#123: Taking the Lid off POTS – Unpacking Pediatric Dysautonomia

October 23, 2024 | By Sam Masur

Audio

Summary:

Does the thought of Postural Orthostatic Tachycardia Syndrome make your heart race? Dr. Kelsey Klaas (Adolescent Medicine at Mayo Clinic) teaches us how to walk with patients and families through a POTS diagnosis. We master the art of orthostatic vitals, learn about the importance of teamwork in POTS management strategies, and touch on the stigma around this diagnosis. This episode is packed with practical tips and expert advice – you won’t want to skip a beat!

POTS Pearls

1. Remember POTS exists, and think about it in any patient with multiple symptoms that include orthostatic intolerance plus fatigue, brain fog, sleep disturbance, GI symptoms, and/or headaches. History is key!
2. Fluids, salt, and graded exercises are the cornerstones of therapy, complemented by medications for symptom management if needed.
3. Recovery from POTS happens over time and requires a team that includes you, patients, families, schools, physical therapists, and specialists.

POTS Notes

Thinking About Syncope

The most common cause of syncope is reflex syncope (aka neurocardiogenic syncope aka vasovagal syncope). Common triggers include, heat, menses/pre-menses, dehydration, fasting, illness or fever, insufficient sleep, or new medications.

Reflex syncope is usually situational and doesn’t typically recur! If it keeps happening, think about anemia, look for weight loss (concerning for an eating disorder or systemic disease), and consider autonomic disorders like POTS.

Red flag syncope symptoms:

• Triggered by exertion
• Sudden syncope without prodrome symptoms
• Lapse in memory longer than a few seconds
• Convulsions or abnormal movements

Expert tip: It’s important to distinguish between presyncope that happens DURING exercise (red flag!) with presyncope that happens AFTER exercise (more consistent with reflex syncope). 

What is POTS? What is Dysautonomia?

Dysautonomia: umbrella term for symptoms related to dysfunction of the autonomic nervous system (not a diagnosis).

Postural orthostatic tachycardia syndrome: dysfunction or unbalance of a normally developed autonomic nervous system (as opposed to autonomic failure, where something is organically wrong with the autonomic nerves) that causes:

1. 3 months or more of fatigue, dizziness, lightheadedness, vision changes, hearing changes, nausea, pain, headaches, and/or sensation of heart racing that occurs when upright and improves when supine
2. Excessive heart rate change (>40 bpm) on tilt table testing
3. No orthostatic hypotension (>20/10 blood pressure drop) on tilt table testing

Pathophysiology of POTS

The pathophysiology of this condition isn’t well understood! It’s probably something to do with inadequate vasoconstriction and inadequate venous return leading to compensatory tachycardia, but we don’t know. There may be some connection to nervous system inflammation (i.e. from a virus or injury), but this is very poorly understood. 

Physiology of standing in a nutshell: When we stand up, blood pools into the lower parts of the body (belly, pelvis, legs), which decreases blood pressure in the upper parts of the body. Pressure sensors in the carotids and aortic arch pick up on this decrease, and send a signal to the brain to fix it. The brain then takes the brake off (decreased parasympathetic tone) and presses on the gas (sympathetic activation) to increase heart rate and vasoconstrict. 

That initial low pressure and compensatory tachycardia is a sign that the autonomic nervous system is working! Many people experience brief lightheadedness when standing, especially when dehydrated, and an increase in heart rate is a normal physiologic response to correct that. 

Expert tip: Googling “autonomic failure” can lead patients to real scary diagnoses (i.e. multisystem atrophy). Dr. Klaas emphasizes that compensatory tachycardia is a sign that the autonomic nervous system is working, even when it leads to unpleasant symptoms.

Anxiety vs POTS

While symptoms may overlap between anxiety/panic and POTS, the triggers are different.

Anxiety is a sympathetic response to mental or emotional stimuli (i.e. fight or flight).

POTS is a sympathetic response to a physical stimuli (i.e. standing, exercise).

Equity and Stigma in POTS

White females are best represented in the current literature on POTS, but this constellation of symptoms is nonspecific and it’s unclear whether this predominance reflects true epidemiology or diagnostic bias. We should think about this diagnosis for all patients, and be sure not to inappropriately dismiss symptoms or attribute them to anxiety alone.

Time pressure in the ED and primary care setting can lead to frustration for both patients and providers, contributing to stigma. Dr. Klaas acknowledges this frustration and reframes the role of the emergency department. Patients go to the ED because they feel like they’re dying, which is appropriate. Now that the ED has determined they aren’t dying (which is good news!), they can come to the clinic to talk about next steps. 

Diagnosing POTS in Primary Care

History

Many POTS patients have >15 unique symptoms as part of their disease, which is hard to address in a 15-minute clinic visit! Pulling in prior medical history of comorbid conditions or prior symptoms can be helpful, as can gathering additional history over multiple visits.

Common comorbid conditions include chronic pain syndromes, joint hypermobility or hypermobile Ehlers Danlos syndrome, autoimmune conditions, migraine or headache disorders, and IBS.

Initial questions to ask:

• How do these symptoms affect your function? (allows for prioritization within broader agenda)
• When is the last time you remember feeling healthy?
• What was happening when this all started? Was there an inciting event, like a concussion, illness (mono and COVID are common), menarche, or a growth spurt?
• How have symptoms evolved over time? Are symptoms improving, worsening, or staying the same?
• What triggers symptoms on a day-to-day basis?
• What are your long-term goals?

Expert tip: Restrictive eating disorders and autonomic disorders can look similar, as both can have changes in eating patterns with orthostatic tachycardia and/or hypotension. In POTS or orthostatic hypotension, comorbid GI symptoms can lead to weight loss. In restrictive eating, weight loss causes orthostatic symptoms. Timeline is important!

How to ACTUALLY take orthostatic vitals (according to experts)

Orthostatic vitals, step by step (aka an active stand test):

1. Have the patient lie completely flat for at least 5 minutes, ideally 10 minutes. Check heart rate and blood pressure 2-3 times during this period.
2. Skip seated heart rate and blood pressure measurements.
3. Have the patient stand up for 10 minutes without leaning, holding onto anything, or interacting with other people. Check heart rate and blood pressure ideally every minute during this period.
4. If the patient has any presyncopal symptoms, have them sit down. 

A drop of >20 mmHg in systolic blood pressure or >10 mmHg in diastolic blood pressure is consistent with orthostatic hypotension. This is different from POTS because a drop in blood pressure SHOULD prompt a compensatory increase in heart rate. If it doesn’t, it’s either:

1. The increase in heart rate occurred between measurements,
2. They’re experiencing vasovagal syncope, or
3. They have true neurogenic syncope (super rare in otherwise healthy kids)

If there’s no change in blood pressure AND heart rate increases by >40 bpm from supine to standing, that’s POTS. While not a validated measurement, it’s a useful clinical tool.

The head-up tilt table test

Tilt table tests are not always needed, and for most patients, a history and active stand test is sufficient. They are helpful if initial management isn’t improving symptoms and you want to confirm the diagnosis. 

Every institution will be a little different, but a consensus statement from the European Federation of Autonomic Societies (EFAS) endorsed by the American Autonomic Society (AAS) and the European Academy of Neurology (EAN) outlines the ideal protocol. The consensus statement recommends against attempting to provoke syncope with IV medications. 

1. The patient is secured to the table and attached to a manual blood pressure cuff, a continuous heart rate monitor, and a continuous blood pressure monitor.
2. The patient lies supine for 10 minutes. 
3. The head of the bed is elevated to 60-70º. 
4. The patient remains in this position for 10-30 minutes.

Typically this test happens at academic centers or larger community practice settings, often within the neurology or cardiology department (which may have slightly different protocols). 

Other useful diagnostics:

• EKG
• Iron deficiency labs
• Vitamin D level
• CBC to check for anemia
• Maybe TSH or other endocrine tests depending on history

When to call a specialist

Not always. If a patient has chronic orthostatic symptoms with no red flags, they likely can be successfully diagnosed with an active stand test and managed by a general pediatrician. 

Consult a specialist when you need help ruling out an alternative diagnosis, like seizures, cardiac arrhythmias, or rheumatologic conditions.

Many patients are interested in investigating an EDS diagnosis. Consulting an EDS specialist can be helpful if there’s a notable family history or a very high Brighton score. Otherwise, Dr. Klaas recommends incorporating physical therapy for hypermobility into the management plan without necessarily pursuing specialty diagnostics for EDS.

POTS Management

Nonpharmacologic management

Foundations of management: fluids, salt, exercise. 

1. Increase water intake to 2-4 liters (64-128 oz) of water daily.
2. Increase salt intake to 8-10 g per day, unless contraindicated by a nephrologist. Start by adding 1 tsp of extra salt to food, then increase from there. Options for salt intake include table salt (free and easy), electrolyte replacement products, salt tablets.
3. Improve cardiovascular conditioning with aerobic exercise and strength training, which improves the heart’s ability to increase contractility, as opposed to just increase in rate. Recumbent exercise is usually better tolerated. Try for 5 days per week and increase duration slowly (10% per week). While not formally studied, there are published protocols for graded exercise for adolescents.  Exercise should feel easy and not cause a “crash” the next day. 

Expert tip: Explain the “why” behind these management strategies! They’re simple, and thus can feel reductive or dismissive if patients don’t understand why you’re recommending them.

Other measures:

• Compression garments can be helpful for some patients. Thigh and abdomen compression with athletic compression shorts or shapewear can be the least expensive way to try this out! Knee-high socks are usually not sufficient. 
• Elevating the head of the bed.
• Ensuring sufficient sleep. 

Accommodations

A lot of patients’ goals are to return to their daily activities, which requires putting together a graded approach to returning to school, gym, sports, etc. You can work with parents and school to help patients gradually increase their involvement over time. 

Pharmacologic Management

Medications are a tool to help patients to engage with day-to-day life and exercise. These are all off-label because there are no FDA-approved medications for POTS symptoms. Stimulants are generally not used in POTS (unless you’re treating ADHD) because it can actually contribute to symptoms.

Midodrine

Dose: Start at 2.5 mg (can go up to 10 mg) three times daily.

Best for patients with low-normal blood pressures.

Common side effects: headaches, piloerection, intracranial hypertension (avoid lying flat within 4 hours of taking it)

Propranolol

Dose: 5 mg or 10 mg three times daily.

Best for patients with higher blood pressures and higher sympathetic tone.

Fludrocortisone

Dr. Klaas’ least favorite because it can cause hypokalemia, secondary adrenal insufficiency, and cardiac and renal fibrosis with long-term use.

Resources

American Autonomic Society: Helpful resources and a speaker’s board that will give talks or Grand Rounds for residency programs.

Intensive inpatient rehab programs that specialize in POTS, like the Pediatric Pain Rehabilitation Center at Mayo Clinic where Dr. Klaas is the medical director.

The Dysautonomia Project: A community-based organization with helpful educational resources for both patients and providers.

Goal

Listeners will be able to counsel patients on the basic pathophysiology, diagnosis, and management of POTS, including nonpharmacologic and pharmacologic management options.

Learning Objectives

After listening to this episode listeners will…  

1. Identify common triggers and causes of vasovagal syncope and distinguish it from other types of syncope.
2. Recognize red flag symptoms associated with syncope that warrant further investigation.
3. Define dysautonomia and Postural Orthostatic Tachycardia Syndrome (POTS) and describe their clinical presentation.
4. Explain the appropriate method for conducting orthostatic vitals and the criteria for diagnosing POTS.
5. Discuss the nonpharmacologic and pharmacologic management strategies for POTS, including lifestyle modifications and medication options.
6. Understand the challenges and importance of addressing equity and stigma in the diagnosis and management of POTS.

Disclosures

Dr. Klaas reports no relevant financial disclosures. The Cribsiders report no relevant financial disclosures. 

Citation

Lidsky H, Klaas K, Masur S, Chiu C, Berk J. “#123: Taking the Lid off POTS: Unpacking Pediatric Dysautonomia”. The Cribsiders Pediatric Podcast. https:/www.thecribsiders.com/ October 23, 2024.