Postural orthostatic tachycardia syndrome (POTS) is a clinical entity characterized by orthostatic intolerance that includes an increase in heart rate of at least 30 bpm when one changes from a supine to an upright position within the first 10 minutes of standing without prolonged bed rest, medications, or other chronic debilitating disorders that impair autonomic reflexes. Clinical complaints in patients with POTS include dizziness, fatigue, confusion, and vision and hearing changes that are felt to be due to decreased cerebral blood flow. POTS is a multisystem disease leading to functional impairment similar to a chronic lung or heart condition and comprises a mixed group of varied disorders associated with similar clinical symptoms.1 Receiving a diagnosis of POTS can be psychologically debilitating.2 POTS may profoundly impact one’s quality of life and basic functioning.3 Appropriate management of and attention to POTS can increase patient quality of life and decrease patient and family anxiety.2 

Vasovagal syncope (VVS), also known as neurocardiogenic syncope or a “simple faint,” is the most common cause of loss of consciousness in childhood.4,5 VVS is characterized by inappropriate vasodilatation leading to transient neurally mediated systemic hypotension and bradycardia resulting in low cerebral blood flow and loss of consciousness.1 VVS in pediatrics is often associated with a positive family history, growth spurt, menstrual cycle, or rapid weight loss.1 VVS is a benign, self-limited problem and is not typically a chronic problem associated with multisystem complaints.

Differentiating between POTS and VVS can be challenging, but is important in determining treatment and offering anticipatory guidance for patients and families. Differentiation also allows for proper medical management as well as appropriate anticipatory guidance on the natural history of the presenting problem.1 Typically, a comprehensive history and physical examination are sufficient to differentiate these 2 entities. One test that has been used in attempts to diagnose these problems is the head-up tilt (HUT) table test. Although some experts still recommend HUT in evaluating this population, several studies have demonstrated suboptimal results when using this test in pediatrics.1,6,9 Half of the patients with initial positive tilt tests had negative tests when repeated with either placebo or treatment.3 Perhaps because of the difficulty of interpreting the results, the use of HUT testing in children and adolescents is declining. A recent query of members of the Pediatric and Congenital Electrophysiology Society found that 24% of the responding pediatric electrophysiologists no longer perform HUT table tests and 76% perform <10 HUT table tests per year.9 In their analysis in this issue of Pediatrics, Medow and colleagues10 examined the utility of HUT in differentiating between POTS and VVS. They performed HUT on patients with recurrent VVS and matched control subjects. Orthostatic heart rates were observed and showed heart rate increases in both groups, with a significantly greater heart rate increase in VVS than control groups (P < .001). An increase in >40 bpm in heart rate by 5 to 10 minutes before syncope with HUT occurred with VVS patients, but not in control patients. It was concluded that VVS patients experience large increases in heart rates during HUT testing and that, therefore, this finding alone should not be used to make the diagnosis of POTS.

A diagnosis of POTS can come with significant psychological effects and should not be taken lightly. As a result, it is imperative for the practitioner to accurately and thoughtfully approach the workup of a patient who may have POTS. Because there is often overlap in some of the symptoms in patients presenting with VVS and POTS, care should especially be taken in differentiating between these 2 entities, primarily by using a comprehensive history as the diagnostic tool. We agree with Medow and colleagues10 in voicing caution toward using results of HUT testing if this test is used in the diagnostic workup to differentiate between POTS and VVS. POTS and VVS are clinical diagnoses that should not be made based on the results of HUT testing or even orthostatic vital signs alone. Proper diagnoses will ultimately lead to appropriate management and counseling and positive outcomes for these patients.

     
  • HUT

    head-up tilt

  •  
  • POTS

    postural orthostatic tachycardia syndrome

  •  
  • VVS

    vasovagal syncope

Opinions expressed in these commentaries are those of the author and not necessarily those of the American Academy of Pediatrics or its Committees.

FUNDING: No external funding.

COMPANION PAPER: A companion to this article can be found online at www.pediatrics.org/cgi/doi/10.1542/peds.2016-3189.

1
Grubb
BP
,
Olshansky
B
.
Synocpe: Mechanism and Management
. 2nd ed.
Malden, Massachusetts
:
Blackwell Publishing
;
2005
2
Anderson
JB
,
Willis
M
,
Lancaster
H
,
Leonard
K
,
Thomas
C
.
The evaluation and management of pediatric syncope.
Pediatr Neurol
.
2016
;
55
:
6
13
[PubMed]
3
Grubb
BP
.
The Fainting Phenomenon: Understanding Why People Faint and What to Do About It
. 2nd ed.
New York, NY
:
Futura Publishing Company
;
2007
4
Driscoll
DJ
,
Jacobsen
SJ
,
Porter
CJ
,
Wollan
PC
.
Syncope in children and adolescents.
J Am Coll Cardiol
.
1997
;
29
(
5
):
1039
1045
[PubMed]
5
Prodinger
RJ
,
Reisdorff
EJ
.
Syncope in children.
Emerg Med Clin North Am
.
1998
;
16
(
3
):
617
626
,
ix
[PubMed]
6
Grubb
BP
,
Temesy-Armos
P
,
Moore
J
,
Wolfe
D
,
Hahn
H
,
Elliott
L
.
The use of head-upright tilt table testing in the evaluation and management of syncope in children and adolescents.
Pacing Clin Electrophysiol
.
1992
;
15
(
5
):
742
748
[PubMed]
7
Grubb
BP
,
Kosinski
DJ
,
Boehm
K
,
Kip
K
.
The postural orthostatic tachycardia syndrome: a neurocardiogenic variant identified during head-up tilt table testing.
Pacing Clin Electrophysiol
.
1997
;
20
(
9 pt 1
):
2205
2212
[PubMed]
8
Berkowitz
JB
,
Auld
D
,
Hulse
JE
,
Campbell
RM
.
Tilt table evaluation for control pediatric patients: comparison with symptomatic patients.
Clin Cardiol
.
1995
;
18
(
9
):
521
525
[PubMed]
9
Batra
AS
,
Balaji
S
.
Usefulness of tilt testing in children with syncope: a survey of pediatric electrophysiologists.
Indian Pacing Electrophysiol J
.
2008
;
8
(
4
):
242
246
[PubMed]
10
Medow
M
,
Merchant
S
,
Suggs
M
,
Terilli
C
,
O’Donnell-Smith
B
,
Stewart
J
.
Postural heart rate changes in young patients with vasovagal syncope.
Pediatrics
.
2017
;
139
(
4
):
e20163189

Competing Interests

POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.

FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.