Postural Orthostatic Tachycardia Syndrome

Postural Orthostatic
Tachycardia Syndrome

 

Trailer

 

I have a former student who, at the age of 13,
was having difficulty with dizziness during the school day.  She frequently needed to sit down, hold on to
the chair in front of her, or be transported from one classroom to another via
a wheelchair or rolling office chair (her preferred method).  There were even times where she seemed to
black out temporarily and collapse. 
After a few months of such occurrences, she and her parents managed to
get a diagnosis: Postural Orthostatic Tachycardia Syndrome or POTS.  Since the initial diagnosis approximately 4
years ago, I have watched the condition progress and contribute to other
related conditions, such as Ehlers-Danlos Syndrome (EDS).  As her friend and mentor, I see the struggle
that she goes through daily just to make it through her classes, let alone
complete her homework and participate in her many extra-curricular activities
afterwards.  I would like to find out
more about POTS and, in particular, how it is connected to EDS.

 

 

Normal Physiology vs POTS Physiology

 

Postural Orthostatic Tachycardia Syndrome is an
autonomic disorder causing a high heart rate (tachycardia) or blood pressure
when a patient is in or moves to (postural) an upright position (orthostatic) (Thanavaro
& Thanavaro, 2011).  When a patient
stands up, gravity causes up to 25% of the blood volume to shift downward (Johnson
et al., 2010).  Baroreceptors in the
heart, lungs, and carotid sinus send signals to the autonomic nervous system that
there is a decrease in cardiac venous return (Johnson et al., 2010). Normal
physiology will compensate by moderately increasing the heart rate and blood pressure
and causing vasoconstriction that will return the blood flow to normal (Johnson
et al., 2010).  In a patient with POTS, there
is a malfunction in the autonomic communication with the blood vessels, causing
blood to pool in the lower part of the body due to vasodilation (Mohr,
2017).  Meanwhile, the heart rate
continues to increase in an attempt to compensate for the reduced blood flow to
the head (Mohr, 2017).

 

 

Signs, Symptoms, and Diagnosis

 

Most of the patients diagnosed with Postural Orthostatic Tachycardia
Syndrome are Caucasian females (Johnson, Mack,
Kuntz, Brands, Porter, & Fischer, 2010). 
POTS often presents between ages 15-50, though it can present as young
as 9 (Johnson et al., 2010).

 

The symptoms of POTS can vary by day and by patient (Mohr,
2017).  Symptoms can include syncope
(fainting), heart palpitations, dizziness, blurred vision, headaches, and weakness
(Low, 2014).  Some symptoms, such as fatigue,
anxiety, and hyperventilation, overlap with panic and anxiety disorders and
thus can lead to misdiagnosis (Low, 2014). 
Poor perfusion to different areas of the body will result in such
symptoms as diminished concentration (or “brain fog”) and cold extremities
(Low, 2014).

 

Receiving a diagnosis of POTS can take a long time due to its
potential misdiagnosis (Mohr, 2017).  When
making a diagnosis, it is important to rule out these disorders as well as epilepsy,
heavy-metal poisoning, medications and other possible causes (Johnson et al.,
2010).  A variety of diagnostic tests are
used to narrow the final diagnosis, including Holter monitor, ECG, or blood
plasma testing (Mohr, 2017).  Additional
testing, such as the thermoregulatory sweat test or quantitative sudomotor axon
reflex test (QSART), may be given to evaluate the autonomic nervous system
(Mohr, 2017).

 

One test that was mentioned in all sources was the tilt
table test.  This test uses a special bed
that can be tilted upwards to between 60° to 80° to simulate standing up from a
supine position (“Tilt Table Testing”). The patient is secured to the bed while
connected to an ECG and blood pressure monitor during the tilting to record any
changes as the positions change (“Tilt Table Testing”).  Medications to increase the heart rate may
given and the tilting repeated (“Tilt Table Testing”).  This test tries induce syncope in a clinical setting,
as the goal is to find what specific circumstances are causing syncope during a
patient’s everyday life (“Tilt Table Testing”).

 

Though POTS can be the primary diagnosis, it may present as a
secondary diagnosis to diseases like lupus or diabetes (Johnson et al., 2010).  Patients with joint hypermobility syndrome or
the hypermobile subtype of Ehlers-Danlos Syndrome (hEDS) have a prevalence of POTS
as high as 41% (Miglis, Schultz, & Muppidi, 2017).  It has been suggested that the collagen deficiency
in the vascular system of an hEDS patient may reduce the vasomotor tone causing
the potential for postural tachycardia to occur, though this has yet to be
proven (Miglis et al., 2017).

 

 

Management Options

 

One of the first management suggestions for someone
with POTS is to increase their hydration to at least 2 liters of water per day (Johnson
et al., 2010).  This, along with raising
the sodium intake to 3,000 mg to 10,000 mg per day increases the overall blood
volume (Mohr, 2017).  If symptoms
persist, medications may be added.  Fludrocortisone
(a mineralocorticoid) is used to increase salt retention (Johnson et al., 2010).  Midodrine can be used to induce
vasoconstriction but must be used carefully as prolonged time in a supine
position within 4 hours of dosing can lead to supine hypertension (Johnson et al.,
2010).  Other management options include
beta blockers, wearing of compression hose, exercise, and raising the head of
the bed (Mohr, 2017).

 

While treating the symptoms of POTS is
important, it was noted in many sources that dealing with the psychological
effects of the daily regimen was just as important.  Selective serotonin reuptake inhibitors and selective
norepinephrine reuptake inhibitors, such as citalopram or fluoxetine, can be
used (Johnson et al., 2010). 
Development of IEP or 504 plans for school-aged patients and therapeutic
counseling were also mentioned as part of the overall management of POTS (Mohr,
2017).

 

 

Personal Impact

 

My former student has many of the symptoms listed as a part
of her daily dealings with POTS.  She has episodes
of “brain fog”, which typically cause her to become extra giggly and excitable.  When her oxygen level improves, she can
become disoriented or frustrated because she is unable to remember things that
just happened.  Luckily, she can also see
the humor in some of the things that she said, wrote, or did in the low O2
state!  She has difficulty walking or standing
for long periods, which can be a difficult thing for a senior going on college
visits, but she always has a water bottle and a stash of goldfish in her bag.  She takes medication to “keep her upright”
multiple times daily, which keeps her on good terms with the school clinic aide.  She has even had a few episodes where her
heart went racing, stopped, and restarted itself.

 

I feel like the research I did for this paper
has allowed me to better understand the situation she deals with daily.  It has also caused some interesting
conversations with her along the way, particularly where the overlap between
POTS and her hEDS is concerned.

 

Reference List

 

Johnson, J. N., Mack, K. J., Kuntz, N. L., Brands, C. K.,
Porter, C. J., & Fischer, P. R. (2010).

Postural
Orthostatic Tachycardia Syndrome: A Clinical Review. Pediatric Neurology, 42(2), 77-85. doi:10.1016/j.pediatrneurol.2009.07.002

 

Low, P. (2014). Postural Orthostatic Tachycardia Syndrome
(POTS). Encyclopedia of the

Neurological Sciences, 3, 964-967. doi:2443/10.1016/B978-0-12-385157-4.00509-1

 

Miglis, M. G., Schultz, B., & Muppidi, S. (2017).
Postural tachycardia in hypermobile Ehlers-

Danlos
syndrome: A distinct subtype? Autonomic
Neuroscience, 208, 146-149. doi:10.1016/j.autneu.2017.10.001

 

Mohr, L. D. (2017). A Case Report and Review of Postural
Orthostatic Syndrome in an

Adolescent.
Journal of Pediatric Health Care,
31(6), 717-723. doi:10.1016/j.pedhc.2017.04.013

 

Thanavaro, J. L., & Thanavaro, K. L. (2011). Postural
orthostatic tachycardia syndrome:

Diagnosis
and treatment. Heart & Lung: The
Journal of Acute and Critical Care, 40(6), 554-560. doi:10.1016/j.hrtlng.2009.12.014

 

Tilt
Table Testing. (n.d.). Retrieved January 21, 2018, from https://www.hopkinsmedicine.org/healthlibrary/test_procedures/cardiovascular/tilt_table_testing_92,P07985