Clinical Definition or Criteria to Diagnose OH & POTS

To make a diagnosis of OH (NMH) or POTS, a certain set of conditions or criteria need to be met. This set of criteria has been set as guidelines by the physician specialists in cardiology and neurology.

Postural Orthostatic Tachycardia Syndrome, POTS, is a syndrome - that means that there are groups of clinical symptoms and characteristics. Not all people have the same symptoms. Not everyone has the same results with the different tests such as the Tilt Table (HUT), levels of norepinephrine NE), and immunologic studies.

Not a lot is understood about the differences in POTS. Some of the differences in test results are just known; it is not yet understood what they mean. We need more information to understand how the differences affect a person's symptoms and life, how they might change management and what they mean for recovery.

To Diagnose Orthostatic Hypotension (OH)

Criteria for the diagnosis of OH: The basic or classic OH is defined as a decrease in the blood pressure (BP) when the person stands up.¹ The BP goes down in the first 3 minutes after the person stands up.

To be "classic OH", the systolic blood pressure (top number) has to go down by at least 20 mmHg or the diastolic (bottom number) drops by 10 mmHg or more. If the person gets orthostatic symptoms, like dizziness or lightheaded feeling, vision change, and feeling of weakness, it is considered to be diagnostic ( the diagnosis is made for orthostatic hypotension (OH). If the person does not get these symptoms, there is still a strong likelihood that the person has orthostatic hypotension (OH).

Additional Criteria: In their 2009 Guidelines, the Task Force for the Diagnosis and Management of Syncope of the European Society of Cardiology, which published the guidelines in collaboration with the Heart Rhythm Society (USA), the American geriatrics Society (AGS) and the American Autonomic Society (AAS) included another potential criteria for the diagnosis: a decrease in systolic (top number)blood pressure (BP) to less than 90 mmHg.⁵

Example:
—The person's BP lying down is 120/80 mmHg. Pulse is 74.
—After standing up for 3 minutes, the blood pressure is 90/64 mm Hg.
—The pulse is still 74.
—The person feels dizzy, has vision change, & weakness.
—This would be "orthostatic hypotension".

Other Names Based on When Symptoms Start:   The drop in blood pressure (BP) and symptoms can come at different times.

If the BP drops
   •   Within 15 seconds of standing up - it's called "initial orthostatic hypotension"¹.
   •   Within 3 minutes of standing up - it's called "classic orthostatic hypotension"¹.
   •   After 3 minutes of standing - it's called "delayed orthostatic hypotension".¹

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To see a comparison of the symptoms , the time symptoms develop the BP and pulse changes, and the diagnosis, go to OI by Time of Symptoms.

For details about orthostatic hypotension, go to Orthostatic Hypotension.

  To Diagnose POTS - Clinical Definition

The definition does not require special testing to get the information about blood pressure, pulse and symptoms. The information can be collected in the physician's office or through a clinical study like a tilt table test.

Criteria: First,a person lies down for 5-20 minutes. Then the blood pressure and pulse are taken lying down. Then, they stand up.

A person is thought to have POTS if  in the first 10 minutes after standing the following 2 things happen: ^1,2
    •  their heart rate goes up at least 30 beats per minute OR it goes higher than 120 beats per minute AND
    •  they get orthostatic symptoms.

This is the criteria used for adults. Some of the studies suggest that the heart rate may be higher with children and adolescents who have POTS.

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Some will call it "mild orthostatic intolerance' if the heart beat goes up more than 30 beats but it doesn't get to 120 bpm⁶.

BP changes: The blood pressure may stay the same, have a small decrease or there might be a small increase.⁷

Some believe other factors should be considered:
 »  The person is not on any medication that would affect the vascular or autonomic tone³
 »  The person has not been on prolonged bedrest.³
 »  The person should have had symptoms for more than 3 months.¹
 »  Other autonomic symptoms that may be present: abnormal sweating, altered ability to regulate body temperature and changes in the bowel and bladder function.¹

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 •  See OI - First Evaluation or Visit for more information about the in-office Standing Up test for blood pressure/pulse.
 •  See Other Tests for the Neural Cause of Syncope and OI to learn more about testing (tilt-table).
 •  For more about POTS - POTS

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References

1. Grubb BP. Postural tachycardia syndrome. Circulation. 2008;117:2814–2817. Abstract. Article PDF.
2. Medow MS, Stewart JM, Sanyal S, Mumtaz A, Stca D and Frishman WH. Pathophysiology, Diagnosis, and Treatment of Orthostatic Hypotension and Vasovagal Syncope. Cardiology in Review 2008;16(1):4-20. Abstract
3. Grubb BP, Row P, Calkins H. Postural tachycardia, orthostatic intolerance and the chronic fatigue syndrome. In: Grubb BP, Olshansky B, eds. Syncope: Mechanisms and Management 2nd Ed. Malden, Mass: Blackwell/ Future Press; 2005:225–244.
4. Thieben MJ, Sandroni P, Sletten DM, et al. Postural orthostatic tachycardia syndrome: The Mayo Clinic experience. Mayo Clin Proc. 2007;82:308–313. Abstract. Article PDF.
5. Moya, Guidelines for the diagnosis and management of syncope (version 2009). European Heart Journal (2009); 30: 2631-2671. Abstract. Article PDF.
6. Low PA, Sandroni P, Joyner and Shen W. Postural Tachycardia Syndrome (POTS). J Cardopvasc Electrophysiology 2009; 20:352-358.  Abstract.  Article PDF
7. Low P, Opfer-Gehrking T, Textor S, Benarroch E, Shen W, Schondorf R, Suarez G, Rummans T. Postural tachycardia syndrome (POTS). Neurology. 1995;45:519–525. Abstract.

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