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POTS: What’s a Pediatrician to Know?

A Todd Davis, MD
Attending physician, Academic General Pediatrics and Primary Care; Co-director, Wellness Program, Siragusa Transplantation Center, Ann & Robert H. Lurie Children's Hospital of Chicago; Professor of Pediatrics, Northwestern University Feinberg School of Medicine
Disclosure: Dr. Davis has no industry relationships to disclose and does not refer to products that are still investigational or not labeled for the use in discussion.
Barbara J. Deal, MD
Division Head, Cardiology; Getz Professor of Cardiology, Ann & Robert H. Lurie Children's Hospital of Chicago; Professor of Pediatrics, Northwestern University Feinberg School of Medicine
Disclosure: Dr. Deal has no industry relationships to disclose and does not refer to products that are still investigational or not labeled for the use in discussion.
Jennifer Winter, APN, NP
Pediatric Nurse Practitioner, Cardiology, Ann & Robert H. Lurie Children's Hospital of Chicago
Disclosure: Ms. Winter has no industry relationships to disclose and does not refer to products that are still investigational or not labeled for the use in discussion.

Other Disclosure Information


Educational objectives

At the conclusion of this activity, participants will be able to:·

  • Recognize the clinical features of postural orthostatic tachycardia syndrome (POTS)
  • Conduct an appropriate evaluation for POTS
  • Explain pathophysiology and treatment approach to the patient and family

Estimated time to complete: 0.5 hours
CME Credit: 0.5

CME credit

Credit statement

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  2. Read the article.
  3. Correctly answer at least 70% of questions on the quiz and answer evaluation questions.

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Introduction

Postural orthostatic tachycardia syndrome (POTS) is a condition characterized by symptoms of cerebral hypoperfusion or sympathetic activation while standing, and relieved by the supine posture.[1,2] This condition is becoming more prevalent in adolescents, and affects females in a ratio approaching 4:1.[1] Patients have an exaggerated heart rate response to standing, achieving an excessive heart rate of at least 120 bpm, or an increase in heart rate of more than 30 bpm (over age 19 years) or 40 bpm (under age 19 years) within the first minutes of upright posture.[3] Symptoms may become disabling, and include dizziness, palpitations, fatigue, difficulty concentrating, chronic headaches, generalized bodily pains, and prominent abdominal complaints, such as nausea, pain, bloating, and constipation or diarrhea (Table 1).

 

Table 1: Symptoms of POTS

Fatigue—may be disabling 
Headaches 
Palpitations, racing heart beat 
Dizziness/lightheadedness 
Exercise intolerance 
Cognitive impairment: “brain fog” 
Gastrointestinal issues: nausea, abdominal pain, constipation 
Insomnia or difficulty staying asleep 
Musculoskeletal pain—generalized body aches 
Heat/cold intolerance 
At Lurie Children’s, we have noted association with ovarian cysts 

The diffuse symptomatology and lack of definable pathology has produced profound skepticism among pediatricians and subspecialists. Families embark on a succession of diagnostic testing, including brain imaging and referral to a series of subspecialists. Delay in diagnosis of autonomic dysfunction negatively impacts the family dynamics as well as the patient’s social life. The family witnesses a profound degree of disability and develops a degree of anger and suspicion towards healthcare providers and teachers, which results in an escalating oppositional relationship. For healthcare providers and school officials, the absence of distinctly identifiable pathology reinforces the view that the condition is psychological in origin and may be a school avoidance maneuver. It is common, then, for a pediatrician to walk into this maelstrom of a debilitated child with no clearly identifiable pathology, school absenteeism, and parents demanding more testing. 

Extensive testing is unrevealing or identifies clinically insignificant abnormalities, provoking further evaluation. This medical odyssey affirms the family’s belief that one specialist will find a pathological entity and a definitive medication that will return their child to “normal.” The family expectation becomes that a single therapeutic intervention or prescription will relieve all symptoms. In the meantime, the child is inactive and may miss extensive periods of school, prolonging the time before recovery may begin.  

Clinical features and pathophysiology

With movement from supine to upright position, gravity acutely pulls approximately 20% of the circulating blood volume to the lower extremities; vasoconstriction augments venous return to the heart. A cardinal feature of POTS is the lack of peripheral vasoconstriction in response to orthostatic change, which leads to a decrease in venous return to the heart. Venous pooling in the lower extremities results in relative hypovolemia, with compensatory rapid increase in heart rate in an attempt to augment cardiac output. The skeletal muscle pump in the lower extremities augments venous return to the heart; this pump is optimized with physical activity. The compensatory tachycardia is a response to reduced stroke volume. Patients with POTS experience a postural decrease in effective perfusion often associated with a sensation of a fast heart rate. Studies have demonstrated relative “small hearts” with reduced cardiac mass;[4] other studies have shown decreased circulatory volumes, low serum iron stores, and hypovitaminosis D. A subset of patients is characterized by a hyperadrenergic response, with postural hypertension, flushing, and marked tachycardia, with elevated serum norepinephrine levels. Patients with POTS share many characteristics of chronic fatigue syndrome, and overlap between the 2 conditions is common.  

POTS has a genetic predisposition for Caucasians, or people of northern European descent; about 12% have affected family members.[5] A specific defect in norepinephrine transporter protein deficiency has been identified in one kindred.[6] The disorder is more common in patients with joint hyper-extensibility, or Ehlers Danlos syndrome. Onset of symptoms is usually in early adolescence, between 12-15 years of age. More than half of cases are preceded by an acute viral illness; other triggers may be injury, surgery, puberty or growth spurts. A typical history is a period of bed rest or immobilization due to one of the above conditions, followed by incapacitation with postural changes, initially described as debilitating dizziness and fatigue. A cascade of bed rest and inactivity ensues. Nausea is often prominent, especially on awakening. Dietary changes to combat nausea include skipping breakfast or lunch, minimizing fluid intake, and a diet rich in “comfort foods” or processed carbohydrates including rice, potatoes, and pasta ensues. As a medical etiology is sought, “somatic hyper-vigilance” is a prominent feature. Families arrive with copious documentation of a multiplicity of aberrations reported, reinforcing the idea that ongoing pathology is worsening.  

Diagnosis

Physical examination is notable for the remarkable similarity in appearance among affected patients. As families tend to be of Northern European heritage, they are often quite fair complexioned, with mottled or purplish marbleized appearance of hands and feet. The physical examination is otherwise unrevealing, with the orthostatic blood pressure demonstrating a marked increase in pulse of at least 30 beats per minute with a change from the supine to the standing position. Hypotension with positional changes is infrequently noted due to the compensatory tachycardia, although the pulse may become thready. Due to inactivity and dietary changes, the patient may have an increased body mass index, although others lose weight due to loss of appetite and nausea. A detailed history should be obtained including onset and duration of symptoms, the hierarchy of symptoms in the order of severity, energy level and daily activity, ability to concentrate, school attendance history, and a review of systems with identification of the most profound areas of concern. Diagnostic evaluation is meant to exclude significant pathological causes of symptoms (Table 2).

Table 2: Evaluation of POTS

 
History:
·       Antecedent illness
·       Chronology
·       Hierarchy of symptoms
 
Physical examination:
·       Exclude signs of disease: neurology, cardiac, abdominal
·       Body mass index
·       Body habitus, joint hyperextensibility
·       Mottling of extremities
·       Orthostatic vital signs: HR and BP supine, 1 and 3 minutes standing
 
Laboratory testing to consider:
·       Electrocardiogram
·       CBC
·       Thyroid function tests
·       Ferritin
·       Vitamin D levels
·       Lipid panel
 
Referrals as needed:
·       Cardiology—Autonomic dysfunction specialists
·       Neurology, especially if profound, disabling headaches
·       Gastrointestinal
·       Pain management or physical therapy
·       Counseling
If headache is the dominant symptom, evaluation by a neurologist is usually obtained or recommended. In the presence of profound fatigue and/or palpitations, an ECG may be obtained. Tests commonly ordered during initial autonomic evaluation include CBC, thyroid function, ferritin, and vitamin D levels.  

POTS patients are characterized by an “un-therapeutic lifestyle” with altered sleep-wake cycles, sedentary and largely supine lifestyle, and irregular eating habits with a diet rich in processed carbohydrates. Bed rest of 1 day results in physical deconditioning, with progressive cardiac atrophy at a rate of 1% per week in bed among otherwise healthy subjects.[7] Diets high in sugar and fat contribute to endothelial dysfunction and lack of vascular reactivity, which may peak within hours of eating. The condition was originally described during the American Civil War by da Costa in 1871, with injured soldiers described as having an “irritable heart.”[8] This war was fought largely by men of northern European ancestry, subsisting on a nutrient-poor diet of hard tack, coffee and salt pork. Following injuries resulting in prolonged immobilization, men were incapacitated and complained of excessive fatigue and palpitations. The contemporary diet, calorie-rich and nutrient-poor, contributes significantly to the perpetuation of this modern version of vascular de-regulation. 

Treatment

Extensive pharmacologic regimens have been prescribed, focusing on mineralocorticoids, beta-blockers, vasoconstrictors, selective serotonin reuptake inhibitors, and stimulants. By focusing on medications, attention is displaced from the basic disordered lifestyle that perpetuates disability. Side effects of these medications include gastric upset, fatigue, dizziness, headaches, and paresthesias. Patients with POTS may be particularly sensitive to medications, compounded by behavioral amplification and unrealistic expectations of therapy. Recent studies have demonstrated the benefits of a graduated program of physical re-training. A multi-faceted approach including dietary manipulation, sleep hygiene, and physical conditioning is necessary to reverse the underlying dystopic state.     

From the pediatrician’s point of view, initiating pharmacologic treatment is not advised, as this reinforces the expectation that a medication will reverse the disorder. Hydration and activity changes may be recommended at the onset of symptoms, with early referral for more thorough evaluation as needed.  

At our center, the cornerstones of therapy include vigorous daily hydration, nutritional changes, and daily aerobic activity (Figure 1).

Daily intake of fluids should avoid soda or sugar-containing beverages, with water intake approaching 80 ounces distributed throughout the day. Dietary changes are perceived as drastic, avoiding processed carbohydrates such as grains, potatoes, rice and pasta, and limiting unhealthy trans-fat intake; increased protein and intake of mono-unsaturated fat is recommended. Supplementation with vitamin B complex and vitamin D3 is usually advised. Daily physical activity and lower body strengthening exercises are essential, gradually increasing the duration of exertion as tolerated. There is increasing evidence that daily aerobic exercise such as rowing or supine bicycle may result in improvement within 3 months,[9,10] building on the concept that physical deconditioning promotes ongoing symptomatology. Pharmacologic treatment in our center is usually withheld until fluid, nutritional and exercise changes are occurring. 

Given the extent of testing and attempted unsuccessful therapies patients and families have experienced, these recommendations are often met with disbelief and disappointment. A lengthy discussion of the pathophysiology of POTS, with confirmation that a distinct entity is recognized as contributing to the illness, is of enormous benefit to families. Reassurance that ongoing advanced diagnostic testing is unlikely to reveal an additional underlying serious illness is necessary. A detailed activity and dietary log is usually needed, to attempt to replace the extreme focus on new sensations. Therapy or family counseling may be recommended, particularly in patients with long-standing symptomatology, due to the profound family disruption of the disorder. 

The duration of symptoms is related to the length of time the patient remains deconditioned, emphasizing the importance of early referral. With relatively early intervention and cooperation with lifestyle changes, significant improvement can occur within months. Patients report that they can predict that changes in sleep, stress or activity will predict days when they will feel “worse,” but otherwise symptoms gradually recede in importance. Our population is skewed towards adolescents and young adults, most of whom have near-resolution of major symptoms by age 21 years.

Conclusion

Longstanding POTS becomes a multi-faceted condition. Comorbidities of anxiety, attention deficit, “brain fog,” decline in academic performance and social isolation may be prominent. While depression is sometimes present in POTS patients, psychological studies have not shown an increased incidence of depression.[11] Delay in diagnosis and implementation of effective therapy results in prolongation of symptomatology, and physical inactivity contributes to a slower recovery.  

After extensive testing, the family is often reluctant to believe that increases in hydration, altered nutrition and daily aerobic exercise will impact their often debilitated and certainly deconditioned child. Furthermore, the patient’s identity may become linked to the family dynamic of searching for a medical answer. Disentanglement of the child-parent dynamic, which can become intensely co-dependent and sickness-focused, is often necessary. In many cases, the family has been changed by the condition and their communal lifestyle has been curtailed. Striving to characterize POTS patients as normal teenagers who have POTS is an important step in helping to create a productive medical and family environment for the patient. Engaging the entire family in a therapeutic lifestyle may allow them to refocus their concerns toward a more productive outcome. Nonetheless, most young people with onset of POTS in adolescence tend to experience marked improvement in their symptomatology by 19-21 years of age. Longer term follow-up will be needed to determine whether patients affected in adolescence will become symptomatic once more in adulthood.     

REFERENCES 

  1. Jarjour IT. Postural tachycardia syndrome in children and adolescents. Semin Pediatr Neurol. 2013;20:18-26.
  2. Stewart JM. Common syndromes of orthostatic  intolerance. Pediatrics. 2013; 131:1-13.
  3. Mathias CJ, Low DA, Iodice V, Owens AP, Kirbis M, Grahame R. Postural tachycardia syndrome – current experience and concepts. Nat Rev Neurol. 2011;8:22-34.
  4. Fu Q, VanGundy TB, Galbreath MM, Shibata S, Jain M, Hastings JL, Bhella PS, Levine BD. Cardiac origins of the postural orthostatic tachycardia syndrome. J Am Coll Cardiol. 2010;55:2858-2868.
  5. Thieben MJ, Sandroni P, Sletten DM, Benrud-Larson LM, Fealey RD, Vernino S, Lennon VA, Shen WK, Low PA. Postural orthostatic tachycardia syndrome: the Mayo clinic experience. Mayo Clin Proc. 2007; 82:308-313.
  6. Shannon JR, Flattem NL, Jordan J, Jacob G, Black BK, Biaggioni I, Blakely RD, Robertson D. Orthostatic intolerance and tachycardia associated with norepinephrine-transporter deficiency. N Engl J Med. 2000; 342:541-549.
  7. Gaffney FA, Nixon JV, Karlsson ES, Campbell W, Dowdey AB, Blomqvist CG. Cardiovascular deconditioning produced by 20 hours of bedrest with head-down tilt (-5 degrees) in middle-aged healthy men. Am J Cardiol. 1985;56:634-638.
  8. Da Costa JM. On irritable heart: a clinical study of a form of functional cardiac disorder and its consequences. Am J Med Sci. 1871;61:17-52.
  9. Shibata S, Fu Qi, Bivens TB, Hastings JL, Wang W, Levine BD. Short-term exercise training improves the cardiovascular response to exercise in the postural orthostatic tachycardia syndrome. J Physiol 2012; 590:3495-3505.   
  10. Nwazue VC, Raj SR. Cofunders of vasovagal syncope: postural tachycardia syndrome. Cardiol Clin 2013;31:101-109.  
  11. Raj V, Haman KL, Raj SR, Byrne D, Blakely RD, Biaggioni I, Robertson D, Shelton RC. Psychiatric profile and attention deficits in postural tachycardia syndrome. J Neurol Neurosurg Psychiatry. 2009;80:339-344.

 


Accreditation Statement

The Northwestern University Feinberg School of Medicine is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

Credit Designation Statement

The Northwestern University Feinberg School of Medicine designates this enduring material for a maximum of 0.5 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.