Prevalence of fibromyalgia in vasovagal syncope

Vasovagal syncope is an acute manifestation of autonomic nervous system dysfunction. This type of syncope is often associated with other dysautonomic expressions such as migraine, gastroparesis, or postural tachycardia syndrome. Autonomic nervous system dysfunction has been proposed as a key element in the pathogenesis of fibromyalgia.

The objectives of this study were to estimate the frequency of fibromyalgia in a sample of patients with vasovagal syncope and also to correlate the presence of syncope and fibromyalgia with different dysautonomic manifestations.

We studied 50 consecutive patients with vasovagal syncope seen at the Syncope Unit of the National Cardiology Institute of Mexico between June 2009 and June 2012. All individuals filled out the Composite Autonomic Symptoms and Signs questionnaire and the Fibromyalgia Impact Questionnaire. All cases underwent a head-up tilt test. A rheumatologist examined all participants to assess the presence of fibromyalgia.

The median age of the studied population was 21 years. Sixty-eight percent of participants were women. Eight cases (16%) had concomitant fibromyalgia. Significantly, all fibromyalgia cases were female. This subgroup of fibromyalgia subjects had more secretomotor complaints (mainly dry eyes and dry mouth) and more bowel constipation than the remainder of the group. Also in this subgroup of fibromyalgia subjects, several significant associations were found between age, blood pressure, number of syncopal episodes, constipation, insomnia, pupillomotor impairment, and disability. In contrast, no correlations were found in the subgroup of fainters without fibromyalgia.

Fibromyalgia was relatively frequent in these women with vasovagal syncope and could be associated with dysautonomic symptoms. Therefore, it seems important to search for dysautonomic comorbidities in patients with vasovagal syncope and/or fibromyalgia, to provide a patient-centered holistic approach, instead of the often currently used therapeutic partition.