Answer: C
The constellation of symptoms described here generates a broad differential diagnosis of cardiac, neurologic, metabolic, and hematologic conditions. The differential diagnosis narrows with an otherwise reassuring history, normal examination, normal electrocardiogram, and unremarkable screening laboratories (normal hematocrit and electrolytes if sent, and a negative pregnancy test).
After evaluation of dangerous causes to her symptoms, we are left with a well appearing woman with resolved symptoms. In the absence of an apparent emergent condition and in the context of now chronic symptoms, her observed tachycardia when standing associated with nausea, lightheadedness, fatigue, and difficulty concentrating suggests Postural Orthostatic Tachycardia Syndrome (POTS).
The basis of this syndrome is failure of peripheral vascular resistance to increase sufficiently with changes in posture (i.e. venous pooling in the extremities and therefore decreased venous return and a compensatory tachycardia). POTS is most common in females (male:female is 1:5) and most are between 12 and 50 years of
age.
POTS can be diagnosed in the presence of chronic symptoms of orthostatic intolerance (of at least 6 months) accompanied by an increase in heart rate of at least 30 beats per minute within 10 minutes of standing
without orthostatic hypotension and in the absence of any other overt cause of orthostasis (e.g. anemia, bleeding, volume depletion, medications).
Although not a diagnosis we are likely to focus on or even to make in the ED, it bears some note: these patients can be labeled as having anxiety, chronic fatigue, or other psychiatric illnesses. POTS reminds us to practice an EM truism for the discharge-to-home disposition: although there doesn’t seem to be anything dangerous going on, that doesn’t mean there isn’t something wrong. Follow-up and more importantly follow-through by a primary care practitioner are warranted.
POTS is not a disease, but a syndrome that may have varied etiologies. Neuropathic POTS and Central Hyperadrenergic POTS both involve some form of dysautonomia, and many have high plasma norepinephrine levels. Other patients may be found to have problems with norepinephrine transport mechanisms or mast cell activation. Most patients with POTS have a disorder in blood volume regulation (many have a plasma volume deficit of 13%). As an outpatient, investigation for pheochromocytoma (urine metanephrine levels), reentrant tachycardias (Holter or event monitor), or subtle cardiomyopathy (echocardiogram) may be pursued.
A clue to POTS in our patient was her constellation of symptoms (worsening now that she has a more active job), a normal electrocardiogram and work up, reproducible symptoms, and dependent dark red mottling of bilateral legs after standing for a few minutes.
Below are photos of a normal (left) and abnormal (right) reactions to standing for five minutes:
The constellation of symptoms described here generates a broad differential diagnosis of cardiac, neurologic, metabolic, and hematologic conditions. The differential diagnosis narrows with an otherwise reassuring history, normal examination, normal electrocardiogram, and unremarkable screening laboratories (normal hematocrit and electrolytes if sent, and a negative pregnancy test).
After evaluation of dangerous causes to her symptoms, we are left with a well appearing woman with resolved symptoms. In the absence of an apparent emergent condition and in the context of now chronic symptoms, her observed tachycardia when standing associated with nausea, lightheadedness, fatigue, and difficulty concentrating suggests Postural Orthostatic Tachycardia Syndrome (POTS).
The basis of this syndrome is failure of peripheral vascular resistance to increase sufficiently with changes in posture (i.e. venous pooling in the extremities and therefore decreased venous return and a compensatory tachycardia). POTS is most common in females (male:female is 1:5) and most are between 12 and 50 years of
age.
POTS can be diagnosed in the presence of chronic symptoms of orthostatic intolerance (of at least 6 months) accompanied by an increase in heart rate of at least 30 beats per minute within 10 minutes of standing
without orthostatic hypotension and in the absence of any other overt cause of orthostasis (e.g. anemia, bleeding, volume depletion, medications).
Although not a diagnosis we are likely to focus on or even to make in the ED, it bears some note: these patients can be labeled as having anxiety, chronic fatigue, or other psychiatric illnesses. POTS reminds us to practice an EM truism for the discharge-to-home disposition: although there doesn’t seem to be anything dangerous going on, that doesn’t mean there isn’t something wrong. Follow-up and more importantly follow-through by a primary care practitioner are warranted.
POTS is not a disease, but a syndrome that may have varied etiologies. Neuropathic POTS and Central Hyperadrenergic POTS both involve some form of dysautonomia, and many have high plasma norepinephrine levels. Other patients may be found to have problems with norepinephrine transport mechanisms or mast cell activation. Most patients with POTS have a disorder in blood volume regulation (many have a plasma volume deficit of 13%). As an outpatient, investigation for pheochromocytoma (urine metanephrine levels), reentrant tachycardias (Holter or event monitor), or subtle cardiomyopathy (echocardiogram) may be pursued.
A clue to POTS in our patient was her constellation of symptoms (worsening now that she has a more active job), a normal electrocardiogram and work up, reproducible symptoms, and dependent dark red mottling of bilateral legs after standing for a few minutes.
Below are photos of a normal (left) and abnormal (right) reactions to standing for five minutes:
(Raj SR, 2013)
Outpatient treatment for POTS includes maximizing volume: patients are asked to increase water intake to 8-10 cups of water daily and to increase their sodium intake up to 8 to 10 g/day (A). (Parenthetically, these patients do well after normal saline in the ED.) Elastic support stockings or hose (medical stockings that support 30 mmHg of compression) can be helpful to relieve symptoms (D). Since these patients have peripheral vasomotor instability, relative vasodilators such as alcohol and extreme heat (C) will exacerbate symptoms.
A structured exercise program (B) has been shown to decrease symptoms and improve quality-of-life measures, presumably through better conditioning and resting tone. In a study by Fu et al, patients who followed a structured exercise regimen increased their blood volume, stroke volume, and left ventricular mass over three months. The authors found that the practice of exercise – not simply the ability to do exercise – is the key in this population.
Other outpatient modalities include fludrocortisone (to enhance sodium retention and therefore volume), DDAVP
(vasopressin-like activity to retain water without retaining sodium), β-blockers (to blunt tachycardic response to standing), and clonidine (decreases centrally mediated CNS outflow).
Bottom Line:
● Assess your patient for emergent causes of postural tachycardia (bleeding, infection, and cardiac,
neurologic, metabolic, toxic, and hematologic conditions)
● In the otherwise well patient with recurrent symptoms, frankly (and of course compassionately) discuss with
the patient the limitations of the acute care investigation and consider recommending a trial of
non-pharmacologic therapy until the patient is able to follow up with the primary care provider
References
Fu Q, Vangundy TB, Galbreath MM, Shibata S, Jain M, Hastings JL, Bhella PS, Levine BD. Cardiac origins of the postural orthostatic tachycardia syndrome. J Am Coll Cardiol. 2010;55:2858-2868.
Raj SR. Clinician Update: Postural Tachycardia Syndrome (POTS). Circulation. 2013;127:2336-2342.
Schondorf R, Low PA. Idiopathic postural orthostatic tachycardia syndrome: an attenuated form of acute pandysautonomia. Neurology. 1993;43:132–7.
Outpatient treatment for POTS includes maximizing volume: patients are asked to increase water intake to 8-10 cups of water daily and to increase their sodium intake up to 8 to 10 g/day (A). (Parenthetically, these patients do well after normal saline in the ED.) Elastic support stockings or hose (medical stockings that support 30 mmHg of compression) can be helpful to relieve symptoms (D). Since these patients have peripheral vasomotor instability, relative vasodilators such as alcohol and extreme heat (C) will exacerbate symptoms.
A structured exercise program (B) has been shown to decrease symptoms and improve quality-of-life measures, presumably through better conditioning and resting tone. In a study by Fu et al, patients who followed a structured exercise regimen increased their blood volume, stroke volume, and left ventricular mass over three months. The authors found that the practice of exercise – not simply the ability to do exercise – is the key in this population.
Other outpatient modalities include fludrocortisone (to enhance sodium retention and therefore volume), DDAVP
(vasopressin-like activity to retain water without retaining sodium), β-blockers (to blunt tachycardic response to standing), and clonidine (decreases centrally mediated CNS outflow).
Bottom Line:
● Assess your patient for emergent causes of postural tachycardia (bleeding, infection, and cardiac,
neurologic, metabolic, toxic, and hematologic conditions)
● In the otherwise well patient with recurrent symptoms, frankly (and of course compassionately) discuss with
the patient the limitations of the acute care investigation and consider recommending a trial of
non-pharmacologic therapy until the patient is able to follow up with the primary care provider
References
Fu Q, Vangundy TB, Galbreath MM, Shibata S, Jain M, Hastings JL, Bhella PS, Levine BD. Cardiac origins of the postural orthostatic tachycardia syndrome. J Am Coll Cardiol. 2010;55:2858-2868.
Raj SR. Clinician Update: Postural Tachycardia Syndrome (POTS). Circulation. 2013;127:2336-2342.
Schondorf R, Low PA. Idiopathic postural orthostatic tachycardia syndrome: an attenuated form of acute pandysautonomia. Neurology. 1993;43:132–7.