Postural tachycardia syndrome: current perspectives

Abstract

Postural tachycardia syndrome (POTS) is the combination of an exaggerated heart rate response to standing, in association with symptoms of lightheadedness or pre-syncope that improve when recumbent. The condition is often associated with fatigue and brain fog, resulting in significant disruptions at a critical time of diagnosis in adolescence and young adulthood. The heterogeneity of the underlying pathophysiology and the variable response to therapeutic interventions make management of this condition challenging for both patients and physicians alike. Here, we aim to review the factors and mechanisms that may contribute to the symptoms and signs of POTS and to present our perspectives on the clinical approach toward the diagnosis and management of this complex syndrome.

Keywords: autonomic; baroreflex; doppler; hypermobility; orthostatic.

Figure 1

Pulse wave Doppler ultrasound in vascular compression syndrome. Notes: Increase in Doppler intensity of the orange spectra and color reversal due to aliasing (blue region in the center of the vessel) indicates increase in blood flow velocity and turbulence in the compressed superior mesenteric artery of a patient upon change in posture from supine (A) to standing (B). In median arcuate ligament syndrome, the celiac artery may become compressed during expiration, resulting in increased blood flow velocity and turbulence seen here as an increase in height during systole and broadening waveform during diastole (C). In thoracic outlet syndrome, the blood flow waveform is completely lost in the axillary artery upon arm raising (D).

Figure 2

Supine and upright heart rate and blood pressure. Notes: Supine and upright HR (orange) and blood pressure (blue) profiles of a normal subject (left panel) and a subject with POTS (right panel) demonstrating an exaggerated HR increase (>30 bpm) and relatively stable blood pressure. Abbreviations: bpm, beats per minute; HR, heart rate; POTS, postural tachycardia syndrome.

Figure 3

Common clinical signs. Notes: (A) Raynaud’s phenomenon; (B) acrocyanosis; (C) hypermobility – demonstrating the ability to bring the thumb in contact with the ipsilateral forearm as part of the Beighton score (for additional information on Beighton scoring system, see Table 2). In (B) the right leg had been dependent whilst the left leg had remained on the bed for a few minutes revealing the color change seen with venous pooling. Images were kindly provided by patients along with their written informed consent to publish the images.