Onlangs verschenen Frontiers in Pediatrics twee studies van Visser,
van Campen en Rowe.
De eerste studie heeft betrekking op de methode waarop POTS objectief vastgesteld wordt.
Posturaal Orthostatisch TachycardieSyndroom (POTS), een stijging van de hartslag in een staande
positie met meer dan 30 slagen per minuut , komt minder vaak voor dan vaak gesuggereerd wordt.
Van de 627 patiënten met de diagnose ME-ICC én CVS, voldeed 24,7% (155/627) aan de criteria.
Hierbij moet wel worden aangetekend dat mensen met 'POTS' én orthostatische hypotensie (OH),
een sterke bloeddruk) niet als POTS-patiënt aangemerkt werden, zodat 'dubbeltellers' wegvallen.
Overigens blijkt uit de tekst van de studie dat 17,1% (107/627) van de patiënten voldeden aan
de (objectieve) criteria voor orthostatische hypotensie (16 'direct'/binnen 3 minuten, 91 vertraagd).
Daarnaast werd bij 6 patiënten (1%) vasovagale syncope ('flauwvallen') geconstateerd.
Dit betekent dat bij 42,7% van de patiënten objectieve afwijkingen geconstateerd werden.
Een korte kanteltafeltest (2 minuten) is onvoldoende om POTS goed in kaart te brengen,
omdat bij meer dan de helft van de ME/CVS-patiënten met POTS het verschijnsel pas later optreedt.
Vertraagd optredende POTS en/of OH werd reeds in 2000 onderkend door Streeten en anderen.
De tweede studie richtte zich op de relatie tussen orthostatische intolerantie en bloedvolume.
Bij de 8 patiënten met een diagnose orthostatische intolerantie (OI) op basis van symptomen
was het bloedvolume significant lager (56 ml/kg) dan dat van de gemiddelde bevolking (70 ml/kg).
Bij de 4 patiënten zonder de diagnose OI was het bloedvolume niet-significant lager (66 ml/kg).
Overigens werd slechts bij 2 van de 8 patiënten met orthostatische intolerantie POTS vastgesteld.
Van de overige 6 patiënten werd bij een kanteltalfeltest (duur?) elders geen POTS waargenomen.
In hoeverre er, onafhankelijk van POTS, sprake was van OH bij de 8 patiënten is onduidelijk.
Slotopmerking:
Zelf als het bloedvolume normaal is, kan het mitochondriale probleem een (belangrijke) rol spelen.
Low sensitivity of abbreviated tilt table testing for
diagnosing postural tachycardia syndrome in adults with ME/CFS.
Front. Pediatr. 2018 Oct 29. doi: 10.3389/fped.2018.00352.
Van Campen CM, Rowe PC, Visser FC.
Introduction:
Orthostatic intolerance is common
among individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).
In some ME/CFS case definitions,
orthostatic intolerance is considered a core feature of the disorder.
Some studies have employed tilt table tests lasting 2-5 minutes
to diagnose one common form of orthostatic intolerance, postural tachycardia syndrome (POTS).
We examined the diagnostic yield of abbreviated durations of tilt testing
in adults meeting criteria for ME/CFS, and
identified the proportion with POTS misdiagnosed using testing of less than 10 minutes.
Methods:
Eligible participants were consecutive individuals
satisfying study criteria for ME/CFS and POTS
evaluated at the Stichting CardioZorg (SCZ, Hoofddorp, NL)
between November 2012 and August 2018.
Individuals being treated
with medications commonly used to manage orthostatic intolerance were excluded.
Head-up tilt table testing involved
15 minutes of supine posture then 20 minutes at 70 degrees upright.
Only the data from the first 10-minutes upright were used.
POTS was defined as
an increase in HR during a maximum of 10 minutes of upright tilt
of at least 30 beats per minute (bpm),
in the absence of either classical or delayed orthostatic hypotension.
We measured the time until HR criteria for POTS were reached
using survival curves, and compared survival curves between subgroups
divided by age, sex, disease duration, and degree of hypocapnia during the test.
Results:
Of 627 individuals with ME/CFS evaluated during the study period,
155 met criteria for POTS.
The median time to reaching HR criteria for POTS was 3 minutes.
A two-minute tilt table test would miss 55% (95% CI, 48 - 63%)
of those meeting POTS criteria over the course of 10 minutes upright.
The median time to reaching HR criteria for POTS
did not differ by sex, age, duration of ME/CFS, or hypocapnia during tilt.
Conclusions:
Abbreviated tilt table testing misses a substantial proportion
of those ultimately diagnosed with POTS during a 10-minute tilt table test, and
should be abandoned for the clinical diagnosis and in epidemiologic studies
designed to estimate the prevalence of POTS among those with ME/CFS.
Keywords:
Postural tachycardia syndrome, chronic fatigue syndrome, Myalgic encephalomyelitis,
Orthostatic Intolerance, Tilt table test
https://www.frontiersin.org/articles/10.3389/fped.2018.00349/full
Blood volume status in CFS/ME correlates with the presence or absence of orthostatic symptoms.
Front. Pediatr. 2018 Oct 29. doi: 10.3389/fped.2018.00352.
Van Campen CM, Rowe PC, Visser FC.
Introduction:
Conflicting data have been published on
the reduction of circulating blood volume
in adults with Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).
The aim of the present study was
to compare blood volumes based on the presence or absence of orthostatic symptoms.
Methods and results:
12 consecutive adults with ME/CFS participated in the study.
All underwent dual isotope blood volume measurement and
were evaluated for a clinical suspicion of orthostatic intolerance (OI).
The mean age was 34 (10) years, and median duration of disease was 7.5 (6-10) years.
The mean (SD) absolute blood volume was 59 (8) ml/kg,
a value -11 (7) ml/kg below the reference blood volume.
Of the 12 patients,
4 had no OI and
8 had a clinical suspicion of OI.
In 8 patients with OI, absolute blood volumes
were significantly lower than for the 4 without OI (56 [2] vs 66 [5]; p<0.05) as were
the differences between the measured and the reference blood volume (-14 [2]; vs -4 [3]; p<0.02).
Conclusions:
Adults with ME/CFS had a significantly lower blood volume
if they had a clinical suspicion of OI
compared to those without a clinical suspicion of OI,
as well as a significantly lower blood volume compared to the expected value.
The data suggest that accounting for symptoms of OI
could enhance the detection of the subset with reduced blood volume.
Keywords:
Orthostatic Intolerance, Chronic fatigue syndrome (CFS), Myalgic encephalomyelitis (ME),
Blood volume assessment, Dual isotope imaging
https://www.frontiersin.org/articles/10.3389/fped.2018.00352/full
|
