Founder of Health Rising and Phoenix Rising
Among the POTS patients, 82.6% fulfilled the diagnostic criteria for POTS in the morning and 52.2% in the afternoon.
This study found that many people who meet the criteria for POTS in the morning don't do so in the afternoon.
It also found that most people who eventually test positive for POTS pass a single POTS; i.e. it's probably necessary to test for it several times. This is at least the second study to suggest this is so.
If a doctor schedules you for a POTS test give them this study and try to get it done in the morning, and if possible, get a couple of tests done.
There is a caveat, though. Almost 50% of the people who test positive for POTS don't have any symptoms of orthostatic intolerance. I don't know if anyone knows why some people with hearts racing have issues while others don't. Clearly more than the heart rate is involved, though.
This big difference between POTS tests in the morning vs afternoon brings up the question whether you are a morning or evening person. Before ME/CFS I couldn't say, but after ME/CFS it's clear I'm not a morning person. All my symptoms are worse in the morning and best in the late afternoon or evening.
Take the "Best time of the day poll" here and let us know.
J Am Soc Hypertens. 2016 Mar;10(3):263-70. doi: 10.1016/j.jash.2016.01.011. Epub 2016 Jan 19.The complexity of diagnosing postural orthostatic tachycardia syndrome: influence of the diurnal variability.Moon J1, Lee HS2, Byun JI2, Sunwoo JS2, Shin JW3, Lim JA2, Kim TJ2, Shin YW2, Lee KJ2, Jeon D2, Jung KH2, Lee ST2, Jung KY2, Chu K4, Lee SK5.
We investigated how the diagnosis of postural orthostatic tachycardia syndrome (POTS) would be changed due to diurnal variability inorthostatic tachycardia. The orthostatic vital sign test was administered to each patient twice, in the afternoon of the day of admission and the next morning (n = 113). Forty-six patients were diagnosed with POTS, and the remaining 67 patients were assigned to non-POTS group. Heart rate increments after standing were larger in the morning than in the afternoon in every group (all P < .001).
Among the POTS patients, 82.6% fulfilled the diagnostic criteria for POTS in the morning and 52.2% in the afternoon. Most POTS group (65.2%) displayed normal result on single orthostatic vital sign test. Orthostatic intolerance symptoms were provoked in only 45.7% of the POTS patients, more frequently in the morning.
In conclusion, diurnal variability in hemodynamic parameters and provoked symptoms significantly challenged the diagnosis of POTS.