scholarly journals Cerebral autoregulation is preserved in postural tachycardia syndrome

2005 ◽  
Vol 99 (3) ◽  
pp. 828-835 ◽  
Author(s):  
Ronald Schondorf ◽  
Julie Benoit ◽  
Reuben Stein
Keyword(s):  
Blood Pressure ◽  
Cerebral Autoregulation ◽  
Orthostatic Intolerance ◽  
Blood Velocity ◽  
Postural Tachycardia Syndrome ◽  
Cerebrovascular Resistance ◽  
Control Subjects ◽  
Postural Tachycardia ◽  
Cerebral Blood Velocity ◽  
Dynamic Cerebral Autoregulation

To test whether cerebral autoregulation is impaired in patients with postural tachycardia syndrome (POTS), we evaluated 17 healthy control subjects and 27 patients with POTS. Blood pressure, heart rate, and cerebral blood velocity (transcranial Doppler) were recorded at rest and during 80° head-up tilt (HUT). Static cerebral autoregulation, as assessed from the change in cerebrovascular resistance during HUT, was the same in POTS and in controls. The properties of dynamic cerebral autoregulation were inferred from transfer gain, coherence, and phase of the relationship between blood pressure and cerebral blood velocity estimated from filtered data segments (0.02–0.8 Hz). Dynamic cerebral autoregulation of patients with POTS did not differ from that of controls. The patients' dynamic cerebral autoregulation did not change over the course of HUT, despite increased tachycardia suggestive of worsening orthostatic stress. Inflation of military anti-shock trouser pants substantially reduced the tachycardia of patients with POTS without affecting cerebral autoregulation. Symptoms of orthostatic intolerance were reduced in one-half of the patients following military anti-shock trouser pants inflation. We conclude that cerebral perfusion and autoregulation in many patients with POTS do not differ from that of normal control subjects.

Dynamic cerebral autoregulation is preserved in neurally mediated syncope

2001 ◽  
Vol 91 (6) ◽  
pp. 2493-2502 ◽  
Author(s):  
Ronald Schondorf ◽  
Reuben Stein ◽  
Richard Roberts ◽  
Julie Benoit ◽  
William Cupples
Keyword(s):  
Cerebral Autoregulation ◽  
Orthostatic Intolerance ◽  
Normal Subjects ◽  
Cerebrovascular Resistance ◽  
Control Subjects ◽  
Neurally Mediated Syncope ◽  
Cerebral Blood Velocity ◽  
Head Up Tilt ◽  
The Relationship ◽  
Dynamic Cerebral Autoregulation

To test whether cerebral autoregulation is impaired in patients with neurally mediated syncope (NMS), we evaluated 15 normal subjects and 37 patients with recurrent NMS. Blood pressure (BP), heart rate, and cerebral blood velocity (CBV) (transcranial Doppler) were recorded at rest and during 80° head-up tilt (HUT). Static cerebral autoregulation as assessed from the change in cerebrovascular resistance during HUT was the same in NMS and controls. Properties of dynamic cerebral autoregulation were inferred from transfer gain, coherence, and phase of the relationship between BP and CBV estimated from filtered data segments (0.02–0.8 Hz). During the 3 min preceding syncope, dynamic cerebral autoregulation of subjects with NMS did not differ from that of controls nor did it change over the course of HUT in patients with NMS or in control subjects. Dynamic cerebral autoregulation was also unaffected by the degree of orthostatic intolerance as inferred from latency to onset of syncope. We conclude that cerebral autoregulation in patients with recurrent syncope does not differ from that of normal control subjects.

scholarly journals Rapid changes in vascular compliance contribute to cerebrovascular adjustments during transient reductions in blood pressure in young, healthy adults

2020 ◽  
Vol 129 (1) ◽  
pp. 27-35 ◽  
Author(s):  
M. Erin Moir ◽  
Stephen A. Klassen ◽  
Mair Zamir ◽  
J. Kevin Shoemaker
Keyword(s):  
Blood Pressure ◽  
Cerebral Autoregulation ◽  
Blood Velocity ◽  
Healthy Adults ◽  
Cerebrovascular Resistance ◽  
Vascular Compliance ◽  
Modeling Approaches ◽  
Rapid Changes ◽  
Dynamic Cerebral Autoregulation

Historically, dynamic cerebral autoregulation has been characterized by adjustments in cerebrovascular resistance following systematic changes in blood pressure. However, with the use of Windkessel modeling approaches, this study revealed rapid and large increases in cerebrovascular compliance that preceded reductions in cerebrovascular resistance following standing-induced blood pressure reductions. Importantly, the rapid cerebrovascular compliance response contributed to preservation of systolic blood velocity during the transient hypotensive phase. These results broaden our understanding of dynamic cerebral autoregulation.

scholarly journals Autonomic dysfunction in post-COVID patients with and witfhout neurological symptoms: a prospective multidomain observational study

2021 ◽  
Author(s):  
Alex Buoite Stella ◽  
Giovanni Furlanis ◽  
Nicolò Arjuna Frezza ◽  
Romina Valentinotti ◽  
Milos Ajcevic ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Orthostatic Intolerance ◽  
Neurological Symptoms ◽  
Postural Tachycardia Syndrome ◽  
Symptom Scale ◽  
Autonomic Symptom ◽  
Postural Tachycardia ◽  
Ambulatory Services

AbstractThe autonomic nervous system (ANS) can be affected by COVID-19, and dysautonomia may be a possible complication in post-COVID individuals. Orthostatic hypotension (OH) and postural tachycardia syndrome (POTS) have been suggested to be common after SARS-CoV-2 infection, but other components of ANS function may be also impaired. The Composite Autonomic Symptom Scale 31 (COMPASS-31) questionnaire is a simple and validated tool to assess dysautonomic symptoms. The aim of the present study was to administer the COMPASS-31 questionnaire to a sample of post-COVID patients with and without neurological complaints. Participants were recruited among the post-COVID ambulatory services for follow-up evaluation between 4 weeks and 9 months from COVID-19 symptoms onset. Participants were asked to complete the COMPASS-31 questionnaire referring to the period after COVID-19 disease. Heart rate and blood pressure were manually taken during an active stand test for OH and POTS diagnosis. One-hundred and eighty participants were included in the analysis (70.6% females, 51 ± 13 years), and OH was found in 13.8% of the subjects. Median COMPASS-31 score was 17.6 (6.9–31.4), with the most affected domains being orthostatic intolerance, sudomotor, gastrointestinal and pupillomotor dysfunction. A higher COMPASS-31 score was found in those with neurological symptoms (p < 0.01), due to more severe orthostatic intolerance symptoms (p < 0.01), although gastrointestinal (p < 0.01), urinary (p < 0.01), and pupillomotor (p < 0.01) domains were more represented in the non-neurological symptoms group. This study confirms the importance of monitoring ANS symptoms as a possible complication of COVID-19 disease that may persist in the post-acute period.

scholarly journals Splanchnic hyperemia and hypervolemia during Valsalva maneuver in postural tachycardia syndrome

2005 ◽  
Vol 289 (5) ◽  
pp. H1951-H1959 ◽  
Author(s):  
Julian M. Stewart ◽  
Marvin S. Medow ◽  
Leslie D. Montgomery ◽  
June L. Glover ◽  
Mark M. Millonas
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Blood Volume ◽  
Phase Ii ◽  
Valsalva Maneuver ◽  
Postural Tachycardia Syndrome ◽  
Peripheral Blood Flow ◽  
Control Subjects ◽  
Arterial Resistance ◽  
Postural Tachycardia

Prior work demonstrated dependence of the change in blood pressure during the Valsalva maneuver (VM) on the extent of thoracic hypovolemia and splanchnic hypervolemia. Thoracic hypovolemia and splanchnic hypervolemia characterize certain patients with postural tachycardia syndrome (POTS) during orthostatic stress. These patients also experience abnormal phase II hypotension and phase IV hypertension during VM. We hypothesize that reduced splanchnic arterial resistance explains aberrant VM results in these patients. We studied 17 POTS patients aged 15–23 yr with normal resting peripheral blood flow by strain gauge plethysmography and 10 comparably aged healthy volunteers. All had normal blood volumes by dye dilution. We assessed changes in estimated thoracic, splanchnic, pelvic-thigh, and lower leg blood volume and blood flow by impedance plethysmography throughout VM performed in the supine position. Baseline splanchnic blood flow was increased and calculated arterial resistance was decreased in POTS compared with control subjects. Splanchnic resistance decreased and flow increased in POTS subjects, whereas splanchnic resistance increased and flow decreased in control subjects during stage II of VM. This was associated with increased splanchnic blood volume, decreased thoracic blood volume, increased heart rate, and decreased blood pressure in POTS. Pelvic and leg resistances were increased above control and remained so during stage IV of VM, accounting for the increased blood pressure overshoot in POTS. Thus splanchnic hyperemia and hypervolemia are related to excessive phase II blood pressure reduction in POTS despite intense peripheral vasoconstriction. Factors other than autonomic dysfunction may play a role in POTS.

Transcranial Doppler Monitoring of Cerebral Blood Velocity During Craniotomy

Neurosurgery ◽  
1989 ◽  
Vol 25 (5) ◽  
pp. 769-776 ◽  
Author(s):  
Cole A. Giller
Keyword(s):  
Blood Pressure ◽  
Transcranial Doppler ◽  
Cerebral Autoregulation ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Cerebral Arteries ◽  
Early Experience ◽  
Blood Velocity ◽  
Doppler Signals ◽  
Cerebral Blood Velocity ◽  
Doppler Techniques

Abstract Transcranial Doppler techniques were used to monitor blood velocity in cerebral arteries continuously during 14 neurosurgical operations performed on 13 patients, including 12 craniotomies. Stable Doppler signals were obtained for prolonged periods of time, and they correlated with intraoperative events. Monitoring during spontaneous blood pressure and CO2 variations allowed assessment of autoregulatory capacity. In particular, 5 of the 7 patients receiving craniotomy for aneurysmal subarachnoid hemorrhage had impaired autoregulation. A 30 to 50% decrease in Doppler velocities was seen in 7 patients after etomidate administration. Early experience suggests that transcranial Doppler monitoring during craniotomy is feasible and can indicate the effects of operative events on blood flow as well as provide an assessment of cerebral autoregulation.

scholarly journals Decreased upright cerebral blood flow and cerebral autoregulation in normocapnic postural tachycardia syndrome

2009 ◽  
Vol 297 (2) ◽  
pp. H664-H673 ◽  
Author(s):  
Anthony J. Ocon ◽  
Marvin S. Medow ◽  
Indu Taneja ◽  
Debbie Clarke ◽  
Julian M. Stewart
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Autoregulation ◽  
Orthostatic Intolerance ◽  
Function Analysis ◽  
Transcranial Doppler Sonography ◽  
Postural Tachycardia Syndrome ◽  
Neurocognitive Deficits ◽  
Postural Tachycardia ◽  
Transfer Function Analysis

Postural tachycardia syndrome (POTS), a chronic form of orthostatic intolerance, has signs and symptoms of lightheadedness, loss of vision, headache, fatigue, and neurocognitive deficits consistent with reductions in cerebrovascular perfusion. We hypothesized that young, normocapnic POTS patients exhibit abnormal cerebral autoregulation (CA) that results in decreased static and dynamic cerebral blood flow (CBF) autoregulation. All subjects had continuous recordings of mean arterial pressure (MAP) and CBF velocity (CBFV) using transcranial Doppler sonography in both the supine supine position and during a 70° head-up tilt. During tilt, POTS patients ( n = 9) demonstrated a higher heart rate than controls ( n = 7) (109 ± 6 vs. 80 ± 2 beats/min, P < 0.05), whereas controls demonstrated a higher MAP than POTS (87 ± 2 vs. 77 ± 3 mmHg, P < 0.05). Also during tilt, mean CBFV decreased 19.5 ± 2.6% in POTS patients versus 10.3 ± 2.0% in controls ( P < 0.05). We then used a transfer function analysis of MAP and CFBV in the frequency domain to quantify these changes. The low-frequency (LF; 0.04–0.15 Hz) component of CBFV variability increased during tilt in POTS patients (supine: 3 ± 0.9 vs. tilt: 9 ± 2, P < 0.02). In POTS patients, there was an increase in LF and high-frequency coherence between MAP and CBFV, an increase in LF gain, and a lack of significant change in phase. Static CA may be less effective in POTS patients compared with controls, since immediately after tilt CBFV decreased more in POTS patients and was highly oscillatory and autoregulation did not restore CBFV to baseline values until the subjects became supine. Dynamic CA may be less effective in POTS patients because MAP and CBFV during tilt became almost perfectly synchronous. We conclude that dynamic and static autoregulation of CBF are less effective in POTS patients compared with control subjects during orthostatic challenge.

scholarly journals Cutaneous constitutive nitric oxide synthase activation in postural tachycardia syndrome with splanchnic hyperemia

2011 ◽  
Vol 301 (3) ◽  
pp. H704-H711 ◽  
Author(s):  
Julian M. Stewart ◽  
Abhinav Nafday ◽  
Anthony J. Ocon ◽  
Courtney Terilli ◽  
Marvin S. Medow
Keyword(s):  
Nitric Oxide ◽  
Dose Response ◽  
Orthostatic Intolerance ◽  
Local Heating ◽  
Postural Tachycardia Syndrome ◽  
Normal Flow ◽  
Control Subjects ◽  
Postural Tachycardia ◽  
Nos Inhibitor ◽  
Neuronal Nos

Models of microgravity are linked to excessive constitutive nitric oxide (NO) synthase (NOS), splanchnic vasodilation, and orthostatic intolerance. Normal-flow postural tachycardia syndrome (POTS) is a form of chronic orthostatic intolerance associated with splanchnic hyperemia. To test the hypothesis that there is excessive constitutive NOS in POTS, we determined whether cutaneous microvascular neuronal NO and endothelial NO are increased. We performed two sets of experiments in POTS and control subjects aged 21.4 ± 2 yr. We used laser-Doppler flowmetry to measure the cutaneous response to local heating as an indicator of bioavailable neuronal NO. To test for bioavailable endothelial NO, we infused intradermal acetylcholine through intradermal microdialysis catheters and used the selective neuronal NOS inhibitor l- Nω-nitroarginine-2,4-l-diamino-butyric amide (Nω, 10 mM), the selective inducible NOS inhibitor aminoguanidine (10 mM), the nonspecific NOS inhibitor nitro-l-arginine (NLA, 10 mM), or Ringer solution. The acetylcholine dose response and the NO-dependent plateau of the local heating response were increased in POTS compared with those in control subjects. The local heating plateau was significantly higher, 98 ± 1%maximum cutaneous vascular conductance (%CVCmax) in POTS compared with 88 ± 2%CVCmax in control subjects but decreased to the same level with Nω (46 ± 5%CVCmax in POTS compared with 49 ± 4%CVCmax in control) or with NLA (45 ± 3%CVCmax in POTS compared with 47 ± 4%CVCmax in control). Only NLA blunted the acetylcholine dose response, indicating that NO produced by endothelial NOS was released by acetylcholine. Aminoguanidine was without effect. This is consistent with increased endothelial and neuronal NOS activity in normal-flow POTS.

Case 67: Ehlers-Danlos Syndrome with Postural Tachycardia Syndrome and Psychogenic Pseudosyncope

2019 ◽  
pp. 349-352
Author(s):  
Peter Novak
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Small Fiber Neuropathy ◽  
Postural Tachycardia Syndrome ◽  
Ehlers Danlos Syndrome ◽  
Postural Tachycardia ◽  
Small Fiber ◽  
Danlos Syndrome

Patient became unresponsive during the first minute of the tilt; she was tachycardic but the blood pressure and cerebral blood flow were stable. Psychogenic pseudosyncope can be superimposed on postural tachycardia syndrome (POTS). Pseudosyncope, small fiber neuropathy, and POTS can be associated with hypermobile Ehlers-Danlos syndrome.

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