Postural Orthostatic Tachycardia Syndrome (POTS) is associated with the onset of tachycardia upon postural change. The current diagnosis involves the measurement of heart rate (HR) and blood pressure (BP) during head-up tilt (HUT) or sit-to-stand test. A positive diagnosis is made if HR changes more than 40 bpm (30 bpm in children younger than 20 ), ignoring all of the BP and most of the HR signals. This study examines 0.1 Hz oscillations in heart rate and blood pressure providing new metrics characterizing the efficacy of the baroreflex. We  extract beat-to-beat HR and SBP during a 10 min interval from 30 controls and 30 POTS patients . We employ Uniform Phase Empirical Mode Decomposition (UPEMD) extracting 0.1 Hz stationary modes from both signals and use  k-means clustering to analyze the outcomes. Results show that the amplitude of the 0.1 Hz oscillations is higher in POTS patients and that the phase response between the two signals is faster . POTS is associated with an increase in 0.1 Hz oscillations in SBP and HR . The best disease indicator is the phase response between the two signals significant both at rest and HUT . The 0.1 Hz phase response and oscillation amplitude metrics provide new markers that can improve POTS diagnostic , eliminating the need for postural change , which often is associated with dizziness or fainting .
Postural Orthostatic Tachycardia Syndrome (POTS) is associated with the onset of tachycardia upon postural change. The current diagnosis involves the measurement of heart rate (HR) and blood pressure (BP) during head-up tilt (HUT) or active standing test. A positive diagnosis is made if HR changes with more than 30 bpm (40 bpm in patients aged 12-19 years ), ignoring all of the BP and most of the HR signals. This study examines 0.1 Hz oscillations in systolic arterial blood pressure (SBP) and HR signals providing additional metrics characterizing the efficacy of the baroreflex. We analyze data from 28 control subjects and 28 POTS patients who underwent HUT. We extract beat-to-beat HR and SBP during a 10 min interval including 5 minutes of baseline and 5 minutes of HUT . We employ Uniform Phase Empirical Mode Decomposition (UPEMD) to extract 0.1 Hz stationary modes from both signals and use random forest machine learning and k-means clustering to analyze the outcomes. Results show that the amplitude of the 0.1 Hz oscillations is higher in POTS patients and that the phase response between the two signals is shorter (p < 0.005) . POTS is associated with an increase in the amplitude of SBP and HR 0.1 Hz oscillation and a shortening of the phase between the two signals . The 0.1 Hz phase response and oscillation amplitude metrics provide new markers that can improve POTS diagnostic augmenting the existing diagnosis protocol only analyzing the change in heart rate .
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sit-to-stand
active standing
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more than 40 bpm (30 bpm in children younger than 20
with more than 30 bpm (40 bpm in patients aged 12-19 years
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heart rate and blood pressure providing new
systolic arterial blood pressure (SBP) and HR signals providing additional
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analyze data from 28 control subjects and 28 POTS patients who underwent HUT. We
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from 30 controls and 30 POTS patients
including 5 minutes of baseline and 5 minutes of HUT
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extracting
to extract
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random forest machine learning and
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faster
shorter (p < 0.005)
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0.1 Hz oscillations in
the amplitude of
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. The best disease indicator is the phase response
0.1 Hz oscillation and a shortening of the phase
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significant both at rest and HUT
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, eliminating the need for postural change , which often is associated with dizziness or fainting
augmenting the existing diagnosis protocol only analyzing the change in heart rate