Normal versus abnormal: What normative data tells us about the utility of heart rate in postural tachycardia, 2019, Baker and Kimpinski

[Ken Turnbull]

The original criterion in the 1993 Schondorf-Low paper was 2SD above the mean for a sex-matched control population which excluded children and adolescents. I'm not sure who originally proposed the 30bpm value but in the 2011 consensus statement the definition is characterized by a sustained heart rate increment of 30 beats/minute within 10 min of standing or head-up tilt. . . For individuals aged 12–19 years the required increment is at least 40 beats/minute.

I don't have the energy to check right now but the history is fairly well-documented in the Gall et al. "Postural Tachycardia Syndrome" book.

I had a look in the textbook but it doesn’t seem to cover the decision on the 30 BPM, unfortunately.

 

[Ken Turnbull]

Dr Peter Novak has commented that he suspects that the majority of chronic orthostatic intolerance is not accompanied by orthostatic abnormalities in blood pressure or heart rate.

But he did describe two new types of chronic OI that fit this profile, so we have to consider that he may be overstating this possibility due to his personal interest in helping those patients:

https://www.brighamhealthonamission...o-pinpoint-causes-of-orthostatic-intolerance/

“We can now diagnose people who were previously thought to have psychiatric illness or had no diagnosis at all,” said Novak.”

 

[Nightsong]

I had a look in the textbook but it doesn’t seem to cover the decision on the 30 BPM, unfortunately.

Thanks. We thought the value was probably based on the Streeten paper (J Lab Clin Med 1988; 111(3):326-35) which I eventually tracked down. The results are in Table 1 - as you can see the upper end for the healthy population is +27 BPM.