POTS and NMH

Lilly Pond at the Arboretum

Since it's Dysautonomia Awareness Month, I thought I'd continue to share a little more about the nitty gritty of these illnesses.

Dysautonomia, as I posted earlier, is a dysregulation of the autonomic nervous system. It is an umbrella term that encompasses several different types of dysfunction.

I have two types of what is called Orthostatic Intolerance: Postural Orthostatic Tachycardia Syndrome (POTS) and Neurally Mediated Hypotension (NMH).

Those of us with OI like to joke that we are 'allergic to gravity!'

The most helpful document I could find explaining these illnesses is available on the CFIDS Association of America website. I highly recommend this for any doctors who find themselves seeing a patient with dysautonomia, for new patients, or even for those of us who have been sick for a long time and need a refresher course. There is also a webinar and slides by Dr. Peter Rowe available. Many other resources are available, and I will share those in a separate post.

Orthostatic Intolerance (OI) is defined by Dr. Peter Rowe at Johns Hopkins University Children's Hospital as:

"an umbrella term for several conditions in which symptoms are made worse by upright posture and improve with recumbency."  

Both NMH and POTS are forms of chronic orthostatic intolerance. As Dr. Rowe states: 

"Hypotension is the medical term for low blood pressure (BP), and tachycardia is the medical term for an increased heart rate (HR)."

Quoting directly from Dr. Rowe's written materials on the CFIDS site:

Postural tachycardia syndrome refers to an exaggerated increase in heart rate with standing. A healthy individual usually has a slight increase in heart rate—by about 10-15 beats per minute—within the first 10 minutes of standing. POTS is considered present if the heart rate increases by 30 beats per minute, or if it reaches 120 beats per minute or higher over the first 10 minutes of standing, accompanied by orthostatic symptoms. POTS is an abnormality in the regulation of heart rate; the heart itself is usually normal.  

As for Neurally Mediated Hypotension (NMH), the Mayo Clinic describes NMH as "low blood pressure from faulty brain signals".

Dr. Rowe describes it as follows:

Neurally mediated hypotension refers to a drop in blood pressure that occurs after being upright. We define NMH by a drop in systolic BP of 25 mm Hg (compared to the BP measured when the person is lying flat) during standing or upright tilt table testing. Although NMH may be slightly more common in people with a low resting blood pressure, most people who develop NMH during standing have a normal resting blood pressure. NMH is an abnormality in the regulation of blood pressure during upright posture. It occurs if too little blood circulates back to the heart when people are upright, a situation that can trigger an abnormal reflex interaction between the heart and the brain that results in a lowering of blood pressure. NMH is sometimes known by the following names: the fainting reflex, delayed orthostatic hypotension, neurocardiogenic syncope, vasodepressor syncope, vaso-vagal syncope. Syncope is the medical term for fainting. 

As Dr. Rowe states, it's also important to note:

Some patients with POTS in the first 10 minutes of upright standing or tilt testing will go on to develop NMH if the test is continued; the two conditions often are found together, and they are not mutually exclusive diagnoses. 

Upon standing two things happen to me:

1. My blood pressure drops

2. My heart rate increases

In my next awareness post, I'll explain how this is diagnosed. In general, because I have so many different symptoms and am not strictly a POTS patient or NMH patient, we refer to me as having Autonomic Nervous System (ANS) Dysfunction or Dysautonomia.

Blessings,

Emily

Note: This post accidentally went out on Monday at the same time as the Monday Dog Blog. Both are now up on my blog, if you click the hot link in the email. Also, any YouTube videos do not show up if you are an email subscriber, and you must click the hot link to go to my blog to view videos. Thanks!