Recent advances in the understanding of the mechanisms underlying postural tachycardia syndrome in children: practical implications for treatment

2016 ◽  
Vol 27 (3) ◽  
pp. 413-417 ◽  
Author(s):  
Xiaochun Zheng ◽  
Yonghong Chen ◽  
Junbao Du
Keyword(s):  
Heart Rate ◽  
Upright Position ◽  
Postural Tachycardia Syndrome ◽  
Postural Orthostatic Tachycardia Syndrome ◽  
Vascular Endothelial ◽  
Vascular Endothelial Function ◽  
Pathophysiological Mechanisms ◽  
Postural Tachycardia ◽  
Β Receptor ◽  
Practical Implications

AbstractPostural tachycardia syndrome is defined by a heart rate increment of 40 beats/minute (bpm) (or a heart rate that exceeds 125 bpm) within 10 minutes of change from the supine position to an upright position in the absence of obvious orthostatic hypotension. There are multiple pathophysiological mechanisms that underlie postural tachycardia syndrome, including peripheral denervation, β-receptor supersensitivity, hypovolaemia, and impaired muscle pump. Some children afflicted with postural orthostatic tachycardia syndrome and hypovolaemic dysregulation have been found to have perturbed renin–angiotensin–aldosterone profile, disturbed vascular endothelial function, and abnormal vasodilation. The hyperadrenergic state in some postural tachycardia syndrome patients is likely a driver for orthostatic tachycardia. Other mechanisms include the presence of treatable autonomic neuropathies. An understanding of these pathophysiological mechanisms might be helpful for the effective treatment of postural tachycardia syndrome.

scholarly journals Characteristics of Heart Rate Reduction with Resumption of Supine Position in the Postural Tachycardia Syndrome: Factors Influencing Recovery

2013 ◽  
Vol 7 (1) ◽  
pp. 36-39 ◽  
Author(s):  
Kenneth A Mayuga ◽  
Christopher E Gaw ◽  
Curtis Tatsuoka ◽  
Fetnat Fouad-Tarazi
Keyword(s):  
Heart Rate ◽  
Supine Position ◽  
Autonomic Function ◽  
Postural Tachycardia Syndrome ◽  
Postural Orthostatic Tachycardia Syndrome ◽  
Rate Reduction ◽  
Postural Tachycardia ◽  
Younger Age ◽  
Head Up Tilt ◽  
Blood Pressures

Objectives: Postural orthostatic tachycardia syndrome (POTS), a heart rate (HR) rise with upright positioning, is dependent on autonomic influences. HR recovery (HR decrease after exercise cessation) is a measure of autonomic function. Characteristics of HR reduction during supine Recovery after head-up Tilt in POTS patients have not been elucidated. Methods: 113 subjects (mean age 41.7 years, 86 female), diagnosed with POTS on head-up Tilt were analyzed. HR’s were recorded during baseline supine position, 70-degree Tilt, and 20 sec, 1 min and 2 min of supine Recovery. Percent HR reduction during Recovery was calculated. Results: Baseline HR was 68.7±13.4 bpm. Maximum HR during Tilt was 109±16.9 bpm. Mean HR was 84.2±20 bpm at 20 sec, 78.5±18.9 bpm at 1-min, and 77.1±18.3 bpm at 2 min of Recovery. Younger age and slower baseline HR were associated with greater HR reductions at 20 sec (p=0.006, p=0.000, respectively). Younger age, slower baseline HR and less time to achieve POTS were associated with greater HR reductions at 1 min (p=0.025, p=0.000, p=0.000, respectively) and at 2 min (p=0.004, p=0.000, p=0.000, respectively). Gender and baseline blood pressures were not significant. Conclusions: In POTS patients, HR quickly decreases upon resuming supine position. Younger age, slower baseline HR and less time to achieve POTS were associated with greater HR reductions during supine Recovery. Further study is needed to determine mechanisms, as well as analyze differences in symptoms or prognosis.

Arterial baroreflex control of heart rate during exercise in postural tachycardia syndrome

2007 ◽  
Vol 103 (4) ◽  
pp. 1136-1142 ◽  
Author(s):  
Shizue Masuki ◽  
John H. Eisenach ◽  
William G. Schrage ◽  
Niki M. Dietz ◽  
Christopher P. Johnson ◽  
...  
Keyword(s):  
Heart Rate ◽  
Baroreflex Sensitivity ◽  
Systolic Pressure ◽  
Upright Position ◽  
Postural Tachycardia Syndrome ◽  
Healthy Controls ◽  
Arterial Baroreflex ◽  
Cycle Exercise ◽  
Baroreflex Control ◽  
Postural Tachycardia

Patients with postural tachycardia syndrome (POTS) have excessive tachycardia without hypotension during orthostasis as well as exercise. We tested the hypothesis that excessive tachycardia during exercise in POTS is not related to abnormal baroreflex control of heart rate (HR). Patients ( n = 13) and healthy controls ( n = 10) performed graded cycle exercise at 25, 50, and 75 W in both supine and upright positions while arterial pressure (arterial catheter) and HR (ECG) were measured. Baroreflex sensitivity of HR was assessed by bolus intravenous infusion of phenylephrine at each workload. In both positions, HR was higher in the patients than the controls during exercise. Supine baroreflex sensitivity (HR/systolic pressure) in POTS patients was −1.3 ± 0.1 beats·min−1·mmHg−1 at rest and decreased to −0.6 ± 0.1 beats·min−1·mmHg−1 during 75-W exercise, neither significantly different from the controls ( P > 0.6). In the upright position, baroreflex sensitivity in POTS patients at rest (−1.4 ± 0.1 beats·min−1·mmHg−1) was higher than the controls (−1.0 ± 0.1 beats·min−1·mmHg−1) ( P < 0.05), and it decreased to −0.1 ± 0.04 beats·min−1·mmHg−1 during 75-W exercise, lower than the controls (−0.3 ± 0.09 beats·min−1·mmHg−1) ( P < 0.05). The reduced arterial baroreflex sensitivity of HR during upright exercise was accompanied by greater fluctuations in systolic and pulse pressure in the patients than in the controls with 56 and 90% higher coefficient of variations, respectively ( P < 0.01). However, when baroreflex control of HR was corrected for differences in HR, it was similar between the patients and controls during upright exercise. These results suggest that the tachycardia during exercise in POTS was not due to abnormal baroreflex control of HR.

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 The preponderance of initial orthostatic hypotension in postural tachycardia syndrome

2020 ◽  
Vol 129 (3) ◽  
pp. 459-466
Author(s):  
Julian M. Stewart ◽  
Archana Kota ◽  
Mary Breige O’Donnell-Smith ◽  
Paul Visintainer ◽  
Courtney Terilli ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Heart Rate Variability ◽  
Cerebral Blood Flow ◽  
Orthostatic Hypotension ◽  
Pressure Recovery ◽  
Postural Tachycardia Syndrome ◽  
Postural Tachycardia ◽  
Initial Orthostatic Hypotension

Significant initial orthostatic hypotension (IOH) occurs in ~50% of postural tachycardia syndrome (POTS) patients and 13% of controls. Heart rate and blood pressure recovery are prolonged in IOH sustaining lightheadedness; IOH is more prevalent and severe in POTS. Altered cerebral blood flow and cardiorespiratory regulation are more prevalent in POTS. Altered heart rate variability and baroreflex gain may cause nearly instantaneous lightheadedness in POTS. IOH alone fails to confer a strong probability of POTS.

068 Morning Cardiovascular Function in Chronic Cannabis Users and Healthy Controls

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A28-A28
Author(s):  
LaTroy Robinson ◽  
Saurabh Thosar ◽  
Alicia Stewart ◽  
Noal Clemons ◽  
Daniel Chess ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Cardiovascular System ◽  
Reactive Hyperemia ◽  
Vascular Endothelial ◽  
Vascular Endothelial Function ◽  
Brachial Artery Diameter ◽  
Cannabis Consumption ◽  
Hyperemic Response

Abstract Introduction In the US cannabis is recreationally legal in 15 states and medically legal in 34 states. Preclinical studies suggest beneficial effects of cannabis on the cardiovascular system (e.g., vasorelaxation). Yet, acute cases of hospitalization after cannabis consumption indicate potential adverse cardiac effects. Vascular endothelial function is a marker of cardiovascular disease and is measured as a change in resting brachial artery diameter (flow-mediated dilation, FMD) during reactive hyperemia. Both resting diameter (positively) and FMD response (negatively) are associated with cardiovascular risk. Resting diameter likely depends on long-term structural changes, and FMD response mostly depends on nitric oxide. Reactive hyperemia is more complex and depends on numerous variables, including adenosine and prostaglandins. FMD is attenuated in the morning when the frequency of adverse cardiovascular events peaks. To begin to understand the effects of chronic cannabis use on the cardiovascular system, in this pilot study, we compared morning measurements of vascular endothelial function, blood pressure, and heart rate between chronic cannabis users and controls while controlling for prior nighttime sleep opportunities. Methods Participants, cannabis non-users (n=5) and users (n=4), 44% female, age 25.4 ± 3.6 years - no demographic differences between groups, kept a consistent 2-week sleep schedule at home followed by an 8h sleep opportunity at their habitual time in the laboratory. Upon-wakening, we measured resting blood pressure, heart rate, baseline diameter, hyperemic response, and FMD. Statistical differences between groups were calculated using a two-tailed t-test. Results Systolic and diastolic blood pressures (p=0.13 and 0.26 respectively), heart rate (p=0.97), and FMD response (p=0.99) did not differ between groups. However, chronic cannabis users had a significantly higher baseline brachial artery diameter (mean difference: 1.04 mm ± 0.26, p=0.005), and lower hyperemic response (mean difference: -7944 iu/s ± 2538, p=0.02) compared to non-users. Conclusion These preliminary findings suggest that chronic cannabis consumption may be associated with adverse structural and functional changes in the vasculature of otherwise healthy young adults. Based on these initial observations, cannabis may act on the cardiovascular system via non-nitric oxide mechanisms. However, it is necessary to increase our sample size to test the robustness of these findings. Support (if any) KL2TR002370, AASM

Case 16: Autonomic Failure or Postural Tachycardia Syndrome?

2019 ◽  
pp. 120-124
Author(s):  
Peter Novak
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Postural Tachycardia Syndrome ◽  
Postural Tachycardia ◽  
Transient Elevation

Small fiber neuropathy is associated with adrenergic failure. Anxiety is common and occasionally can be identified as a transient elevation of heart rate, blood pressure, and cerebral blood flow velocity.

scholarly journals Nitric Oxide and Regulation of Heart Rate in Patients With Postural Tachycardia Syndrome and Healthy Subjects

Hypertension ◽  
2013 ◽  
Vol 61 (2) ◽  
pp. 376-381 ◽  
Author(s):  
Alfredo Gamboa ◽  
Luis E. Okamoto ◽  
Satish R. Raj ◽  
André Diedrich ◽  
Cyndya A. Shibao ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Heart Rate ◽  
Healthy Subjects ◽  
Postural Tachycardia Syndrome ◽  
Postural Tachycardia
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