Sex differences in heart rate responses to script-driven imagery soon after trauma and risk of posttraumatic stress disorder.

OBJECTIVE: To investigate in trauma survivors the predictive validity of heightened physiological responsivity to script-driven imagery for the development of posttraumatic stress disorder (PTSD) and to evaluate the interactive effect of survivors' sex. Physiological responses to idiosyncratic trauma reminders may be predictive of later PTSD. The majority of previous studies have been cross sectional and have produced mixed findings. Sex differences may contribute to this heterogeneity. METHODS: Heart rate (HR) and respiratory sinus arrhythmia were measured at 2 weeks post trauma in 158 assault survivors during baseline and as they listened to an idiosyncratic trauma script. At 6 months, 15.2% of male and 28.1% of female participants met the diagnostic criteria for PTSD. RESULTS: Generalized linear model and logistic regression analyses showed that HR response to script-driven imagery and sex interacted in predicting PTSD symptom severity at 6 months. Women had greater PTSD symptom severities overall. Female HR responders to script-driven imagery showed the highest PTSD symptom severities and were almost three times more likely to develop PTSD at 6 months compared with men and female nonresponders (odds ratio, 2.72; 95% confidence interval, 1.13-6.57). Respiratory sinus arrhythmia responder type did not predict PTSD (odds ratio, 0.64; 95% confidence interval, 0.30-1.33). CONCLUSION: Female trauma survivors who respond to trauma reminders with increased HR may be at particular risk of developing PTSD. Physiological reactivity to trauma cues may be a useful index for screening and prevention of PTSD.

Cardiac vagal control in the severity and course of depression: the importance of symptomatic heterogeneity.

BACKGROUND: Impaired cardiac vagal control (CVC), as indexed by respiratory sinus arrhythmia, has been investigated as a risk factor for major depressive disorder (MDD), but prior findings are mixed with respect to whether impaired CVC predicts greater global depression severity and/or a more severe course of disorder. One possible explanation for mixed findings is that CVC abnormalities in MDD are related more closely to specific depression symptoms than to the syndrome as a whole. METHODS: Depression severity (both global and symptom-specific indices) and electrocardiogram measures of resting CVC were obtained from 151 diagnosed MDD participants at intake, before randomization to a novel treatment for depression (acupuncture), and again after 8 and 16 weeks. RESULTS: Resting CVC did not predict global indices of depression in cross-sectional or longitudinal analyses. In symptom-specific analyses, resting CVC was positively related to sad mood and crying and inversely related to middle and late insomnia. Improvement in late insomnia was related to increases in CVC over time. LIMITATIONS: Relationships between CVC and MDD were studied only within the clinical range of severity. Symptom analyses were exploratory and hence did not correct for Type I error. CONCLUSIONS: Resting CVC did not exhibit concurrent or prospective relations with overall depression severity but a few specific symptoms did. Symptomatic heterogeneity across samples may account for mixed findings within the CVC-depression literature.

Cardiorespiratory effects of breathing and relaxation instruction in myocardial infarction patients.

The effect of individual instruction in relaxation and breathing, additional to an exercise training program, was investigated in 76 post-myocardial infarction patients after rehabilitation and at 3 months follow-up. Respiration rate (RR), heart rate (HR) and respiratory sinus arrhythmia (RSA) were the outcome variables used to compare experimental (exercise plus relaxation) and control (exercise without relaxation) groups. HR and RR decreased slightly during 20-min sessions of supine measurement. This response did not vary between sessions (pre-rehabilitation, post-rehabilitation and after 3-month follow-up). RSA tended to decrease during the sessions. The within-session reduction in RSA became more apparent in the control group after treatment and less so in the experimental group. RR decreased in the experimental group after rehabilitation, but not in the control group. HR decreased for all patients, but the decrease was larger in the experimental group. This effect was associated with the lower RR. RSA did not change in the control group but increased in the experimental group, during both normal and deep breathing. This effect was also associated with a slower RR and became marginally significant when RR was statistically controlled for. We conclude that the relaxation intervention induced a slower breathing pattern which was associated with beneficial effects on resting HR and RSA. Further study is warranted to clarify the degree to which reduced respiration rate is an indicator of lower sympathetic arousal or merely a concomitant of the learned breathing technique.

Influence of music on heart rate variability and comfort--a consideration through comparison of music and noise.

By considering three kinds of music and noise, this research investigates the influence of music on the living body by comparing the difference of influence on heart rate variability and comfort when subjects listen to music and are exposed to noise. We used two pieces of classical music, rock music, and noise recorded by a tape recorder. The following conclusions were made from the findings of the research: 1) Hearing classical music results in a small variance of Mayer Wave related Sinus Arrhythmia (MWSA) component and Respiratory Sinus Arrhythmia (RSA) component compared with a body being at rest. This is because the sympathetic nerve is suppressed by the sound of classical music. With rock music and noise, however, the MWSA component increases and the RSA component decreases. 2) From a psychological evaluation, we found that classical music tends to cause comfort and rock music and noise tend to cause discomfort. 3) A correlation was found between the balance of the MWSA component and the RSA component and the psychological evaluation. As the comfort increases, the variance of MWSA decreases; as discomfort increases, the variance of MWSA increases.

Baseline respiratory sinus arrhythmia and heart-rate responses during auditory stimulation of children with attention-deficit hyperactivity disorder.

During passive and active listening tasks baseline respiratory sinus arrhythmia and heart-rate responses were studied of 18 children with Attention-Deficit Hyperactivity Disorder (ADHD) and 49 healthy school children. The experimental procedure included baseline recording (no task), a passive listening task, instructions, and both simple and discriminative active-listening tasks. ADHD subjects showed less respiratory sinus arrhythmia than normal children but were similarly responsive to tone stimuli.