Heart rate variability in patients with fibromyalgia and patients with chronic fatigue syndrome: a systematic review.
Meeus, Mira, Goubert, Dorien, De Backer, Fien et al.·Seminars in arthritis and rheumatism·2013
This review looked at 16 studies comparing heart rhythm patterns between people with fibromyalgia, chronic fatigue syndrome, and healthy controls. Both conditions showed changes in how the heart responds to stress, but the patterns were different: fibromyalgia patients had heart rhythm problems throughout the day, while CFS patients mainly showed them during sleep. Exercise helped improve heart rhythm patterns in fibromyalgia patients.