Lower Respiratory Sinus Arrhythmia Research Articles

The association between maternal smoking and secondhand exposure and autonomic functioning at 2–4 weeks of age

This study examined the association between maternal smoking and exposure to environmental tobacco smoke (ETS) during pregnancy and infant heart rate. Participants were 62 mother–infant dyads where mother smoked during pregnancy, 47 dyads where mother did not smoke during pregnancy but was exposed to ETS and 47 dyads where mother did not smoke and was not exposed to ETS. Average heart rate (HR) and respiratory sinus arrhythmia (RSA) were assessed at 2–4 weeks of age during sleep. Infants in both exposure groups had higher HR and lower RSA than nonexposed infants. Furthermore, boys in both exposure groups had higher HR and lower RSA than girls. These results highlight the importance of considering prenatal ETS exposure and infant gender when assessing infant outcomes.

Gender and Communal Trait Differences in the Relations Among Social Behaviour, Affect Arousal, and Cardiac Autonomic Control

To examine the relation between social behaviour and vagal activity, the communal behaviour of healthy college men (N = 33) and women (N = 33) was manipulated while monitoring heart rate (HR) and respiratory sinus arrhythmia (RSA). The subjects were classified as low or high on communal trait. Communal behaviour was manipulated by having the subjects behave in an agreeable or quarrelsome manner in scripted role-plays. HR, RSA and self-report arousal were obtained during or immediately following baseline, experimental and relaxation periods. 2 (Gender) x 2 (Communal Trait; low/high) x 2 (Condition; agreeable/quarrelsome) ANCOVAs were performed. Men had lower RSA values when behaving in a quarrelsome fashion than agreeable and lower RSA values than women in the quarrelsome condition. In the latter condition, low communal men reported more arousal than other groups. Strong but opposite associations between RSA and affect arousal were observed in low communal men and woman. Men, especially more quarrelsome (less communal) men exhibited weaker vagal control during arousing social situations.

Vagal withdrawal to a sad film predicts subsequent recovery from depression

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.

Low respiratory sinus arrhythmia and prolonged psychophysiological arousal in posttraumatic stress disorder: heart rate dynamics and individual differences in arousal regulation

Background There is extensive evidence that the parasympathetic branch of the autonomic nervous system can modulate psychophysiological arousal. To date, no studies have investigated associations between cardiac vagal tone and the time course of arousal during exposure to trauma-related stimuli in posttraumatic stress disorder (PTSD). Methods Thirty-one subjects, 29 with PTSD and 2 with partial PTSD, had electrocardiograms recorded during baseline and 2-minute traumatic and neutral script-driven imagery periods. Heart rate, respiratory sinus arrhythmia (RSA), and heart rate half-recovery to the trauma script were quantified, and subjects were divided into low and high baseline RSA groups. Results Across all participants, heart rate significantly increased from the neutral to the trauma script and RSA significantly decreased from baseline to trauma script ( p < .05). As predicted, low RSA subjects had more prolonged heart rate increases to the trauma script than high RSA subjects ( p < .001), and heart rate half-recovery was negatively correlated to baseline RSA ( r = −.50, p = .005). Conclusions This study is the first to find decreased RSA in response to a traumatic reminder and an association between low baseline RSA and sustained conditioned arousal in PTSD. Low vagal tone may account for deficient arousal and emotion regulation capacities often observed in PTSD.

Postural effect on respiratory sinus arrhythmia with various respiratory frequencies.

Heart rate variations during steady state respiration with various frequencies were studied on seven healthy male students at two different body positions. Respiration was controlled at four different frequencies (0.083, 0.100, 0.200, 0.250Hz), and the tidal volume was simultaneously controlled at 1500ml (0.083, 0.100Hz) or 1000ml (0.200, 0.250Hz). A tilting bed was used for changing body position, and the measurements were conducted at horizontal and vertical position. RSA (respiratory sinus arrhythmia) amplitude at 0.250Hz was significantly decreased at vertical position compared with horizontal position. At 0.200Hz the significant decrease could not be obtained although some tendency of decrease appeared. Contrary to these high frequencies, the amplitudes at low frequencies (0.083, 0.100Hz) were significantly increased (p < 0.01) during vertical position. This postural effect on the low frequency RSA could be regarded as a similar result on MWSA (Mayer wave relate sinus arrhythmia) which reflects sympathetic nervous activity. Furthermore, the ratio between the amplitude at 0.100Hz and that at 0.250Hz was significantly correlated with mean heart rate (n = 56, r = 0.73). From these results it was assumed that the RSA amplitude at low frequency associate a with not only parasympathetic nerves but also sympathetic nerves whereas the amplitude at high frequency was solely mediated by parasympathetic nerves.

The relationships between sympathetic and parasympathetic tones and cardiovascular responses during active coping

The relationships between sympathetic and parasympathetic tones and a variety of cardiovascular measures were examined in 27 male college students subjected to an active coping, namely a reaction time task, for five minutes. The results demonstrated an enhanced sympathetic tone during the first one minute (P1), indicating the decreases of pre-ejection period (PEP), left ventricular ejection time, and electromechanical systole (QS2), and the increase of QT/QS2. The reactivities of QT/QS2 and PEP defined by mean changes in the P1 period differed in their relationship with cardiovascular responses in the last four minutes. Although the PEP reactivity was associated with the cardiac performance (stroke volume and PEP/LVET), the QT/QS2 reactivity was correlated with the mean blood pressure (MBP). The reactivities of respiratory sinus arrhythmia (RSA) were defined by the residual difference obtained by subtracting values estimated by baseline RSAs from the mean value of changes during five minutes period. Subjects with high RSA reactivity (vagal withdrawal) showed higher heart rate and MBP than those with low RSA reactivity. The results are discussed with respect to the cardiac loading factors and hemodynamics.

Heart Rate Offset Responses to Visual Stimuli in Infants from 14 to 26 Weeks of Age

ABSTRACTHeart rate offset responses to visual stimuli were studied in infants tested cross‐sectionally at 14, 20, and 26 weeks of age. In Experiments 1 and 2, offset responses were measured in each infant following visual stimuli presented with three procedures. The fixed interval method consisted of stimulus presentations of 7 s in duration. The infant control method consisted of stimulus presentations which were terminated when the infant looked away from them. The interrupted stimulus method consisted of stimulus presentations which were terminated when the infant looked away toward an interrupting, secondary stimulus. In Experiment 3 these procedures were compared with two procedures in which stimulus termination occurred at the point of heart rate deceleration or the return of heart rate toward prestimulus level. The stimuli in Experiment 1 were checkerboard patterns, in Experiment 2 were complex and varying stimuli, and in Experiment 3 were either TV stimuli or an overhead light.The offset responses were similar for the fixed interval and infant control methods, and consisted of brief heart rate decelerations. The magnitude of the heart rate response was generally small (1.5 to 2 bpm), with the largest heart rate response being 4 bpm. The pre‐offset heart rate response was similar for the infant control and interrupted stimulus and heart rate acceleration trials, with heart rate showing a return to prestimulus levels immediately preceding subject‐controlled fixation termination. Infants with high levels of respiratory sinus arrhythmia (RSA) measured during a 5‐min baseline showed larger heart rate offset responses than did low RSA infants. These results call into question the interpretation of heart rate offset responses in the context of Sokolov's model of the orienting response. However, the offset paradigm is useful in the study of subject‐controlled attention processes.