Michael M. Myers

Maternal stress responses and anxiety during pregnancy: effects on fetal heart rate.

This study examined the effect of an acute maternal stress response and anxiety on fetal heart rate. Seventeen healthy, 3rd-trimester pregnant women (mean age = 26 +/- 6 years) were instrumented for continuous electrocardiography, blood pressure (BP), respiration, and fetal heart rate (HR). Subjects completed the state anxiety subscale of the State Trait Personality Inventory (STPI), then rested quietly in a semirecumbent position for a 5-min baseline period, followed by either a 5-min arithmetic or Stroop color-word task. Over the entire 5-min stress period and when averaged across all subjects, the stressors led to significant increases in maternal systolic BP and respiratory rate but changes in maternal HR, diastolic BP, and fetal HR were not significant. However, when subjects were dichotomized into groups that had above or below average anxiety scores [ANX(+) and ANX(-)], both groups had similar respiration rate increases to the stressors, but the BP and fetal heart rate (FHR) responses were significantly different. Women in the ANX(-) group had significantly greater BP responses compared to women in the ANX(+) group whereas the fetuses of ANX(+) women showed significant HR increases and the fetuses of ANX(-) women exhibited nonsignificant decreases. These findings suggest that womens acute emotional reactivity during pregnancy can influence fetal HR patterns and that a stress-induced increase in maternal BP is not the primary signal by which a womens stress response is transduced to her fetus. The results are consistent with the hypothesis that maternal psychological variables may shape the neurobehavioral development of the fetus.

Maternal mental representations of the child in an inner-city clinical sample: Violence-related posttraumatic stress and reflective functioning

Abstract Parental mental representations of the child have been described in the clinical literature as potentially useful risk-indicators for the intergenerational transmission of violent trauma. This study explored factors associated with the quality and content of maternal mental representations of her child and relationship with her child within an inner-city sample of referred, traumatized mothers. Specifically, it examined factors that have been hypothesized to support versus interfere with maternal self- and mutual-regulation of affect: posttraumatic stress disorder (PTSD) and maternal reflective functioning (RF). More severe PTSD, irrespective of level of RF, was significantly associated with the distorted classification of non-balanced mental representations on the Working Model of the Child Interview (WMCI) within this traumatized sample. Higher Levels of RF, irrespective of PTSD severity, were significantly associated with the balanced classification of maternal mental representations on the WMCI. Level of maternal reflective functioning and severity of PTSD were not significantly correlated in this sample. Clinical implications are discussed.

Cardiac autonomic control buffers blood pressure variability responses to challenge: a psychophysiologic model of coronary artery disease.

This article presents a model that identifies effects of blood pressure variability (BPV) as a possible mechanism by which psychological/psychiatric factors and health behaviors confer increased risk of coronary artery disease (CAD) and acute coronary syndromes. Recent research in vascular biology and dynamics of coronary artery blood flow suggests that BPV may have pathogenic effects on the coronary endothelium, plaque formation, and plaque stability. Thus, BPV may be a risk factor for cardiovascular disease independent of mean arterial pressure. The model proposes that autonomic control of the heart exerts a buffering or inhibitory influence on oscillations in blood pressure. Established psychological/behavioral risk factors for CAD, such as depression, hostility, and anxiety, as well as physical deconditioning and aging, are associated with diminished autonomic control of the heart, which may disinhibit pathogenic BPV. Together, these data suggest a coherent, testable psychophysiological model of CAD. In this article, we review these data and make recommendations for research to examine the model.

Fetal heart rate reactivity differs by women's psychiatric status: An early marker for developmental risk?

OBJECTIVE To determine whether there are differences in fetal heart rate (FHR) reactivity associated with womens psychiatric status. METHOD In 57 women in their 36th to 38th week of pregnancy (mean age 27 +/- 6 years), electrocardiogram, blood pressure (BP), respiration (RSP), and FHR were measured during baseline and a psychological challenge (a Stroop color-word matching task). Subjects underwent the Structured Clinical Interview for DSM-IV (SCID) and completed the Spielberger State-Trait Anxiety Inventory prior to testing. RESULTS There was a significant main effect of maternal diagnostic group on FHR reactivity during the Stroop task even after controlling for birth weight and womens BP reactivity (F4,44 = 2.68, p =.04). Fetuses of depressed women had greater heart rate increases compared to fetuses of women with anxiety disorders and those of healthy, low-anxiety women (post hoc comparisons using the Fisher protected least significant difference test; t = 4.12, p <.05; t = 4.72, p <.01, respectively). There was a similar pattern comparing fetuses of healthy, high-anxiety women to the same two groups (t = 3.29, p <.05; t = 3.99, p <.05, respectively). There were no group differences in FHR during a resting baseline period (F4,52 = 1.2, p =.35). CONCLUSIONS Maternal mood disturbance is associated with alterations in childrens physiological reactivity prior to birth.

Components of heart rate reactivity during mental arithmetic with and without speaking

Reactivity to psychological stressors has been hypothesized to be related to the development of cardiovascular disease. Because mental arithmetic (MA) has been shown to produce significant increases in heart rate and blood pressure, it is one of the most commonly utilized laboratory psychological stressors. However, the use of MA to assess hemodynamic reactivity raises two issues: 1) increases in heart rate can be produced by vagal withdrawal, sympathetic activation, or a combination of the two, and these mechanisms may differ in their pathogenic implications; and 2) in most MA studies, subjects are instructed to perform the task aloud, thus raising the possibility that speaking may interfere with respiratory patterns which in turn can influence hemodynamic outcomes. To address these two issues, we studied heart rate responses of 10 subjects to 2 different versions of MA and a control condition in which vocalization of answers was manipulated. Heart rate (HR), heart rate variability (HRV) in the low frequency (LB) and respiratory frequency (RSA) bands, and respiratory rate were measured. Results indicate that, although the two task conditions produced similar heart rate increases, RSA decreased only in the nonspeaking condition. Overall, the findings suggest that HR changes during MA are attributable to vagal withdrawal but that vocalization of answers during the task interferes with analysis of HRV, thus obscuring the mechanisms responsible for these changes.

Heart period variability and psychopathology in urban boys at risk for delinquency

To examine associations between heart period variability (HPV) and psychopathology in young urban boys at risk for delinquency, a series of 697-11-year-old younger brothers of adjudicated delinquents received a standardized psychiatric evaluation and an assessment of heart period variability (HPV). Psychiatric symptoms were rated in two domains: externalizing and internalizing psychopathology. Continuous measures of both externalizing and internalizing psychopathology were associated with reductions in HPV components related to parasympathetic activity. These associations could not be explained by a number of potentially confounding variables, such as age, ethnicity, social class, body size, or family history of hypertension. Although familial hypertension predicted reduced HPV and externalizing psychopathology, associations between externalizing psychopathology and HPV were independent of familial hypertension. Psychiatric symptoms are associated with reduced HPV in young urban boys at risk for delinquency.

Hostility, Gender, and Cardiac Autonomic Control

Objective Although considerable evidence implicates hostility in the development of coronary artery disease (CAD), the pathogenic mechanisms remain poorly understood. We have developed a psychophysiological model that holds that altered autonomic nervous system function links psychological traits with CAD outcomes. In laboratory studies, stressors reduce high-frequency (HF) heart period variability, an index of cardiac vagal modulation. With ambulatory electrocardiographic recording, we demonstrated in a predominantly male sample that hostility was inversely associated with HF power, but only during waking hours. These findings are consistent with the hypothesis that hostile individuals experience multiple stressful interpersonal transactions each day, resulting in overall lower HF power during the day but not at night. Methods To further evaluate this hypothesis, we screened 96 subjects using the Cook-Medley Hostility Scale and selected 15 men and 15 women representing a wide distribution of hostility. These subjects were studied in a laboratory session assessing reactivity to psychological and orthostatic challenges with continuous electrocardiographic, blood pressure, and respiration monitoring. We predicted that for men and women, hostility would be inversely related to reductions in HF power in response to challenge. Results In response to mental stressors, all measures of heart period variability change were inversely related to hostility as predicted. No such relationships were found for responses to tilt. The data suggested a possible effect of gender on these relationships. Conclusions These data add to the growing body of evidence showing that hostility influences vagal modulation of the cardiovascular system and suggest that altered autonomic control is a pathogenic mechanism linking hostility and CAD.

Effects of women's stress-elicited physiological activity and chronic anxiety on fetal heart rate.

ABSTRACT. This study examined the effects of pregnant women’s acute stress reactivity and chronic anxiety on fetal heart rate (HR). Thirty-two healthy third trimester pregnant women were instrumented to monitor continuous electrocardiography, blood pressure, respiration, and fetal HR. Subjects completed the trait anxiety subscale of the State Trait Anxiety Index, then rested quietly for a 5-minute baseline period, followed by a 5-minute Stroop color-word matching task and a 5-minute recovery period. Fetal HR changes during women’s recovery from a stressful task were associated with the women’s concurrently collected HR and blood pressure changes (r = .63, p < .05). Fetal HR changes during recovery, as well as during women’s exposure to the Stroop task, were correlated with their mothers’ trait anxiety scores (r = .39, p < .05 and r = −.52, p < .01, respectively). Finally, a combination of measures of women’s cardiovascular activity during recovery and trait anxiety scores accounted for two thirds of the variance in fetal HR changes during the same recovery period (R2 = .69, p < .001). The results from this study link changes in fetal behavior with acute changes in women’s cardiovascular activity after psychological stress and women’s anxiety status. This indicates that variations in women’s emotion-based physiological activity can affect the fetus and may be centrally important to fetal development.

Distorted Maternal Mental Representations and Atypical Behavior in a Clinical Sample of Violence-Exposed Mothers and Their Toddlers

ABSTRACT Objective: To determine whether maternal violence-related posttraumatic stress disorder (PTSD), reflective functioning (RF), and/or quality of mental representations of her child predicts maternal behavior within a referred sample of mothers exposed to interpersonal violence and their children (aged 8–50 months). Method: A total of 41 dyads completed 2 videotaped visits including measures of maternal mental representations and behavior. Results: Negative and distorted maternal mental representations predicted atypical behavior (Cohens d > 1.0). Although maternal PTSD and RF impacted mental representations, no significant relationships were found between PTSD, RF, and overall atypical caregiving behavior. Severity of maternal PTSD was, however, positively correlated with the avoidant caregiving behavior subscale. Conclusions: Maternal mental representations of her child are useful risk indicators that mark dysregulation of trauma-associated emotions in the caregiver.

The Effect of Aerobic Training and Cardiac Autonomic Regulation in Young Adults

OBJECTIVES We tested the effect of aerobic exercise on autonomic regulation of the heart in healthy young adults. METHODS Healthy, sedentary young adults (n = 149; age = 30.4 +/- 7.53 years) were randomized to receive 12 weeks of either aerobic conditioning or strength training. Primary outcomes were heart rate and RR interval variability (RRV) measured before and after training and after 4 weeks of sedentary deconditioning. RRV, a noninvasive index of cardiac autonomic regulation, reflects variability in the intervals between consecutive R waves of the electrocardiogram. RESULTS Aerobic conditioning but not strength training led to a significant increase in aerobic capacity (3.11 mL/kg/min), a decrease in heart rate (-3.49 beats per minute), and an increase in high-frequency RRV (0.25 natural log msec2), each of which returned to pretraining levels after deconditioning. Significant 3-way interactions, however, revealed autonomic effects only in men. CONCLUSIONS In sedentary, healthy young adults, aerobic conditioning but not strength training enhances autonomic control of the heart, but post hoc analyses suggested that gender plays a significant role in this exercise-related cardioprotection.