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 Table of Contents  
Year : 2019  |  Volume : 6  |  Issue : 2  |  Page : 79-82

Clinical profile and cardiovascular autonomic function tests in patients with postural orthostatic tachycardia syndrome

1 Department of Physiology, Christian Medical College, Ludhiana, Punjab, India
2 Department of Neurology, Christian Medical College, Ludhiana, Punjab, India

Date of Submission30-May-2018
Date of Decision24-Jun-2018
Date of Acceptance12-Jul-2018
Date of Web Publication23-May-2019

Correspondence Address:
Suchitra Deolalikar
Department of Physiology, Christian Medical College, Ludhiana - 141 008, Punjab
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/cjhr.cjhr_81_18

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Background: Postural orthostatic tachycardia syndrome (POTS) is an autonomic disorder characterized by the clinical symptoms of orthostatic intolerance such as light-headedness, fatigue, sweating, tremor, anxiety, palpitation, exercise intolerance, and near syncope on standing in the absence of orthostatic hypotension. Objective: The objective of this study is to evaluate the clinical profile and autonomic parameters in patients with POTS. Materials and Methods: A total of 70 patients with POTS underwent cardiovascular autonomic function tests, i.e., heart rate (HR) response to deep breathing, heart rate and blood pressure (BP) changes in Valsalva maneuver and tilt study in the autonomic laboratory of the Department of Neurology from January 2014 to February 2016 using WR Medical Works, USA. Results: Mean age of cohort was 28.07 ± 10.64 years, and there were 36 (51%) women. Light-headedness 59 (84.3%) was the most common orthostatic symptom, followed by dizziness 56 (80%), palpitation 41 (58.57%), anxiety 26 (37.14%), loss of consciousness 21 (30%), disequilibrium 19 (27.14%), visual symptoms 12 (17.14%), weakness 8 (11.43%), and shortness of breath 2 (2.86%). The average heart rate response to deep breathing was 24.79 ± 7.20 bpm. Average Valsalva ratio was 1.78 ± 0.30. During the tilt, average maximum HR increase was 43.47 ± 11.19 bpm. Conclusion: POTS is an underrecognized disorder and majority of them present with vague orthostatic symptoms ways, hence clinicians should be made aware of the symptomatology. The tilt table test with beat-to-beat monitoring of HR and BP is the standard test for diagnosis.

Keywords: Cardiovascular autonomic function tests, clinical profile, Postural orthostatic tachycardia syndrome

How to cite this article:
Neeraj, Deolalikar S, Pannu A, Pandian JD. Clinical profile and cardiovascular autonomic function tests in patients with postural orthostatic tachycardia syndrome. CHRISMED J Health Res 2019;6:79-82

How to cite this URL:
Neeraj, Deolalikar S, Pannu A, Pandian JD. Clinical profile and cardiovascular autonomic function tests in patients with postural orthostatic tachycardia syndrome. CHRISMED J Health Res [serial online] 2019 [cited 2022 Jul 7];6:79-82. Available from: https://www.cjhr.org/text.asp?2019/6/2/79/258980

  Introduction Top

Postural orthostatic tachycardia syndrome (POTS), an autonomic disorder, is characterized by the clinical symptoms of orthostatic intolerance such as light-headedness, sweating, tremor, fatigue, anxiety, palpitation, exercise intolerance, and near syncope on the upright posture, which are relieved on lying down. It is more common in females in the age group of 12–50 years with a male-to-female ratio of 1:5.[1] It is defined as the presence of symptoms of orthostatic intolerance associated with an increment in heart rate (HR) of 30 bpm or tachycardia >120 bpm within first 10 min of standing or upright tilt without evidence of orthostatic hypotension. Symptoms must occur in the absence of causes leading to orthostatic tachycardia such as prolonged bed rest, use of drugs that affect autonomic regulation (vasodilators, diuretics, antidepressants, or anxiolytic agents), or chronic debilitating disorders that cause tachycardia (such as dehydration, anemia, or hyperthyroidism).[2]

POTS is an underrecognized disorder as majority of the patients present with vague orthostatic symptoms making it difficult to diagnose. To the best of our knowledge, the documentation of this entity in published research from the developing countries has not been ample enough to state the magnitude of this condition. Hence, this study was undertaken to study the clinical profile and autonomic parameters in patients with POTS.

  Materials and Methods Top

This prospective study was approved by the Institutional Research Committee and was conducted in the autonomic laboratory of the Department of Neurology, from January 2014 to February 2016. A total of 70 patients were included in the study. Inclusion criteria were as follows: (a) patients with HR increase of ≥30 bpm or HR ≥120 bpm within 10 min of standing or upright tilt; (b) patients with symptoms of light-headedness, weakness, palpitations, blurred vision, breathing difficulties, nausea, or headache lasting for >3 months. Exclusion criteria were as follows: (a) patients with orthostatic hypotension (systolic blood pressure [SBP] fall of ≥30 mmHg within 3 min of standing up or head-up tilt); (b) pregnancy or lactation; (c) presence of any other cause of autonomic failure; and (d) presence of systemic diseases affecting the autonomic nervous system and patients on therapy with anticholinergic drugs, α- and β-adrenergic antagonists, or other medications that could interfere with testing of autonomic function.[3]

Patients presenting with symptoms suggestive of POTS underwent standardized autonomic function tests. Following cardiovascular autonomic function tests were performed using the equipment made by WR Medical Works, USA, after taking informed written consent of each patient.

  1. Automatic tilt table test
  2. Heart rate response to deep breathing (HRDB)
  3. Valsalva maneuver.

Head-up tilt table test

It assesses the adrenergic vasomotor function. In this setup, an automated tilt table is used. The baseline SBP, diastolic blood pressure (DBP), and HR were recorded before the tilt.[4] The tilt study was performed for 10 min for 80° of head-up tilting. HR and blood pressure (BP) changes and symptoms during the tilt were recorded. The Finapress (Bmeye – Nexfin Monitor, the Netherlands) was used to record BP continuously from the fingertip.

Heart rate response to deep breathing

It assesses cardiovagal function. The patient breathes at a rate of 6 breaths per minute (inspiratory and expiratory cycles of 5 s each). Eight cycles were recorded and repeated after a rest period of 5 min. The five largest consecutive responses were read from the computer using a cursor, averaged, and the HR range (maximum–minimum) was derived.[4]

Valsalva maneuver

It assesses cardiovagal and adrenergic vasomotor functions. The patient while rested and recumbent was asked to maintain a column of mercury at 40 mmHg for 15 s through a bugle. The procedure was repeated 3 times. The Valsalva ratio (VR) was derived from the maximum HR divided by the lowest HR occurring following the maneuvers.[4]

Statistical analysis

Descriptive statistics are presented as percentages, mean ± standard deviation, and categorical variables are expressed as count (percentages). All statistical analysis was performed using SPSS, version 21.0. Armonk, NY: IBM Corp.

  Results Top

Out of 115 patients referred to the autonomic laboratory during the study period with complaints of falls, syncope, and orthostatic intolerance, 70 were diagnosed to have POTS after tilt study. Mean age was 28.07 ± 10.64 years (Range: 18-55 years), and there were 36 (51%) women. Symptomatology of patients is presented in [Table 1] and [Table 2]. The average HRDB was 24.79 ± 7.20 bpm. Average VR was 1.78 ± 0.30. During the tilt, average maximum HR increase was 43.47 ± 11.19 bpm. [Figure 1] shows the typical HR and BP responses to tilt in a patient with POTS.
Table 1: Orthostatic symptom in patients with postural orthostatic tachycardia syndrome

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Table 2: Nonorthostatic symptoms in patients with postural orthostatic tachycardia syndrome

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Figure 1: Heart rate and blood pressure response to tilt in normal patient (upper) and in a patient with postural orthostatic tachycardia syndrome (lower)

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  Discussion Top

The common orthostatic presenting symptoms in our study were light-headedness, dizziness, anxiety, loss of consciousness, disequilibrium, palpitations, and visual symptoms. The clinical symptoms in our patients were similar to those of reported by Pandian et al.[3] Patients with POTS had normal VR ratio and HRDB suggesting a normal parasympathetic function. These results were in agreement with previous studies done by Ewing et al.,[5] Khandelwal et al.,[6] and Novak.[7] The HR increment of 43.47 bpm during tiltup was consistent with previous study[8] which showed increase of HR by 44.0 bpm. The HR increment besides being a compensatory mechanism to maintain SBP and cerebral perfusion at adequate level[9] is also suggestive of excessive sympathetic activation. Orthostatic hypotension is not seen in POTS patients. Nearly 20%–30% of patients with POTS experience syncope,[10] often through a vasovagal mechanism. Many of the patients reported in earlier studies documented onset of their symptoms following an acute febrile viral illness, as well as after pregnancy, surgery, sepsis, or trauma.[8] Sandroni et al.,[11] in their study, reported antecedent viral infection in some POTS patients, but none of patients in the present study had any preceding viral infection.

Many POTS patients report cognitive problems, though the mechanisms for this are not clear. Arnold et al. in their follow-up study of cognitive function in patients with POTS identified selective attention deficit, decreased cognitive processing speed, and difficulty in executive function.[12] Ocon et al. found that there is worsening of executive function with increased orthostatic stress in POTS patients.[13]

POTS patients may also complain of poor sleep quality and excessive daytime sleepiness leading to poor quality of life.[14],[15] Dependent acrocyanosis (dark-red discoloration of legs) is another major feature present in 40%–50% of patients with POTS. Studies suggest that decreased blood flow in the skin causes this problem.[16]

Severe fatigue is common in POTS (93%) and many patients (64%) also fulfill the criteria for chronic fatigue syndrome.[17] Patients may also have chronic joint pain or Ehlers–Danlos syndrome (hypermobility type), as these disorders may also be associated with POTS.[18]

There is possibility of patients with POTS to be misdiagnosed as its symptoms overlap with many other disorders such as anxiety, inappropriate sinus tachycardia syndrome, neurogenic orthostatic hypotension, and chronic fatigue syndrome. Consequently, diagnosis of POTS is commonly delayed by several years.[8]

POTS can be classified as primary or secondary [Table 3].[19],[20],[21],[22],[23] Primary POTS is not associated with any medical condition, whereas secondary POTS occurs in conjunction with some known diseases or disorders such as benign joint hypermobility syndrome.[24]
Table 3: Classification of postural orthostatic tachycardia syndrome

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The most common form of primary POTS is partial dysautonomic form in which patients suffer from peripheral autonomic neuropathy marked by the failure of the peripheral vasculature to maintain required vascular resistance when challenged with gravitational stress leading to pooling of blood in the lower parts of body during the upright posture.[6] Partial dysautonomic form may have autoimmune etiology resulting from the development of autoantibodies against α3 acetylcholine receptors of the peripheral ganglia.

Another form of primary POTS, termed hyperadrenergic, is far less common and could be due to the impaired clearance or decreased uptake by the synaptic cleft. These patients often complain of profuse sweating, anxiety, tremulousness, and high DBP.[7] This type is thought to be due to an underlying genetic disorder.

POTS is a disorder with variable prognosis. Efforts should be made to determine and treat causes that can be reversed. It is important to educate the patient about the nature of the disorder. The patient should avoid aggravating factors such as dehydration and extreme heat. They are advised to increase their fluid intake (up to 3 L/day) and dietary salt intake (8–10 g/day).[25] Symptoms are improved with exercise training. Fu et al.[26] and Fu and Levine[27] in their study on POTS patients found that exercise intervention reduced orthostatic tachycardia and improved quality of life in these patients. Other appropriate methods such as compression stockings and pharmacological agents which increase peripheral resistance or augment circulatory fluid volume would also be helpful.[1],[9],[20]

  Conclusion Top

POTS is an underrecognized clinical problem with multiple etiologies. Frequent and recurrent episodes of syncope or presyncope have negative effect on quality of life and lead to substantial morbidity. Autonomic tests such as tilt table test are helpful to establish the diagnosis of POTS. A variety of treatments, including exercise and medications, can improve symptoms for the majority of people with POTS.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Agarwal AK, Garg R, Ritch A, Sarkar P. Postural orthostatic tachycardia syndrome. Postgrad Med J 2007;83:478-80.  Back to cited text no. 1
Raj SR. Postural tachycardia syndrome (POTS). Circulation 2013;127:2336-42.  Back to cited text no. 2
Pandian JD, Dalton K, Henderson RD, McCombe PA. Postural orthostatic tachycardia syndrome: An underrecognized disorder. Intern Med J 2007;37:529-35.  Back to cited text no. 3
Low PA. Laboratory evaluation of autonomic function. In: Low PA, editor. Clinical Autonomic Disorders: Evaluation and Management. 2nd ed. Philadelphia: Lippincott Raven Publishers; 1997. p. 179-208.  Back to cited text no. 4
Ewing DJ, Martyn CN, Young RJ, Clarke BF. The value of cardiovascular autonomic function tests: 10 years experience in diabetes. Diabetes Care 1985;8:491-8.  Back to cited text no. 5
Khandelwal E, Jaryal AK, Deepak KK. Cardiovascular autonomic functions & cerebral autoregulation in patients with orthostatic hypotension. Indian J Med Res 2011;134:463-9.  Back to cited text no. 6
[PUBMED]  [Full text]  
Novak P. Quantitative autonomic testing. J Vis Exp 2011;53:2502.  Back to cited text no. 7
Thieben MJ, Sandroni P, Sletten DM, Benrud-Larson LM, Fealey RD, Vernino S, et al. Postural orthostatic tachycardia syndrome: The mayo clinic experience. Mayo Clin Proc 2007;82:308-13.  Back to cited text no. 8
Kanjwal Y, Kosinski D, Grubb BP. The postural orthostatic tachycardia syndrome: Definitions, diagnosis, and management. Pacing Clin Electrophysiol 2003;26:1747-57.  Back to cited text no. 9
Ojha A, Chelimsky TC, Chelimsky G. Comorbidities in pediatric patients with postural orthostatic tachycardia syndrome. J Pediatr 2011;158:20-3.  Back to cited text no. 10
Sandroni P, Opfer-Gehrking TL, McPhee BR, Low PA. Postural tachycardia syndrome: Clinical features and follow-up study. Mayo Clin Proc 1999;74:1106-10.  Back to cited text no. 11
Arnold AC, Haman K, Garland EM, Raj V, Dupont WD, Biaggioni I, et al. Cognitive dysfunction in postural tachycardia syndrome. Clin Sci (Lond) 2015;128:39-45.  Back to cited text no. 12
Ocon AJ, Messer ZR, Medow MS, Stewart JM. Increasing orthostatic stress impairs neurocognitive functioning in chronic fatigue syndrome with postural tachycardia syndrome. Clin Sci (Lond) 2012;122:227-38.  Back to cited text no. 13
Bagai K, Song Y, Ling JF, Malow B, Black BK, Biaggioni I, et al. Sleep disturbances and diminished quality of life in postural tachycardia syndrome. J Clin Sleep Med 2011;7:204-10.  Back to cited text no. 14
Mallien J, Isenmann S, Mrazek A, Haensch CA. Sleep disturbances and autonomic dysfunction in patients with postural orthostatic tachycardia syndrome. Front Neurol 2014;5:118.  Back to cited text no. 15
Raj SR. The postural tachycardia syndrome (POTS): Pathophysiology, diagnosis & management. Indian Pacing Electrophysiol J 2006;6:84-99.  Back to cited text no. 16
Okamoto LE, Raj SR, Peltier A, Gamboa A, Shibao C, Diedrich A, et al. Neurohumoral and haemodynamic profile in postural tachycardia and chronic fatigue syndromes. Clin Sci (Lond) 2012;122:183-92.  Back to cited text no. 17
Mathias CJ, Low DA, Iodice V, Owens AP, Kirbis M, Grahame R, et al. Postural tachycardia syndrome – Current experience and concepts. Nat Rev Neurol 2011;8:22-34.  Back to cited text no. 18
Grubb BP. Postural tachycardia syndrome. Circulation 2008;117:2814-7.  Back to cited text no. 19
Soliman K, Sturman S, Sarkar PK, Michael A. Postural orthostatic tachycardia syndrome (POTS): A diagnostic dilemma. Br J Cardiol 2010;17:36-9.  Back to cited text no. 20
Shannon JR, Flattem NL, Jordan J, Jacob G, Black BK, Biaggioni I, et al. Orthostatic intolerance and tachycardia associated with norepinephrine-transporter deficiency. N Engl J Med 2000;342:541-9.  Back to cited text no. 21
Blair P. Grubb. The postural tachycardia syndrome: When to consider it in adolescents. Fam Pract Recertification 2006;28:19-30.  Back to cited text no. 22
Gazit Y, Nahir AM, Grahame R, Jacob G. Dysautonomia in the joint hypermobility syndrome. Am J Med 2003;115:33-40.  Back to cited text no. 23
Kaur N, Arun VA, Rana S, Sashindran VK. Benign joint hypermobility syndrome with postural orthostatic tachycardia syndrome and acrocyanosis. Med J DY Patil Univ 2017;10:175-8.  Back to cited text no. 24
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Jones PK, Shaw BH, Raj SR. Clinical challenges in the diagnosis and management of postural tachycardia syndrome. Pract Neurol 2016;16:431-8.  Back to cited text no. 25
Fu Q, Vangundy TB, Galbreath MM, Shibata S, Jain M, Hastings JL, et al. Cardiac origins of the postural orthostatic tachycardia syndrome. J Am Coll Cardiol 2010;55:2858-68.  Back to cited text no. 26
Fu Q, Levine BD. Exercise in the postural orthostatic tachycardia syndrome. Auton Neurosci 2015;188:86-9.  Back to cited text no. 27


  [Figure 1]

  [Table 1], [Table 2], [Table 3]


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