Temporal changes in complexity of cardiovascular regulation during head-up tilt test by entropic measures of fluctuations of heart period intervals and systolic blood pressure

2014 ◽  
Author(s):  
Dorota Wejer ◽  
Agnieszka Kaczkowska ◽  
Danuta Makowiec ◽  
Zbigniew R. Struzik ◽  
Beata Graff ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Cardiovascular Regulation ◽  
Temporal Changes ◽  
Tilt Test ◽  
Heart Period ◽  
Head Up Tilt ◽  
Head Up Tilt Test

scholarly journals Diagnosis and prevention of the vasodepressor type of neurally mediated syncope in Japanese patients

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0251450
Author(s):  
Misaki Hasegawa ◽  
Tomoyoshi Komiyama ◽  
Kengo Ayabe ◽  
Susumu Sakama ◽  
Tetsuri Sakai ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Adenylate Cyclase ◽  
Systolic Blood Pressure ◽  
Healthy Volunteers ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Tilt Test ◽  
Neurally Mediated Syncope ◽  
Head Up Tilt ◽  
Head Up Tilt Test

We investigated circulatory dynamics in patients with vasodepressor type neurally mediated syncope (VT-NMS) by performing high-resolution Holter electrocardiography and a correlation analysis of changes in adenylate cyclase activity, blood pressure, and pulse during the head-up tilt test. Holter electrocardiography was performed for 30 patients. Adenylate cyclase activity was evaluated in lymphocytes from blood samples taken at rest and during the head-up tilt test. There was no change in autonomic nerve fluctuation during electrocardiography in VT-NMS patients, but our results showed a significant difference in blood pressure and adenylate cyclase activity between VT-NMS patients and healthy volunteers; the systolic blood pressure of VT-NMS patients decreased after 5 min, while at 10 min, the adenylate cyclase activity was the highest (0.53%) and the systolic blood pressure was the lowest (111.8 mm Hg). Pulse rates increased after 10 min. VT-NMS patients showed higher blood pressure, pulse rate, and adenylate cyclase activity during the tilt test than did healthy volunteers. In patients with syncope, standing for longer than 10 minutes may increase the risk of VT-NMS. From our results, we consider it likely that high systolic blood pressure and adenylate cyclase activity at rest cause fainting in VT-NMS patients. Our findings may be helpful for identifying individuals with a high risk of developing NMS in the healthy population.

scholarly journals Haemodynamic Characteristics And Factors Influencing The Head-Up Tilt Test In Patients With Orthostatic Hypotension

2021 ◽  
Author(s):  
Wang Jiayu ◽  
Wu Yueyang ◽  
Wang Yongjun ◽  
Zhao Xingquan ◽  
Wang Yilong ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Stroke Volume ◽  
Systolic Blood Pressure ◽  
Orthostatic Hypotension ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Tilt Test ◽  
Head Up Tilt ◽  
Head Up Tilt Test

Abstract Background: Failure to activate autonomic neural and hormonal reflex mechanisms could result in orthostatic hypotension. Patients with orthostatic hypotension often experience symptoms of cerebral hypoperfusion, including syncope. The purpose of this study was to investigate the haemodynamic characteristics of patients with orthostatic hypotension and the factors affecting blood pressure regulation.Methods: This retrospective study enrolled 45 patients who were diagnosed with typical orthostatic hypotension by the head-up tilt test at Beijing Tiantan Hospital, Capital Medical University from June 2019 to December 2020. Changes in haemodynamic parameters in these patients were compared in the supine and tilted upright positions.Results: For all patients, haemodynamic parameters in the supine and tilted upright positions were compared, and systolic blood pressure, diastolic blood pressure, mean blood pressure, cardiac output and stroke volume were all significantly decreased per minute. Heart rate significantly increased per minute, but systemic vascular resistance did not significantly change. The absolute value, percentage and rate of increases in heart rate and the absolute value, percentage and rate of decreases in stroke volume from the supine to the titled upright position were significantly lower in patients 60 years and older than in patients under 60 years old. Linear regression analyses found that the changes in heart rate, stroke volume and systemic vascular resistance were related to changes in systolic blood pressure, while the changes in stroke volume and systemic vascular resistance had more important effects on systolic blood pressure.Conclusions: In patients with orthostatic hypotension, we observed no significant increase in systemic vascular resistance from the supine position to the tilted upright position. Nevertheless, an increase in systemic vascular resistance had a significant impact on the maintenance of systolic blood pressure. In addition, in orthostatic hypotension patients younger than 60 years of age, heart rate increased while stroke volume decreased significantly after tilting upright compared with orthostatic hypotension patients older than 60 years of age and older.

scholarly journals Relation of body mass index (BMI) with cardiovascular response to head up tilt in healthy subjects

2020 ◽  
Vol 15 (1) ◽  
pp. 6-10
Author(s):  
Sadia Afrin Rimi ◽  
Shamima Sultana ◽  
Iffat Rezwana ◽  
Sultana Ferdousi
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Healthy Subjects ◽  
Cardiovascular Response ◽  
Tilt Test ◽  
Tilt Table ◽  
Chi Square ◽  
Female Head ◽  
Head Up Tilt

Background: Tilt table test is used for the last few decades to detect cause in unexplained syncope. The response to tilting may vary physiologically with obesity. Objective: To assess the relationship of BMI to cardiovascular response to tilting. Methods: This experimental study was conducted from March 2019 to Feb 2020 on 90 healthy subjects with different BMI. Fifty one subjects of both gender with BMI 18.5-24.9 kg/m2 were included in the non-obese group and 39 subjects of both gender with BMI of 25-29.9 kg/m2 were included in overweight group and they were further subdivided into male and female. Head up tilting was done for 10 minutes at 600 by using a motorized tilt table. Systolic blood pressure (SBP), diastolic blood pressure (DBP) were recorded by an automatic sphygmomanometer. Heart rate (HR) and peripheral capillary oxygen saturation (SpO2) were measured by a pulse oximeter. For statistical analysis, Independent sample ‘t’ test, Pearson’s correlation test and Chi square tests were applied. Results: Significantly smaller rise of heart rate was observed in overweight males and greater fall of systolic blood pressure was observed in overweight females. Conclusion: This study concluded that over weight is associated with reduced orthostatic tolerance to head up tilt test in both genders. J Bangladesh Soc Physiol. 2020, June; 15(1): 6-10

Abnormal passive head-up tilt test in subjects with symptoms of anxiety power spectral analysis study of heart rate and blood pressure

1997 ◽  
Vol 60 (2) ◽  
pp. 121-131 ◽  
Author(s):  
Gianfranco Piccirillo ◽  
Santagada Elvira ◽  
Carmela Bucca ◽  
Emanuela Viola ◽  
Mauro Cacciafesta ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Spectral Analysis ◽  
Power Spectral Analysis ◽  
Tilt Test ◽  
Analysis Study ◽  
Power Spectral ◽  
Head Up Tilt ◽  
Head Up Tilt Test

scholarly journals Nonlinear effects of respiration on the crosstalk between cardiovascular and cerebrovascular control systems

2016 ◽  
Vol 374 (2067) ◽  
pp. 20150179 ◽  
Author(s):  
Vlasta Bari ◽  
Andrea Marchi ◽  
Beatrice De Maria ◽  
Gianluca Rossato ◽  
Giandomenico Nollo ◽  
...  
Keyword(s):  
Control Systems ◽  
Cerebral Blood Flow Velocity ◽  
Nonlinear Effects ◽  
Tilt Test ◽  
Control Mechanisms ◽  
Heart Period ◽  
Regulatory Systems ◽  
Head Up Tilt ◽  
Head Up Tilt Test ◽  
The Impact

Cardiovascular and cerebrovascular regulatory systems are vital control mechanisms responsible for guaranteeing homeostasis and are affected by respiration. This work proposes the investigation of cardiovascular and cerebrovascular control systems and the nonlinear influences of respiration on both regulations through joint symbolic analysis (JSA), conditioned or unconditioned on respiration. Interactions between cardiovascular and cerebrovascular regulatory systems were evaluated as well by performing correlation analysis between JSA indexes describing the two control systems. Heart period, systolic and mean arterial pressure, mean cerebral blood flow velocity and respiration were acquired on a beat-to-beat basis in 13 subjects experiencing recurrent syncope episodes (SYNC) and 13 healthy individuals (non-SYNC) in supine resting condition and during head-up tilt test at 60° (TILT). Results showed that JSA distinguished conditions and groups, whereas time domain parameters detected only the effect of TILT. Respiration affected cardiovascular and cerebrovascular regulatory systems in a nonlinear way and was able to modulate the interactions between the two control systems with different outcome in non-SYNC and SYNC groups, thus suggesting that the analysis of the impact of respiration on cardiovascular and cerebrovascular regulatory systems might improve our understanding of the mechanisms underpinning the development of postural-related syncope.

scholarly journals Mathematical modeling of the cardiovascular autonomic control in healthy subjects during a passive head-up tilt test

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yurii M. Ishbulatov ◽  
Anatoly S. Karavaev ◽  
Anton R. Kiselev ◽  
Margarita A. Simonyan ◽  
Mikhail D. Prokhorov ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiovascular System ◽  
Healthy Subjects ◽  
Low Frequency ◽  
Tilt Test ◽  
Peripheral Vascular ◽  
Control Loops ◽  
Head Up Tilt ◽  
Head Up Tilt Test

Abstract A mathematical model is proposed for the autonomic control of cardiovascular system, which takes into account two separated self-exciting sympathetic control loops of heart rate and peripheral vascular tone. The control loops are represented by self-exciting time-delay systems and their tone depends on activity of the aortic, carotid, and lower-body baroreceptors. The model is used to study the dynamics of the adaptive processes that manifest in a healthy cardiovascular system during the passive head-up tilt test. Computer simulation provides continuous observation of the dynamics of the indexes and variables that cannot be measured in the direct experiment, including the noradrenaline concentration in vessel wall and heart muscle, tone of the sympathetic and parasympathetic control, peripheral vascular resistance, and blood pressure. In the supine and upright positions, we estimated the spectral characteristics of the model variables, especially in the low-frequency band, and the original index of total percent of phase synchronization between the low-frequency oscillations in heart rate and blood pressure signals. The model demonstrates good quantitative agreement with the dynamics of the experimentally observed indexes of cardiovascular system that were averaged for 50 healthy subjects.

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