Cardiorespiratory functional disorders: A transnosologic approach

Functional disorders affecting the cardiorespiratory system are common. Non-cardiac chest pain affects more than 10% of the population. It can result from gastro-oesophageal reflux or chest wall disorders but is also very often associated with anxiodepressive disorders, particularly panic disorder. Postural orthostatic tachycardia syndrome (POTS), a rarer entity, is characterized by a sharp increase in heart rate without orthostatic hypotension when standing. The pathophysiological mechanisms of POTS include 'partial' autonomic neuropathy, hypovolaemia and noradrenergic dysregulation, but it is also closely linked to anxiety disorders and deconditioning to exertion. Functional respiratory disorders, particularly hyperventilation syndrome, are accompanied by various manifestations ranging from tetany to gastrointestinal symptoms. They are highly prevalent, especially among women and people suffering from anxiety, and particularly in the case of associated respiratory disease such as asthma. The diagnosis of hyperventilation syndrome is based on the Nijmegen questionnaire. The pathophysiology does not necessarily involve hypocapnia but is related to cerebral conditioning phenomena and vicious circles linked to anticipatory anxiety. Cardiorespiratory functional disorders are often linked to each other and to other functional somatic disorders and have in common a dysregulation of the autonomic nervous system. Psychological, cognitive and behavioural factors play a central role in their persistence. While each has its specificities, all have a complex circular causality. Their management currently relies primarily on physical rehabilitation, often associated with symptomatic treatments such as beta-blockers. The place of cognitive and behavioral therapies would be well worth exploring in these disorders.