by Bill Snyder
Postural tachycardia syndrome (PoTS) is a poorly understood disorder that primarily affects women and is characterized by lightheadedness, extreme fatigue and chronically rapid heart rate upon standing. Currently there is no approved medication to treat it.
There is evidence that patients with PoTS have impaired endothelial function, the inability of arteries to appropriately dilate in response to a stimulus like sheer stress — increased blood flow that raises pressure in the blood vessel wall.
Alfredo Gamboa, MD, MSCI, and colleagues analyzed three measures of endothelial function. Reporting in the journal Hypertension, they determined that one measure, called flow-mediated dilation, was significantly lower in the brachial artery of PoTS patients compared to healthy controls.
While further study is needed, these findings provide new insight into the pathophysiology of PoTS and suggest that therapies aimed at lowering sympathetic tone, such as those used to treat high blood pressure, may relieve the symptoms of this enigmatic and debilitating disease.
The research was supported in part by National Institutes of Health grant TR000445.
