POTS and vasovagal syncope are two types of orthostatic intolerance. Orthostatic intolerance is the development of symptoms when standing upright, which are typically relieved when reclining. In fact, there are three types of orthostatic intolerance: orthostatic hypotension, vasovagal syncope, and postural orthostatic tachycardia syndrome.
The key difference between POTS and vasovagal syncope is their cause. POTS is a condition that causes a number of symptoms such as a fast heart rate, dizziness and fatigue when people transition from lying down to standing up while vasovagal syncope is a condition that causes temporary loss of consciousness that is associated with a drop in blood pressure and heart rate.
CONTENTS
1. Overview and Key Difference
2. What is POTS
3. What is Vasovagal Syncope
4. Similarities – POTS and Vasovagal Syncope
5. POTS vs Vasovagal Syncope in Tabular Form
6. Summary – POTS vs Vasovagal Syncope
7. FAQ – POTS and Vasovagal Syncope
What is POTS?
POTS (postural orthostatic tachycardia syndrome) causes the heart to beat faster than normal when people transition from sitting or lying down to standing up. POTS is a type of orthostatic intolerance. POTS mainly affects women and people assigned female at birth aged 15 to 50 years. POTS has several possible symptoms, such as dizziness, fainting, brain fog, heart palpitation, exhaustion, feeling nervous, shakiness or excessive sweating, shortness of breath, chest pain, headache, feeling sick, bloating, pale face, disrupted sleep from chest pain. POTS can be caused by peripheral denervation (loss of nerve supply), an overactive sympathetic nervous system, and reduced blood volume.
Figure 01: Acrocyanosis in a POTS Patient
POTS can be diagnosed through physical examination, tilt table test, blood test, urine test, QSART test, skin nerve biopsy, tuberculin skin test, echocardiogram, blood volume and haemodynamic studies. Furthermore, the treatment options for POTS include exercise and physical activity, diet and nutrition.
What is Vasovagal Syncope?
Vasovagal syncope happens when people faint because the body overreacts to certain triggers, such as extreme emotional distress or sight of blood. The signs and symptoms of this condition are pale skin, lightheadedness, tunnel vision, nausea, feeling warm, a clod clammy sweat, blurred vision, jerky, abnormal movements, slow, weak pulse, and dilated pupils. Vasovagal syncope occurs when there is a malfunction in the region of the nervous system that manages heart rate and blood pressure in response to triggers like the sight of blood, standing up for a long duration, heat exposure, having blood drawn, seeing blood, fear of bodily injury, and straining such as bowel movement.
Vasovagal syncope can be diagnosed through physical examination, electrocardiogram, echocardiogram, exercise stress test, blood test, and tilt table test. Furthermore, treatment options for vasovagal syncope include giving fludrocortisone acetate to regulate blood pressure, therapies such as foot exercises, wearing compression stockings or tensing your leg muscles when standing, and surgery like inserting an electronic pacemaker to regulate heartbeat.
Similarities Between POTS and Vasovagal Syncope
- POTS and vasovagal syncope are two disorders of orthostatic intolerance.
- Both conditions may have similar overlapping symptoms, such as light-headedness, pale skin, clammy sweat, etc.
- Both conditions can be diagnosed through physical examination, tilt table test, blood test, and echocardiogram.
- They can be treated through specific therapies.
Difference Between POTS and Vasovagal Syncope
Definition
- POTS is a condition that causes a specific group of symptoms, such as a fast heart rate, dizziness, and fatigue that frequently occur when standing upright.
- Vasovagal syncope is a condition that leads to fainting in some people in response to triggers like seeing blood or extreme emotional distress.
Causes
- POTS occurs due to peripheral denervation, an overactive sympathetic nervous system, and reduced blood volume.
- Vasovagal syncope occurs when there is a malfunction in the region of the nervous system that regulates heart rate and blood pressure in response to triggers such as the sight of blood, standing for a long period of time, heat exposure, intense emotions, intense pain, prolonged exercise, dehydration, and skipping meals.
Symptoms
- Symptoms of POTS include severe fatigue, light-headedness, brain fog, forceful heartbeats, nausea and vomiting, headaches, pale face, excessive sweating, shakiness, intolerance of exercise, and and purple discoloration of the hands and feet if the limbs are lower than the level of the heart.
- Nausea, vomiting, turning pale, sweaty palms, dizziness, and blurred vision are the symptoms of vasovagal syncope.
Diagnosis
- POTS can be diagnosed with tilt table test, Valsalva maneuver, quantitative sudomotor axon reflex test (QSART) , and MRI.
- Vasovagal syncope can be diagnosed with physical examination, electrocardiogram (ECG), echocardiogram, exercise stress test, and blood test.
Treatment
- Modifying behavior or environment to avoid the worsening of symptoms, wearing compression garments to reduce excessive blood pooling in the legs, and practicing certain postures while sitting or sleeping may help reduce POTS symptoms.
- Avoiding triggers such as standing for a long time or the sight of blood, discontinuing medicines that lower blood pressure, moderate exercise training, drinking plenty of fluids, taking a higher salt diet to help keep up blood volume, and wearing compression stockings or abdominal binders can help to manage vasovagal syncope.
The following table summarizes the difference between POTS and vasovagal syncope.
Summary – POTS vs Vasovagal Syncope
Orthostatic intolerance is the development of symptoms when standing upright. POTS and vasovagal syncope are two different types of orthostatic intolerance disorders. POTS is when the heart rate increases very quickly after getting up from sitting or lying down while vasovagal syncope is passing out fainting when the blood pressure and heart rate drop suddenly in response to triggers like sight of blood, standing up for long duration, etc. This summarizes the difference between POTS and vasovagal syncope.
FAQ: POTS and Vasovagal Syncope
1. What are the disorders of orthostatic tolerance?
- Disorders orthostatic intolerance is a disabling syndrome that most commonly occurs when standing in an upright position and is characterized by pronounced tachycardia and symptoms such as fatigue, light-headedness, dizziness, palpitations, and syncope.
2. What are POTS and its symptoms?
- Postural orthostatic tachycardia syndrome (POTS) is a disorder that can make someone feel symptoms such as fainting or dizziness, brain fog, heart palpitation, exhaustion, nervousness, shakiness or excessive sweating, shortness of breath, chest pain, headache, sickness, bloating, pale face and discoloration in the body parts such as in limbs, and disrupted sleep.
3. Can POTS be cured?
- There is no known cure for this condition. But it can be managed in most patients with exercise, diet, and medications such as beta-blockers, Ivabradine, and Verapamil.
4. What is the main cause of vasovagal syncope?
- Vasovagal syncope occurs when the part of the nervous system that regulates heart rate and blood pressure malfunctions in response to a trigger, such as the sight of blood and emotional distress.
5. What are the main symptoms of vasovagal syncope?
- The main symptoms of vasovagal syncope may include transient loss of consciousness and postural tone, dizziness, light-headedness, diaphoresis, nausea, and visual disturbances.
Reference:
1. “Postural tachycardia syndrome (PoTS).” NHS Choices, NHS.
2. “Vasovagal Syncope: Symptoms, Causes and Treatment.” Cleveland Clinic.
Image Courtesy:
1. “Dependent Acrocyanosis in a Norwegian 33-year old male POTS patient” By Pots Syndrome – (CC BY-SA 2.0) via Commons Wikimedia
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