Autonomic dysfunction in autoimmune rheumatic disease

Cardiovascular and neurological manifestations are known to occur in patients with autoimmune rheumatic disease (ARD), often in subclinical form. The term autonomic nervous system (ANS) describes nerves that are concerned predominantly with the regulation of bodily functions. It is comprised of sympathetic and parasympathetic nerves, and their function is complementary. ANS involvement has rarely been studied in patients with ARD, and studies have shown conflicting results. This may be because symptoms of autonomic dysfunction are nonspecific and extremely varied, and may pertain to several systems like the gastrointestinal, cardiovascular, and nervous. Moreover, tests to detect autonomic dysfunction are not routinely employed in clinical rheumatological practice. Another difficulty is to differentiate cardiovascular effects of drugs from ARD involvement. Previous studies on this topic found signs of parasympathetic and sympathetic dysfunction in variable proportions in patients with autoimmune diseases, between 24% and 100% in various tests depending on the methods used. Cardiovascular autonomic dysfunction is the most common type of ANS dysfunction, and was revealed in the majority of ARD patients.