Founder of Health Rising and Phoenix Rising
Heart rate variability is another matter entirely. It refers to variability in the electrical signals in the heart. With HRV more is less; more heart rate variability the better. Reduced heart variability has been associated with earlier death but is one of the most consistent findings in the FM and chronic fatigue syndrome literature. In both diseases reduced HRV variability suggests the sympathetic nervous system is on high alert while the parasympathetic nervous system is
These researchers determined if this disordered electrical signaling of the heart - this reduced heart rate variability - during rest and during deep breathing was associated with pain. Several studies and some researchers and doctors including Dr. Julia Newton and Dr. Martinez-Levin believe autonomic nervous system problems play a key role in producing fatigue and pain in ME/CFS and FM and other diseases. (Newton believes they may underlie all fatigue and disorders). Vollmer's ME/CFS studies have linked reduced HRV to problems with cognition and sleep and we just saw evidence that vagus nerve stimulation can produce miracles in at least some people with fibromyalgia.
The links appear to be there...but did this study bear them out?
It did. This study further cemented the association between overactivation of the sympathetic nervous system (fight or flight) and the underactivation of the parasympathetic nervous system (PNS) in fibromyalgia. It suggested that the overactive fight or flight response on in FM virtually all the time; during deep breathing and that it doesn't stop for rest. (Indeed, other studies have shown that it doesn't stop for sleep either. Increased heart rates during sleep are present).
The study also found that this increased fight or flight response makes a difference. The greater the reductions in parasympathetic nervous system functioning found - the greater the pain the FM patients were in.
How to rein in the fight or flight response? As noted above surgically implanted vagus nerve stimulators- if available - are an expensive and hard to find but possibly highly effective option. Cheaper options stimulating vagus nerve endings in the ear are being developed. Some beta blockers work in some patients and meditation and mindfulness can, over time, turn up the "rest and digest" response and reduce the "fight or flight response" at least to some extent.
The study wasn't a game changer but it did validate one of the most important andd intriguing findings in FM - reduced HRV. It can only provide a boost for funding in this possible vital area.
Pain Pract. 2015 Jun 1. doi: 10.1111/papr.12321. [Epub ahead of print] Respiratory Sinus Arrhythmia and its Association with Pain in Women with Fibromyalgia Syndrome. Zamunér AR1, Forti M1, Andrade CP1, Avila MA1, da Silva E1.
To assess the cardiac autonomic control at rest and during the deep breathing test (DBT) and its association with pain in women withfibromyalgia syndrome (FMS).
The study included 20 women with FMS and 20 healthy women (control group, CG). The pain was quantified by assessing the pressure pain threshold (PPT), VAS of pain, and the pain component of the SF-36 questionnaire. The RR intervals were recorded in the supine position and during the DBT. The heart rate variability (VHR) was measured by methods in the time and frequency domain.
The group with FMS had abnormal cardiac autonomic modulation at rest and during DBT, compared to CG (P < 0.05). Positive correlations were found between PPT and the E/I ratio (r = 0.70), ΔFC (r = 0.66) and power spectrum density (DEP, r = 0.56) indices of DBT, as well as between pain component of the SF-36 and the E/I ratio (r = 0.49), ΔFC (r = 0.45) and DEP (r = 0.50) indices of DBT. Significant correlations were observed between the FIQ questionnaire and the LF/HF ratio index in the supine position and the E/I ratio (r = -0.63), ΔFC (r = -0.54), and DEP (r = -0.51) indices of DBT.
The results of VHR indices during the supine position and the DBT women with FMS suggest impairment of neurocardiac integrity associated with pain and the impact of FMS on the quality of life.