Poor (wo)man’s tilt test and treatment options
POTS is typically diagnosed with a tilt test and transcranial Doppler. Dr. Taub described her “poor man’s tilt test” of asking the patient to lie down for 5-10 minutes and then having the patient stand up.
She likes the fact that transcranial Doppler helps validate the brain fog that patients report, which can be dismissed as “just your excuse for not wanting to work.” If blood perfusion to the brain is cut by 40%-50%, “how are you going to think clearly?” she said.
Dr. Shouman noted that overall volume expansion with salt water, compression garments, and a graduated exercise program play a major role in the rehabilitation of all POTS patients.
He likes to tailor treatments to the most likely underlying cause. But patients should first undergo a medical assessment by their internists to make sure there isn’t a primary lung or heart problem.
“Once the decision is made for them to be evaluated in the autonomic practice and [a] POTS diagnosis is made, I think it is very useful to determine what type of POTS,” he said.
With hyperadrenergic POTS, “you are looking at a standing norepinephrine level of over 600 pg/mL or so.” For these patients, drugs such as ivabradine or beta-blockers can help, he noted.
Dr. Taub recently conducted a small study that showed a benefit with the selective If channel blocker ivabradine for patients with hyperadrenergic POTS unrelated to COVID-19. She tends to favor ivabradine over beta-blockers because it lowers heart rate but not blood pressure. In addition, beta-blockers can exacerbate fatigue and brain fog.
A small crossover study will compare propranolol and ivabradine in POTS. For someone who is very hypovolemic, “you might try a salt tablet or a prescription drug like fludrocortisone,” Dr. Taub explained.
Another problem that patients with POTS experience is an inability to exercise because of orthostatic intolerance. Recumbent exercise targets deconditioning and can tamp down the hyperadrenergic effect. Dr. Shouman’s approach is to start gradually with swimming or the use of a recumbent bike or a rowing machine.
Dr. Taub recommends wearables to patients because POTS is “a very dynamic condition” that is easy to overmedicate or undermedicate. If it’s a good day, the patients are well hydrated, and the standing heart rate is only 80 bpm, she tells them they could titrate down their second dose of ivabradine, for example. The feedback from wearables also helps patients manage their exercise response.
For Dr. Shouman, wearables are not always as accurate as he would like. He tells his patients that it’s okay to use one as long as it doesn’t become a source of anxiety such that they’re constantly checking it.
POTS hope: A COVID-19 silver lining?
With increasing attention being paid to long-haul COVID-19, are there any concerns that POTS will get lost among the myriad symptoms connected to PASC?
Dr. Shouman cautioned, “Not all long COVID is POTS,” and said that clinicians at long-haul clinics should be able to recognize the different conditions “when POTS is suspected. I think it is useful for those providers to make the appropriate referral for POTS clinic autonomic assessment.”
He and his colleagues at Mayo have seen quite a few patients who have post–COVID-19 autonomic dysfunction, such as vasodepressor syncope, not just POTS. They plan to write about this soon.
“Of all the things I treat in cardiology, this is the most complex, because there’s so many different systems involved,” said Dr. Taub, who has seen patients recover fully from POTS. “There’s a spectrum, and there’s people that are definitely on one end of the spectrum where they have very severe diseases.”
For her, the important message is, “No matter where you are on the spectrum, there are things we can do to make your symptoms better.” And with grant funding for PASC research, “hopefully we will address the mechanisms of disease, and we’ll be able to cure this,” she said.
Dr. Patel has served as a consultant for Bayer, Janssen, AstraZeneca, and Heartflow and has received research grants from Bayer, Janssen, AstraZeneca, and the National Heart, Lung, and Blood Institute. Dr. Shouman reports no relevant financial relationships. Dr. Taub has served as a consultant for Amgen, Bayer, Esperion, Boehringer Ingelheim, Novo Nordisk, and Sanofi; is a shareholder in Epirium Bio; and has received research grants from the National Institutes of Health, the American Heart Association, and the Department of Homeland Security/FEMA.
A version of this article first appeared on Medscape.com.