What is Postural Orthostatic Tachycardia Syndrome?
Postural orthostatic tachycardia syndrome (POTS) is a condition related to the involuntary functions of your body, like your heart rate or blood pressure, behaving unusually. This can lead to your heart beating too fast when you stand up, and sometimes you may feel like fainting. For adults, this syndrome is diagnosed when a person’s heart rate goes up by 30 beats per minute or more within the first 10 minutes of standing up or tilting their head upward. It’s also important that this doesn’t happen because of a drop in blood pressure when standing up. POTS mostly affects women of childbearing age between 15 and 50 years old, with symptoms including fatigue, headaches, heart palpitations, disturbed sleep, nausea, and bloating.
There are many reasons why someone could have POTS, including abnormal responses in the nervous system, low blood volume, problems with the immune system, heart-related problems, or a lack of physical fitness. These various causes make it a complex condition to understand. What’s more, POTS can have a big impact on someone’s day-to-day life, affecting basic tasks and overall quality of life. This makes it necessary to further explore this condition so better care and management can be offered to those struggling with this increasingly common syndrome.
What Causes Postural Orthostatic Tachycardia Syndrome?
Several theories have been proposed to understand the different forms of a condition known as postural orthostatic tachycardia syndrome (POTS). In simple terms, POTS is a condition that affects your heart rate and blood pressure when you stand up from a lying or sitting position, often causing dizziness, fainting and rapid heartbeat. Here are some of the ways it can occur:
Neuropathic POTS happens because of an issue with your body’s nervous system, specifically, nerve damage in your lower limbs. This nerve damage can reduce your blood vessels’ ability to narrow down and prevent blood from pooling in your legs. In such cases, your cardiovascular system has to work extra hard to maintain normal blood pressure.
Hyperadrenergic POTS affects roughly 30 to 60% of people with POTS and comes with symptoms like heart palpitations, shaking, high blood pressure, anxiety, and a rapid heartbeat. This happens due to higher levels of a hormone called norepinephrine in the blood when standing.
In some cases, certain medications designed to manage mental health conditions, such as depression, anxiety, and difficulty concentrating, can cause this subtype of POTS due to interference with norepinephrine levels.
Hypovolemic POTS is seen in up to 70% of POTS patients and is characterized by lower than normal amounts of blood or red blood cells in the body. This subtype can also be accompanied by unusually low levels of renin and aldosterone, two hormones essential for maintaining the right amount of blood volume. It’s generally associated with gastrointestinal conditions that lead to excessive fluid loss or less fluid intake (for instance, nausea, vomiting, diarrhea).
The Autoimmune subtype of POTS occurs due to overactive immune response in your body against your own cells, very much like other autoimmune disorders such as rheumatoid arthritis, lupus, and Sjogren’s syndrome. It has been recognized that individuals with POTS may have higher levels of certain antibodies, leading to immune system-related conditions such as Hashimoto’s thyroiditis.
Lastly, Deconditioning POTS is often noticed in individuals who have experienced physical or cardiovascular strain, although it’s not clear if this is a cause or an effect of the condition. Basically, if a person is not physically active for a long period, it can lead to POTS-like symptoms. This kind of POTS is commonly seen in people who stay in bed for a long time or are in environments with minimal gravity. This condition can often bring about a vicious cycle where lack of physical activity and constant tiredness lead to even worse symptoms.
Risk Factors and Frequency for Postural Orthostatic Tachycardia Syndrome
Postural orthostatic tachycardia syndrome, one of the most common types of orthostatic intolerance worldwide, is thought to impact over half a million patients in the United States alone. Its prevalence isn’t well understood, especially on a global scale, but estimates suggest it could affect between 0.2 to 1% of the population in developed countries. The condition is most commonly found amongst young, Caucasian females who haven’t yet experienced menopause, with a ratio of 4.5 to 1. It primarily affects those between 15 and 45 years old, with most cases appearing between 15 and 25 years old. This syndrome has a notable overlap with chronic fatigue syndrome and a variety of autoimmune disorders.
Signs and Symptoms of Postural Orthostatic Tachycardia Syndrome
POTS (Postural Orthostatic Tachycardia Syndrome) often impacts young women between the ages of 15 and 25. People with POTS frequently experience ongoing symptoms such as weariness, feeling faint, heart palpitations, problems with cognitive function, and occasionally fainting. They may also have autonomic dysfunction, which can lead to digestive issues like nausea and abdominal pain, as well as bladder problems like suprapubic pain and increased frequency of urination.
Things like viral infections, injury, surgery, and pregnancy may trigger these symptoms. There doesn’t seem to be a strong correlation to family history, possibly because POTS is a complex and ongoing syndrome. It’s crucial to think about contributing factors, like physical fitness level, sleep habits, fluid intake, and whether or not the person is currently taking any medications or supplements.
During a physical exam, doctors may notice symptoms like swelling in the limbs, acrocyanosis (bluish discoloration of the skin), damp skin, overly flexible joints, and changes in sensation in the limbs. Even if these specific findings are not present, it does not mean the person does not have POTS.
Testing for Postural Orthostatic Tachycardia Syndrome
If you’re suspected to have a condition called postural orthostatic tachycardia syndrome, the first steps your doctor will take is to make sure other issues like heart defects or hormone problems aren’t causing your symptoms. They’ll also check how long you’ve been experiencing your symptoms, review any medications you’re taking, and assess for other related health issues, like digestive, nervous system, or mental health problems.
To gather all this information, your doctor will ask you about your health history, do a physical exam, and likely order some basic lab tests. In addition, they may also run some specific heart tests, like an electrocardiogram (tests electrical activity of the heart), echocardiogram (creates images of your heart), or a Holter monitor (records heart’s rhythms).
If the doctor finds that you’re having other specific issues such as poor physical endurance, digestive problems, urinary issues, or symptoms related to adrenaline, they might need to do some further testing. This could include an exercise test, testing your thyroid function, looking for signs of autoimmune diseases, checking adrenaline levels in your blood and urine, or consulting with a specialist.
There’s also a test called an active stand test. In this test, you’ll lie down for 10 minutes while your blood pressure and heart rate are measured. Then, you’ll stand up, and these measurements will be taken again at different time points. Another test is the head-up tilt table test, which is considered the gold standard for assessing intolerance to standing up in postural orthostatic tachycardia syndrome. This test involves having your heart rate measured while you’re tilted upward on a table. If your heart rate increases by 30 beats per minute or more within the first 10 minutes of standing or the tilt table test, without significant drop in your blood pressure, it can be an indication of this syndrome.
Treatment Options for Postural Orthostatic Tachycardia Syndrome
When it comes to managing Postural Orthostatic Tachycardia Syndrome (POTS), two main approaches are used: non-pharmacologic and pharmacologic methods. Effective management involves accurately diagnosing the condition, educating the patient about it, and sticking to the recommended therapy.
Educating patients about POTS is very important due to the often vague and chronically debilitating nature of the disease. Doctors need to ensure that patients understand the condition, can ask and get answers to any questions they have, and understand the need for a multi-faceted therapeutic approach to treatment in order to improve their quality of life. Don’t forget that treatments for POTS are usually tailored individually, according to various key symptoms (for example, having an unusually high or low volume of blood).
Exercise conditioning, or gradually introducing physical exercise into the patient’s regular routine, is a key part of managing POTS. Because symptoms of POTS often get worse with activity, patients often start with low-intensity exercises that avoid upright positioning—like rowing and swimming—and then gradually increase intensity over 3 months. Results have shown symptom improvement, with increased oxygen intake, increased heart mass, and increased heart muscle volume. In fact, at the conclusion of the study, less than half of the patients still met the criteria for POTS.
Other non-medicine based interventions include physically resisting the urge to faint by using maneuvers like muscle contraction, leg crossing, forward bending, wearing compression garments, increasing fluid and salt intake, and avoiding factors that increase symptoms like caffeine, alcohol, and prolonged heat exposure.
Pharmacologic therapies (which are treatments involving medication) are not the first choice of treatment for POTS. They are typically used in severe cases where the goal is to stabilize the patient to continue physical reconditioning. These medications have not been proven to be more effective than non-pharmacologic approaches and should be used with caution due to potential side effects. Currently, no drug has been approved by the US Food and Drug Administration for the treatment of POTS. However, a few drugs are used, despite not being specifically labelled for POTS. These include fludrocortisone (which increases salt retention and blood volume), midodrine (which increases venous return); clonidine and alpha-methyldopa (which may be beneficial where high blood pressure is a dominant symptom), and beta-blockers and pyridostigmine (which can reduce tachycardia, or rapid heart rate).
As a general rule, medicines that increase heart rate or make it harder for the body to cope with rapid changes in posture should be avoided. However, certain medications could be considered given the patient’s specific history and symptoms.
What else can Postural Orthostatic Tachycardia Syndrome be?
The signs and symptoms of postural orthostatic tachycardia syndrome can often look like other illnesses. This is particularly true because the syndrome affects many systems in the body. It’s critical to get a full medical history and physical examination to determine when the signs started, how long they have been occurring, family medical history, and medication use, especially in individuals who are most at risk, such as young white females. Also, certain diagnostic tests are important.
The doctor also needs to rule out other illnesses, which could include:
- Heart abnormalities
- Heart rhythm problems
- Blood clot in the lungs (pulmonary embolism)
- Heart attack
- Chronic fatigue syndrome
- Fibromyalgia
- Anemia
- Adrenal insufficiency
- Lupus
- Sjogren’s syndrome
- Rheumatoid arthritis
- Vasculitis
- Diabetes
- Infections
- Thyroid disease
- Kidney disease
- Nerve damage in the limbs (peripheral neuropathies)
- Abnormal function of the autonomic nervous system (central dysautonomia)
- Pheochromocytoma
- Cancer
- Epilepsy
- Anxiety or depression
- Bad reactions to medications
What to expect with Postural Orthostatic Tachycardia Syndrome
The overall outlook for patients diagnosed with postural orthostatic tachycardia syndrome, often known as POTS, is generally good; however, we don’t have a lot of data about their long-term health yet. It’s encouraging to see that over half of the patients no longer show symptoms of POTS within five years, often in the first one or two years.
These patients no longer experience symptoms such as dizziness or fainting when they stand up, and they have minimal difficulties in their daily activities. Younger patients tend to do quite well, and it’s rare to see new cases of POTS in patients over 50 years old. Even better, POTS has not been directly responsible for any deaths.
Possible Complications When Diagnosed with Postural Orthostatic Tachycardia Syndrome
The information is limited regarding the specific complications that can arise from Postural Orthostatic Tachycardia Syndrome. However, it’s known this condition can greatly affect a person’s quality of life and daily activities. It can worsen physical and cardiovascular health, which might make some people more susceptible to higher rates of infections and blood clots. It can also negatively affect psychological and mental processes. Despite getting treatment, individuals often continue experiencing feelings of anxiety, depression, and constant fatigue. This suggests that mental and behavioral treatments might be beneficial options to consider.
Complications of Postural Orthostatic Tachycardia Syndrome can include:
- Worsened physical health
- Cardiovascular deconditioning
- Increased susceptibility to infections
- Risk of blood clots
- Negative impact on mental processes
- Increased anxiety
- Depression
- Persistent fatigue
Preventing Postural Orthostatic Tachycardia Syndrome
Like mentioned before, teaching the patient is a very important step when we’re trying to manage postural orthostatic tachycardia syndrome, a condition where a person’s heart rate increases significantly upon standing. This includes explaining how to recognize their symptoms, what makes them worse or better, combined ways to treat the problem, and how to focus on getting better in their daily lives. This information should be easy to understand. Just like with many long-term health issues, building a strong relationship between the doctor and patient through regular check-ups, careful tracking of the condition, and bringing in a specialist if needed, will help the patient stick to the treatment and recover faster.
