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► Chapter 1: POTS and Associated Disorders
► Chapter 2: Signs and Symptoms
► Chapter 3: Causes and Treatment
► Chapter 4: Living with POTS
► Chapter 5: Research and Resources
► Chapter 6: Medical Definitions
Chapter 1: POTS and Associated Disorders
A person first coming to grips with a diagnosis of POTS (Postural Orthostatic Tachycardia Syndrome) enters a world of confusing and overlapping symptoms, conditions, terminology and acronyms.
It’s common to hear the words “POTS” and “dysautonomia” used interchangeably. Technically, dysautonomia is an umbrella term for several malfunctions of the autonomic nervous system including POTS.
As we will explore in greater detail in Part 3, the autonomic nervous systems controls those bodily functions that do not require conscious thought. Things like heart rate, blood pressure, and digestion stay on “auto pilot” as we go about our day-to-day lives.
People who live with some form of dysautonomia become unusually aware of these systems when they experience the negative effects of poor circulation, abnormal blood pressure, or a high heart rate.
In the case of POTS, this awareness becomes triggered by the simple act of standing up. The autonomic nervous system improperly controls the reaction of the body to the gravitational pull of standing and adverse symptoms result, including, but not limited to, fainting.
Estimates suggest that more than 25 million people around the world deal with some kind of dysautonomia. None are “curable” per se, but all can be managed or improved once a correct diagnosis is made, often through dietary changes or environmental modifications.
In isolation, POTS is most often a condition seen in young people, usually after an intense growth spurt. To distinguish this variant from other types, it is generally referred to as “Developmental POTS.” Many such cases resolve over time with the help of correct supportive strategies.
However, POTS can also manifest due to other causes and in connection with other conditions, greatly complicating both treatment and management.
Unfortunately, there is not only a lack of public awareness about the various forms of dysautonomia, but also a shocking level of misunderstanding among doctors themselves. Many POTS patients, especially young people, experience years of endless rounds of tests only to be told they have a psychological problem.
Developmental POTS is one of the most prevalent forms of dysautonomia. It is believed to affect 1 out of 100 teenagers. This means in America alone, there could be 500,000 to 3,000,000 people at any one time dealing with a host of symptoms that include, but are not limited to:
- tachycardia (racing heart rate)
- chest pains
- shortness of breath
- gastrointestinal upset
- exercise intolerance
- temperature sensitivity
Young women are most likely to suffer from Developmental POTS and to grapple with a level of disability comparable to that seen in COPD and congestive heart failure. The severity of their symptoms increases markedly during menstruation when their overall blood volume drops.
Thankfully most cases of Developmental POTS resolve over a period of time. Supportive measures involving diet and lifestyle are typically effective and fairly simple to put into place.
The condition can exist in concert with many other illnesses, however, including diabetes, multiple sclerosis, rheumatoid arthritis, celiac, Sjogren’s syndrome, lupus, and Parkinson’s, and thus may affect almost anyone at any time in their lives.
Along with POTS, the two other most common forms of dysautonomia are Neurocardiogenic Syncope (NCS) and Multiple System Atrophy (MSA). NCS causes one or two fainting spells over the course of a person’s life. In severe cases however, the patient faints several times per day. This increases their risk for broken bones and even traumatic brain injury. The patient’s ability to work, attend school, or engage in social activities is severely compromised.
MSA is a fatal neurodegenertive disorder similar to Parkinson’s disease that occurs in adults age 40 and up. Within 2 years of diagnosis, a patient with MSA is typically bedridden. Most die within 5-10 years. MSA is rare, currently affecting approximately 350,000 patients worldwide.
POTS or Postural Orthostatic Tachycardia Syndrome refers to an abnormal increase in heart rate relative to posture.
People with POTS experience “orthostatic intolerance,” or adverse reactions when standing upright from a sitting or horizontal position. Severity varies from feeling weak or lightheaded, to actual dizziness and fainting within 10 minutes, a symptom called “syncope.”
In chronic cases, a POTS patient may not be able to stand or walk for even brief periods, a disability potentially complicated by the concurrent presence of low blood pressure (hypotension.)
Although the medical definition of POTS is straightforward, the syndrome is not as simplistic as it might appear on first blush, which we will explore throughout this text.
The specific criteria for a diagnosis of POTS is the experience of a heart rate increase of 30-40 beats per minute (bpm) upon standing, or having a standing heart rate of more than 120 bpm. These symptoms must continue for more than six months.
Diagnosis may be difficult, however, since POTS is rarely the first condition considered. Patients go through rounds of testing looking for other causes due in large part to the widespread unawareness of POTS in the broader medical community.
Once POTS is correctly identified, however, it can be treated or managed. If the cause is developmental in nature, the symptoms often disappear over time. POTS is not a deadly condition, but it can be a life-altering one even in the short term.
The acronym POTS was coined in 1993 by a team of researchers at the Mayo Clinic led by Dr. Phillip A. Low, Professor of Neurology.* Over the past 150 years, multiple labels have been used for the disorder to which this shorthand refers, including, but not limited to:
- DaCosta’s Syndrome – This name is in tribute to Jacob Mendes Da Costa who described and studied the disorder during the American Civil War.
- Soldier’s Heart – The name “Soldier’s Heart” was the colloquial name for Da Costa’s Syndrome, also dating to the United States in the 1860s.
- Mitral Valve Prolapse Syndrome – This is an extant syndrome in which the valve separating the upper and lower chambers on the left side of the heart does not function appropriately. It may cause POTS-like symptoms, but it is not the cause of POTS as it is understood in modern terms.
- Neurocirculatory Asthenia – The term “neurocirculatory asthenia” replaced “DeCostas’s Syndrome” in popular usage during the First World War. During the same time period, the British referred to the condition as “Effort Syndrome.”
- Chronic Orthostatic Intolerance – Chronic orthostatic intolerance is a phrase you will still see used today, especially in relation to chronic fatigue syndrome. It is descriptively accurate in that it means a person has an ongoing intolerance to standing or being upright without experiencing negative symptoms.
- Orthostatic Tachycardia – Orthostatic tachycardia is also used to describe instances of rapid heartbeat when a person moves from a reclining or sitting position to an upright one.
- Postural Tachycardia Syndrome – Postural Tachycardia Syndrome is the phrase from which the acronym POTS is derived. It has been in popular use since 1993.
* Dr. Low remains a leading researcher in the field of human autonomic dysfunction, orthostatic intolerance, and postural tachycardia syndrome. Please see Part 5 for a partial listing of his more recent academic publications on the subject.
Once regarded as a psychological condition, POTS is now understood to be a malfunction of the autonomic nervous system with multiple potential causes. Technically it is a “nervous condition,” but not in a psychological sense.
In the most abbreviated terms, a person with POTS experiences an abnormal increase in heart rate on standing from a seated position or from lying down.
The resulting effects are similar to instances of low blood pressure, however, the patient’s BP may remain stable. Some of the likely symptoms include:
- fainting, often within 10 minutes of standing
- tremorsor “shakiness”
- brain“fog” / poor concentration
- discoloration in the handsand feet
- chest pains
Anxiety is not the direct cause of POTS, but the patient may develop anxiety out of fear over what might happen when they stand. This nervousness often must be addressed as part of the treatment because it makes patients reluctant to continue to engage in daily activities, leading many to become sedentary or even bedridden.
Depression often results from this dramatic change in quality of life, creating a vicious psychological cycle that is often mistaken for the primary illness rather than being recognized as a psychological complication of the underlying disorder.
Researchers now understand POTS can take multiple forms, leading to increased sophistication in both diagnostic and treatment protocols in just the last 20 years.
Classifications of POTS
The following classifications are applied to POTS. The designations may refer to identified causes of the syndrome, or to the manner in which the symptoms present.
High / Low Flow
This system focuses on irregularities in peripheral blood blow and peripheral arterial resistance. The three designated groups are:
(Please note the abbreviation Pv stands for pulmonary venous pressure. Pulmonary circulation carries deoxygenated blood away from the heart and to the lungs for oxygenation before returning the blood to the heart.)
Low Blood Flow, High Arterial Resistance, High-Pv
Defects in local blood flow regulation and mild absolute hypovolemia (decreased volume of circulating blood) cause “Low Flow POTS.” Recent research ties this condition to reduced levels of neuronal nitric oxide (nNOS).
Normal Blood Flow, Arterial Resistance, and Pv
In this group, patients have normal peripheral resistance when reclining that becomes “enhanced” upon standing. Venous pooling, the accumulation of blood due to gravitational pool, is observed in the splanchnic vascular bed.
(Splanchnic circulation consists of three vascular beds. Together they are comprised of the stomach, pancreas, small intestine, and colon.)
High Blood Flow, Low Arterial Resistance, Normal-to-Decreased Pv
In “High Flow POTS,” inadequate peripheral vasoconstriction (contraction or narrowing of the blood vessels) when lying down or standing leads to high cardiac output, the amount of blood pumping through the circulatory system per minute.
Developmental POTS most often affects teenagers age 12-14 after a rapid growth surge. Symptoms worsen until age 16, and in 80% of cases disappear by age 19-24. Researchers have not identified a definitive cause for this developmental variant.
“Deconditioning” refers to being out of shape after an injury or illness necessitating prolonged bed rest. Inefficient heart function triggers the symptoms when the person stands up. In turn, patients don’t attempt exercise to avoid the negative reaction, worsening both their level of deconditioning and their orthostatic symptoms.
Classification by Primary Symptoms
Other classifying terminology used with POTS include:
- hypovolemic, associated with low blood volume
- partial dysautonomicor neuropathic, associated with a partial autonomic neuropathy (damage to the autonomic nerves)
- This form of POTS begins suddenly following a viral illness, pregnancy, surgery, trauma, or a course of immunizations.
- hyperadrenergic, associated with elevated levels of norepinephrine and a rise in systolic blood pressure when standing
This form is much less common and can be mistaken for an adrenaline-producing tumor, which should be diagnostically ruled out.
Who Develops POTS?
Although anyone can develop POTS, the syndrome is most often seen in healthy women (75-80% of cases) between the ages of 14 and 50. Research has identified a genetic component within some families.
Even given this profile, however, POTS can present as a sudden onset syndrome in the aftermath of an acute illness, an experience of trauma, exposure to toxins.
POTS can overlap other diseases and syndromes. In these cases, resolving the underlying condition does not always eradicate the POTS symptoms.
Some initial causes or complications to be ruled out include prolonged deconditioning from illness, chronic dehydration, diabetic neuropathy, and negative drug reactions. Particular care should be taken with diuretics and blood pressure medications.
What Causes POTS?
The question, “What causes POTS?” is the most difficult to answer, and is a topic that will be taken up in greater detail in Part 3. This “heterogeneous” syndrome (one with many causes) can be seen as part of a group of disorders with similar clinical manifestations.
For this reason, patients must understand that POTS is not a disease, but rather a cluster of symptoms pointing to different causal agents. Identifying those causes in each patient is the greatest challenge of dealing with a diagnosis of POTS. In some cases, doctors are forced to declare the case idiopathic, meaning “of unknown origin.”
The conditions listed in the next section are some of the illnesses doctors may seek to rule out in arriving at a clinical explanation for POTS-like symptoms. I am not attempting an encyclopedic explanation of these illnesses.
The following material is only a brief overview of each since they may come up in consultations with doctors and can be the explanation for the symptoms a patient is experiencing.
Clearly if any of these illnesses is diagnosed, patients and their families should immediately learn as much as possible about the illness, its effects, complications, and treatment.
Statistical Overview of POTS
According to the Mayo Clinic, the following statistics are true of POTS and POTS patients:
- Approximately 75% of those affected are women. Of those 75-80% are of menstruating age.
- Women are 5 times more likely than men to develop POTS.
- POTS affects approximately 1 out of every 100 teenagers.
- At least 50% of cases involve some abnormal and often degenerative state of the nervous system (neuropathy/neuropathic.)
- Approximately 1 out of 7 cases shows evidence of an autoimmune component.
- One study determined that of 152 POTS patients, 12.5% had a family member with a similar history of orthostatic intolerance.
- Approximately one-third of POTS patients also present with digestive problems.
- In 1999, an estimated 500,000 people in the United States were dealing with POTS.*
* It is extremely difficult to arrive at a workable estimate of how many people suffer from POTS. The upsurge in research in the past 20 years has led to more accurate diagnoses, but total population numbers are still very sketchy and vary widely.
Associated / Related Nervous Disorders
Cultivating a broader understanding of POTS means understanding, at least in a peripheral way, the disorders and conditions that are often concurrent with the syndrome and its symptoms. These include, but are not limited to the following:
“Amyloidosis” does not refer to a single disease, but rather to a group of disorders. All involve abnormal groupings of proteins fibers in tissues called amyloid deposits, which break down at a very slow rate. The deposits can occur anywhere in the body or may be localized to one organ or tissue type where they alter structural components and interfere with function.
Thirty different proteins can accumulate in this fashion, but not all are linked to significant disease. Each protein type presents with a different clinical picture and set of symptoms specific to the affected region. Variation among patients can be considerable.
Two of the most common are associated with underlying conditions and are systemic (affecting the whole body). The first of these, AL amyloidosis, is seen most often with non-malignant bone marrow disorders.
AL can, however, also be present in multiple myeloma (bone cancer) cases. The second, AA amyloidosis is present with some type of chronic inflammation like rheumatoid arthritis.
No specific anti-amyloid drugs are available outside the laboratory setting. Treatment focuses on stabilizing organ function. Often the deposits do diminish over time when the underlying condition responds to treatment.
Autoimmune Autonomic Ganglionopathy
The rare condition Autoimmune Autonomic Ganglionopathy (AAG) causes the body to damage receptors in the autonomic ganglia of peripheral nerve fibers. AAG is a treatable disorder than can affect males and females regardless of age. About one-third of patients experience spontaneous improvement, but with incomplete recovery. Onset may be acute, subacute, or gradual and the course of the disease is variable.
Symptoms may include:
- severe low blood pressureupon standing
- constipationand associated gastrointestinal issues
- urinary retention
- fixed and dilated pupils
- dry mouthand eyes
Many of these symptoms are POTS like, but no clear link exists between the two conditions. The rarity of AAG has not led to any extensive clinical trials to determine optimal treatment protocols.
Although most people are aware of diabetes in a peripheral sense, few understand the mechanism underlying this common disease. The food that we eat is broken down into blood glucose, a form of sugar, which is the body’s primary source of fuel.
After food is digested, the glucose produced passes into the blood stream and is distributed among the body’s cells where it is used as energy and for growth. For glucose to enter the cells, however, insulin, a hormone produced by the pancreas, must also be present.
When diabetes develops, the pancreas make too little or too much insulin, or the cells are unable to respond to the insulin that is produced. Glucose builds up in the blood and is then lost in large doses via the urine. The body derives no energy benefit under these circumstances.
The three types of diabetes are Type 1, Type 2, and gestational. Type 1 is an autoimmune disease. The body’s immune system destroys the beta cells in the pancreas that produce insulin. Patients with this form of the disease must take insulin daily.
Type 1 develops most often in children, but can appear at any age. Symptoms include excessive thirst, frequent urination, constant hunger, blurred vision, extreme fatigue, and weight loss. If left untreated, the patient may lapse into a fatal diabetic coma.
Type 2 is the most common, affecting 90-95% of diagnosed diabetic cases. It is associated with aging, obesity, and physical inactivity. This form of the disease has both genetic and ethnic links (African American, Mexican American, and Pacific Islander.)
Although insulin is being produced, the body is insulin resistant and does not effectively use the hormone. Symptoms, if present, include fatigue, thirst, hunger, frequent urination, slow healing of wounds, blurred vision, and weight loss.
Gestational diabetes develops late in pregnancy and disappears after the child is born. A reasonable body weight and being physically active are good preventive measures. The condition surfaces in 3-8% of pregnancies in the United States. Like Type 2, gestational diabetes has genetic and ethnic links.
The autoimmune disorder Sjogren’s often appears alongside other autoimmune conditions including rheumatoid arthritis and lupus. It affects the mucous membranes and moisture-secreting glands of the eyes and mouth causing chronic dryness.
In most cases, patients are 40 years or older at the time of diagnosis. The condition is more common in women, with treatment focusing on symptom relief. The eyes burn and itch, with a sandy, gritty sensation, while the mouth feels stuffed with cotton, to the point that swallowing and speaking become difficult.
Additional symptoms may include:
- painful, swollen and/or stiff joints
- swollen salivary glands behind the jaw and in front of the ear
- dry skin or rashes
- vaginal dryness
- a dry, persistent cough
- prolonged fatigue
The condition may cause damage to multiple systems and organs including the thyroid, kidneys, liver, lungs, nerves, and skin.
The specific cause of Sjogren’s syndrome is unknown. A genetic connection is suspected, but a triggering mechanism, like a viral or bacterial infection, appears to be necessary.
With sarcoidosis small collections of inflammatory cells form in the lungs, lymph nodes, eyes, and skin as well as other parts of the body.
The exact cause is not known, but the formations are believed to be in response to some inhaled substance. Most patients require only modest treatment protocols.
Sarcoidosis may be self-limiting, or progressively damage organs over a period of years.
Both the severity and speed of onset vary depending on the organs affected. Some patients are asymptomatic. These cases are diagnosed by accident when an X-ray is ordered for another reason. The major symptoms, if present include:
- swollen lymph nodes
- weight loss
Eventually, all sarcoidosis patients experience lung problems including:
- persistent dry cough
- chest pain
- shortness of breath
In 25% of cases skin problems also develop including:
- An inflamed and tender red / purple rash on the shins and ankles.
- Disfiguring skin sores on the cheeks, nose, and ears.
- Pigment changes that may be darker or lighter.
- Subcutaneous nodules around scars or tattoos.
Potential problems with the eyes and vision include:
- severe redness
- sensitivity to light
Chronic sarcoidosis can cause the following long-term effects:
- Irreversible damage to the tissues between the air sacs in the lung affecting the ability to breathe.
- Severe eye inflammationprogressing to eventual blindness and (more rarely) cataracts and glaucoma.
- Alterations in the body’s ability to process calciumleading to kidney failure.
- Granulomas(granulated masses of tissue) in the heart that disrupt electrical signals and cause abnormal rhythms.
In a small number of sarcoidosis cases granulomas also form in the brain and spinal cord where they disrupt the activities of the central nervous system. Facial paralysis develops if the facial nerves become inflamed.
In cases of lupus (systemic lupus erythematosus) the body’s immune system malfunctions, attacking and damaging various tissues. Symptoms include:
- deep fatigue
- persistent low-grade fever
- severe joint pain
- muscle aches
- skin rash(face or body)
- extreme sun sensitivity
- weight loss
- mental confusion
- chest painon taking a deep breath
- nose, mouth, or throat sores
- enlarged lymph nodes
- poor circulation in the extremities
- hair loss
Lupus cannot be cured. Patients can lead a normal but challenging life unless the function of major organs is threatened. Successful management relies on medication and associated care protocols.
A Chiari malformation (CM) exists when the cerebellum sits too low in the rear of the skull, below the funnel-like opening for the spinal canal called the foramen magnum. The resulting pressure blocks the flow of cerebrospinal fluid (CSF), which surrounds and cushions both the brain and the spinal cord.
Developmental defects, genetic mutations, or poor prenatal nutrition cause primary or congenital CM. Injury, infection, or an exposure to harmful substances leads to excessive drainage of spinal fluid, which can cause secondary or acquired CM. Four classifications indicate severity and the parts of the brain protruding into the spinal canal:
- Type 1: The lower cerebellum(cerebellar tonsils) extends into the foramen magnum, but does not involve the brain This is the most common CM and often causes no symptoms. Type 1 is first detected in adolescence or young adulthood during an examination for another condition and is the only acquired CM.
- In Type II or classic CM both cerebellar and brainstem tissue extends into the foramen magnum. The nerves connecting the two halves of the cerebellum, the cerebellar vermis are absent or incomplete. Myelomeningocele, a form of spina bifida, often accompanies Type II CM. The spinal canal and backbone fail to close before birth. The spinal cord and its protective membrane protrude through a sac-like opening in the back, with partial or complete paralysis occurring below this protrusion.
- In Type III, the most serious CM, the cerebellumand brain stem herniate through the foramen magnum and into the spinal cord causing severe neurological defects. The protrusion can include the brain’s fourth ventricle, which connects to the upper parts of the brain and circulates CSF. In a small percentage of cases, the herniated tissue enters the pouch-like occipital encephalocele at the back of the head or neck or the covering of the brain and spinal cord protrude from an abnormal opening at the rear of the skull.
- In the rare Type IV CM, parts of the cerebellumare missing (cerebellar hypoplasia), and portions of the skull and spinal cord are visible even though the cerebellar tonsils are in their normal location.
CM symptoms include:
- neck pain
- balance problems
- muscular weakness
- abnormal sensation in the extremities
- visual problems
- difficulty swallowing
- ringing or buzzing in the ears
- hearing loss
- loss of hand / eye coordination
- deterioration of fine motor skills
In infants, expected symptoms include irritability at mealtime, difficulty swallowing, gagging, vomiting, excessive drooling, an inability to gain weight, a weak cry, a stiff neck, breathing problems, and developmental delays.
When an organism adapts to a less demanding environment the decreased physical activity results in muscle loss called “deconditioning.”
Illness, orthopedic casting, aging, paralysis, and low gravity environments (space exploration), all cause deconditioning. The abnormal distribution of bodily fluids under these circumstances, including blood volume changes, can trigger a POTS episode.
Delta Storage Pool Deficiency
A deficiency in dense granules in blood platelets causes Delta Storage Pool Deficiency, a condition discovered in the 1970s. Dense granules release chemicals necessary for clotting. The major symptoms include:
- bleedingin the nose and mouth
- potential severe bleedingfrom injuries
- excessive menstrual bleeding
- bleedingcomplications in childbirth
To diagnose Delta SPD blood work is taken to measure clotting time and platelet aggregation (clumping). Microscopic studies reveal the number of dense granules and help doctors to eliminate other platelet disorders.
No medicine exists to increase the number of dense granules. Medications used to maintain the condition include DDAVP to —improve clotting, and Amicar, which interrupts the breakdown of clots. Prior to surgery, patients with Delta SPD may require a platelet transfusion.
Patients should avoid aspirin and nonsteroidal anti-inflammatories like ibuprofen and naproxen and mitigate activities with an increased risk of bleeding.
Ehlers Danlos Syndrome
The inherited collagen protein disorders collectively named Ehlers Danlos Syndrome causes hyper-flexible joints. Concurrently, fragile, “stretchy” skin and veins may make wound stitching difficult or even impossible.
The more severe Vascular Ehlers-Danlos may lead to rupturing of blood vessels, the intestines, or the uterus. Patients with this variant of the syndrome should seek genetic counseling before starting a family.
- loose joints that move beyond a normal range
- weakened connective tissue that can be stretched beyond normal limits
- slowly healing skin with excessive scarring
- harmless fatty lumps around the knees or elbows
People with Vascular Ehlers-Danlos syndrome tend to exhibit distinctive facial features including a thin nose, thin upper lip, small earlobes and prominent eyes. The skin appears translucent and bruises easily. The underlying blood vessels may also be visible.
A virus transmitted through saliva causes infectious mononucleosis. Labeled the “kissing disease,” mono can also be passed on through a cough or sneeze or by sharing eating utensils.
The disease is not as contagious as the common cold and is most prevalent and severe in adolescents and young adults. The virus incubates for 4-6 weeks before some combination of the following symptoms manifest:
- overall malaise
- sore throat
- swollen lymph nodes (neck and armpits)
- swollen tonsils
- skin rash
- soft, swollen spleen
The fever and sore throat diminish after 2 weeks, but the fatigue, enlarged lymph nodes, and swollen spleen take an additional 2 weeks or more to resolve. Rest and good hydration are essential for recovery.
Epstein Barr Virus
The Epstein–Barr virus (EBV) causes infectious mononucleosis, and is associated with Hodgkin’s lymphoma, Burkitt’s lymphoma, nasopharyngeal carcinoma, and conditions appearing with HIV.
Researchers believe infection with Epstein-Barr elevates the risk for the development of other autoimmune diseases including dermatomyositis (an inflammatory connective tissue disease), systemic lupus erythematosus, rheumatoid arthritis, Sjögren’s syndrome, and multiple sclerosis.
The virus, which is part of the herpes family, is transmitted through saliva and also via genital secretions.
Deer ticks in North America and Europe spread Lyme disease, caused by the bacterium Borrelia burgdorferi. People who spend time in wooded or grassy areas face the greatest risk. Patients who receive appropriate antibiotics quickly recover completely, but later stage treatment progresses more slowly.
Early signs and symptoms (within one month of infection) include:
- A small, inflamed bump at the site of the tick bitethat expands into a bull’s eye pattern called an erythema migrans rash.
- Fever, chills, headache, and body aches.
Later stage symptoms include:
- Severe joint painand swelling, especially in the knees.
- Meningitis(inflammation of the membranes surrounding the brain.)
- Bell’s Palsy(temporary paralysis of one side of the face.)
- Weakness and numbness in the limbs with impaired muscle movement.
Less common symptoms include:
- Irregular heartbeat.
- Eye inflammation.
- Liver inflammation.
- Debilitating fatigue.
Untreated Lyme disease can spread throughout the body for years after the initial infection and contribute to neurological problems and the development of arthritis.
Extra-Pulmonary Mycoplasma Pneumonia
The bacteria species Mycoplasma pneumoniae, spread through respiratory droplet transmission, causes mycoplasma or “walking” pneumonia.
Unlike other forms of pneumonia, this protracted illness causes pharyngitis and bronchitis. The protracted course of walking pneumonia, which can become chronic, may play a role in the development of rheumatoid arthritis and other rheumatological diseases.
The chronic liver infection Hepatitis C, though often asymptomatic, causes scarring and ultimately cirrhosis. Liver failure, cancer, and life-threatening esophageal and gastric varices (enlarged veins) may result. Primary blood-to-blood transmission may be from intravenous drug use, blood transfusions, or poorly sterilized medical equipment.
Treatment in 50-80% of cases results in a cure, but Hepatitis C remains the leading cause of liver transplantations. Standard drugs used to combat the disease include peginterferon, ribavirin, boceprevir and telaprevir. There is no vaccine against Hepatitis C.
The inflammatory disease multiple sclerosis (MS) damages the insulating covers of nerve cells in the brain and spinal cord disrupting the communication network of the central nervous system. MS can follow a relapsing, remitting course. Patients suffer isolated attacks or progressively worsening symptoms that over time lead to permanent neurological damage.
Researchers do not know the exact cause of MS, but genetic and environmental factors are believed to play a role. There is no cure. Treatment focuses on improving function following an attack and preventing future episodes. The disease appears twice as often in women with onset between the ages of 20 and 50.
Other conditions or circumstances that may include POTS symptoms include:
- mitochondrial disorders (blood cell defects)
- mast cell activation disorders (histamine and inflammatory reactions)
- paraneoplastic syndrome (a rare immune system response)
- heavy metal poisoning
- vitamin deficiencies
Chapter 2: Signs and Symptoms
POTS cannot be reduced to a simple description like, “I stand up and then I faint.” There are numerous signs and symptoms associated with the syndrome.
When some combination of the following has been in place for six months or more and the correct tests have been performed, a definitive diagnosis is more likely.
- A feeling of being lightheaded upon standingwith possible heart palpitations and a “tremulous” or shaky feeling.
- Some type of visual disturbance like “seeing stars” or blurring.
- An uncomfortable feeling in the head (throbbing) and possibly in the neck.
- An inability to concentrate or think clearly. Often described as “brain fog”
- Feeling tired and experiencing weakness.
- Fainting spells, generally within 10 minutes of standing.
- Nausea or “queasiness.”
- Discomfort in the chest including being short of breath.
POTS patients often experience difficulty with associated anxiety as they become increasingly apprehensive about standing. This leads to additional symptoms including:
- Gastrointestinal upsets like constipation and bloating and/or episodes of diarrhea.
- Changes in sweating, usually increased with a sense of feeling “clammy.”
- Insomnia that exacerbates the overall problem of fatigue.
In cases with POTS-like symptoms, any or all of the following diagnostic tests may be used to arrive at an explanation for what is happening to the body, particularly within the autonomic nervous system.
Each of the following 10 diagnostic tests is routinely used to evaluate patients suffering from symptoms typically seen in POTS. All are designed to understand aspects of blood flow and nerve function as they relate to posture and other external stimuli.
Multiple tests are employed in an effort to create a complete picture of exactly what precedes an episode.
The posture study monitors heart rate, blood pressure, and the plasma concentrations that regulate them when the patient is lying down and standing. Blood is drawn from an IV in the arm during the test. The patient lies still while baseline readings are taken. The patient then stands up for 30 minutes while the measurements are repeated.
POTS patients will show an increased heart rate of 30 beats per minute when they stand and an accompanying drop in blood pressure of < 20/10 mm Hg. Some will also show elevated norepinephrine levels of > 600pg/mL.
Head Up Tilt Table
Doctors use the tilt table to evaluate cardiovascular response to positional changes. In POTS cases they are looking for a sudden drop in blood pressure with either an increase in pulse rate or fainting when the patient is upright.
To perform the test, the patient lies on the table with straps around the abdomen and legs and then is gradually tilted upright between 60-80 degrees for 45 minutes. The intended purpose is to replicate the patient’s problem in a controlled setting.
POTS patients will show an increase in heart rate of > 30 beats/minute during the head up tilt with little or no change in blood pressure, usually < 20/10 mm Hg.
A cardiac output test judges the amount of blood the heart can pump by measuring pulmonary blood flow. The patient is forced to breathe through the mouth while wearing a device containing oxygen and two inert gases. A clamp renders respiration through the nose impossible.
One of the inert gases is blood soluble, disappearing as the patient breathes in direct proportion to the rate of pulmonary blood flow. The other gas does not enter the bloodstream, therefore allowing for lung volume to also be measured.
(Note that there are other methods for measuring cardiac output. This method is, however, quite common.)
Beat-to-Beat Blood Pressure
Beat-to-beat blood pressure testing non-invasively tracks changes in response to various tests through a bracelet-like wrist device with a Velcro strap secured around one finger. This monitor is worn for the duration of any other type of testing being performed.
In the Valsalva maneuver, the patient blows against a resisting surface for several seconds followed by a period of relaxation. The action of the blowing increases pressure in the chest and abdomen, forcing blood out of the chest and down into the arms with a brief increase in blood pressure. This is referred to as Phase I.
The stroke volume, which is the amount of blood ejected by the heart with each beat, plummets due to the decreased entry of blood from the veins as a consequence of the straining. The brain senses these changes as well as the concurrent increases in nerve traffic causing more norepinephrine to be released. This tightens blood vessels throughout the body. This is Phase II.
Phase III begins when the patient relaxes, causing a brief drop in blood pressure before the blood rushes back into the chest. Blood pressure increases in Phase IV and since the blood vessels are constricted, an overshoot of blood pressure is produced, outflow falls, and with it the heart rate.
Observing these various changes and their rate and interaction gives physicians information about sympathetic and parasympathetic function. Patients with the kind of autonomic dysfunction present in POTS will likely have an exaggerated blood pressure increases in Phases II and IV.
Heart rate normally varies with the breath, increasing when we breathe in and decreasing when we breathe out. These changes, which are controlled by the parasympathetic nervous systems are called respiratory sinus arrhythmia.
In a sinus arrhythmia test, the patient’s heart rate is monitored while taking a series of deep breaths, roughly six per minute. A difference of 15 beats between minimum and maximum heart rate is considered within normal range.
Typically patients with POTS will have normal results on this test, but if abnormalities do show up, they may suggest a diagnosis of a condition other than POTS or of a condition present in conjunction with POTS.
A Transcranial Doppler test determines the velocity of cerebral blood flow. The patient is in an upright position, standing or on a tilt board. A Doppler probe placed near the temple emits high-frequency sound waves that are used to map the speed of blood flow in the cerebral vessels. In patients with POTS the expected results would be decreased velocity when in an upright position.
Cold Pressor Test
During a cold pressor test the patient plunges their hand in a tub of ice cold water and leaves it submerged for 1-2 minutes while both heart rate and blood pressure are monitored.
The normal reflexive action is an increase in heart rate and systolic blood pressure. A patient with POTS, however, will show increases in systolic and diastolic blood pressure much greater than those observed in normal individuals.
The QSART is a sweat test that gauges the ability of sympathetic nerves in the skin to release acetylcholine. If the individual has lost sympathetic nerve terminals, no sweat will be produced. If the person has a brain abnormality that inhibits sweat production as the temperature increases, they will still sweat during a QSART test. Therefore, the QSART helps to distinguish between loss of terminals and misregulation of signals sent along the sympathetic nerves.
The test is performed by wiping the leg and wrist with acetone and then alcohol. This cleans and dries the skin. Next, four electrodes are placed on three areas of the leg and one of the wrist.
The electrodes are filled with acetylcholine, which is activated with a mild electrical current to stimulate sweat gland activity while allowing the body to release its own acetylcholine causing sweating in adjacent sites. The entire procedure requires about 45 minutes.
Measuring the degree of sweating response helps doctors to determine the exact nature of sympathetic dysfunction that may be contributing to the symptoms seen in POTS.
The Endothelial Function test judges the function of the cells that line the blood vessels. A baseline blood pressure reading is taken first before an uninflated blood pressure cuff is placed on the non-dominant arm for later use. The index finger of each hand is then placed inside a plastic cylinder called an EndoPat probe, which will measure arterial tone.
Baseline readings are again taken while the patient sits still for 5 minutes, at which time the blood pressure cuff is inflated to a level greater than the systolic blood pressure for the purpose of stopping blood flow for 5 minutes. Then the cuff is deflated and additional readings taken over another 5 minute period.
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