GeneHealth - Your precision medicine

Postural Orthostatic Tachycardia Syndrome

Disease Details

Family Health Simplified

Buy Membership

Description: Postural orthostatic tachycardia syndrome (POTS) is a condition characterized by an excessive increase in heart rate when transitioning from lying down to standing up, often accompanied by symptoms like dizziness, lightheadedness, and fainting.
Type: Postural Orthostatic Tachycardia Syndrome (POTS) is primarily a form of dysautonomia that affects the autonomic nervous system, leading to an abnormal increase in heart rate upon standing. The type of genetic transmission for POTS is still under investigation, but it is believed to have a hereditary component in some cases. Familial patterns suggest that it can run in families, indicating a possible genetic predisposition, though a specific mode of inheritance has not been firmly established.
Signs And Symptoms: In adults, the primary manifestation is an increase in heart rate of more than 30 beats per minute within ten minutes of standing up. The resulting heart rate is typically more than 120 beats per minute. For people between ages 12 and 19, the minimum increase for a POTS diagnosis is 40 beats per minute. POTS is often accompanied by common features of orthostatic intolerance—in which symptoms that develop while upright are relieved by reclining. These orthostatic symptoms include palpitations, light-headedness, chest discomfort, shortness of breath, nausea, weakness or "heaviness" in the lower legs, blurred vision, and cognitive difficulties. Symptoms may be exacerbated with prolonged sitting, prolonged standing, alcohol, heat, exercise, or eating a large meal.Up to one-third of POTS patients experience fainting for many reasons, including but not limited to standing, physical exertion, or heat exposure. POTS patients may also experience orthostatic headaches. Some POTS patients may develop blood pooling in the extremities, characterized by a reddish-purple color of the legs and/or hands upon standing. 48% of people with POTS report chronic fatigue and 32% report sleep disturbances. Other POTS patients only exhibit the cardinal symptom of orthostatic tachycardia. Additional signs and symptoms are varied, and may include excessive sweating, lack of sweating, heat intolerance, digestive issues such as nausea, indigestion, constipation or diarrhea, post-exertional malaise, coat-hanger pain, brain fog, and syncope or presyncope.Whereas POTS is primarily characterized by its profound impact on the autonomic and cardiovascular systems, it can lead to substantial functional impairment. This impairment, often manifesting as symptoms such as fatigue, cognitive dysfunction, and sleep disturbances, can significantly diminish the patient's quality of life.
Prognosis: POTS has a favorable prognosis when managed appropriately. Symptoms improve within five years of diagnosis for many patients, and 60% return to their original level of functioning. Approximately 90% of people with POTS respond to a combination of pharmacological and physical treatments. Those who develop POTS in their early to mid teens will likely respond well to a combination of physical methods as well as pharmacotherapy. Outcomes are more guarded for adults newly diagnosed with POTS. Some people do not recover, and a few even worsen with time. The hyperadrenergic type of POTS typically requires continuous therapy. If POTS is caused by another condition, outcomes depend on the prognosis of the underlying disorder.
Onset: Postural Orthostatic Tachycardia Syndrome (POTS) typically has an onset in adolescence or early adulthood, though it can occur at any age. It is more common in females than males. The exact cause can vary, but it often follows a viral illness, surgery, or trauma.
Prevalence: Postural Orthostatic Tachycardia Syndrome (POTS) is estimated to affect approximately 0.1-1% of the general population. It is more commonly diagnosed in women, particularly those aged 15-50.
Epidemiology: The prevalence of POTS is unknown. One study estimated a minimal rate of 170 POTS cases per 100,000 individuals, but the true prevalence is likely higher due to underdiagnosis. Another study estimated that there are at least 500,000 cases in the United States. POTS is more common in women than men, with a female-to-male ratio of 4:1. Most people with POTS are aged between 20 and 40, with an average onset of 21. Diagnoses of POTS beyond age 40 are rare, perhaps because symptoms improve with age.As recently stated, up to one-third of POTS patients also present with Vasovagal Syncope (VVS). This ratio is probably higher if pre-Syncope patients, patients that report the symptoms of Syncope without overt fainting, were included. Given the difficulty with current autonomic measurements in quantitatively isolating and differentiating Parasympathetic (Vagal) activity from Sympathetic activity without assumption or approximation, the current direction of research and clinical assessment is understandable: perpetuating uncertainty regarding underlying cause, prescribing beta-blockers and proper daily hydration as the only therapy, not addressing the orthostatic dysfunction as the underlying cause, and recommending acceptance and associated lifestyle changes to cope.
Direct measures of Parasympathetic (Vagal) activity obviates the uncertainty and lack of true relief of POTS as well as VVS. For example, the hypothesis that POTS is an auto-immune disorder may be an indication that a significant number of POTS cases are indeed co-morbid with VVS. Remember the Parasympathetic Nervous System is the memory for, and controls and coordinates, the immune system. If Parasympathetic (Vagal) over-, or prolonged-, activation is chronic then portions of the immune system may remain active beyond the limits of the infection. Given that portions of the immune system are not of self, these portions remain active and continue to “feed.” Once the only source of “feed” is self, the immune system begins to attack the host. This is the definition of autoimmune. This is a counter-hypothesis that may provide a simpler explanation with a more immediate plan for therapy and relief. For it may be that relieving the Vagal over-activation, will retires the self-attacking portion of the immune system, thereby relieving the autoimmunity.
Another example may be “Hyperadrenergic POTS.” A counter hypothesis and perhaps a simpler explanation that leads to more direct therapy and improved outcomes is again the fact that POTS and VVS may be co-morbid. It is well known that Parasympathetic (Vagal) over-activation may cause secondary Sympathetic over-activation. Without direct Parasympathetic (Vagal) measures, the resulting assumption is that the secondary Sympathetic over-activation (the definition of “hyperadrenergic”) is actually the primary autonomic dysfunction. Simply treating the (secondary) Sympathetic over-activation may be just treating a symptom in these cases, which may work for a while but then the body compensates and more medication is needed or the patient become unresponsive and the permanent degraded lifestyles are considered the only option. Again, this is unfortunate. Given that cases of POTS with VVS involves different portions of the nervous system (Parasympathetic and Sympathetic), and that both branches may be treated simultaneously, albeit differently, true relief of both conditions, as needed, is quite possible, and the cases of these newer hypothesized causes may be relieved with current, less expensive, and shorter-term therapy modalities.
Intractability: Postural Orthostatic Tachycardia Syndrome (POTS) is generally considered a chronic condition that can be challenging to manage, but it is not necessarily intractable. Many patients can find partial or significant relief through a combination of lifestyle adjustments, such as increased salt and fluid intake, physical therapy, and medications. However, the response to treatments can vary widely among individuals, and some may experience persistent symptoms despite various interventions.
Disease Severity: Postural Orthostatic Tachycardia Syndrome (POTS) severity can vary widely among individuals. Some people experience mild symptoms that can be managed with lifestyle adjustments, while others may have severe, debilitating symptoms that significantly impact daily activities.
Healthcare Professionals: Disease Ontology ID - DOID:0111154
Pathophysiology: Postural Orthostatic Tachycardia Syndrome (POTS) primarily involves abnormal autonomic nervous system function, which regulates heart rate and blood pressure. The key feature is an excessive increase in heart rate (tachycardia) upon standing, often without a significant drop in blood pressure. The underlying mechanisms may include:

1. **Hypovolemia**: Reduced blood volume can lead to decreased venous return to the heart when standing, triggering a compensatory increase in heart rate.
2. **Peripheral Dysautonomia**: Faulty peripheral autonomic nerves may fail to properly constrict blood vessels upon standing, causing blood pooling in the lower extremities and necessitating increased heart rate to maintain adequate blood flow.
3. **Hyperadrenergic State**: Excessive release of norepinephrine upon standing can lead to symptoms of increased heart rate and sometimes high blood pressure.
4. **Immune System Dysfunction**: Some patients have autoimmune antibodies that target parts of the autonomic nervous system.
5. **Impaired Renin-Aldosterone Response**: Dysregulation in this system, important for blood pressure and fluid balance, can contribute to the symptoms.

These factors result in inadequate blood flow to the brain upon standing, causing dizziness, lightheadedness, and other symptoms associated with POTS.
Carrier Status: Postural Orthostatic Tachycardia Syndrome (POTS) is not typically associated with a carrier status because it is not a single-gene inherited disorder. It is a condition that affects the autonomic nervous system, leading to an abnormal increase in heart rate upon standing. The exact cause of POTS is not fully understood, but it is believed to result from a combination of genetic, environmental, and possibly autoimmune factors.
Mechanism: Postural Orthostatic Tachycardia Syndrome (POTS) involves a significant increase in heart rate when transitioning from a supine to an upright position. Several mechanisms may contribute to this condition:

1. **Autonomic Nervous System Dysfunction:** Impairment in the autonomic control, leading to inadequate vasoconstriction upon standing, results in blood pooling in the lower extremities and decreased venous return to the heart, compensating by increasing heart rate.

2. **Hypovolemia:** Reduced blood volume can exacerbate symptoms, causing the heart to work harder to maintain adequate blood pressure and perfusion.

3. **Baroreceptor Sensitivity:** Altered sensitivity or function of baroreceptors, which help regulate blood pressure, can contribute to the abnormal cardiovascular response seen in POTS.

Molecular mechanisms involved in POTS include:

1. **Norepinephrine Transporter Dysfunction:** Reduced activity of norepinephrine transporters can cause increased circulating levels of norepinephrine, leading to excessive adrenergic stimulation and tachycardia.

2. **Autoimmune Factors:** Some patients with POTS have autoantibodies against adrenergic receptors, which can impair normal receptor function and exacerbate symptoms by disrupting normal autonomic regulation.

3. **Genetic Factors:** Mutations or polymorphisms in genes involved in autonomic control, such as those encoding adrenergic receptors or enzymes involved in norepinephrine synthesis and breakdown, may predispose individuals to POTS.

4. **Endothelial Dysfunction:** Abnormalities in endothelial function can impair vasodilation and blood vessel tone, contributing to blood pooling and the resultant compensatory increase in heart rate.

Research on POTS is ongoing, and understanding of this complex syndrome continues to evolve.
Treatment: POTS treatment involves using multiple methods in combination to counteract cardiovascular dysfunction, address symptoms, and simultaneously address any associated disorders. For most patients, water intake should be increased, especially after waking, in order to expand blood volume (reducing hypovolemia). Eight to ten cups of water daily are recommended. Increasing salt intake, by adding salt to food, taking salt tablets, or drinking sports drinks and other electrolyte solutions is an effective way to raise blood pressure by helping the body retain water. Different physicians recommend different amounts of sodium to their patients. Combining these techniques with gradual physical training enhances their effect. In some cases, when increasing oral fluids and salt intake is not enough, intravenous saline or the drug desmopressin is used to help increase fluid retention.Large meals worsen symptoms for some people. These people may benefit from eating small meals frequently throughout the day instead. Alcohol and food high in carbohydrates can also exacerbate symptoms of orthostatic hypotension. Excessive consumption of caffeine beverages should be avoided, because they can promote urine production (leading to fluid loss) and consequently hypovolemia. Exposure to extreme heat may also aggravate symptoms.Prolonged physical inactivity can worsen the symptoms of POTS. Techniques that increase a person's capacity for exercise, such as endurance training or graded exercise therapy, can relieve symptoms for some patients. Aerobic exercise performed for 20 minutes a day, three times a week, is sometimes recommended for patients who can tolerate it. Exercise may have the immediate effect of worsening tachycardia, especially after a meal or on a hot day. In these cases, it may be easier to exercise in a semi-reclined position, such as riding a recumbent bicycle, rowing, or swimming.When changing to an upright posture, finishing a meal, or concluding exercise, a sustained hand grip can briefly raise the blood pressure, possibly reducing symptoms. Compression garments can also be of benefit by constricting blood pressures with external body pressure.Aggravating factors include exertion (81%), continued standing (80%), heat (79%), and after meals (42%).
Compassionate Use Treatment: Postural Orthostatic Tachycardia Syndrome (POTS) is a condition characterized by an excessive heart rate increase upon standing. For compassionate use or experimental treatment, options are typically considered for patients who have not responded to standard therapies. Some potential treatments include:

1. **Ivabradine**: Originally used for heart failure and inappropriate sinus tachycardia, Ivabradine can help reduce heart rate without affecting blood pressure.

2. **Mestinon (Pyridostigmine)**: This medication enhances communication between nerves and muscles and can be considered to improve autonomic nervous system function.

3. **Fludrocortisone**: While commonly used to treat adrenal insufficiency, in POTS it can help improve blood volume and blood pressure.

4. **Droxidopa**: An FDA-approved drug for neurogenic orthostatic hypotension, Droxidopa can sometimes be used off-label for POTS to help enhance blood pressure and reduce symptoms.

5. **Ranolazine**: Traditionally used for angina, Ranolazine may be used off-label to manage symptoms in POTS patients by stabilizing heart rhythms.

Experimental therapies and participation in clinical trials could involve autonomic modulation, various immunotherapies, or other novel approaches. Consulting a specialist is essential to evaluate the suitability and obtain the necessary approvals for these treatments.
Lifestyle Recommendations: For postural orthostatic tachycardia syndrome (POTS), lifestyle recommendations often include:

1. **Increased Fluid and Salt Intake**: Consume more fluids and increase salt intake (under a doctor's guidance) to help expand blood volume and improve circulation.
2. **Compression Garments**: Wearing compression stockings can help reduce blood pooling in the legs.
3. **Gradual Physical Activity**: Engage in a graduated exercise program to strengthen the cardiovascular system. Begin with recumbent exercises and gradually increase intensity.
4. **Avoid Prolonged Standing**: Minimize activities that involve long periods of standing.
5. **Elevate Head of Bed**: Sleeping with the head of the bed elevated can help improve symptoms.
6. **Small, Frequent Meals**: Eat smaller, more frequent meals to avoid blood pressure drops after eating.
7. **Avoid Triggers**: Identifying and avoiding specific triggers that aggravate symptoms, such as stress, extreme heat, or dehydration.

Consult with a healthcare professional for a tailored management plan.
Medication: If nonpharmacological methods are ineffective, medication may be necessary. Medications used may include beta blockers, pyridostigmine, midodrine, or fludrocortisone. As of 2013, no medication has been approved by the U.S. Food and Drug Administration to treat POTS, but a variety are used off-label. Their efficacy has not yet been examined in long-term randomized controlled trials.Fludrocortisone may be used to enhance sodium retention and blood volume, which may be beneficial not only by augmenting sympathetically mediated vasoconstriction, but also because a large subset of POTS patients appear to have low absolute blood volume. However, fludrocortisone may cause hypokalemia.While people with POTS typically have normal or even elevated arterial blood pressure, the neuropathic form of POTS is presumed to constitute a selective sympathetic venous denervation. In these patients the selective Alpha-1 adrenergic receptor agonist midodrine may increase venous return, enhance stroke volume, and improve symptoms. Midodrine should only be taken during the daylight hours as it may promote supine hypertension.Sinus node blocker Ivabradine can successfully restrain heart rate in POTS without affecting blood pressure, demonstrated in approximately 60% of people with POTS treated in an open-label trial of ivabradine experienced symptom improvement.Pyridostigmine has been reported to restrain heart rate and improve chronic symptoms in approximately half of people. However, it may cause GI side effects that limit its use in around 20% of its patient population.The selective alpha-1 agonist phenylephrine has been used successfully to enhance venous return and stroke volume in some people with POTS. However, this medication may be hampered by poor oral bioavailability.
Repurposable Drugs: Several repurposable drugs have been investigated for managing symptoms of Postural Orthostatic Tachycardia Syndrome (POTS). These include:

1. **Beta-blockers (e.g., propranolol, metoprolol)**: Used to manage heart rate.
2. **Fludrocortisone**: A mineralocorticoid that helps retain sodium and expand blood volume.
3. **Midodrine**: An alpha-1 agonist that can help increase blood pressure.
4. **Ivabradine**: Works by selectively inhibiting the If current in the sinoatrial node, reducing heart rate without affecting blood pressure.
5. **Pyridostigmine**: An acetylcholinesterase inhibitor that may improve symptoms by enhancing the autonomic nervous system function.
6. **Clonidine**: An alpha-2 agonist that can help modulate autonomic dysfunction.

These medications are often used off-label to alleviate POTS symptoms, and their use should be tailored to each patient's specific condition under medical supervision.
Metabolites: In postural orthostatic tachycardia syndrome (POTS), there are a few metabolites that have been identified to play a role. Elevated levels of norepinephrine when standing are commonly observed in individuals with POTS. Additionally, disturbances in other catecholamines and serotonin metabolites may also be present. Assessing these metabolites can be crucial for understanding the underlying mechanisms and guiding appropriate treatment strategies.
Nutraceuticals: For Postural Orthostatic Tachycardia Syndrome (POTS), specific nutraceuticals (nutrition-based supplements) that may help manage symptoms include:

1. **Electrolytes:** Electrolyte supplements, including sodium, can help with blood volume expansion and improve symptoms.
2. **Omega-3 and Omega-6 Fatty Acids:** These can help improve cardiovascular health.
3. **Coenzyme Q10:** May support heart function and energy levels.
4. **Magnesium:** Can help with muscle function and may alleviate some symptoms like muscle cramps and fatigue.
5. **B Vitamins:** Specifically B12 and B6 for energy production and nervous system health.
6. **Iron:** If a deficiency is present, iron supplements can help increase energy by addressing anemia.

Always consult with a healthcare provider before starting any new supplement regimen.
Peptides: Postural Orthostatic Tachycardia Syndrome (POTS) is a condition that predominantly affects the autonomic nervous system, leading to an abnormal increase in heart rate when transitioning from sitting or lying down to a standing position. While peptides are generally short chains of amino acids and are not typically the primary treatment for POTS, research into their potential roles may be ongoing. However, as of now, standard management usually involves lifestyle modifications, increased fluid and salt intake, compression garments, physical therapy, and medications like beta-blockers or fludrocortisone. If you need information about specific peptides related to POTS, consulting recent medical literature and clinical trials would be beneficial.