Heart Rate Variability in Complex Regional Pain Syndrome during Rest and Mental and Orthostatic Stress

Abstract

Background: Complex regional pain syndrome (CRPS) is a pain condition with regional sensory and autonomic abnormalities in the affected limb. The authors studied systemic autonomic and hemodynamic function in CRPS patients during rest, and during orthostatic and mental arithmetic stress. Methods: Twenty patients with CRPS and 20 age-, sex-, and body mass index-matched control subjects participated. Mean values of heart rate variability, baroreceptor sensitivity, blood pressure, stroke volume, cardiac output, and total peripheral resistance were estimated during supine rest and 60°t ilt-table testing. On a separate day, heart rate variability was also measured during mental arithmetic stress testing induced by a paced auditory serial addition task. Results: Heart rate was increased and heart rate variability reduced in patients with CRPS patients compared with control subjects during rest and mental and orthostatic stress,

Using complexity metrics with R-R intervals and BPM heart rate measures

“…Interestingly, while the classical measure of heart rate level as well as the non-linear recurrence measures classify the two resting phases as similar (but different from the exercise phase), the fractal scaling properties of heart beat activity are different from the pre-resting phase to exercise, but remain similar to exercise during post-rest. This could be an example of known long-term carry-over effects in heart rate variability (e.g., Akselrod et al, 1981; Terkelsen et al, 2012): A kind of hysteresis effect that governs long-term development of physiological processes (such as the long-term changes of heart physiology and activity patters through repeated-short-term events, as for instance exercise) and is better detectable by complexity metrics compared to linear measures, such as the overall level of activity or linear power-spectral density analysis (Webber et al, 2009). The result is supported by findings of Karavirta et al (2009) indicating that long-term exercise gains in older participants of endurance and strength training went together with increased fractal scaling exponents of heart beat activity.…”

Neurogenic neuroinflammation in fibromyalgia and complex regional pain syndrome

“…118,119 Similar observations have been reported in patients with CRPS; for instance, increased heart rate, reduced heart rate variability, and inability to protect cardiac output during ortho static stress. 120 Patients with CRPS also show hyper responsiveness to a vasoconstrictive stimulus (infusion of increasing concentrations of noradrenaline into the dorsal hand vein). 121 Important interactions between the sympathetic nervous system and the innate immune system occur via dendritic cells, which are modulated by adreno receptors.…”

Sensing the body in chronic pain: A review of psychophysical studies implicating altered body representation

“…In addition, HRV provides a measure of sympathetic and parasympathetic activity, as well as a potential marker for deficits in self-regulation. HRV has been extensively investigated in a range of chronic pain disorders, such as CLBP (Gockel et al, 2008), chronic neck-shoulder pain (Hallman et al, 2011(Hallman et al, , 2013, fibromyalgia (Mostoufi et al, 2012), CRPS (Terkelsen et al, 2012), and phantom limb pain (Sarabia Cachadiña et al, 2013). Collectively, these studies unanimously support autonomic dysregulation in pain populations, reflected by increased resting heart rate and reduced HRV.…”