Palpitations and Tachycardia in Fibromyalgia Syndrome
Palpitations and Tachycardia in Fibromyalgia Syndrome
Clinically Characterized by the presence of chronic widespread pan and tenderness,
 Fibromyalgia (FM) is one of the most common "functional" syndromes. FM is currently conceived
 of as representing a prototype of central pain, i.e. a condition in which sensitization of
 the central nervous system results in a overall increase in the processing of painful
 stimuli, as well as an impairment of pain inhibition. This condition is responsible for
 significant a social and economic burden and is estimated to affect up to 5% of all women.
 The 1990 American College of Rheumatology (ACR) classification criteria for FM are the
 current standard for studying FM, and require the presence of widespread pain lasting over 3
 months, as well as documentation of tenderness in at least 11 of 18 pre-defined "tender
 points. Multiple additional symptoms, which are not part of the classification criteria,
 include among others sleep disturbances, mood disturbances, cognitive dysfunction,
 vulvodynia, dysmenorrhea, sexual dysfunction and weight fluctuations. In addition, FM is well
 known to overlap both clinically and epidemiologically with an ever increasing number of
 other "functional" disorders, including irritable bowel syndrome (IBS), Temporomandibular
 joint disorder (TMJD), functional dyspepsia etc. In addition to the central symptom of pain,
 FM patients frequently complain of non- specific symptoms which are potentially autonomically
 - mediated. Thus, palpitations, fatigue and inability to stand for long periods of time are
 all common complaints. About 80-90 percent of FM patients have one or more symptoms
 associated with autonomic dysfunction. The most common of them is presyncope (62.5%),
 followed by syncope (12.5%), palpitations on standing (12.5%) and dizziness (12.5%) (14).
 Some of these symptoms overlap with those of the postural tachycardia syndrome (POTS). POTS
 is a common dysautonomia, characterized by remarkable increased heart rate during the
 assumption of the upright posture (>30 bpm). According to our experience, FM is found, at
 least, in 15% of POTS patients. But, no data exists about the incidence of POTS in patients
 with FM.The role of the autonomic nervous system (ANS) in initiating and maintaining the
 syndrome of FM has been studies (and debated) over the last decade. The ANS is an extremely
 complex system, regulating involuntary body functions, including heart rate, intestinal
 motility, urination, and sexual activity, among many other variables. Notably, the vagus has
 an inhibitory effect on pain. Deterioration in the vagal control is "associated" with
 increased pain sensation. Previous studies have indicated that FM patients may have an
 increase in sympathetic control over the cardiovascular system with a reciprocal decrease in
 parasympathetic control. High sympathetic tone is usually associated with a lower threshold
 to pain. But, the contribution of the ANS to the pathogenesis of FM syndrome remains unclear.
 Evidently, the ANS interacts with other components of the CNS in the pathogenesis of FM,
 including pain processing centers in the thalamus and amygdala, as well as with the
 hypothalamic-pituitary-adrenal (HPA) axis.
Inclusion Criteria:

 -  ACR 1990 criteria for fibromyalgia: widespread pain lasting 3 months

 -  Tenderness in 11 of 18 points

 Exclusion Criteria:

 -  Unable to provide informed concent

 -  Known tachyarrhythmia