac branch), SV and PEP (myocardial branch), and TPR (vasomotor branch) were identified. Baroreflex sensitivity (BRS) was represented by the slope of the regression line between values in the sequences; baroreflex effectiveness (BEI) was indexed by the proportion of progressive SBP changes that elicited reflex responses. Patients exhibited lower BRS in the three branches, lower BEI in the cardiac and vasomotor branches, and reduced reactivity in cardiac BRS and BEI, SBP, IBI, SV, and PEP. Moreover, BRS and BEI were inversely related to clinical pain, cold pressor pain, depression, trait anxiety, sleep problems, and fatigue. Reduced function of the three baroreflex branches implies diminished resources for autonomic inotropic, chronotropic, and vascular regulation in fibromyalgia. Blunted stress reactivity indicates a limited capacity for autonomic cardiovascular adjustment to situational requirements. The associations of BRS and BEI with pain perception may reflect the antinociceptive effects arising from baroreceptor afferents, where reduced baroreflex function may contribute to the hyperalgesia characterizing fibromyalgia. The associations with affective impairments, sleep problems, and fatigue suggest that baroreflex dysfunctions are also involved in the secondary symptoms of the disorder.

Linking the hemodynamic consequences of adverse childhood experiences to an altered HPA axis and acute stress response

Adverse childhood experiences (ACEs), such as maltreatment and severe household dysfunction, represent a significant threat to public health as ACEs are associated with increased prevalence of several chronic diseases. Biological embedding, believed to be rooted in dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, is the prevailing theory by which chronic diseases become imprinted in individuals following childhood adversity. A shift towards HPA axis hypoactivity occurs in response to ACEs exposure and is proposed to contribute towards altered cortisol secretion, chronic low-grade inflammation, and dysregulated hemodynamic and autonomic function. This shift in HPA axis activity may be a long-term effect of glucocorticoid receptor methylation with downstream effects on hemodynamic and autonomic function. Emerging evidence suggests syncopal tendencies are increased among those with ACEs and coincides with altered neuroimmune function. Similarly, chronic low-grade inflammation may contribute towards arterial baroreceptor desensitization through increased arterial stiffness, negatively impacting autonomic regulation following posture change and increasing rates of syncope in later life, as has been previously highlighted in the literature. Although speculative, baroreceptor desensitization may be secondary to increased arterial stiffness and changes in expression of glucocorticoid receptors and arginine vasopressin, which are chronically altered by ACEs. Several research gaps and opportunities exist in this field and represent prospective areas for future investigation. Here, we synthesize current findings in the areas of acute psychosocial stress reactivity pertaining to HPA axis function, inflammation, and hemodynamic function while suggesting ideas for future research emphasizing systemic interactions and postural stress assessments among those with ACEs. This review aims to identify specific pathways which may contribute towards orthostatic intolerance in populations with history of childhood adversity.

Baroreceptor Modulation of the Cardiovascular System, Pain, Consciousness, and Cognition

Baroreceptors are mechanosensitive elements of the peripheral nervous system that maintain cardiovascular homeostasis by coordinating the responses to external and internal environmental stressors. While it is well known that carotid and cardiopulmonary baroreceptors modulate sympathetic vasomotor and parasympathetic cardiac neural autonomic drive, to avoid excessive fluctuations in vascular tone and maintain intravascular volume, there is increasing recognition that baroreceptors also modulate a wide range of non-cardiovascular physiological responses via projections from the nucleus of the solitary tract to regions of the central nervous system, including the spinal cord. These projections regulate pain perception, sleep, consciousness, and cognition. In this article, we summarize the physiology of baroreceptor pathways and responses to baroreceptor activation with an emphasis on the mechanisms influencing cardiovascular function, pain perception, consciousness, and cognition. Understanding baroreceptor-mediated effects on cardiac and extra-cardiac autonomic activities will further our understanding of the pathophysiology of multiple common clinical conditions, such as chronic pain, disorders of consciousness (e.g., abnormalities in sleep-wake), and cognitive impairment, which may result in the identification and implementation of novel treatment modalities. © 2021 American Physiological Society. Compr Physiol 11:1373-1423, 2021.

Contribution of Baroreceptor Function to Pain Perception and Perioperative Outcomes

Baroreceptors are mechanosensitive elements of the peripheral nervous system that maintain homeostasis by coordinating physiologic responses to external and internal stimuli. While it is recognized that carotid and cardiopulmonary baroreceptor reflexes modulate autonomic output to mitigate excessive fluctuations in arterial blood pressure and to maintain intravascular volume, increasing evidence suggests that baroreflex pathways also project to key regions of the central nervous system that regulate somatosensory, somatomotor, and central nervous system arousal. In addition to maintaining autonomic homeostasis, baroreceptor activity modulates the perception of pain, as well as neuroimmune, neuroendocrine, and cognitive responses to physical and psychologic stressors. This review summarizes the role that baroreceptor pathways play in modulating acute and chronic pain perception. The contribution of baroreceptor function to postoperative outcomes is also presented. Finally, methods that enhance baroreceptor function, which hold promise in improving postoperative and pain management outcomes, are presented.

Heart Rate Variability and Cognitive Function: A Systematic Review

Background: Autonomic dysfunctions may precede the development of cognitive impairment, but the connection between these dimensions is unclear. This systematic review aims to analyze the relationship between heart rate variability (HRV) and cognitive functions.

Methods: The review process was conducted according to the PRISMA-Statement. Restrictions were made, selecting the studies in English and published in peer-review journals, including at least one cognitive measure and presenting the measurement of HRV. Studies that included participants with medical conditions, dementia, psychiatric disorders, strokes, and traumatic brain injury were excluded. Twenty studies were selected, with a total of 19,431 participants. The results were divided into different cognitive domains determined a priori: global cognitive functioning, attention, processing speed, executive functions, memory, language and visuospatial skills.

Results: Both increased sympathetic activity and decreased parasympathetic activity seem to be associated with a worse performance in the cognitive domains considered, in the absence of dementia and severe cardiovascular diseases or other medical and psychiatric diseases.

Conclusion: The results highlight the influence of the autonomic nervous system (ANS) in cognitive functioning. However, the marked interest facing toward a specific domain, i.e., the executive functions, and the relatively small number of the studies on this topic do not allow understanding better this relationship. Despite these limits, HRV could be considered a promising early biomarker of cognitive impairment in populations without dementia or stroke. This index should be evaluated within a preventative perspective to minimize the risk of developing cognitive impairment.

Autonomic Cardiovascular Dysregulation at Rest and During Stress in Chronically Low Blood Pressure

Abstract. Chronic low blood pressure (hypotension) is accompanied by symptoms such as fatigue, reduced drive, faintness, dizziness, cold limbs, and concentration difficulties. The study explored the involvement of aberrances in autonomic cardiovascular control in the origin of this condition. In 40 hypotensive and 40 normotensive subjects, impedance cardiography, electrocardiography, and continuous blood pressure recordings were performed at rest and during stress induced by mental calculation. Parameters of cardiac sympathetic control (i.e., stroke volume, cardiac output, pre-ejection period, total peripheral resistance), parasympathetic control (i.e., heart rate variability), and baroreflex function (i.e., baroreflex sensitivity) were obtained. The hypotensive group exhibited markedly lower stroke volume, heart rate, and cardiac output, as well as higher pre-ejection period and baroreflex sensitivity than the control group. Hypotension was furthermore associated with a smaller blood pressure response during stress. No group differences arose in total peripheral resistance and heart rate variability. While reduced beta-adrenergic myocardial drive seems to constitute the principal feature of the autonomic impairment that characterizes chronic hypotension, baroreflex-related mechanisms may also contribute to this state. Insufficient organ perfusion due to reduced cardiac output and deficient cardiovascular adjustment to situational requirements may be involved in the manifestation of bodily and mental symptoms.

Blood pressure-related pain modulation in fibromyalgia: Differentiating between static versus dynamic pain indicators

INTRODUCTION

Resting blood pressure (BP) has been found to be inversely associated with evoked pain responsiveness in healthy populations. However, some reports suggest that BP-related pain modulation may be dysfunctional in chronic pain patients. This study examined whether BP-related pain modulation, indexed by both static and dynamic evoked pain responses, is altered in fibromyalgia (FM) patients compared to pain-free individuals.

METHOD

Pain threshold and tolerance as static evoked pain measures and slowly repeated evoked pain (SREP) as a dynamic evoked pain index were measured in 30 FM patients and 27 healthy controls. BP was continuously recorded throughout a 5 minute pre-pain rest period.

RESULTS

SREP sensitization was observed only in the FM group. Higher BP predicted elevated pain threshold and tolerance in healthy individuals, but not in FM. Conversely, BP was inversely associated with SREP sensitization in FM whereas no association was found in healthy controls.

CONCLUSIONS

Static evoked pain measures suggested BP-related pain inhibitory dysfunction in FM. In contrast, for pain sensitization as indexed by SREP, FM displayed the expected BP-related inhibitory effects. BP-related pain modulation is manifested in FM differentially for static versus dynamic pain indicators. Use of both types of evoked pain measures may be valuable in the study of mechanisms underlying altered pain modulatory systems in FM.

Association of Sympathovagal Imbalance With Cognitive Impairment in Type 2 Diabetes in Adults

OBJECTIVE

Sympathovagal imbalance (SVI) has been reported to be associated with metabolic derangements in type 2 diabetes. We investigated the association of SVI with cognitive impairment in patients with type 2 diabetes.

METHODS

Patients with a new diagnosis of type 2 diabetes (n=43) and age-matched healthy control subjects (n=43) were recruited for the study. Body mass index and blood pressure measurements were recorded. SVI was assessed by spectral analysis of heart rate variability (HRV), and cognitive function was assessed by recording the positive wave that appears in 300 milliseconds from application of stimulus in event-related potential tracing (P300). Insulin resistance was determined by the homeostatic model assessment of insulin resistance (HOMA-IR) formula using blood glucose and insulin data, and oxidative stress was assessed by estimation of malondialdehyde. Association of various factors with cognitive impairment was evaluated by Pearson correlation analysis, and independent contributions of these factors to cognitive impairment were assessed by multiple regression analysis.

RESULTS

P300 latency was significantly prolonged in the diabetes group compared with the control group. Ratio of low-frequency to high-frequency power (LF-HF ratio) of HRV, the marker of SVI was found to be significantly correlated and linked with P300. Malondialdehyde and HOMA-IR were correlated with LF-HF ratio.

CONCLUSION

Treatment-naïve patients with type 2 diabetes have SVI and considerable cognitive impairment. Insulin resistance and oxidative stress contribute to cognitive impairment, and SVI could be the physiologic link to cognitive impairment in treatment-naïve patients with type 2 diabetes.

Cardiac cycle time effects on selection efficiency in vision

The effect of cardiac cycle time on attentional selection was investigated in an experiment in which participants classified target letters in a visual selection task. Stimulus onsets were aligned to the R wave of the electrocardiogram and stimuli presented either during the ventricular systole or diastole. Selection efficiency was operationalized as difference in target selection performance under conditions of homogeneous and heterogeneous distractors. Differences in performance (i.e., the impact selection difficulty had on the ability to select the target) were attenuated for stimuli presented during the ventricular systole compared to the diastole. Increased baroafferent signal transmission during the systole appears to reduce interference of highly distracting stimuli on visual selection efficiency.

The effects of sighing on the cardiovascular system

Elicitation of high-amplitude oscillations in the cardiovascular system may serve to dampen psychophysiological reactivity to emotional and cognitive loading. Prior work has used paced breathing to impose clinically valuable high-amplitude ∼ 0.1 Hz oscillations. In this study, we investigated whether rhythmical sighing could likewise produce high-amplitude cardiovascular oscillations in the very low frequency range (0.003-0.05 Hz). ECG, respiration, skin conductance, and beat-to-beat blood pressure were collected in 24 healthy participants during baseline, 0.1 Hz paced breathing, and 0.02 Hz paced sighing (1 sigh every 50s, with normal breathing interspersed). Results showed that each sigh elicited a strong, well-defined reaction in the cardiovascular system. This reaction did not habituate when participants repeatedly sighed for 8.5 min. The result was a high-amplitude 0.02 Hz oscillation in multiple cardiovascular parameters. Thus, paced sighing is a reliable method for imposing very low frequency oscillations in the cardiovascular system, which has research and clinical implications that warrant further study.

Autonomic cardiovascular regulation and cortical tone

This study aimed to investigate interactions between tonic cortical arousal and features of autonomic cardiovascular regulation. In 50 healthy subjects, the power spectrum of the spontaneous EEG was obtained at resting state. Concurrently, respiratory sinus arrhythmia (RSA), baroreflex sensitivity (BRS) and R-wave to pulse interval (RPI) were recorded as indices of cardiovascular control. At the bivariate level, only a negative correlation between beta power recorded at frontal electrode positions and RPI was found. However, when common variance of BRS and RSA was controlled for in multiple regression analyses, a positive association between alpha power and RSA, and an inverse relationship with BRS, also arose. The findings concerning RPI and RSA are suggestive of a relationship between higher levels of cortical tone and increased sympathetic and reduced vagal cardiac influences. The inverse association between BRS and alpha activity may reflect bottom-up modulation of cortical arousal by baroreceptor afferents.

A computational physiology approach to personalized treatment models: the beneficial effects of slow breathing on the human cardiovascular system

Heart rate variability biofeedback intervention involves slow breathing at a rate of ∼6 breaths/min (resonance breathing) to maximize respiratory and baroreflex effects on heart period oscillations. This intervention has wide-ranging clinical benefits and is gaining empirical support as an adjunct therapy for biobehavioral disorders, including asthma and depression. Yet, little is known about the system-level cardiovascular changes that occur during resonance breathing or the extent to which individuals differ in cardiovascular benefit. This study used a computational physiology approach to dynamically model the human cardiovascular system at rest and during resonance breathing. Noninvasive measurements of heart period, beat-to-beat systolic and diastolic blood pressure, and respiration period were obtained from 24 healthy young men and women. A model with respiration as input was parameterized to better understand how the cardiovascular processes that control variability in heart period and blood pressure change from rest to resonance breathing. The cost function used in model calibration corresponded to the difference between the experimental data and model outputs. A good match was observed between the data and model outputs (heart period, blood pressure, and corresponding power spectral densities). Significant improvements in several modeled cardiovascular functions (e.g., blood flow to internal organs, sensitivity of the sympathetic component of the baroreflex, ventricular elastance) were observed during resonance breathing. Individual differences in the magnitude and nature of these dynamic responses suggest that computational physiology may be clinically useful for tailoring heart rate variability biofeedback interventions for the needs of individual patients.

The effect of baroreceptor stimulation on pain perception depends on the elicitation of the reflex cardiovascular response: evidence of the interplay between the two branches of the baroreceptor system

We examined the impact of baroreceptor stimulation on pain and cardiovascular responses in 39 healthy participants. Carotid baroreceptors were stimulated with external suction (-50 mmHg, stimulation) or pressure (+8 mmHg, control). Pain was induced by pressure to the nail of the left-index finger and quantified by a visual analog scale. Pain decreased heart rate (HR) and increased blood pressure (BP). Baroreceptor stimulation further decreased HR and reduced the BP increase. Pain experience failed to differ between baroreceptor stimulation conditions. However, significant results were obtained when trials were categorized according to the magnitude of the HR deceleration elicited by baroreceptor stimulation. In trials with strong baroreceptor-elicited HR deceleration pain intensity was lower than in trials both with inactive baroreceptor stimulation (pressure trials) or trials with small baroreceptor-elicited HR responses. Anti-nociceptive effects of baroreceptor stimulation depend on the activation of the reflex cardiovascular response. Central nervous inhibition due to baroreceptor stimulation only occurs if the peripheral cardiovascular response is engaged.

The behavioral impact of baroreflex function: a review

The baroreflex consists of a negative feedback loop adjusting heart activity to blood pressure fluctuations. This review is concerned with interactions between baroreflex function and behavior. In addition to changes in baroreflex cardiac control subject to behavioral manipulations, interindividual differences in reflex function predicted psychological and central nervous features. The sensitivity of the reflex was inversely related to cognitive performance, evoked potential amplitudes, experimental pain sensitivity, and the severity of clinical pain. Possible variables moderating the strength of the associations are tonic blood pressure, gender, and psychiatric disease. It is suggested that these observations reflect inhibition of higher brain function by baroreceptor afferents. While in many cases increased baroreflex function implies stronger inhibition, individual and situational factors modulate the behavioral impact of cardiac regulation.

Decentralized cardiovascular autonomic control and cognitive deficits in persons with spinal cord injury

Spinal cord injury (SCI) results in motor and sensory impairments that can be identified with the American Spinal Injury Association (ASIA) Impairment Scale (AIS). Although, SCI may disrupt autonomic neural transmission, less is understood regarding the clinical impact of decentralized autonomic control. Cardiovascular regulation may be altered following SCI and the degree of impairment may or may not relate to the level of AIS injury classification. In general, persons with lesions above T1 present with bradycardia, hypotension, and orthostatic hypotension; functional changes which may interfere with rehabilitation efforts. Although many individuals with SCI above T1 remain overtly asymptomatic to hypotension, we have documented deficits in memory and attention processing speed in hypotensive individuals with SCI compared to a normotensive SCI cohort. Reduced resting cerebral blood flow (CBF) and diminished CBF responses to cognitive testing relate to test performance in hypotensive non-SCI, and preliminary evidence suggests a similar association in individuals with SCI. Persons with paraplegia below T7 generally present with a normal cardiovascular profile; however, our group and others have documented persistently elevated heart rate and increased arterial stiffness. In the non-SCI literature there is evidence supporting a link between increased arterial stiffness and cognitive deficits. Preliminary evidence suggests increased incidence of cognitive impairment in individuals with paraplegia, which we believe may relate to adverse cardiovascular changes. This report reviews relevant literature and discusses findings related to the possible association between decentralized cardiovascular autonomic control and cognitive dysfunction in persons with SCI.

Interactions between autonomic cardiovascular regulation and cortical activity: a CNV study

The study investigated interactions between autonomic cardiovascular regulation and cortical activity. In 54 healthy subjects, baroreflex sensitivity (BRS) and respiratory sinus arrhythmia (RSA) were assessed at resting conditions. As an EEG indicator of cortical excitability, the contingent negative variation (CNV) was induced using a constant foreperiod reaction time task. At bivariate level, only RSA showed a moderate positive correlation with the CNV recorded at frontal electrodes. However, when common variance of BRS and RSA was controlled for in multiple regression analysis, an inverse association between BRS and the frontal CNV also arose. The inverse association between BRS and the CNV is discussed as reflecting bottom-up modulation of cortical excitability by baroreceptor afferents. The positive correlation between RSA and the CNV may relate to the interplay between prefrontal processing and cardiac vagal tone.

Measurement of vascular tone and stroke volume baroreflex gain

The arterial baroreflex system (BRS) consists of at least three closed-loop control systems: the heart rate (HR), vascular tone (VT), and stroke volume (SV) BRSs. Whereas HR-BRS gain is well studied, VT-BRS and SV-BRS gain are not. This study aimed to develop a method for quantifying VT-BRS and SV-BRS gain using an established HR-BRS gain measurement approach. ECG and beat-to-beat blood pressure (BP) were recorded in 31 young healthy participants during three tasks. Sequences of R-to-R wave intervals (RRI) of the ECG, pulse transit time (PTT), and SV were measured to assess HR-, VT-, and SV-BRS gain using the cross-spectral technique of computing the BP-RRI, BP-PTT, and BP-SV transfer functions. Gain in each BRS arch was measured in individuals with intact BRS functioning. Functional overlap and independence was noted in the BRS arches. The implications of the proposed method are discussed.

Relationships between baroreceptor cardiac reflex sensitivity and cognitive performance: modulations by gender and blood pressure

This study aimed at replicating and extending previous results on the association between baroreceptor reflex sensitivity (BRS) and cognitive performance. Thirty men and 31 women performed an arithmetic task. After adjusting for numerical aptitude and effort, no predictors of performance were found in men. In women, the relationships between BRS and parameters related to correct responses were modulated by blood pressure (BP). BRS was inversely associated with these parameters for participants with BP>1 SD above the mean, whereas the associations were positive in participants with BP<1 SD below the mean. Also for women, BRS was positively associated with number of errors during the task. These results suggest that the relation between BRS and performance varies as a function of the type of cognitive processes assessed and that the central nervous system effects of the baroreceptors on cognitive functioning are modulated by gender and BP.

Anger expression and suppression among patients with essential hypertension

OBJECTIVE

Hypertension (HTN) is among the seven psychosomatic diseases for which mental etiologies were proposed in 1950s. The objective of this study was to evaluate the rate of anger suppression and expression in individuals with hypertension referred to the heart clinic of "Fatemeh Zahra" Hospital, Sari, Iran.

METHODS

200 patients with primary hypertension were categorized as the case group. One hundred healthy individuals older than 30 years without previous history of arterial hypertension and severe mental disorders were considered as the control group. Both groups were matched in terms of age, gender and level of education. The Spielberger questionnaire was used to assess the trait anger, anger in and anger out. The data were analyzed using SPSS software with statistical tests such as t-test, chi-square and regression.

RESULTS

The trait anger and anger suppression in patients with hypertension were significantly higher than the control group (P < 0.001); however, anger out was not significantly different between the two groups (P = 0.984).

CONCLUSION

Considering the fact that trait anger and anger suppression is more prevalent among people with hypertension than healthy individuals, it seems suitable to provide education concerning anger management and emotional expression for these patients with regard to the anger issue which is a psychosomatic aspect of the disease.

Comparison of baroreceptor cardiac reflex sensitivity estimates from inter-systolic and ECG R-R intervals

Baroreceptor reflex sensitivity (BRS) is frequently evaluated using the spontaneous sequence method. Many of these studies use the inter-systolic interval (ISI) derived from a blood pressure monitor (e.g., Finapres) as interbeat interval measure instead of the traditionally recommended R-R series derived from the ECG. In this study, we examine possible differences between estimates of BRS from ISI and ECG R-R intervals. BRS was evaluated in 35 participants under three conditions: rest, mental arithmetic, and recovery periods. Although correlations between the two estimates are very high (all rs>.9), small but significant differences were found: the measures from ISI systematically yield higher BRS values and result in the detection of a greater number of reflex sequences. The higher BRS values from measures of ISI are due to the effects of pulse transit time fluctuations associated with the sequences of change in blood pressure.

Aberrances in autonomic cardiovascular regulation in fibromyalgia syndrome and their relevance for clinical pain reports

OBJECTIVE

To investigate autonomic cardiovascular regulation in fibromyalgia syndrome (FMS).

METHODS

In 35 patients and 29 healthy controls, electrocardiography, impedance cardiography, and finger continuous blood pressure measurements were conducted. Assessed parameters comprised blood pressure, R-R interval (RRI), heart rate variability, baroreflex sensitivity (BRS), stroke volume, and left ventricular ejection time (LVET). To evaluate cardiovascular autonomic reactivity to mental stress, parameters were obtained at rest and during an arithmetic task. As an estimate of clinical pain severity, participants completed the McGill Pain Inventory.

RESULTS

Patients exhibited lower power in all heart rate variability frequency bands (p < .05), lower BRS (7.13 +/- 3.45 versus 10.73 +/- 5.72 ms/mmHg), as well as reduced stroke volume, LVET, and RRI (p < .05). Stress-induced modulations were less pronounced in BRS, LVET, blood pressure, and RRI (all p < .05). Across the whole sample and in both subgroups, BRS (r = -.40) and blood pressure (r = -.39) correlated negatively with pain severity.

CONCLUSIONS

The data suggest that autonomic cardiovascular regulation in FMS is impaired in terms of reduced sympathetic and parasympathetic influences, as well as baroreflex malfunctioning. Furthermore, autonomic cardiovascular adjustment to acute stress is blunted. The inverse association between BRS and pain severity reflects the well-documented pain inhibition through the baroreceptor system. On account of this and the reduced baroreflex function in FMS, one may assume deficient ascending pain inhibition arising from the cardiovascular system, which may contribute to hyperalgesia that is characteristic of the disorder.