scholarly journals Altered Causal Coupling Pathways within the Central-Autonomic-Network in Patients Suffering from Schizophrenia

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 733 ◽  
Author(s):  
Schulz ◽  
Haueisen ◽  
Bär ◽  
Voss
Keyword(s):  
Blood Pressure ◽  
Vascular System ◽  
Regulatory Mechanisms ◽  
Partial Directed Coherence ◽  
Central Autonomic Network ◽  
Respiratory Inductive Plethysmography ◽  
Coupling Structure ◽  
Central Activity ◽  
Cardiorespiratory Coupling ◽  
Short Time

The multivariate analysis of coupling pathways within physiological (sub)systems focusing on identifying healthy and diseased conditions. In this study, we investigated a part of the central-autonomic-network (CAN) in 17 patients suffering from schizophrenia (SZO) compared to 17 age–gender matched healthy controls (CON) applying linear and nonlinear causal coupling approaches (normalized short time partial directed coherence, multivariate transfer entropy). Therefore, from all subjects continuous heart rate (successive beat-to-beat intervals, BBI), synchronized maximum successive systolic blood pressure amplitudes (SYS), synchronized calibrated respiratory inductive plethysmography signal (respiratory frequency, RESP), and the power PEEG of frontal EEG activity were investigated for 15 min under resting conditions. The CAN revealed a bidirectional coupling structure, with central driving towards blood pressure (SYS), and respiratory driving towards PEEG. The central-cardiac, central-vascular, and central-respiratory couplings are more dominated by linear regulatory mechanisms than nonlinear ones. The CAN showed significantly weaker nonlinear central-cardiovascular and central-cardiorespiratory coupling pathways, and significantly stronger linear central influence on the vascular system, and on the other hand significantly stronger linear respiratory and cardiac influences on central activity in SZO compared to CON, and thus, providing better understanding of the interrelationship of central and autonomic regulatory mechanisms in schizophrenia might be useful as a biomarker of this disease.

scholarly journals STUDIES IN EDEMA

1909 ◽  
Vol 11 (5) ◽  
pp. 627-640
Author(s):  
Moyer S. Fleisher ◽  
Leo Loeb
Keyword(s):  
Blood Pressure ◽  
Sodium Chloride ◽  
Blood Vessels ◽  
Calcium Chloride ◽  
Intravenous Infusion ◽  
Vascular System ◽  
Characteristic Curve ◽  
Short Time

1. As a result of the intravenous infusion of a solution of sodium chloride a characteristic curve indicating the fluid retained in the vascular system is obtained. In the first period of the infusion the maximum of retention of fluid is noted. Then more fluid is removed from the blood vessels, so that for a short time a fall in the curve of dilution takes place, after which the dilution again slowly increases. 2. This curve is not materially changed by the addition of calcium chloride or of adrenalin to the infused solution, and under such conditions adrenalin does not lead to an increased pressing out of fluid from the vascular system, although is causes a constant and decided rise in blood pressure. Myocarditic lesions lead to an increased intravascular retention of fluid. Nephrectomy does not lead to an increased intravascular retention of fluid, but probably causes a diminution of the amount of fluid retained in the blood vessels.

Quantification of the Central Cardiovascular Network Applying the Normalized Short-time Partial Directed Coherence Approach in Healthy Subjects

2018 ◽  
Vol 57 (03) ◽  
pp. 129-134 ◽  
Author(s):  
Steffen Schulz ◽  
Mathias Bolz ◽  
Karl-Jürgen Bär ◽  
Andreas Voss
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous System ◽  
Systolic Blood Pressure ◽  
Healthy Subjects ◽  
Spectral Power ◽  
Partial Directed Coherence ◽  
Regulatory Processes ◽  
The Central Nervous System ◽  
Short Time

Summary Background: The central control of the autonomic nervous system (ANS) and the complex interplay of its components can be described by a functional integrated mode – the central autonomic network (CAN). CAN represents the integrated functioning and interaction between the central nervous system (CNS) and ANS (parasympathetic and sympathetic activity). Objective: This study investigates the central cardiovascular network (CCVN) as a part of the CAN, during which heart rate (HR), systolic blood pressure (SYS) and frontal EEG activity in 21 healthy subjects (CON) will be analysed. The objective of this study is to determine how these couplings (central-cardiovascular) are composed by the different regulatory aspects of the CNS-ANS interaction. Methods: To quantify the short-term instantaneous causal couplings within the CCVN, the normalized short time partial directed coherence (NSTPDC) approach was applied. It is based on an m-dimensional MAR process to determine Granger causality in the frequency domain. Results: We found that CCVN were of bidirectional character, and that the causal influences of central activity towards HR were stronger than those towards systolic blood pressure. This suggests that the central-cardiac closed-loop regulation process in CON focuses mainly on adapting the heart rate via the sinoatrial node rather than focusing on SYS. The CNS-ANS coupling directions with respect to central spectral power bands were characterized as mostly bidirectional, where HR and SYS acted as drivers in nearly every frequency band (unidirectional for α, α1 and α2). Conclusion: This study provides a more indepth understanding of the interplay of neuronal and autonomic cardiovascular regulatory processes in healthy subjects, as well as a greater insight into the complex CAN.

Analysis of heart rate-based control of arterial blood pressure

1996 ◽  
Vol 271 (2) ◽  
pp. H812-H822 ◽  
Author(s):  
W. C. Rose ◽  
J. S. Schwaber
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Vascular System ◽  
Reciprocal Relation ◽  
Arterial Baroreflex ◽  
Arterial Blood ◽  
Limited Effectiveness ◽  
Filling Time

Vagal control of the heart is the most rapidly responding limb of the arterial baroreflex. We created a mathematical model of the left heart and vascular system to evaluate the ability of heart rate to influence blood pressure. The results show that arterial pressure depends nonlinearly on rate and that changes in rate are of limited effectiveness, particularly when rate is increased above the basal level. A 10% change in heart rate from rest causes a change of only 2.4% in arterial pressure due to the reciprocal relation between heart rate and stroke volume; at higher rates, insufficient filling time causes stroke volume to fall. These findings agree well with published experimental data and challenge the idea that changes in heart rate alone can strongly and rapidly affect arterial pressure. Possible implications are that vagally mediated alterations in inotropic and dromotropic state, which are not included in this model, play important roles in the fast reflex control of blood pressure or that the vagal limb of the baroreflex is of rather limited effectiveness.

Water aerobics is followed by short-time and immediate systolic blood pressure reduction in overweight and obese hypertensive women

2016 ◽  
Vol 10 (7) ◽  
pp. 570-577 ◽  
Author(s):  
Raphael Martins Cunha ◽  
Gisela Arsa ◽  
Eduardo Borba Neves ◽  
Lorena Curado Lopes ◽  
Fabio Santana ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Blood Pressure Reduction ◽  
Pressure Reduction ◽  
Short Time

scholarly journals Time-Frequency Analysis of Cardiovascular and Cardiorespiratory Interactions During Orthostatic Stress by Extended Partial Directed Coherence

Entropy ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 468 ◽  
Author(s):  
Sonia Charleston-Villalobos ◽  
Sina Reulecke ◽  
Andreas Voss ◽  
Mahmood R. Azimi-Sadjadi ◽  
Ramón González-Camarena ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Information Flow ◽  
Orthostatic Intolerance ◽  
Linear Method ◽  
Orthostatic Stress ◽  
Partial Directed Coherence ◽  
Sinus Arrhythmia ◽  
Time Frequency

In this study, the linear method of extended partial directed coherence (ePDC) was applied to establish the temporal dynamic behavior of cardiovascular and cardiorespiratory interactions during orthostatic stress at a 70° head-up tilt (HUT) test on young age-matched healthy subjects and patients with orthostatic intolerance (OI), both male and female. Twenty 5-min windows were used to analyze the minute-wise progression of interactions from 5 min in a supine position (baseline, BL) until 18 min of the orthostatic phase (OP) without including pre-syncopal phases. Gender differences in controls were present in cardiorespiratory interactions during OP without compromised autonomic regulation. However in patients, analysis by ePDC revealed considerable dynamic alterations within cardiovascular and cardiorespiratory interactions over the temporal course during the HUT test. Considering the young female patients with OI, the information flow from heart rate to systolic blood pressure (mechanical modulation) was already increased before the tilt-up, the information flow from systolic blood pressure to heart rate (neural baroreflex) increased during OP, while the information flow from respiration to heart rate (respiratory sinus arrhythmia) decreased during the complete HUT test. Findings revealed impaired cardiovascular interactions in patients with orthostatic intolerance and confirmed the usefulness of ePDC for causality analysis.

scholarly journals Cardiovascular Pleiotropic Effects of Natriuretic Peptides

2019 ◽  
Vol 20 (16) ◽  
pp. 3874 ◽  
Author(s):  
Forte ◽  
Madonna ◽  
Schiavon ◽  
Valenti ◽  
Versaci ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Natriuretic Peptide ◽  
Natriuretic Peptides ◽  
Vascular System ◽  
Ischemia Reperfusion ◽  
Pressure Overload ◽  
Pleiotropic Effects ◽  
Current Evidence ◽  
Loss Of Function ◽  
Cardiac Phenotype

Atrial natriuretic peptide (ANP) is a cardiac hormone belonging to the family of natriuretic peptides (NPs). ANP exerts diuretic, natriuretic, and vasodilatory effects that contribute to maintain water–salt balance and regulate blood pressure. Besides these systemic properties, ANP displays important pleiotropic effects in the heart and in the vascular system that are independent of blood pressure regulation. These functions occur through autocrine and paracrine mechanisms. Previous works examining the cardiac phenotype of loss-of-function mouse models of ANP signaling showed that both mice with gene deletion of ANP or its receptor natriuretic peptide receptor A (NPR-A) developed cardiac hypertrophy and dysfunction in response to pressure overload and chronic ischemic remodeling. Conversely, ANP administration has been shown to improve cardiac function in response to remodeling and reduces ischemia-reperfusion (I/R) injury. ANP also acts as a pro-angiogenetic, anti-inflammatory, and anti-atherosclerotic factor in the vascular system. Pleiotropic effects regarding brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) were also reported. In this review, we discuss the current evidence underlying the pleiotropic effects of NPs, underlying their importance in cardiovascular homeostasis.

scholarly journals Cerebral blood flow regulation in end-stage kidney disease

2020 ◽  
Vol 319 (5) ◽  
pp. F782-F791
Author(s):  
Justin D. Sprick ◽  
Joe R. Nocera ◽  
Ihab Hajjar ◽  
W. Charles O’Neill ◽  
James Bailey ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Kidney Disease ◽  
Cerebral Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Regulatory Mechanisms ◽  
End Stage Kidney Disease ◽  
Increased Risk ◽  
End Stage

Patients with chronic kidney disease (CKD) and end-stage kidney disease (ESKD) experience an increased risk of cerebrovascular disease and cognitive dysfunction. Hemodialysis (HD), a major modality of renal replacement therapy in ESKD, can cause rapid changes in blood pressure, osmolality, and acid-base balance that collectively present a unique stress to the cerebral vasculature. This review presents an update regarding cerebral blood flow (CBF) regulation in CKD and ESKD and how the maintenance of cerebral oxygenation may be compromised during HD. Patients with ESKD exhibit decreased cerebral oxygen delivery due to anemia, despite cerebral hyperperfusion at rest. Cerebral oxygenation further declines during HD due to reductions in CBF, and this may induce cerebral ischemia or “stunning.” Intradialytic reductions in CBF are driven by decreases in cerebral perfusion pressure that may be partially opposed by bicarbonate shifts during dialysis. Intradialytic reductions in CBF have been related to several variables that are routinely measured in clinical practice including ultrafiltration rate and blood pressure. However, the role of compensatory cerebrovascular regulatory mechanisms during HD remains relatively unexplored. In particular, cerebral autoregulation can oppose reductions in CBF driven by reductions in systemic blood pressure, while cerebrovascular reactivity to CO2 may attenuate intradialytic reductions in CBF through promoting cerebral vasodilation. However, whether these mechanisms are effective in ESKD and during HD remain relatively unexplored. Important areas for future work include investigating potential alterations in cerebrovascular regulation in CKD and ESKD and how key regulatory mechanisms are engaged and integrated during HD to modulate intradialytic declines in CBF.

An Attempt of Assessment of the Condition of the Regulatory Mechanisms of Blood Pressure by a Dynamic Cold Pressor Test

2009 ◽  
Vol 154 (S312) ◽  
pp. 213-214
Author(s):  
J. Brod ◽  
V. Fenc ◽  
M. Gérová ◽  
Z. Hejl ◽  
J. Jirka ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Regulatory Mechanisms ◽  
Pressor Test

scholarly journals FLUORESCEIN CIRCULATION TIME AS A PROGNOSTIC SIGN IN EXPERIMENTAL TRAUMATIC SHOCK

1946 ◽  
Vol 84 (6) ◽  
pp. 549-558 ◽  
Author(s):  
S. C. Wang ◽  
E. E. Painter ◽  
R. R. Overman
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Vascular System ◽  
Peripheral Circulation ◽  
Traumatic Shock ◽  
Systemic Circulation ◽  
The Other ◽  
Circulation Time ◽  
Peripheral Vascular ◽  
Made In

Repeated determinations of the circulation time by the fluorescein method were made in normal and shocked dogs. In normal animals the circulation time ranges from 9 to 16 seconds with an average of 12.6 seconds. In traumatic shock the circulation time is invariably prolonged. For prognosis in the traumatized animal two determinations of fluorescein circulation time separated by an interval of 1 hour are essential. If the second circulation time is longer than the first and both are over 30 seconds, the animal will not survive without therapy. On the other hand, if the second circulation time is below 25 seconds or is considerably shorter than the first, the prognosis is good. In many of these experiments the change in circulation time appeared to be the earliest index of eventual recovery or death. It gave a clue to the fate of the animal when no decisive judgment could be made from the blood pressure and heart rate. In three dogs the cyanide and fluorescein circulation times were compared during shock. It was found that the cyanide circulation time, though increased in shock, remained at a fairly constant value while over the same period the fluorescein circulation time showed progressive changes. This discrepancy between the cyanide and fluorescein methods may be explained by the fact that the former does not include the minute peripheral systemic circulation. Since the study of shock is concerned with tissue anoxia and is primarily a phenomenon of the failure of the peripheral circulation, it is important to choose procedures such as the fluorescein method as a measure of the condition of the peripheral vascular system.

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