Search results for " Baroreflex"

showing 9 items of 9 documents

Modulation of Heart Rate by Acute or Chronic Aerobic Exercise. Potential Effects on Blood Pressure Control.

2017

It was initially assumed that heart rate and arterial blood pressure were modulated by normal respiration and muscle contraction. The arterial baroreflex, an inverse relationship between blood pressure and heart rate, was later reported. Nonetheless, it was then assumed that those responses involved vagal modulation. We summarize available evidence on the modulation of heart rate by acute or chronic aerobic exercise as well as its potential implications on blood pressure (BP) control. Numerous studies have tried to clarify whether aerobic exercise modifies neurally-mediated vasoconstriction, but they report contradictory results. In view of these incongruities, the aim of this narrative rev…

0301 basic medicinemedicine.medical_specialtyhypertensionBlood Pressureexercise; arterial baroreflex; autonomous nervous system; blood pressure; heart rate; hypertension.Disease03 medical and health sciences0302 clinical medicineHeart Rateautonomous nervous systemInternal medicineDrug DiscoveryHeart rateRespirationHeart rate variabilityMedicineAerobic exerciseAnimalsHumansCardiovascular fitnessExercisePharmacologybusiness.industryarterial baroreflex030229 sport sciences030104 developmental biologyBlood pressureCardiologymedicine.symptombusinessVasoconstrictionCurrent pharmaceutical design
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Cardiovascular control and time domain granger causality: Insights from selective autonomic blockade

2013

We studied causal relations among heart period (HP), systolic arterial pressure (SAP) and respiration (R) according to the definition of Granger causality in the time domain. Autonomic pharmacological challenges were used to alter the complexity of cardiovascular control. Atropine (AT), propranolol and clonidine (CL) were administered to block muscarinic receptors, β-adrenergic receptors and centrally sympathetic outflow, respectively. We found that: (i) at baseline, HP and SAP interacted in a closed loop with a dominant causal direction from HP to SAP; (ii) pharmacological blockades did not alter the bidirectional closed-loop interactions between HP and SAP, but AT reduced the dominance of…

AdultMaleGeneral MathematicsGeneral Physics and AstronomyBlood PressurePropranololPharmacologyBaroreflexArterial pressure variability; Autonomic nervous system; Baroreflex; Cardiovascular control; Granger causality; Heart rate variability; Mathematics (all); Engineering (all); Physics and Astronomy (all)Models BiologicalPhysics and Astronomy (all)Engineering (all)Respiratory RateGranger causalityBiological ClocksHeart RateMuscarinic acetylcholine receptormedicineHumansHeart rate variabilityAutonomic nervous systemMathematics (all)Computer SimulationHeart rate variabilityFeedback PhysiologicalChemistryGeneral EngineeringMiddle AgedBaroreflexClonidineAtropineAutonomic nervous systemCardiovascular controlSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaGranger causalityFemaleArterial pressure variabilityAutonomic Nerve Blockmedicine.drug
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Strength and Latency of the HP-SAP Closed Loop Variability Interactions in Subjects Prone to Develop Postural Syncope

2019

The coupling and latency between heart period (HP) and systolic arterial pressure (SAP) variability can be investigated along the two arms of the HP-SAP closed loop, namely along the baroreflex feedback from SAP to HP, and along the feedforward pathway from HP to SAP. This study investigates the HP-SAP closed loop variability interactions through cross-correlation function (CCF). Coupling strength and delay between HP and SAP variability series were monitored in 13 subjects prone to develop orthostatic syncope (SYNC, 28±9 yrs, 5 males) and in 13 subjects with no history of postural syncope (noSYNC, age: 27±8 yrs, 5 males). Analysis was carried out at rest in supine position (REST) and durin…

AdultMalemedicine.medical_specialtySupine positiongenetic structuresBlood Pressure030204 cardiovascular system & hematologyBaroreflexSyncope03 medical and health sciencesYoung Adult0302 clinical medicineHeart RateInternal medicineHeart ratemedicineHumansComputer SimulationLatency (engineering)business.industryFeed forwardPostural syncopeHeartBaroreflexAdult Blood Pressure Computer Simulation Heart Rate Humans Male Syncope Young Adult Baroreflex HeartBlood pressureCardiologybusinessClosed loop030217 neurology & neurosurgeryAnnual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference
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Evidence of unbalanced regulatory mechanism of heart rate and systolic pressure after acute myocardial infarction

2002

The interactions between systolic arterial pressure (SAP) and R-R interval (RR) fluctuations after acute myocardial infarction (AMI) were investigated by measures of synchronization separating the feedback from the feedforward control and capturing both linear and nonlinear contributions. The causal synchronization, evaluating the ability of RR to predict SAP (χs/t) or vice versa (χt/s), and the global synchronization (χ) were estimated at rest and after head-up tilt in 35 post-AMI patients, 20 young and 12 old. Significance and nonlinearity of the coupling were assessed by surrogate data analysis. Tilting increased the number of young subjects in which RR-SAP link was significant (from 17…

Adultmedicine.medical_specialtyPhysiologyMyocardial InfarctionHemodynamicsBlood PressureSynchronizationAutonomic Nervous SystemHeart RatePhysiology (medical)Internal medicineHeart ratemedicineNonlinear couplingHumansMyocardial infarctionNonlinear couplingAgedFeedback PhysiologicalSurrogate data analysisbusiness.industryCausal analysicausal analysis; nonlinear coupling; synchronization; baroreflex regulationcausal analysisBaroreflexMiddle Agedmedicine.diseaseEndocrinologyBlood pressureNeural regulationSystolic arterial pressureCardiologyBaroreflex regulationCardiology and Cardiovascular Medicinebusiness
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Vascular resistance arm of the baroreflex: methodology and comparison with the cardiac chronotropic arm.

2020

Baroreflex response consists of cardiac chronotropic (effect on heart rate), cardiac inotropic (on contractility), venous (on venous return) and vascular (on vascular resistance) arms. Because of its measurement simplicity, cardiac chronotropic arm is most often analysed. The aim was to introduce a method to assess vascular baroreflex arm, and to characterize its changes during stress. We evaluated the effect of orthostasis and mental arithmetics (MA) in 39 (22 female, median age: 18.7 yrs.) and 36 (21 female, 19.2 yrs.) healthy volunteers, respectively. We recorded systolic and mean blood pressure (SBP and MBP) by volume-clamp method and R-R interval (RR) by ECG. Cardiac output (CO) was re…

ChronotropicMalemedicine.medical_specialtyAdolescentPhysiologyBlood Pressure030204 cardiovascular system & hematologyBaroreflex03 medical and health sciences0302 clinical medicineHeart RatePhysiology (medical)Internal medicinemedicineHumansimpedance cardiographyCardiac OutputArterial baroreflexHeart rate responsemedicine.diagnostic_testbusiness.industrymusculoskeletal neural and ocular physiologyArterial baroreflexBaroreflexspectral couplingImpedance cardiographymedicine.anatomical_structureBlood pressureSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaVascular resistanceCardiologyFemaleVascular Resistancebusiness030217 neurology & neurosurgeryJournal of applied physiology (Bethesda, Md. : 1985)
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Nonlinear effects of respiration on the crosstalk between cardiovascular and cerebrovascular control systems.

2016

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…

Mean arterial pressuremedicine.medical_specialtySupine positionGeneral Mathematics0206 medical engineeringGeneral Physics and Astronomy02 engineering and technology030204 cardiovascular system & hematologyBaroreflexCerebral autoregulationCardiovascular System03 medical and health sciencesPhysics and Astronomy (all)0302 clinical medicineEngineering (all)Conditional joint symbolic analysiInternal medicineRespirationmedicineHeart rate variabilityAutonomic nervous system; Baroreflex; Cerebral autoregulation; Conditional joint symbolic analysis; Head-up tilt; Heart rate variability; Mathematics (all); Physics and Astronomy (all); Engineering (all)Autonomic nervous systemMathematics (all)Heart rate variabilitybusiness.industryAutonomic nervous system; Baroreflex; Cerebral autoregulation; Conditional joint symbolic analysis; Head-up tilt; Heart rate variability; Mathematics (all); Engineering (all); Physics and Astronomy (all)Head-up tiltGeneral EngineeringBaroreflex020601 biomedical engineeringCerebral autoregulationAutonomic nervous systemCerebral blood flowConditional joint symbolic analysisSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaCardiologybusinessPhilosophical transactions. Series A, Mathematical, physical, and engineering sciences
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Input for baroreflex analysis: which blood pressure signal should be used?

2022

The baroreflex (BR) is an important physiological regulatory mechanism which reacts to blood pressure perturbations with reflex changes of target variables such as the heart period (electrocardiogram derived RR interval) or the peripheral vascular resistance (PVR). Evaluation of cardiac chronotropic (RR as a target variable) and vascular resistance (target PVR) BR arms was in previous studies mainly based on the use of the spontaneous variability of the systolic or diastolic blood pressure (SBP, DBP), respectively, as the input signals. The use of other blood pressure measures such as the mean blood pressure (MBP) as an input signal for BR analysis is still under investigation. Making the a…

Settore ING-INF/06 - Bioingegneria Elettronica E InformaticaArterial baroreflex blood pressure cardiovascular variability spectral analysis transfer function head-up tilt mental arithmetic task muscle sympathetic nerve activity
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Disentangling cardiovascular control mechanisms during head-down tilt via joint transfer entropy and self-entropy decompositions

2015

A full decomposition of the predictive entropy (PE) of the spontaneous variations of the heart period (HP) given systolic arterial pressure (SAP) and respiration (R) is proposed. The PE of HP is decomposed into the joint transfer entropy (JTE) from SAP and R to HP and self-entropy (SE) of HP. The SE is the sum of three terms quantifying the synergistic/redundant contributions of HP and SAP, when taken individually and jointly, to SE and one term conditioned on HP and SAP denoted as the conditional SE (CSE) of HP given SAP and R. The JTE from SAP and R to HP is the sum of two terms attributable to SAP or R plus an extra term describing the redundant/synergistic contribution to the JTE. All q…

Supine positionInformation storageComputer sciencePhysiologyAutonomic nervous system; Baroreflex; Blood pressure variability; Cardiopulmonary coupling; Heart rate variability; Information dynamics; Multivariate linear regression analysis; Physiology; Physiology (medical)Cardiovascular controlAutonomic Nervous Systemlcsh:PhysiologyNuclear magnetic resonanceCardiopulmonary couplingPhysiology (medical)Cardiac controlHeart rate variabilityOriginal Researchlcsh:QP1-981redundancymultivariate linear regression analysiscardiopulmonary couplingBaroreflexHead-Down TiltInformation dynamicSynergySettore ING-INF/06 - Bioingegneria Elettronica E InformaticaSystolic arterial pressureTransfer entropyblood pressure variabilityMultivariate linear regression analysiinformation dynamicsAlgorithmFrontiers in Physiology
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Information domain approach to the investigation of cardio-vascular, cardio-pulmonary, and vasculo-pulmonary causal couplings

2011

The physiological mechanisms related to cardio-vascular (CV), cardio-pulmonary (CP), and vasculo-pulmonary (VP) regulation may be probed through multivariate time series analysis tools. This study applied an information domain approach for the evaluation of non-linear causality to the beat-to-beat variability series of heart period (t), systolic arterial pressure (s), and respiration (r) measured during tilt testing and paced breathing (PB) protocols. The approach quantifies the causal coupling from the series i to the series j (C(ij)) as the amount of information flowing from i to j. A measure of directionality is also obtained as the difference between two reciprocal causal couplings (D(i…

medicine.medical_specialtySupine positioncausalityPhysiologySpeech recognitionBaroreflexlcsh:Physiologypaced breathingconditional entropyhead-up tiltInternal medicinePhysiology (medical)medicineHeart rate variabilitybaroreflexarterial pressure variabilityrespiratory sinus arrhythmiaVagal toneRespiratory systemOriginal Researchlcsh:QP1-981business.industryheart rate variabilityCardiorespiratory fitnessBlood pressureSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaCardiologyBreathingArterial pressure variability; Baroreflex; Causality; Conditional entropy; Head-up tilt; Heart rate variability; Paced breathing; Respiratory sinus arrhythmia; Physiology; Physiology (medical)business
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