Postural Orthostatic Tachycardia Syndrome
POTS is a disorder of the autonomic nervous system in which the cardinal manifestation is symptomatic orthostatic tachycardia. POTS patients have high levels of heart rate increase, high levels of upright plasma norepinephrine, and many patients have a low blood volume.
POTS is characterized by orthostatic tachycardia in the absence of hypotension. Patients with POTS have symptoms which include lightheadedness, exercise intolerance, fatigue, headache, and mental clouding. They also may demonstrate difficulty sleeping and especially diminished stage II sleep similar to those who suffer from insomnia. POTS patients frequently complain of significant exercise intolerance including activities of daily living. The disorder primarily affects woman of childbearing age with a ratio of 4:1, with autoimmune diseases and irritable bowel syndrome additionally being seen in patients with POTS. Patients frequently report that their symptoms onset was following an acute stressor such as pregnancy or major surgery or may develop more insidiously. About 80% of female patients report an exacerbation of symptoms in the premenstrual phase of their ovulatory cycle.
Physical findings with postural orthostatic tachycardia syndrome include acrocyanosis, low blood volume, dysautonomia, high levels of circulating norepinephrine, excessive sympathetic discharge, and Mast cell activation. Acrocyanosis is identified by skin color changes, dark red mottling in the distal part of the limbs especially the LE with standing.
Comparing normal subjects to POTS’s patients with a 60 degree head up tilt table test over a period of 30 minutes, POTS patients demonstrate normal blood pressure, but a greater than or equal to 30 beats per minute increase in resting heart rate. In younger patients (12-19 years) a > 40 beats per minute change should be used. Patients with POTS are differentiated from those with orthostatic hypotension in that those with hypotension have a fall in blood pressure on standing up with a decrease greater than 20 mm systolic and 10 mm of the diastolic pressure.
A common physical clinical finding with POTS patients is a restriction of peripheral nerve mobility, and especially the sympathetic nervous system is located primarily in the thoracolumbar spine. Patients with POTS often have mild to moderate laxity of connective tissue including muscles, ligaments, and tendons, but a paradoxical reduction in the mobility of nerves, especially the sympathetic chain ganglia located in the thoracic and upper lumbar regions. Many patients will present with a flat lumbar and thoracic curvature to the spine, which anatomically places the sympathetic chain ganglia in a posture that eases tension on that structure. When patients perform normal activities of daily living, or sports activities which require more excursion of their joints, this may place extra stress on the tight nervous system. Through manipulation of the nervous system, if its length can be normalized, it can help improve the function of the sympathetic nervous system. A physical therapist well versed in the pathophysiology of the nervous system, and methods of nervous system manipulation will help in reducing many physical manifestations of the disorder. A Silver Spring physical therapist who understands the pacing requirements of these patients can also help in restoring function to this group, through graded exercise.
The physical therapists at SP.OR.T.S. are knowledgeable on POTS evaluation and treatment. Contact Sports & Orthopaedic Therapy Services in Silver Spring, MD, if you are having difficulty managing your signs and symptoms with a diagnosis of POTS.