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Cardiac vagal tone (CVT), a key determinant of resting heart rate (HR), is progressively withdrawn with incremental exercise and nearly abolished at maximal effort. While maximal HR decreases with age, there remains a large interindividual variability of results for any given age. In the present study, we hypothesized that CVT does not contribute to age-independent maximal HR. Data were obtained from 1 000 (39±14 years old) healthy subjects (719 men) who were not taking medications affecting CVT or maximal HR performed a clinically normal and truly maximal cardiopulmonary exercise testing. CVT was estimated using the cardiac vagal index (CVI), a dimensionless ratio obtained by dividing 2 cardiac cycle durations – end of exercise and pre-exercise -, reflecting HR increases during a 4-s unloaded cycling test (a vagally-mediated response). Maximal HR was expressed as % of that predicted by age (208–0.7 × age (years)). Linear regression analyses identified that CVI can explain only 1% of the % age-predicted maximal HR variability with a high standard error of estimate (~6.3%), indicating the absence of a true physiological cause-effect relationship. In conclusion, the influence of CVI on % of age-predicted maximal HR is null in healthy subjects, suggesting distinct physiological mechanisms and potential clinical complementary role for these exercise-related variables.

We conducted a theoretical study of the physiological significance of respiratory sinus arrhythmia (RSA), a phenomenon used as an index of cardiac vagal tone and wellbeing, whereby the heart rate (HR) increases during inspiration and decreases during expiration. We first tested the hypothesis that RSA improves gas exchange efficiency but found that although gas exchange efficiency improved with slow and deep breathing and with increased mean heart rate, this was unrelated to RSA. We then formulated and tested a new hypothesis: that RSA minimizes the work done by the heart while maintaining physiological levels of arterial carbon dioxide. We tested the new hypothesis using two methods. First, the HR for which the work is minimized was calculated using techniques from optimal control theory. This calculation was done on simplified models that we derived from a previously published model of gas exchange in mammals. We found that the calculated HR was remarkably similar to RSA and that this became more profound under slow and deep breathing. Second, the HR was prescribed and the work done by the heart was calculated by conducting a series of numerical experiments on the previously published gas exchange model. We found that cardiac work was minimized for RSA-like HR functions, most profoundly under slow and deep breathing. These findings provide novel insights into potential reasons for and benefits of RSA under physiological conditions.

There is considerable controversy around the factors influencing the attentional biases involved in anxiety, controversies pinpointing to the role of trait anxiety (TA) in these biases. Previous studies have disregarded psychophysiological factors, such as cardiac vagal control, from the relation between TA and attention biases to threat, though cardiac vagal control serves as a proxy of attention regulation. By using a spatial cueing task, the present correlational study examines cardiac vagal tone as a moderator of the relation between TA and attention biases to threat. Cardiac vagal tone was indexed by high-frequency heart-rate variability (HF-HRV) and recorded, at baseline, from participants with high trait anxiety (HTA, N = 34) or low trait anxiety (LTA, N = 40). Our data indicate that HF-HRV significantly moderates the relation between TA and disengagement bias, but does not moderate the relation between TA and engagement bias. Extended analysis on the significant moderation showed that HF-HRV moderated the relation between TA and disengagement bias in the case of the participants with mean to low HF-HRV values. This was not the case for the participants with high values of HF-HRV. Our results suggest implications for redefining groups at risk for anxiety disorders, as well as future considerations of the cardiac vagal tone in attention bias research.

Four studies examined the relationship between self-esteem and cardiac vagal tone (level of influence of the parasympathetic nervous system on the heart), a variable with health implications for heart disease and auto-immune disorders. Building on evidence that self-esteem provides a sense of security and that a sense of security affects cardiac vagal tone, we theorize that self-esteem should impact cardiac vagal tone. Two experiments showed that positive self-esteem relevant feedback increases cardiac vagal tone relative to negative feedback. Two correlational studies showed that higher self-esteem measured daily over the course of 2 weeks predicted higher resting cardiac vagal tone. Theoretical and physical health implications are discussed.

Because the vagus nerve is implicated in control of inflammation, we investigated if brain death (BD) causes impairment of the parasympathetic nervous system, thereby contributing to inflammation. BD was induced in rats. Anaesthetised ventilated rats (NBD) served as control. Heart rate variability (HRV) was assessed by ECG. The vagus nerve was electrically stimulated (BD + STIM) during BD. Intestine, kidney, heart and liver were recovered after 6 hours. Affymetrix chip-analysis was performed on intestinal RNA. Quantitative PCR was performed on all organs. Serum was collected to assess TNF alpha concentrations. Renal transplantations were performed to address the influence of vagus nerve stimulation on graft outcome. HRV was significantly lower in BD animals. Vagus nerve stimulation inhibited the increase in serum TNF alpha concentrations and resulted in down-regulation of a multiplicity of pro-inflammatory genes in intestinal tissue. In renal tissue vagal stimulation significantly decreased the expression of E-selectin, IL1 beta and ITGA6. Renal function was significantly better in recipients that received a graft from a BD + STIM donor. Our study demonstrates impairment of the parasympathetic nervous system during BD and inhibition of serum TNF alpha through vagal stimulation. Vagus nerve stimulation variably affected gene expression in donor organs and improved renal function in recipients.

OBJECTIVES: to determine if there are differences in cardiac vagal tone values in non-obese healthy, adult men with and without unfavorable anthropometric characteristics. INTRODUCTION: It is well established that obesity reduces cardiac vagal tone. However, it remains unknown if decreases in cardiac vagal tone can be observed early in non-obese healthy, adult men presenting unfavorable anthropometric characteristics. METHODS: Among 1688 individuals assessed between 2004 and 2008, we selected 118 non-obese (BMI

We investigated the temperamental traits high-intensity pleasure (temperamental activation) and shyness (temperamental inhibition) in relation to autonomic function as measured by heart rate (HR), respiratory sinus arrhythmia (RSA), and baroreflex sensitivity (BRS) in 938 10-13-year-old preadolescents from a population cohort. Temperament was evaluated by parent reports on the Revised Early Adolescent Temperament Questionnaire. Autonomic measurements were obtained in supine and standing position. High-intensity pleasure was negatively associated with supine HR and positively with supine RSA and BRS in both genders. Shyness was positively related to supine BRS in girls only. Orthostatic-based autonomic reactivity (difference) scores adjusted for supine values were unrelated to temperamental measures. It appeared that higher scores on temperamental activation and inhibition are associated with higher cardiac vagal activity (RSA) and/or flexible regulation of autonomic balance (BRS), implicating healthy physiological functioning. Moreover, results suggest a physiological basis promoting the tendency towards engagement in high-intensity activities. (C) 2009 Elsevier B.V. All rights reserved.

Context: It has been hypothesized that depression is associated with lower heart rate variability and decreased cardiac vagal control. This may play an important role in the risk of cardiovascular disease among depressed individuals. Objective: To determine whether heart rate variability was lower in depressed individuals than in healthy controls in a large adult sample. Design: Cross-sectional analyses from a large depression cohort study. Setting: The Netherlands Study of Depression and Anxiety. Participants: Two thousand three hundred seventy-three individuals ( mean age, 41.8 years; 66.8% female) who participated in the Netherlands Study of Depression and Anxiety. Included were 524 controls, 774 individuals with a diagnosis of major depressive disorder ( MDD) earlier in life ( remitted MDD), and 1075 individuals with current MDD based on the Composite International Diagnostic Interview. This sample was sufficiently powered to examine the confounding effects of lifestyle, comorbid anxiety, and antidepressants. Main Outcome Measures: The standard deviation of normal-to-normal beats ( SDNN) and cardiac vagal control, as indexed by respiratory sinus arrhythmia ( RSA), were measured during 1 1/2 hours of ambulatory recording of electrocardiograms and thorax impedance. Multivariate analyses were conducted to compare SDNN and RSA across depression groups after adjustment for demographics, health, lifestyle, comorbid anxiety, and psychoactive medication. Results: Individuals with remitted and current MDD had a lower mean SDNN and RSA compared with controls ( SDNN, 3.1-5.7 milliseconds shorter, P Conclusions: This study shows that depression is associated with significantly lowered heart rate variability. However, this association appears to be mainly driven by the effect of antidepressants.

The present study investigated the effects of long-duration exercise on heart rate variability [as a marker of cardiac vagal tone (VT)]. Heart rate variability (time series analysis) was measured in mongrel dogs ( n = 24) with healed myocardial infarctions during 1 h of submaximal exercise (treadmill running at 6.4 km/h at 10% grade). Long-duration exercise provoked a significant (ANOVA, all P < 0.01, means ± SD) increase in heart rate (1st min, 165.3 ± 15.6 vs. last min, 197.5 ± 21.5 beats/min) and significant reductions in high frequency (0.24 to 1.04 Hz) power (VT: 1st min, 3.7 ± 1.5 vs. last min, 1.0 ± 0.9 ln ms2), R-R interval range (1st min, 107.9 ± 38.3 vs. last min, 28.8 ± 13.2 ms), and R-R interval SD (1st min, 24.3 ± 7.7 vs. last min 6.3 ± 1.7 ms). Because endurance exercise training can increase cardiac vagal regulation, the studies were repeated after either a 10-wk exercise training ( n = 9) or a 10-wk sedentary period ( n = 7). After training was completed, long-duration exercise elicited smaller increases in heart rate (pretraining: 1st min, 156.0 ± 13.8 vs. last min, 189.6 ± 21.9 beats/min; and posttraining: 1st min, 149.8 ± 14.6 vs. last min, 172.7 ± 8.8 beats/min) and smaller reductions in heart rate variability (e.g., VT, pretraining: 1st min, 4.2 ± 1.7 vs. last min, 0.9 ± 1.1 ln ms2; and posttraining: 1st min, 4.8 ± 1.1 vs. last min, 2.0 ± 0.6 ln ms2). The response to long-duration exercise did not change in the sedentary animals. Thus the heart rate increase that accompanies long-duration exercise results, at least in part, from reductions in cardiac vagal regulation. Furthermore, exercise training attenuated these exercise-induced reductions in heart rate variability, suggesting maintenance of a higher cardiac vagal activity during exercise in the trained state.

Cardiac vagal tone, as indexed by abnormalities in the level and/or reactivity of respiratory sinus arrhythmia (RSA), has been related to psychiatric impairment, including risk for depression. Longitudinal studies of depression have focused on RSA levels and have found mixed support for the hypothesis that low RSA levels predict a more pernicious course of depression. The current investigation focuses on the relation between RSA reactivity and the course of depression. We measured depressed persons' RSA reactivity to sadness-, fear-, and amusement-inducing emotion films and reassessed participants' diagnostic status 6 months later. Depressed persons who exhibited a higher degree of vagal withdrawal to the sad film were more likely to recover from depression. Implications for the study of RSA in depression are discussed.

In dogs with spontaneous heart disease, an electronically generated measurement of cardiac vagal tone, the cardiac index of parasympathetic activity, was a sensitive, simple and inexpensive measure of the severity of heart failure. Dogs with cardiac disease and an index score less than 3 were at 15.8 (95 per cent confidence interval 2.9 to 87.2) times the risk of dying within a year than those with a score of 3 and over. The measurement of the index provided an objective and reliable beat-by-beat measurement of cardiac vagal tone, which was prognostically useful in dogs with heart disease.

This study is an investigation of linkages between marital quality (conflict and harmony)and infants' emotional and physiological regulation. It was hypothesized that infants exposed to greater levels of marital conflict would demonstrate lower levels of emotional and physiological regulation. Fifty-six low-risk infants and their mothers attended a laboratory session when infants were 6 months of age. A baseline EKG was gathered to assess infants' cardiac vagal tone and the Bayley Scales of Infant Development and Behavior Rating Scales were administered. Mothers also completed Braiker and Kelley's (1979) marital quality questionnaire. Consistent with past research with preschoolers, marital conflict was found to be linked to lower levels of emotion regulation in infants. However, unlike past research (Gottman & Katz, 1989), results indicated that marital conflict was associated with lower levels of cardiac vagal tone in infants as opposed to higher levels of vagal tone among preschoolers. These findings a...

OBJETIVO: Determinar a sensibilidade, a especificidade, os valores preditivos positivo e negativo e a acurácia de diferentes critérios eletrocardiográficos para vagotonia. MÉTODOS: Foram avaliados 74 atletas olímpicos brasileiros (51 homens e 23 mulheres) com idade entre 16 e 42 anos (24 ± 5 anos), tendo sido realizados, entre outros exames, um ECG de repouso de 12 derivações e uma avaliação do tônus vagal cardíaco (TVC) pelo teste de exercício sem carga de quatro segundos (T4s), cujo índice B/C (indicativo da magnitude do TVC) foi utilizado como padrão-ouro. O T4s é um teste que se baseia no mecanismo da taquicardia inicial do exercício e foi anteriormente padronizado e validado como capaz de avaliar o TVC sem influência do componente simpático. Dados de 10 atletas foram excluídos devido à presença de critérios ecocardiográficos para hipertrofia ventricular esquerda, ainda que provavelmente fisiológica. Com o auxílio de curvas ROC (receiver operating characteristic), selecionou-se o ponto de corte com a melhor combinação entre sensibilidade (Sens) e especificidade (Esp) para cada variável do ECG, calculando-se os valores preditivos positivo (VPP) e negativo (VPN) e a acurácia (AC). Foram ainda correlacionados o índice B/C e as variáveis do ECG. RESULTADOS: Há fraca associação entre o índice B/C e as variáveis do ECG, à exceção da duração do intervalo R-R (r = 0,353; P = 0,004), que também apresentou curva ROC significativa (chi2= 0,863; P = 0,002), sendo que o critério intervalo R-R > ou = 990ms apresentou os seguintes resultados: Sens - 100%; Esp - 73%; VPP 20%; VPN 100%; AC 75%. As variáveis do ECG que apresentaram pontos de corte com acurácia > 80% foram: amplitude da onda T em V5 > ou = 8,0mm; amplitude da onda T em V6 > ou = 7,0mm; amplitude da onda Q em V5 > ou = 7,0mm; amplitude da onda R em V4 > ou = 50,0mm; presença de supradesnível de ponto J em duas ou mais derivações; presença de supradesnível de segmento S-T em cinco ou mais derivações e presença de transição precordial rápida. DISCUSSÃO E CONCLUSÃO: O desempenho dos critérios eletrocardiográficos em termos de VPP, VPN e AC foi muito limitado, com a exceção da duração do intervalo R-R. A combinação de outros critérios como amplitude da onda T em V5 e V6, amplitude da onda R em V4 e presença de supradesnível de ponto J e do segmento S-T em várias derivações pode auxiliar na predição de vagotonia.OBJECTIVE: To determine sensitivity (Sens), specificity (Spec), positive (PPV) and negative (NPV) predictive value, and accuracy of different electrocardiographic criteria for vagotonia. METHODS: Seventy-four Olympic athletes (51 male and 23 female; age = 24 ± 5 years) underwent an evaluation consisting of a 12-lead resting electrocardiogram (ECG), and an assessment of cardiac vagal tone (CVT) by the 4-second cycling exercise testing (4-sET), with the B/C index utilized as the gold standard. The 4-sET is a well-standardized and valid protocol for CVT assessment based on the mechanism of exercise-onset tachycardia regardless of the sympathetic component. Using ROC (receiver operating characteristic) curves, the authors selected the cut-point with the best sensitivity (Sens)/specificity (Spec) ratio for each ECG variable, and calculated the positive (PPV) and negative predictive values (NPV), and accuracy (AC). The authors also correlated B/C index with ECG variables. RESULTS: B/C index showed a poor association with ECG variables, with the exception of R-R interval (r = 0.353; P = 0.004), that also presented a significant ROC curve (chi2= 0.863; P = 0.002), whereas the R-R interval > or = 990 ms criterion showed the following results: Sens - 100%; Spec - 73%; VPP 20%; VPN 100%; AC 75%. The ECG variables that presented cut-points with accuracy > 80% were: T-wave amplitude in lead V5 > or = 8.0 mm; T-wave amplitude in lead V6 > or = 7.0 mm; Q-wave amplitude in V5 > or = 7.0 mm; R-wave amplitude in V4 > or = 50.0 mm; presence of J-point elevation in two or more leads; presence of S-T segment elevation in five or more leads, and presence of fast precordial transition. DISCUSSION AND CONCLUSION: The performance of ECG criteria considering PPV, NPV, and AC was generally very poor, with the exception of the R-R interval. The combination of other criteria such as T-wave amplitude in leads V5 and V6, R-wave amplitude in V4, and presence of J-point and S-T segment elevation in several leads should help predicting vagotonia.

OBJETIVO: Determinar a sensibilidade, a especificidade, os valores preditivos positivo e negativo e a acurácia de diferentes critérios eletrocardiográficos para vagotonia. MÉTODOS: Foram avaliados 74 atletas olímpicos brasileiros (51 homens e 23 mulheres) com idade entre 16 e 42 anos (24 ± 5 anos), tendo sido realizados, entre outros exames, um ECG de repouso de 12 derivações e uma avaliação do tônus vagal cardíaco (TVC) pelo teste de exercício sem carga de quatro segundos (T4s), cujo índice B/C (indicativo da magnitude do TVC) foi utilizado como padrão-ouro. O T4s é um teste que se baseia no mecanismo da taquicardia inicial do exercício e foi anteriormente padronizado e validado como capaz de avaliar o TVC sem influência do componente simpático. Dados de 10 atletas foram excluídos devido à presença de critérios ecocardiográficos para hipertrofia ventricular esquerda, ainda que provavelmente fisiológica. Com o auxílio de curvas ROC (receiver operating characteristic), selecionou-se o ponto de corte com a melhor combinação entre sensibilidade (Sens) e especificidade (Esp) para cada variável do ECG, calculando-se os valores preditivos positivo (VPP) e negativo (VPN) e a acurácia (AC). Foram ainda correlacionados o índice B/C e as variáveis do ECG. RESULTADOS: Há fraca associação entre o índice B/C e as variáveis do ECG, à exceção da duração do intervalo R-R (r = 0,353; P = 0,004), que também apresentou curva ROC significativa (chi2= 0,863; P = 0,002), sendo que o critério intervalo R-R > ou = 990ms apresentou os seguintes resultados: Sens - 100%; Esp - 73%; VPP 20%; VPN 100%; AC 75%. As variáveis do ECG que apresentaram pontos de corte com acurácia > 80% foram: amplitude da onda T em V5 > ou = 8,0mm; amplitude da onda T em V6 > ou = 7,0mm; amplitude da onda Q em V5 > ou = 7,0mm; amplitude da onda R em V4 > ou = 50,0mm; presença de supradesnível de ponto J em duas ou mais derivações; presença de supradesnível de segmento S-T em cinco ou mais derivações e presença de transição precordial rápida. DISCUSSÃO E CONCLUSÃO: O desempenho dos critérios eletrocardiográficos em termos de VPP, VPN e AC foi muito limitado, com a exceção da duração do intervalo R-R. A combinação de outros critérios como amplitude da onda T em V5 e V6, amplitude da onda R em V4 e presença de supradesnível de ponto J e do segmento S-T em várias derivações pode auxiliar na predição de vagotonia. OBJECTIVE: To determine sensitivity (Sens), specificity (Spec), positive (PPV) and negative (NPV) predictive value, and accuracy of different electrocardiographic criteria for vagotonia. METHODS: Seventy-four Olympic athletes (51 male and 23 female; age = 24 ± 5 years) underwent an evaluation consisting of a 12-lead resting electrocardiogram (ECG), and an assessment of cardiac vagal tone (CVT) by the 4-second cycling exercise testing (4-sET), with the B/C index utilized as the gold standard. The 4-sET is a well-standardized and valid protocol for CVT assessment based on the mechanism of exercise-onset tachycardia regardless of the sympathetic component. Using ROC (receiver operating characteristic) curves, the authors selected the cut-point with the best sensitivity (Sens)/specificity (Spec) ratio for each ECG variable, and calculated the positive (PPV) and negative predictive values (NPV), and accuracy (AC). The authors also correlated B/C index with ECG variables. RESULTS: B/C index showed a poor association with ECG variables, with the exception of R-R interval (r = 0.353; P = 0.004), that also presented a significant ROC curve (chi2= 0.863; P = 0.002), whereas the R-R interval > or = 990 ms criterion showed the following results: Sens - 100%; Spec - 73%; VPP 20%; VPN 100%; AC 75%. The ECG variables that presented cut-points with accuracy > 80% were: T-wave amplitude in lead V5 > or = 8.0 mm; T-wave amplitude in lead V6 > or = 7.0 mm; Q-wave amplitude in V5 > or = 7.0 mm; R-wave amplitude in V4 > or = 50.0 mm; presence of J-point elevation in two or more leads; presence of S-T segment elevation in five or more leads, and presence of fast precordial transition. DISCUSSION AND CONCLUSION: The performance of ECG criteria considering PPV, NPV, and AC was generally very poor, with the exception of the R-R interval. The combination of other criteria such as T-wave amplitude in leads V5 and V6, R-wave amplitude in V4, and presence of J-point and S-T segment elevation in several leads should help predicting vagotonia.

Individuals with schizophrenia face significant challenges in daily functioning, and although social cognition predicts how well patients respond to these challenges, associated physiological mechanisms remain unspecified. The present study draws from polyvagal theory and tested the hypothesis that respiratory sinus arrhythmia (RSA), an established indicator of the capacity to self-regulate and adapt to environmental demands, combines with social cognition to predict functional outcome. Using data from 41 schizophrenia patients and 36 healthy comparison subjects, we replicated group differences in RSA and social cognition and also demonstrated that RSA and social cognition interact to predict how effectively patients manage work and independent living activities. Specifically, RSA did not enhance functional outcomes when social cognition was already strong, but higher levels of RSA enabled effective role functioning when social-cognitive performance was impaired. Jointly, RSA and social cognition accounted for 40% of the variance in outcome success, compared with 21% when evaluating social cognition alone. As polyvagal theory suggests, physiological flexibility and self-regulatory capacity may compensate for poorer social-cognitive skills among schizophrenia patients.

BackgroundEmotion regulation theory aims to explain the interactions between individuals and the environment. In this context, Emotion Regulation Difficulties (ERD) disrupt the physiological component of emotions through the autonomic nervous system and are involved in several psychopathological states.ObjectiveWe were interested in comparing the influence of a film-elicited emotion procedure on the autonomic nervous system activity of two groups with different levels of emotion regulation difficulties.MethodsA total of 63 women (undergraduate students) ranging from 18 to 27 (20.7 ± 1.99) years old were included. Using the upper and lower quartile of a questionnaire assessing the daily difficulties in regulating emotions, two groups, one with low (LERD) and one with high (HERD) levels of emotion regulation difficulties, were constituted and studied during a film-elicited emotion procedure. Cardiac vagal activity (HF-HRV) was analyzed during three periods: baseline, film-elicited emotion, and recovery.ResultsThe cardiovascular results showed a decrease in HF-HRV from baseline to elicitation for both groups. Then, from elicitation to recovery, HF-HRV increased for the LERD group, whereas a low HF-HRV level persisted for the HERD group.ConclusionsThe HERD group exhibited inappropriate cardiac vagal recovery after a negative emotion elicitation had ended. Cardiac vagal tone took longer to return to its initial state in the HERD group than in the LERD group. Prolonged cardiac vagal suppression might constitute an early marker of emotion regulation difficulties leading to lower cardiac vagal tone.

Positive affect (PA) has been suggested to benefit health via psychobiological pathways. Studies found higher cardiac vagal tone in individuals who exhibit a positive emotional style.This study aimed to examine the relationship between momentary-assessed PA and nocturnal heart rate (HR) and heart rate variability (HRV) in everyday life.Participants were 60 healthy adults who provided multiple ratings of activated (e.g., dynamic, activated) and deactivated PA (e.g., relaxed, even-tempered) and negative affect (NA) throughout one day. HR and HRV were recorded the subsequent night.Aggregated deactivated PA throughout the day was associated with higher nocturnal HRV and lower HR. Activated PA and NA were unrelated with both cardiac variables. Findings were independent of other demographic and behavioral confounds.Feeling relaxed, calm, content, and even-tempered throughout the day might have beneficial effects on the heart during sleep, although the causality of this effect remains speculative because of the correlational design of this study.

Objective: We studied the effect of weight reduction on cardiac parasympathetic activity (PSA) in obese women. We also studied the relationship between the changes of PSA, resting energy expenditure (REE), and major cardiovascular risk factors. Research Methods and Procedures: Changes of cardiac vagal tone, an index of PSA, REE, and major cardiovascular risk factors, were measured in 52 healthy obese women after a 6-month weight reduction. Ten of the women were remeasured at 12 and 24 months. Cardiac vagal tone was assessed by a vagal tone monitor and REE by indirect calorimeter. Results: Cardiac vagal tone increased significantly (p = 0.046), averaging a 9.5% weight loss in 6 months. The vagal tone increased further with weight loss during the following 6 months, and thereafter, it declined with weight regain. The increase of cardiac vagal tone correlated significantly with decreases of body weight, fat mass, waist circumference, serum insulin, and heart rate. REE adjusted for fat-free mass and age did not change with weight loss and was not related to cardiac vagal tone at any time-point. Discussion: Cardiac PSA activity increases with weight loss in obese women. This increase may not be maintained long-term if body weight is regained. The rise of cardiac PSA is correlated with decreases of body fat mass, abdominal fat, serum insulin, and heart rate. Cardiac PSA is not related to REE.

The present study examined the relation between early emotion regulation and later compliance. When infants were 5, 10, and 18 months of age, they participated in a frustration task. The degree to which they reacted negatively to the stimuli and the behaviors they used to regulate that response were coded. Baseline heart rate also was recorded and a measure of cardiac vagal tone (VNA) was derived. Several tasks (electrode placement, toy clean-up, and test situation) were administered to elicit compliance/noncompliance when the participants were 30 months of age. Results revealed that infants who demonstrated low levels of regulatory behavior were more likely to be noncompliant as toddlers. Several interaction effects suggested that the prediction to later noncompliance was also dependent upon the infants' level of reactivity. Cardiac vagal tone also was related to compliance but in a contradictory fashion. High VNA was related to noncompliance to toy clean-up, whereas low VNA was related to noncompliance to electrode placement. The data provide support for a developmental model of compliance that includes the ability to regulate emotional arousal.

Sixty 12-week-old infants participated in a laboratory study to explore the relations between temperament and cardiac vagal tone. Temperament was evaluated via laboratory observations and maternal ratings. Cardiac vagal tone, measured as the amplitude of respiratory sinus arrhythmia, was quantified from beat-to-beat heart period data collected during a resting baseline period and during the laboratory assessment of temperament. Specific hypotheses were investigated relating temperament to both basal cardiac vagal tone and changes in cardiac vagal tone during social/attention challenges. Infants with higher baseline cardiac vagal tone were rated in the laboratory as showing fewer negative behaviors and were less disrupted by the experimental procedure. Infants who decreased cardiac vagal tone during the laboratory assessment were rated on maternal report temperament scales as having longer attention spans, and being more easily soothed.

The relation between two dimensions of vagal tone (Vna), indexed by a baseline measure of Vna and suppression of Vna and temperamental reactivity and behavioral regulation was investigated. Forty-one children were observed during a series of episodes designed to elicit temperamental reactivity and behavioral regulation. Heart rate was recorded during these baseline, positive, negative, and delay episodes, from which measures of vagal tone were computed. Across the entire sample, vagal tone decreased from the baseline episode to the three affect tasks. Baseline measures of vagal tone were related to the tendency to show a decrease in vagal tone: Children who consistently suppressed vagal tone (showed a decrease to all the affect tasks) had higher baseline vagal tone. Baseline vagal tone was related to temperamental reactivity for the positive and negative tasks, but not the delay tasks. Vagal suppression (vagal difference score) was related to several of the behavioral regulation strategies used by the children in the affect-eliciting situations. These findings are discussed in terms of the adaptive value of physiological regulation in the development of regulatory behaviors that may be critical to social development.

The current research examines individual differences in flexible emotional attention. In two experiments, we investigated the relationship between individual differences in cardiac vagal tone and top-down and bottom-up processes associated with emotional attention. To help determine the role of cortical and subcortical mechanisms underlying top-down and bottom-up emotional attention, fearful faces at broad, high, and low spatial frequency were presented as cues that triggered either exogenous or endogenous orienting. Participants with lower heart rate variability (HRV) exhibited faster attentional engagement to low-spatial-frequency fearful faces at short stimulus-onset asynchronies, but showed delayed attentional disengagement from high-spatial-frequency fearful faces at long stimulus-onset asynchronies in contrast to participants with higher HRV. This research suggests that cardiac vagal tone is associated with more adaptive top-down and bottom-up modulation of emotional attention. Implications for various affective disorders, including depression, anxiety disorders, and posttraumatic stress disorder, are discussed.

Parasympathetic regulation of heart rate through the vagus nerve--often measured as resting respiratory sinus arrhythmia or cardiac vagal tone (CVT)--is a key biological correlate of psychological well-being. However, recent theorizing has suggested that many biological and psychological processes can become maladaptive when they reach extreme levels. This raises the possibility that CVT might not have an unmitigated positive relationship with well-being. In line with this reasoning, across 231 adult participants (Mage = 40.02 years; 52% female), we found that CVT was quadratically related to multiple measures of well-being, including life satisfaction and depressive symptoms. Individuals with moderate CVT had higher well-being than those with low or high CVT. These results provide the first direct evidence of a nonlinear relationship between CVT and well-being, adding to a growing body of research that has suggested some biological processes may cease being adaptive when they reach extreme levels.

Cardiac vagal tone is a construct that describes the functional relationship between the brainstem and the heart. Cardiac vagal tone is measured by quantifying the amplitude of respiratory sinus arrhythmia, a component of heart rate variability reflecting the functional output of vagal pathways on the heart. Although there is an extensive literature evaluating baseline vagal tone and its relation to behavior, the relation between individual differences in the ability to regulate cardiac vagal tone and behavior has been theoretically vague. This article introduces a theoretical model to explain the relation between vagal tone during steady states and vagal reactivity (i.e., the vagal brake) in response to environmental challenges. Based upon the proposed model, it was hypothesized that infants who had difficulties in regulating the vagal brake (i.e., decreasing cardiac vagal tone) during social/attention tasks would have difficulties developing appropriate social interactions requiring reciprocal engagement and disengagement strategies. Data from 24 infants are presented. The findings support the model and demonstrate that infants with difficulties in decreasing vagal tone during a social/attention task at 9 months of age had significantly more behavioral problems at 3 years of age.

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The stability of infant temperament and autonomic patterning (heart period and cardiac vagal tone) was examined longitudinally when infants were 5, 10, and 18 months of age. Behavioral measures of reactivity and regulation to frustration tasks, and maternal perceptions of infant temperament were obtained at each age along with baseline measures of cardiac activity. No stability was found from 5 to 10 months while some stability of behavior and autonomic patterning was identified from 10 to 18 months, with the exception of negative reactivity. High levels of cardiac vagal tone (V) were associated with negative reactivity at 18 months. When examining groups based on degrees of reactivity and regulation, we found infants who responded negatively to frustration but who also displayed more regulatory behavior to have higher V.

The ability to regulate emotion is a crucial process that humans utilize in order to adapt to the demands of environmental constraints. Individuals exposed to early adverse life events such as being born at an extremely low birth weight (ELBW, 501–1000 g) are known to have problems regulating emotion which have been linked to the development of psychopathology in this population. Recent studies have used psychophysiological measures, such as electroencephalogram (EEG) and cardiac vagal tone, to index emotion regulatory processes. The purpose of this paper was three-fold: (1) to investigate the relation between ELBW and emotion regulation issues (pathway 1), (2) to review studies investigating the relation between early emotion regulation and later internalizing problems (pathway 2); and (3) to provide a model in which two psychophysiological measures (i.e., frontal EEG asymmetry and cardiac vagal tone) are suggested to understand the proposed conceptual pathways in the relation between ELBW and psychopathology.

Twenty-six full-term infants were evaluated at 1-, 3-, and 6-months postpartum to explore the stability of Porges' (1985a) cardiac vagal tone index. One-month vagal tone (V) was not found to be associated with either 3- or 6-month measures of cardiac vagal tone, however, 3-month cardiac vagal tone was found to be predictive of 6-month cardiac vagal tone. Interestingly, 1-month heart period range was predictive of 6-month heart period range. These findings both replicate and extend previous research examining early patterns of development in cardiac indices.

Mothers classified as ‘depressed’, ‘non-depressed’ or ‘low scoring’ on the Beck Depression Inventory and their 3-month-old infants were videotaped during 3-minute face-to-face play interactions. Infants' facial expressions were coded using the AFFEX facial expression coding system and their EKG was recorded during the interactions to assess the relationship between cardiac measures and facial expressivity. Infants of both ‘depressed’ and ‘low scoring’ mothers showed significantly more sad and anger expressions and fewer interest expressions than infants of nondepressed mothers. Cardiac vagal tone, (quantified from the amplitude of respiratory sinus arrhythmia) was correlated with infants' joy and interest expressions and with self-comfort behaviours in the non-depressed and low scoring groups, but not in the depressed group. The results suggest that matermal depression affects infants' affective state and appearance as well as their biobehavioural emotional regulation systems.

A previous study has shown that greater cardiac vagal tone, reflecting effective self-regulatory capacity, was correlated with superior visual discrimination of fearful faces at high spatial frequency Park et al. (Biological Psychology 90:171–178, 2012b). The present study investigated whether individual differences in cardiac vagal tone (indexed by heart rate variability) were associated with different event-related brain potentials (ERPs) in response to fearful and neutral faces. Thirty-six healthy participants discriminated the emotion of fearful and neutral faces at broad, high, and low spatial frequencies, while ERPs were recorded. Participants with low resting heart rate variability—characterized by poor functioning of regulatory systems—exhibited significantly greater N200 activity in response to fearful faces at low spatial frequency and greater LPP responses to neutral faces at high spatial frequency. Source analyses—estimated by standardized low-resolution brain electromagnetic tomography (sLORETA)—tended to show that participants with low resting heart rate variability exhibited increased source activity in visual areas, such as the cuneus and the middle occipital gyrus, as compared with participants with high resting heart rate variability. The hyperactive neural activity associated with low cardiac vagal tone may account for hypervigilant response patterns and emotional dysregulation, which heightens the risk of developing physical and emotional problems.

The neurovisceral integration model (Thayer, J. F., & Lane, R. D., 2000, A model of neurovisceral integration in emotion regulation and dysregulation. Journal of Affective Disorders, 61, 201-216. doi:10.1016/S0165-0327(00)00338-4) proposes that individual differences in heart rate variability (HRV)-an index of cardiac vagal tone-are associated with attentional and emotional self-regulation. In this article, we demonstrate that individual differences in resting HRV predict the functioning of the inhibition of return (IOR), an inhibitory attentional mechanism highly adaptive to novelty search, in response to affectively significant face cues. As predicted, participants with lower HRV exhibited a smaller IOR effect to fearful versus neutral face cues than participants with higher HRV, which shows a failure to inhibit attention from affectively significant cues and instigate novelty search. In contrast, participants with higher HRV exhibited similar IOR effects to fearful and neutral face cues, which shows an ability to inhibit attention from cues and instigate novelty search. Their ability to inhibit attention was most pronounced to high spatial frequency fearful face cues, suggesting that this effect may be mediated by cortical mechanisms. The current research demonstrates that individual differences in HRV predict attentional inhibition and suggests that successful inhibition and novelty search may be mediated by cortical inhibitory mechanisms among people with high cardiac vagal tone.

The goals of this study were to examine: (a) normative developmental changes in heart period and cardiac vagal tone: and (b) the reliability and stability over time of individual differences in the two measures. When the 73 infants participating in this short-term longitudinal study were 5, 7, 10, and 13 months old, a 5-min sample of cardiac activity was collected while the infants sat on thier mothers' laps in a quiet, attentive state. A second 5-min sample of cardiac activity was also collected at 7, 10, and 13 months followin a 20-min long battery of emotion-eliciting stimuli. Significant developmental increases were observed in heart period but not in the measure of cardiac vagal tone. Stress-related decreases in cardiac vagal tone and increases in heart rate were observed after the emotion-eliciting stimuli ended. Individual differences in measures of heart period and cardiac vagal tone were stable over 2- and 3-month periods.

a b s t r a c t The neurovisceral integration model (Thayer and Lane, 2000) proposes that vagally mediated heart rate variability (HRV)—an index of cardiac vagal tone—is associated with autonomic flexibility and emotional self-regulation. Two experiments examined the relationship between vagally mediated HRV and visual perception of affectively significant stimuli at different spatial frequencies. In Experiment 1, HRV was positively correlated with superior performance discriminating the emotion of affectively significant (i.e., fearful) faces at high spatial frequency (HSF). In Experiment 2, processing goals moderated the rela- tionship between HRV and successful discrimination of HSF fearful faces. In contrast to Experiment 1, discriminating the expressiveness of HSF fearful faces was not correlated with HRV. The current research suggests that HRV is positively associated with superior visual discrimination of affectively significant stimuli at high spatial frequency, and this relationship may be sensitive to the top-down influence of different processing goals.

Sucking frequency, heart rate, and cardiac vagal tone (V) were monitored in neonates during manipulations of sweet gustatory stimulation. In response to increased sweetness, reductions in cardiac vagal tone and increases in heart rate paralleled increased sucking frequency. Individual differences in cardiac vagal tone were correlated with the magnitude of heart rate changes to gustatory stimulation.

Background: Respiratory sinus arrhythmia (RSA) has been proposed as a physiological marker of emotion-regulation capacity, and shown to be cross-sectionally associated with depression. Little is known about the role of RSA as a predictor of (subclinical) depressive symptoms over time and as a modifier of the depressogenic effect of stressful life events (SLEs).Methods: In a longitudinal population-based study with data collected in 1653 adolescents twice (at age 11 and 13.5 years, respectively), RSA was assessed in supine position at the first assessment wave. Depressive symptoms were assessed at both waves and SLEs experienced between the two waves at the last wave.Results: Low levels of RSA were not associated with concurrent or future depressive symptoms, and did not enhance the depressogenic effects of SLEs.Conclusions: In a normal population of young adolescents, a low level of RSA does not identify adolescents at risk for depressive symptoms when confronted with SLEs. In post hoc analyses, among those reporting high exposure to stressful life events, higher RSA tended to predict less self-reported anxiety and more self-reported somatic symptoms as compared to those with lower RSA. (C) 2009 Elsevier B.V. All rights reserved.

Context: It has been hypothesized that depression is associated with lower heart rate variability and decreased cardiac vagal control. This may play an important role in the risk of cardiovascular disease among depressed individuals. Objective: To determine whether heart rate variability was lower in depressed individuals than in healthy controls in a large adult sample. Design: Cross-sectional analyses from a large depression cohort study. Setting: The Netherlands Study of Depression and Anxiety. Participants: Two thousand three hundred seventy-three individuals ( mean age, 41.8 years; 66.8% female) who participated in the Netherlands Study of Depression and Anxiety. Included were 524 controls, 774 individuals with a diagnosis of major depressive disorder ( MDD) earlier in life ( remitted MDD), and 1075 individuals with current MDD based on the Composite International Diagnostic Interview. This sample was sufficiently powered to examine the confounding effects of lifestyle, comorbid anxiety, and antidepressants. Main Outcome Measures: The standard deviation of normal-to-normal beats ( SDNN) and cardiac vagal control, as indexed by respiratory sinus arrhythmia ( RSA), were measured during 1 1/2 hours of ambulatory recording of electrocardiograms and thorax impedance. Multivariate analyses were conducted to compare SDNN and RSA across depression groups after adjustment for demographics, health, lifestyle, comorbid anxiety, and psychoactive medication. Results: Individuals with remitted and current MDD had a lower mean SDNN and RSA compared with controls ( SDNN, 3.1-5.7 milliseconds shorter, P Conclusions: This study shows that depression is associated with significantly lowered heart rate variability. However, this association appears to be mainly driven by the effect of antidepressants.

Etude des relations entre des mesures de l'activite cardiaque et vagale et la reactivite de l'enfant lors d'une etude longitudinale de la naissance a 5 mois.

We examined whether spontaneous baroreflex modulation of heart rate and other indexes of cardiac vagal tone could be altered by passive stretch of the human calf muscle during graded concurrent activation of the muscle metaboreflex. Ten healthy subjects performed four trials: a control trial, resting for 1.5 min (0% trial); or 1.5 min of one-legged isometric plantar flexor exercise at 30, 50, and 70% maximal voluntary contraction. The incremental increases in blood pressure (BP) caused were then partially sustained by subsequent local circulatory occlusion (CO). After 3.5 min of CO alone, sustained calf stretch and CO were applied for 3 min. Spontaneous baroreflex sensitivity (SBRS) was progressively decreased with increasing exercise intensity ( P < 0.05). During CO, stretch decreased SBRS and increased BP similarly in all trials ( P < 0.05). Within 15 s of stretch onset, heart rate (HR) increased by 6 ± 1, 6 ± 1, 8 ± 1, and 6 ± 2 beats/min in the 0, 30, 50, and 70% trials, respectively ( P < 0.05), and root mean square of successive differences was decreased from CO-alone levels ( P < 0.05). During the second and third minutes of stretch, HR fell back but remained significantly above CO levels, and common coefficient of variance of R-R interval decreased progressively with increasing prior exercise intensity ( P < 0.05; 70% trial). This suggests that passive stretch of the human calf muscles decreases cardiac vagal outflow irrespective of the levels of BP increase caused by muscle metaboreflex activation and implies that central modulation of baroreceptor input, mediated by the actions of stretch-activated mechanoreceptive muscle afferent fibers, continues.

The NeuroScope, a specific and sensitive indicator of cardiac vagal tone, was used to look for differences in autonomic tone between 25 dogs with naturally occurring diabetes mellitus and 23 healthy control dogs, to determine whether there was any correlation between the dogs' cardiac vagal tone, the duration of diabetes and the adequacy of glycaemic control. The cardiac index of parasympathetic activity (cipa) was determined for each dog over a period of 2600 heartbeats. The mean, median and modal cipa values were significantly lower in the diabetic dogs than in the healthy dogs. There was no significant relationship between the cipa values and the duration of disease or the adequacy of recent glycaemic control in the diabetic dogs, but there was a significant inverse relationship between the cipa values and the bodyweight of the diabetic dogs that was not evident in the normal dogs. The conclusions were based on a 500-heartbeat interval selected from the 2600 heartbeats recorded.

Heart rate responses of 84 near-term fetuses to recorded female voices were examined in 166 trials of auditory stimulation. Each fetus was presented with a 2-min recording of their mother's voice and a 2-min recording of a female stranger's voice, in counterbalanced order, with a 10-min rest period between trials. High frequency heart rate variability during a 2-min baseline period was used to estimate cardiac vagal tone for each trial. Differential heart rate responses to familiar and unfamiliar voice recordings were observed during a 2-min poststimulus period, only when estimated cardiac vagal tone was high. This finding suggests that vagal tone plays a moderating role in the cardiac responses of term fetuses to familiar and unfamiliar stimuli. 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 543-547, 2007.

Relations between maternal postpartum behavior and the emergence of parent-infant relatedness as a function of infant autonomic maturity were examined in 56 premature infants (birthweight = 1000-1500 g) and 52 full-term infants. Maternal behavior, mother depressive symptoms, and infant cardiac vagal tone were assessed in the neonatal period. Infant-mother and infant-father synchrony, maternal and paternal affectionate touch, and the home environment were observed at 3 months. Premature birth was associated with higher maternal depression, less maternal behaviors, decreased infant alertness, and lower coordination of maternal behavior with infant alertness in the neonatal period. At 3 months, interactions between premature infants with their mothers and fathers were less synchronous. Interaction effects of premature birth and autonomic maturity indicated that preterm infants with low vagal tone received the lowest amounts of maternal behavior in the postpartum and the least maternal touch at 3 months. Infant-mother and infant-father synchrony were each predicted by cardiac vagal tone and maternal postpartum behavior in both the preterm and full-term groups. Among preterm infants, additional predictors of parent-infant synchrony were maternal depression (mother only) and the home environment (mother and father). Findings are consistent with evolutionary perspectives on the higher susceptibility of dysregulated infants to rearing contexts and underscore the compensatory mechanisms required for social-emotional growth under risk conditions for parent-infant bonding.

Vagal tone has been proposed both as an index of emotion regulation and cognitive ability. To assess the relation between vagal tone and emotion regulation and cognitive ability, the present research prospectively measured vagal tone (measured either as high-frequency spectral power or respiratory sinus arrhythmia) in healthy participants exposed to high stress. The participants were active duty military personnel (men) enrolled in high intensity military training: Survival School (Experiments 1 and 3) and Combat Diver Qualification Course (Experiment 2). We consistently observed a significant relationship between low vagal tone and superior performance. The data suggest that vagal suppression is associated with enhanced performance under conditions of high stress and that this enhanced performance may be related to emotion regulation and cognitive functioning.