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Quinn C, Monaghan A, Foran T, Kenny RA, Gormley J. A Review of Heart Rate and Blood Pressure Responses to Active Standing in Healthy Adults. Curr Aging Sci 2022; 15:198-208. [PMID: 35440341 DOI: 10.2174/1874609815666220419102648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/16/2022] [Accepted: 03/06/2022] [Indexed: 06/14/2023]
Abstract
OBJECTIVES This review outlines the normal heart rate and blood pressure response to active standing, the physiological mechanisms governing these, and the effect of ageing on the responses. METHODS A literature search was conducted to identify articles investigating the normal heart rate and/or blood pressure response to standing. RESULTS Heart rate when standing increases and then decreases and recovers to baseline. Blood pressure responses are inverse. Skeletal muscle contraction and the baroreceptor reflex drive this. With ageing, heart rate response attenuates and the initial blood pressure response increases. DISCUSSION Normal heart rate and blood pressure responses are attributed to the baroreceptor reflex and skeletal muscle contraction. Decreased muscle strength and baroreceptor sensitivity are associated with ageing, suggesting a possible benefit in improving skeletal muscle strength to maintain an efficient response. Understanding these responses and their variation with ageing is clinically relevant and may be beneficial in improving rehabilitation outcomes.
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Affiliation(s)
- Caitríona Quinn
- Discipline of Physiotherapy, Trinity Centre for Health Sciences, Trinity College Dublin, Dublin Ireland
| | - Ann Monaghan
- Department of Medical Gerontology, Trinity College Dublin, Dublin, Ireland
| | - Tim Foran
- Medical Physics and Bioengineering Department of Discipline of Physiotherapy, Trinity Centre for Health Sciences, St. James's Hospital, TRIL Centre, St James's Hospital, Dublin 8, Dublin, Ireland
| | - Rose Anne Kenny
- Department of Medical Gerontology, Trinity College Dublin, Dublin, Ireland
| | - John Gormley
- Discipline of Physiotherapy, Trinity Centre for Health Sciences, Trinity College Dublin, Dublin Ireland
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Maw M, Schlöglhofer T, Marko C, Aigner P, Gross C, Widhalm G, Schaefer AK, Schima M, Wittmann F, Wiedemann D, Moscato F, Kudlik D, Stadler R, Zimpfer D, Schima H. A Sensorless Modular Multiobjective Control Algorithm for Left Ventricular Assist Devices: A Clinical Pilot Study. Front Cardiovasc Med 2022; 9:888269. [PMID: 35548436 PMCID: PMC9081924 DOI: 10.3389/fcvm.2022.888269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/31/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundContemporary Left Ventricular Assist Devices (LVADs) mainly operate at a constant speed, only insufficiently adapting to changes in patient demand. Automatic physiological speed control promises tighter integration of the LVAD into patient physiology, increasing the level of support during activity and decreasing support when it is excessive.MethodsA sensorless modular control algorithm was developed for a centrifugal LVAD (HVAD, Medtronic plc, MN, USA). It consists of a heart rate-, a pulsatility-, a suction reaction—and a supervisor module. These modules were embedded into a safe testing environment and investigated in a single-center, blinded, crossover, clinical pilot trial (clinicaltrials.gov, NCT04786236). Patients completed a protocol consisting of orthostatic changes, Valsalva maneuver and submaximal bicycle ergometry in constant speed and physiological control mode in randomized sequence. Endpoints for the study were reduction of suction burden, adequate pump speed and flowrate adaptations of the control algorithm for each protocol item and no necessity for intervention via the hardware safety systems.ResultsA total of six patients (median age 53.5, 100% male) completed 13 tests in the intermediate care unit or in an outpatient setting, without necessity for intervention during control mode operation. Physiological control reduced speed and flowrate during patient rest, in sitting by a median of −75 [Interquartile Range (IQR): −137, 65] rpm and in supine position by −130 [−150, 30] rpm, thereby reducing suction burden in scenarios prone to overpumping in most tests [0 [−10, 2] Suction events/minute] in orthostatic upwards transitions and by −2 [−6, 0] Suction events/min in Valsalva maneuver. During submaximal ergometry speed was increased by 86 [31, 193] rpm compared to constant speed for a median flow increase of 0.2 [0.1, 0.8] L/min. In 3 tests speed could not be increased above constant set speed due to recurring suction and in 3 tests speed could be increased by up to 500 rpm with a pump flowrate increase of up to 0.9 L/min.ConclusionIn this pilot study, safety, short-term efficacy, and physiological responsiveness of a sensorless automated speed control system for a centrifugal LVAD was established. Long term studies are needed to show improved clinical outcomes.Clinical Trial RegistrationClinicalTrials.gov, identifier: NCT04786236.
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Affiliation(s)
- Martin Maw
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
- Ludwig-Boltzmann-Institute for Cardiovascular Research, Vienna, Austria
| | - Thomas Schlöglhofer
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
- Ludwig-Boltzmann-Institute for Cardiovascular Research, Vienna, Austria
| | - Christiane Marko
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Philipp Aigner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Ludwig-Boltzmann-Institute for Cardiovascular Research, Vienna, Austria
| | - Christoph Gross
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Gregor Widhalm
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | | | - Michael Schima
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Franziska Wittmann
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Dominik Wiedemann
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Francesco Moscato
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Ludwig-Boltzmann-Institute for Cardiovascular Research, Vienna, Austria
| | | | | | - Daniel Zimpfer
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Heinrich Schima
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
- Ludwig-Boltzmann-Institute for Cardiovascular Research, Vienna, Austria
- *Correspondence: Heinrich Schima
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Gregory SD, Pauls JP, Wu EL, Stephens A, Steinseifer U, Tansley G, Fraser JF. An advanced mock circulation loop for in vitro cardiovascular device evaluation. Artif Organs 2020; 44:E238-E250. [PMID: 31951020 DOI: 10.1111/aor.13636] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/11/2019] [Accepted: 01/07/2020] [Indexed: 11/28/2022]
Abstract
Controlled and repeatable in vitro evaluation of cardiovascular devices using a mock circulation loop (MCL) is essential prior to in vivo or clinical trials. MCLs often consist of only a systemic circulation with no autoregulatory responses and limited validation. This study aimed to develop, and validate against human data, an advanced MCL with systemic, pulmonary, cerebral, and coronary circulations with autoregulatory responses. The biventricular MCL was constructed with pneumatically controlled hydraulic circulations with Starling responsive ventricles and autoregulatory cerebral and coronary circulations. Hemodynamic repeatability was assessed and complemented by validation using impedance cardiography data from 50 healthy humans. The MCL successfully simulated patient scenarios including rest, exercise, and left heart failure with and without cardiovascular device support. End-systolic pressure-volume relationships for respective healthy and heart failure conditions had slopes of 1.27 and 0.54 mm Hg mL-1 (left ventricle), and 0.18 and 0.10 mm Hg mL-1 (right ventricle), aligning with the literature. Coronary and cerebral autoregulation showed a strong correlation (R2 : .99) between theoretical and experimentally derived circuit flow. MCL repeatability was demonstrated with correlation coefficients being statistically significant (P < .05) for all simulated conditions while MCL hemodynamics aligned well with human data. This advanced MCL is a valuable tool for inexpensive and controlled evaluation of cardiovascular devices.
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Affiliation(s)
- Shaun D Gregory
- Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia.,Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia.,School of Engineering and Built Environment, Griffith University, Southport, QLD, Australia.,School of Medicine, University of Queensland, Brisbane, QLD, Australia
| | - Jo P Pauls
- Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia.,School of Engineering and Built Environment, Griffith University, Southport, QLD, Australia.,School of Medicine, University of Queensland, Brisbane, QLD, Australia
| | - Eric L Wu
- Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia.,School of Medicine, University of Queensland, Brisbane, QLD, Australia
| | - Andrew Stephens
- Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia.,Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Ulrich Steinseifer
- Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia.,Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Geoff Tansley
- Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia.,School of Engineering and Built Environment, Griffith University, Southport, QLD, Australia
| | - John F Fraser
- Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia.,School of Medicine, University of Queensland, Brisbane, QLD, Australia
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