Decreased chaos of heart rate time series in children of patients with panic disorder

Abstract

This study examined the differences of heart rate variability measures between children of parents with panic disorder and children of healthy controls using linear as well as nonlinear techniques. Supine and standing heart rate variability indices were measured in all children using power spectral analysis and a measure of chaos, the largest Lyapunov exponent (LLE) of heart rate time series. No significant differences emerged between the children of panic disorder parents and children of normal controls on any of the spectral heart rate variability measures. However, children of patients with panic disorder had significantly lower LLE of heart rate time series in supine posture, suggesting a relative decrease of cardiac vagal function in this group of children. This suggests a possible heritable effect of certain measures of heart rate variability, as previous studies showed decreased heart rate variability in patients with panic disorder using spectral as well as nonlinear techniques. Recent evidence also suggests that some of these nonlinear measures are superior or of additional value to the traditional time and frequency domain measures of heart rate variability to predict serious ventricular arrhythmias and sudden death.

Effect of Parasympathetic Stimulation on Brain Activity During Appraisal of Fearful Expressions

“…These findings strongly endorse the perspective that the degree to which viscerosensory afferent information impacts upon both neural reactivity and emotional processing is highly dependent on the integrity of parasympathetic autonomic control and individual characteristics in basal vagal cardiovascular regulation. Lower vagal activity has been linked to reduced prefrontal inhibitory control over the amygdala (Thayer et al, 2009), and is observed in patients with generalized anxiety disorders, panic disorder, and even children of patients with panic disorder (see Friedman, 2007 for a review ;Srinivasan et al, 2002). Here, we show that individuals with lower HRV were more responsive towards the CS, by reporting a stronger deactivation of amygdala and lower rating of fearful stimuli, according to the literature reporting that higher parasympathetic tone is associated with reduced sensitivity to fear perception (Thayer et al, 2009).…”

Individual differences in fear-potentiated startle as a function of resting heart rate variability: Implications for panic disorder

“…Whereas a review of the evidence for low HRV as an endophenotype for panic disorder or psychopathology more generally is beyond the scope of the present paper, much of this evidence in the case of panic disorder has been summarized previously (Friedman and Thayer, 1998a;Friedman, 2007). Specifically, 1) low HRV is associated with panic disorder (Friedman and Thayer, 1998a,b), 2) HRV is heritable (Wang et al, 2005;Snieder et al, 2007;Thayer et al, 2003), 3) low HRV in panic disorder is state independent, that is, is present in the absence of panic symptoms (Friedman et al, 1993;Friedman and Thayer, 1998b), 4) low HRV and panic disorder co-aggregate within families (Friedman and Thayer, 1998a;Friedman, 2007), and 5) lower HRV is found in children of patients with panic disorder compared to children of normal controls (Srinivasan et al, 2002). Moreover, there is a continuum with some endophenotypes being closer to the genes and some being closer to the phenotype or behavior.…”

Heart rate variability biofeedback: how and why does it work?

“…Total HRV in these studies generally is measured by the standard deviation of normal beat-to-beat intervals, i.e., intervals controlled by central nervous system input to the sinoatrial node of the heart, rather than by abnormal cardiac function). People with simpler patterns of HRV appear to be similarly compromised (Otsuka et al, 1997; Srinivasan et al, 2002; Yeragani et al, 2002; Skinner et al, 2008a,b, 2009; Huikuri et al, 2009). For this reason, HRV is often seen as a measure of physical and emotional resilience.…”