Wednesday, May 04, 2011
Postural orthostatic tachycardia syndrome (POTs)
The above video from Mayo Clinic explains it well. (HT to Clinical Cases and Images).
Two free full text reviews are available (see here and here).
Points of interest:
POTS is a “pervasive” circulatory disease involving multiple autonomic and volume regulating mechanisms.
Ganglionic acetylcholine receptor antibodies are found in a small percentage of patients suggesting that it is an autoimmune disorder in some.
Although a genetic mechanism has been found in some patients (involving norepi re-uptake) environmental factors are suggested by the cases that follow viral illness and surgery.
In additional to circulatory symptoms a wide variety of non-circulatory symptoms (GI, constitutional) have been described as being frequent.
Tilt-table testing is the principal diagnostic modality. It can also test for vaso-vagal syncope and orthostatic hypotension, conditions which overlap considerably with POTS.
Many treatments are discussed in the review articles. The Mayo video emphasizes exercise, adequate fluid and salt intake and beta blockers as the principal therapeutic approaches. Beta blockers, however, are controversial, are down played in one of the above linked reviews and considered contraindicated in the other.