Correlates and predictors of symptom severity over time in people under investigation for postural orthostatic tachycardia syndrome (POTS).

Abstract

OBJECTIVE Postural Orthostatic Tachycardia Syndrome (POTS) is a poorly understood chronic disorder characterised by an unexplained excessive increase in heartbeat upon standing. The aim of this study was to investigate psychosocial and physiological correlates and predictors of symptom severity over time in patients presenting with POTS-like symptoms. METHODS Longitudinal cohort study of patients under investigation for POTS (n = 149). Patients completed questionnaires at one month pre-clinic appointment and 6 months later. Diagnosis, blood pressure (BP) and heart rate (HR) measures were collected from medical records. Data were analysed using hierarchical linear multiple regression. RESULTS Orthostatic and small fibre neuropathy (SFN) symptoms remained stable over time and were significantly correlated with distress, cardiac anxiety, threatening views of the illness, and cognitive-behavioural responses to symptoms, but not with emotional reactivity or social support. Baseline psychosocial factors collectively explained 48% (F = 5.37, p < .001) of the variance in orthostatic symptoms, and 35% (F = 3.49, p < .001) of the variance of SFN symptoms at baseline, but a non-significant amount of variance in symptoms at 6 months when controlling for baseline symptoms. Haemodynamic measures explained a significant 4% (F = 3.37, p = .026) of variance of orthostatic symptoms at 6 months. CONCLUSION Symptom burden in patients with suspected POTS remained high over 6 months. Psychosocial factors explained a large amount of the variance in symptoms at baseline. As symptoms did not change/improve over time, baseline symptoms accounted for most of the variance in symptoms at 6 months. An integrated approach addressing psychosocial factors alongside medical treatments may promote adjustment to the condition and lessen symptom burden for this group.