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Tamborini A, Gharib M. Validation of a Suprasystolic Cuff System for Static and Dynamic Representation of the Central Pressure Waveform. J Am Heart Assoc 2024; 13:e033290. [PMID: 38591330 DOI: 10.1161/jaha.123.033290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 03/14/2024] [Indexed: 04/10/2024]
Abstract
BACKGROUND Noninvasive pulse waveform analysis is valuable for central cardiovascular assessment, yet controversies persist over its validity in peripheral measurements. Our objective was to compare waveform features from a cuff system with suprasystolic blood pressure hold with an invasive aortic measurement. METHODS AND RESULTS This study analyzed data from 88 subjects undergoing concurrent aortic catheterization and brachial pulse waveform acquisition using a suprasystolic blood pressure cuff system. Oscillometric blood pressure (BP) was compared with invasive aortic systolic BP and diastolic BP. Association between cuff and catheter waveform features was performed on a set of 15 parameters inclusive of magnitudes, time intervals, pressure-time integrals, and slopes of the pulsations. The evaluation covered both static (subject-averaged values) and dynamic (breathing-induced fluctuations) behaviors. Peripheral BP values from the cuff device were higher than catheter values (systolic BP-residual, 6.5 mm Hg; diastolic BP-residual, 12.4 mm Hg). Physiological correction for pressure amplification in the arterial system improved systolic BP prediction (r2=0.83). Dynamic calibration generated noninvasive BP fluctuations that reflect those invasively measured (systolic BP Pearson R=0.73, P<0.001; diastolic BP Pearson R=0.53, P<0.001). Static and dynamic analyses revealed a set of parameters with strong associations between catheter and cuff (Pearson R>0.5, P<0.001), encompassing magnitudes, timings, and pressure-time integrals but not slope-based parameters. CONCLUSIONS This study demonstrated that the device and methods for peripheral waveform measurements presented here can be used for noninvasive estimation of central BP and a subset of aortic waveform features. These results serve as a benchmark for central cardiovascular assessment using suprasystolic BP cuff-based devices and contribute to preserving system dynamics in noninvasive measurements.
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Affiliation(s)
- Alessio Tamborini
- Department of Medical Engineering California Institute of Technology Pasadena CA USA
| | - Morteza Gharib
- Department of Medical Engineering California Institute of Technology Pasadena CA USA
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Gruenewald T, Seeman TE, Choo TH, Scodes J, Snyder C, Pavlicova M, Weinstein M, Schwartz JE, Mukkamala R, Sloan RP. Cardiovascular variability, sociodemographics, and biomarkers of disease: the MIDUS study. Front Physiol 2023; 14:1234427. [PMID: 37693005 PMCID: PMC10484414 DOI: 10.3389/fphys.2023.1234427] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/09/2023] [Indexed: 09/12/2023] Open
Abstract
Introduction: Like heart rate, blood pressure (BP) is not steady but varies over intervals as long as months to as short as consecutive cardiac cycles. This blood pressure variability (BPV) consists of regularly occurring oscillations as well as less well-organized changes and typically is computed as the standard deviation of multiple clinic visit-to-visit (VVV-BP) measures or from 24-h ambulatory BP recordings (ABPV). BP also varies on a beat-to-beat basis, quantified by methods that parse variation into discrete bins, e.g., low frequency (0.04-0.15 Hz, LF). However, beat-to-beat BPV requires continuous recordings that are not easily acquired. As a result, we know little about the relationship between LF-BPV and basic sociodemographic characteristics such as age, sex, and race and clinical conditions. Methods: We computed LF-BPV during an 11-min resting period in 2,118 participants in the Midlife in the US (MIDUS) study. Results: LF-BPV was negatively associated with age, greater in men than women, and unrelated to race or socioeconomic status. It was greater in participants with hypertension but unrelated to hyperlipidemia, hypertriglyceridemia, diabetes, elevated CRP, or obesity. LF-diastolic BPV (DBPV), but not-systolic BPV (SBPV), was negatively correlated with IL-6 and s-ICAM and positively correlated with urinary epinephrine and cortisol. Finally, LF-DBPV was negatively associated with mortality, an effect was rendered nonsignificant by adjustment by age but not other sociodemographic characteristics. Discussion: These findings, the first from a large, national sample, suggest that LF-BPV differs significantly from VVV-BP and ABPV. Confirming its relationship to sociodemographic risk factors and clinical outcomes requires further study with large and representative samples.
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Affiliation(s)
- Tara Gruenewald
- Department of Psychology, Chapman University, Orange, CA, United States
| | - Teresa E. Seeman
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States
| | - Tse-Hwei Choo
- Mental Health Data Science Division, New York State Psychiatric Institute, New York, NY, United States
| | - Jennifer Scodes
- Mental Health Data Science Division, New York State Psychiatric Institute, New York, NY, United States
| | - Clayton Snyder
- Mental Health Data Science Division, New York State Psychiatric Institute, New York, NY, United States
| | - Martina Pavlicova
- Department of Biostatistics, Mailman School of Public Health, Columbia University Irving Medical Center, New York, NY, United States
| | | | - Joseph E. Schwartz
- Renaissance School of Medicine, Stony Brook University, New York, NY, United States
- Department of Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Ramakrishna Mukkamala
- Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Richard P. Sloan
- Division of Behavioral Medicine, Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, United States
- New York State Psychiatric Institute, New York, NY, United States
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Bergholz A, Greiwe G, Kouz K, Saugel B. Continuous Blood Pressure Monitoring in Patients Having Surgery: A Narrative Review. Medicina (Kaunas) 2023; 59:1299. [PMID: 37512110 PMCID: PMC10385393 DOI: 10.3390/medicina59071299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/11/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023]
Abstract
Hypotension can occur before, during, and after surgery and is associated with postoperative complications. Anesthesiologists should thus avoid profound and prolonged hypotension. A crucial part of avoiding hypotension is accurate and tight blood pressure monitoring. In this narrative review, we briefly describe methods for continuous blood pressure monitoring, discuss current evidence for continuous blood pressure monitoring in patients having surgery to reduce perioperative hypotension, and expand on future directions and innovations in this field. In summary, continuous blood pressure monitoring with arterial catheters or noninvasive sensors enables clinicians to detect and treat hypotension immediately. Furthermore, advanced hemodynamic monitoring technologies and artificial intelligence-in combination with continuous blood pressure monitoring-may help clinicians identify underlying causes of hypotension or even predict hypotension before it occurs.
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Affiliation(s)
- Alina Bergholz
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Gillis Greiwe
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Karim Kouz
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Bernd Saugel
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Outcomes Research Consortium, Cleveland, OH 44195, USA
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Fortrat JO, Ravé G. Autonomic Nervous System Influences on Cardiovascular Self-Organized Criticality. Entropy (Basel) 2023; 25:880. [PMID: 37372224 DOI: 10.3390/e25060880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/28/2023] [Accepted: 05/28/2023] [Indexed: 06/29/2023]
Abstract
Cardiovascular self-organized criticality has recently been demonstrated. We studied a model of autonomic nervous system changes to better characterize heart rate variability self-organized criticality. The model included short and long-term autonomic changes associated with body position and physical training, respectively. Twelve professional soccer players took part in a 5-week training session divided into "Warm-up", "Intensive", and "Tapering" periods. A stand test was carried out at the beginning and end of each period. Heart rate variability was recorded beat by beat (Polar Team 2). Bradycardias, defined as successive heart rates with a decreasing value, were counted according to their length in number of heartbeat intervals. We checked whether bradycardias were distributed according to Zipf's law, a feature of self-organized criticality. Zipf's law draws a straight line when the rank of occurrence is plotted against the frequency of occurrence in a log-log graph. Bradycardias were distributed according to Zipf's law, regardless of body position or training. Bradycardias were much longer in the standing position than the supine position and Zipf's law was broken after a delay of four heartbeat intervals. Zipf's law could also be broken in some subjects with curved long bradycardia distributions by training. Zipf's law confirms the self-organized nature of heart rate variability and is strongly linked to autonomic standing adjustment. However, Zipf's law could be broken, the significance of which remains unclear.
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Affiliation(s)
- Jacques-Olivier Fortrat
- CHU Angers, Médecine Vasculaire, INSERM, CNRS, MITOVASC, Equipe CarMe, SFR ICAT, Université d'Angers, 49933 Angers, France
| | - Guillaume Ravé
- Toulouse Football Club, 1 Allée Gabriel Biénès, 31400 Toulouse, France
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Samimi H, Dajani HR. A PPG-Based Calibration-Free Cuffless Blood Pressure Estimation Method Using Cardiovascular Dynamics. Sensors (Basel) 2023; 23:4145. [PMID: 37112490 PMCID: PMC10146008 DOI: 10.3390/s23084145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/18/2023] [Accepted: 04/19/2023] [Indexed: 06/19/2023]
Abstract
Traditional cuff-based sphygmomanometers for measuring blood pressure can be uncomfortable and particularly unsuitable to use during sleep. A proposed alternative method uses dynamic changes in the pulse waveform over short intervals and replaces calibration with information from photoplethysmogram (PPG) morphology to provide a calibration-free approach using a single sensor. Results from 30 patients show a high correlation of 73.64% for systolic blood pressure (SBP) and 77.72% for diastolic blood pressure (DBP) between blood pressure estimated with the PPG morphology features and the calibration method. This suggests that the PPG morphology features could replace the calibration stage for a calibration-free method with similar accuracy. Applying the proposed methodology on 200 patients and testing on 25 new patients resulted in a mean error (ME) of -0.31 mmHg, a standard deviation of error (SDE) of 4.89 mmHg, a mean absolute error (MAE) of 3.32 mmHg for DBP and an ME of -4.02 mmHg, an SDE of 10.40 mmHg, and an MAE of 7.41 mmHg for SBP. These results support the potential for using a PPG signal for calibration-free cuffless blood pressure estimation and improving accuracy by adding information from cardiovascular dynamics to different methods in the cuffless blood pressure monitoring field.
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Kouz K, Brockmann L, Timmermann LM, Bergholz A, Flick M, Maheshwari K, Sessler DI, Krause L, Saugel B. Endotypes of intraoperative hypotension during major abdominal surgery: a retrospective machine learning analysis of an observational cohort study. Br J Anaesth 2023; 130:253-261. [PMID: 36526483 DOI: 10.1016/j.bja.2022.07.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 07/27/2022] [Accepted: 07/30/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Intraoperative hypotension is associated with myocardial injury, acute kidney injury, and death. In routine practice, specific causes of intraoperative hypotension are often unclear. A more detailed understanding of underlying haemodynamic alterations of intraoperative hypotension may identify specific treatments. We thus aimed to use machine learning - specifically, hierarchical clustering - to identify underlying haemodynamic alterations causing intraoperative hypotension in major abdominal surgery patients. Specifically, we tested the hypothesis that there are distinct endotypes of intraoperative hypotension, which may help refine therapeutic interventions. METHODS We conducted a secondary analysis of intraoperative haemodynamic measurements from a prospective observational study in 100 patients who had major abdominal surgery under general anaesthesia. We used stroke volume index, heart rate, cardiac index, systemic vascular resistance index, and pulse pressure variation measurements. Intraoperative hypotension was defined as any mean arterial pressure ≤65 mm Hg or a mean arterial pressure between 66 and 75 mm Hg requiring a norepinephrine infusion rate exceeding 0.1 μg kg-1 min-1. To identify endotypes of intraoperative hypotension, we used hierarchical clustering (Ward's method). RESULTS A total of 615 episodes of intraoperative hypotension occurred in 82 patients (46 [56%] female; median age: 64 [57, 73] yr) who had surgery of a median duration of 270 (195, 335) min. Hierarchical clustering revealed six distinct intraoperative hypotension endotypes. Based on their clinical characteristics, we labelled these endotypes as (1) myocardial depression, (2) bradycardia, (3) vasodilation with cardiac index increase, (4) vasodilation without cardiac index increase, (5) hypovolaemia, and (6) mixed type. CONCLUSION Hierarchical clustering identified six endotypes of intraoperative hypotension. If validated, considering these intraoperative hypotension endotypes may enable causal treatment of intraoperative hypotension.
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Affiliation(s)
- Karim Kouz
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lennart Brockmann
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lea Malin Timmermann
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alina Bergholz
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Moritz Flick
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kamal Maheshwari
- Department of Outcomes Research, Cleveland Clinic, Cleveland, OH, USA; Department of General Anesthesiology, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Daniel I Sessler
- Department of Outcomes Research, Cleveland Clinic, Cleveland, OH, USA
| | - Linda Krause
- Institute of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Bernd Saugel
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Outcomes Research Consortium, Cleveland, OH, USA.
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Bergholz A, Meidert AS, Flick M, Krause L, Vettorazzi E, Zapf A, Brunkhorst FM, Meybohm P, Zacharowski K, Zarbock A, Sessler DI, Kouz K, Saugel B. Effect of personalized perioperative blood pressure management on postoperative complications and mortality in high-risk patients having major abdominal surgery: protocol for a multicenter randomized trial (IMPROVE-multi). Trials 2022; 23:946. [PMID: 36397173 PMCID: PMC9670085 DOI: 10.1186/s13063-022-06854-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/19/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Intraoperative hypotension is common in patients having non-cardiac surgery and is associated with serious complications and death. However, optimal intraoperative blood pressures for individual patients remain unknown. We therefore aim to test the hypothesis that personalized perioperative blood pressure management-based on preoperative automated blood pressure monitoring-reduces the incidence of a composite outcome of acute kidney injury, acute myocardial injury, non-fatal cardiac arrest, and death within 7 days after surgery compared to routine blood pressure management in high-risk patients having major abdominal surgery. METHODS IMPROVE-multi is a multicenter randomized trial in 1272 high-risk patients having elective major abdominal surgery that we plan to conduct at 16 German university medical centers. Preoperative automated blood pressure monitoring using upper arm cuff oscillometry will be performed in all patients for one night to obtain the mean of the nighttime mean arterial pressures. Patients will then be randomized either to personalized blood pressure management or to routine blood pressure management. In patients assigned to personalized management, intraoperative mean arterial pressure will be maintained at least at the mean of the nighttime mean arterial pressures. In patients assigned to routine management, intraoperative blood pressure will be managed per routine. The primary outcome will be a composite of acute kidney injury, acute myocardial injury, non-fatal cardiac arrest, and death within 7 days after surgery. DISCUSSION Our trial will determine whether personalized perioperative blood pressure management reduces the incidence of major postoperative complications and death within 7 days after surgery compared to routine blood pressure management in high-risk patients having major abdominal surgery. TRIAL REGISTRATION ClinicalTrials.gov NCT05416944. Registered on June 14, 2022.
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Affiliation(s)
- Alina Bergholz
- grid.13648.380000 0001 2180 3484Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Agnes S. Meidert
- grid.411095.80000 0004 0477 2585Department of Anaesthesiology, University Hospital LMU Munich, Munich, Germany
| | - Moritz Flick
- grid.13648.380000 0001 2180 3484Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Linda Krause
- grid.13648.380000 0001 2180 3484Institute of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Eik Vettorazzi
- grid.13648.380000 0001 2180 3484Institute of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Antonia Zapf
- grid.13648.380000 0001 2180 3484Institute of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Frank M. Brunkhorst
- grid.275559.90000 0000 8517 6224Center for Clinical Studies, Jena University Hospital, Jena, Germany ,grid.275559.90000 0000 8517 6224Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | - Patrick Meybohm
- grid.411760.50000 0001 1378 7891Department of Anesthesiology, Intensive Care, Emergency and Pain Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Kai Zacharowski
- grid.411088.40000 0004 0578 8220Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - Alexander Zarbock
- grid.16149.3b0000 0004 0551 4246Department of Anesthesiology, Intensive Care, and Pain Medicine, University Hospital Münster, Münster, Germany
| | - Daniel I. Sessler
- grid.239578.20000 0001 0675 4725Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH USA ,grid.512286.aOutcomes Research Consortium, Cleveland, OH USA
| | - Karim Kouz
- grid.13648.380000 0001 2180 3484Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Bernd Saugel
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany. .,Outcomes Research Consortium, Cleveland, OH, USA.
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Kouz K, Wegge M, Flick M, Bergholz A, Moll-Khosrawi P, Nitzschke R, Trepte CJC, Krause L, Sessler DI, Zöllner C, Saugel B. Continuous intra-arterial versus intermittent oscillometric arterial pressure monitoring and hypotension during induction of anaesthesia: the AWAKE randomised trial. Br J Anaesth 2022; 129:478-486. [PMID: 36008202 DOI: 10.1016/j.bja.2022.06.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 11/02/2022] Open
Abstract
BACKGROUND Hypotension during induction of anaesthesia is associated with organ injury. Continuous arterial pressure monitoring might help reduce hypotension. We tested the hypothesis that continuous intra-arterial compared with intermittent oscillometric arterial pressure monitoring reduces hypotension during induction of anaesthesia in noncardiac surgery patients. METHODS In this single-centre randomised trial, 242 noncardiac surgery patients in whom intra-arterial arterial pressure monitoring was planned were randomised to unblinded continuous intra-arterial or to intermittent oscillometric arterial pressure monitoring (with blinded intra-arterial arterial pressure monitoring) during induction of anaesthesia. The primary endpoint was the area under a mean arterial pressure (MAP) of 65 mm Hg within the first 15 min of induction of anaesthesia. Secondary endpoints included areas under MAP values of 60, 50, and 40 mm Hg and durations of MAP values <65, <60, <50, and <40 mm Hg. RESULTS There were 224 subjects available for analysis. The median (25th-75th percentile) area under a MAP of 65 mm Hg was 15 (2-36) mm Hg • min in subjects assigned to continuous intra-arterial monitoring and 46 (7-111) mm Hg • min in subjects assigned to intermittent oscillometric monitoring (P<0.001). Subjects assigned to continuous intra-arterial monitoring had smaller areas under MAP values of 60, 50, and 40 mm Hg and shorter durations of MAP values <65, <60, <50, and <40 mm Hg than subjects assigned to intermittent oscillometric monitoring. CONCLUSION Continuous intra-arterial arterial pressure monitoring reduces hypotension during induction of anaesthesia compared with intermittent oscillometric arterial pressure monitoring in noncardiac surgery patients. In patients for whom an arterial catheter is planned, clinicians might therefore consider inserting the arterial catheter before rather than after induction of anaesthesia. CLINICAL TRIALS REGISTRATION NCT04894019.
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Affiliation(s)
- Karim Kouz
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mirja Wegge
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Moritz Flick
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alina Bergholz
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Parisa Moll-Khosrawi
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Rainer Nitzschke
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Constantin J C Trepte
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Linda Krause
- Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Daniel I Sessler
- Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA; Outcomes Research Consortium, Cleveland, OH, USA
| | - Christian Zöllner
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Bernd Saugel
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Outcomes Research Consortium, Cleveland, OH, USA.
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Chalkias A, Xenos M. Relationship of Effective Circulating Volume with Sublingual Red Blood Cell Velocity and Microvessel Pressure Difference: A Clinical Investigation and Computational Fluid Dynamics Modeling. J Clin Med 2022; 11:jcm11164885. [PMID: 36013124 PMCID: PMC9410298 DOI: 10.3390/jcm11164885] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/12/2022] [Accepted: 08/18/2022] [Indexed: 11/18/2022] Open
Abstract
The characteristics of physiologic hemodynamic coherence are not well-investigated. We examined the physiological relationship between circulating blood volume, sublingual microcirculatory perfusion, and tissue oxygenation in anesthetized individuals with steady-state physiology. We assessed the correlation of mean circulatory filling pressure analogue (Pmca) with sublingual microcirculatory perfusion and red blood cell (RBC) velocity using SDF+ imaging and a modified optical flow-based algorithm. We also reconstructed the 2D microvessels and applied computational fluid dynamics (CFD) to evaluate the correlation of Pmca and RBC velocity with the obtained pressure and velocity fields in microvessels from CFD (pressure difference, (Δp)). Twenty adults with a median age of 39.5 years (IQR 35.5−44.5) were included in the study. Sublingual velocity distributions were similar and followed a log-normal distribution. A constant Pmca value of 14 mmHg was observed in all individuals with sublingual RBC velocity 6−24 μm s−1, while a Pmca < 14 mmHg was observed in those with RBC velocity > 24 μm s−1. When Pmca ranged between 11 mmHg and 15 mmHg, Δp fluctuated between 0.02 Pa and 0.1 Pa. In conclusion, the intact regulatory mechanisms maintain a physiological coupling between systemic hemodynamics, sublingual microcirculatory perfusion, and tissue oxygenation when Pmca is 14 mmHg.
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Affiliation(s)
- Athanasios Chalkias
- Department of Anesthesiology, Faculty of Medicine, University of Thessaly, 41500 Larisa, Greece
- Outcomes Research Consortium, Cleveland, OH 44195, USA
- Committee on Shock, Hellenic Society of Cardiopulmonary Resuscitation, 10434 Athens, Greece
- Correspondence:
| | - Michalis Xenos
- Section of Applied and Computational Mathematics, Department of Mathematics, University of Ioannina, 45110 Ioannina, Greece
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Chalkias A, Laou E, Papagiannakis N, Spyropoulos V, Kouskouni E, Theodoraki K, Xanthos T. Assessment of Dynamic Changes in Stressed Volume and Venous Return during Hyperdynamic Septic Shock. J Pers Med 2022; 12:jpm12050724. [PMID: 35629145 PMCID: PMC9146182 DOI: 10.3390/jpm12050724] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/19/2022] [Accepted: 04/28/2022] [Indexed: 02/04/2023] Open
Abstract
The present work investigated the dynamic changes in stressed volume (Vs) and other determinants of venous return using a porcine model of hyperdynamic septic shock. Septicemia was induced in 10 anesthetized swine, and fluid challenges were started after the diagnosis of sepsis-induced arterial hypotension and/or tissue hypoperfusion. Norepinephrine infusion targeting a mean arterial pressure (MAP) of 65 mmHg was started after three consecutive fluid challenges. After septic shock was confirmed, norepinephrine infusion was discontinued, and the animals were left untreated until cardiac arrest occurred. Baseline Vs decreased by 7% for each mmHg decrease in MAP during progression of septic shock. Mean circulatory filling pressure (Pmcf) analogue (Pmca), right atrial pressure, resistance to venous return, and efficiency of the heart decreased with time (p < 0.001 for all). Fluid challenges did not improve hemodynamics, but noradrenaline increased Vs from 107 mL to 257 mL (140%) and MAP from 45 mmHg to 66 mmHg (47%). Baseline Pmca and post-cardiac arrest Pmcf did not differ significantly (14.3 ± 1.23 mmHg vs. 14.75 ± 1.5 mmHg, p = 0.24), but the difference between pre-arrest Pmca and post-cardiac arrest Pmcf was statistically significant (9.5 ± 0.57 mmHg vs. 14.75 ± 1.5 mmHg, p < 0.001). In conclusion, the baseline Vs decreased by 7% for each mmHg decrease in MAP during progression of hyperdynamic septic shock. Significant changes were also observed in other determinants of venous return. A new physiological intravascular volume existing at zero transmural distending pressure was identified, termed as the rest volume (Vr).
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Affiliation(s)
- Athanasios Chalkias
- Department of Anesthesiology, Faculty of Medicine, University of Thessaly, 41500 Larisa, Greece;
- Outcomes Research Consortium, Cleveland, OH 44195, USA
- Hellenic Society of Cardiopulmonary Resuscitation, 11528 Athens, Greece
- Correspondence:
| | - Eleni Laou
- Department of Anesthesiology, Faculty of Medicine, University of Thessaly, 41500 Larisa, Greece;
| | - Nikolaos Papagiannakis
- First Department of Neurology, Eginition University Hospital, Medical School, National and Kapodistrian University of Athens, 11528 Athens, Greece;
| | | | - Evaggelia Kouskouni
- Department of Biopathology, Aretaieion University Hospital, Medical School, National and Kapodistrian University of Athens, 11528 Athens, Greece;
| | - Kassiani Theodoraki
- Department of Anesthesiology, Aretaieion University Hospital, National and Kapodistrian University of Athens, 15772 Athens, Greece;
| | - Theodoros Xanthos
- School of Medicine, European University Cyprus, Nicosia 2404, Cyprus;
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11
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Otani K, Funada H, Teranishi R, Okada M, Yamawaki H. Cardiovascular Characteristics of Zucker Fatty Diabetes Mellitus Rats, an Animal Model for Obesity and Type 2 Diabetes. Int J Mol Sci 2022; 23:4228. [PMID: 35457048 DOI: 10.3390/ijms23084228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 12/02/2022] Open
Abstract
Zucker fatty diabetes mellitus (ZFDM) rats harboring the missense mutation (fa) in a leptin receptor gene have been recently established as a novel animal model of obesity and type 2 diabetes (T2D). Here, we explored changes in cardiovascular dynamics including blood pressure and heart rate (HR) associated with the progression of obesity and T2D, as well as pathological changes in adipose tissue and kidney. There was no significant difference in systolic blood pressure (SBP) in ZFDM-Leprfa/fa (Homo) compared with ZFDM-Leprfa/+ (Hetero) rats, while HR and plasma adrenaline in Homo were significantly lower than Hetero. The mRNA expression of monocyte chemotactic protein-1 in perirenal white adipose tissue (WAT) from Homo was significantly higher than Hetero. Interscapular brown adipose tissue (BAT) in Homo was degenerated and whitened. The plasma blood urea nitrogen in Homo was significantly higher than Hetero. In summary, we demonstrated for the first time that HR and plasma adrenaline concentration but not SBP in Homo decrease with obesity and T2D. In addition, inflammation occurs in WAT from Homo, while whitening occurs in BAT. Further, renal function is impaired in Homo. In the future, ZFDM rats will be useful for investigating metabolic changes associated with the progression of obesity and T2D.
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12
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Boonruangkan J, Farrokhi H, Rohith TM, Kwok S, Carney TJ, Su PC, Kim YJ. Label-free quantitative measurement of cardiovascular dynamics in a zebrafish embryo using frequency-comb-referenced-quantitative phase imaging. J Biomed Opt 2021; 26:JBO-210182RR. [PMID: 34773396 PMCID: PMC8589177 DOI: 10.1117/1.jbo.26.11.116004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
SIGNIFICANCE Real-time monitoring of the heart rate and blood flow is crucial for studying cardiovascular dysfunction, which leads to cardiovascular diseases. AIM This study aims at in-depth understanding of high-speed cardiovascular dynamics in a zebrafish embryo model for various biomedical applications via frequency-comb-referenced quantitative phase imaging (FCR-QPI). APPROACH Quantitative phase imaging (QPI) has emerged as a powerful technique in the field of biomedicine but has not been actively applied to the monitoring of circulatory/cardiovascular parameters, due to dynamic speckles and low frame rates. We demonstrate FCR-QPI to measure heart rate and blood flow in a zebrafish embryo. FCR-QPI utilizes a high-speed photodetector instead of a conventional camera, so it enables real-time monitoring of individual red blood cell (RBC) flow. RESULTS The average velocity of zebrafish's RBCs was measured from 192.5 to 608.8 μm / s at 24 to 28 hour-post-fertilization (hpf). In addition, the number of RBCs in a pulsatile blood flow was revealed to 16 cells/pulse at 48 hpf. The heart rates corresponded to 94 and 142 beats-per-minute at 24 and 48 hpf. CONCLUSIONS This approach will newly enable in-depth understanding of the cardiovascular dynamics in the zebrafish model and possible usage for drug discovery applications in biomedicine.
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Affiliation(s)
- Jeeranan Boonruangkan
- Nanyang Technological University, School of Mechanical and Aerospace Engineering, Singapore
| | - Hamid Farrokhi
- Nanyang Technological University, School of Mechanical and Aerospace Engineering, Singapore
| | - Thazhe M. Rohith
- Nanyang Technological University, School of Mechanical and Aerospace Engineering, Singapore
| | - Samuel Kwok
- Nanyang Technological University, Lee Kong Chian, School of Medicine, Singapore
| | - Tom J. Carney
- Nanyang Technological University, Lee Kong Chian, School of Medicine, Singapore
| | - Pei-Chen Su
- Nanyang Technological University, School of Mechanical and Aerospace Engineering, Singapore
| | - Young-Jin Kim
- Nanyang Technological University, School of Mechanical and Aerospace Engineering, Singapore
- Korea Advanced Institute of Science and Technology, Department of Mechanical Engineering, Daejeon, Republic of Korea
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13
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D'Orsi L, Curcio L, Cibella F, Borri A, Gavish L, Eisenkraft A, De Gaetano A. A mathematical model of cardiovascular dynamics for the diagnosis and prognosis of hemorrhagic shock. Math Med Biol 2021; 38:417-441. [PMID: 34499176 DOI: 10.1093/imammb/dqab011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 08/16/2021] [Accepted: 08/16/2021] [Indexed: 11/13/2022]
Abstract
A variety of mathematical models of the cardiovascular system have been suggested over several years in order to describe the time-course of a series of physiological variables (i.e. heart rate, cardiac output, arterial pressure) relevant for the compensation mechanisms to perturbations, such as severe haemorrhage. The current study provides a simple but realistic mathematical description of cardiovascular dynamics that may be useful in the assessment and prognosis of hemorrhagic shock. The present work proposes a first version of a differential-algebraic equations model, the model dynamical ODE model for haemorrhage (dODEg). The model consists of 10 differential and 14 algebraic equations, incorporating 61 model parameters. This model is capable of replicating the changes in heart rate, mean arterial pressure and cardiac output after the onset of bleeding observed in four experimental animal preparations and fits well to the experimental data. By predicting the time-course of the physiological response after haemorrhage, the dODEg model presented here may be of significant value for the quantitative assessment of conventional or novel therapeutic regimens. The model may be applied to the prediction of survivability and to the determination of the urgency of evacuation towards definitive surgical treatment in the operational setting.
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Affiliation(s)
- Laura D'Orsi
- National Research Council of Italy, Institute for Systems Analysis and Computer Science 'A. Ruberti', Biomathematics Laboratory, UCSC Largo A. Gemelli 8, 00168 Rome, Italy
| | - Luciano Curcio
- National Research Council of Italy, Institute for Biomedical Research and Innovation, Biomathematics Laboratory, Via Ugo La Malfa, 153, 90146 Palermo, Italy
| | - Fabio Cibella
- National Research Council of Italy, Institute for Biomedical Research and Innovation, Biomathematics Laboratory, Via Ugo La Malfa, 153, 90146 Palermo, Italy
| | - Alessandro Borri
- National Research Council of Italy, Institute for Systems Analysis and Computer Science 'A. Ruberti', Biomathematics Laboratory, UCSC Largo A. Gemelli 8, 00168 Rome, Italy
| | - Lilach Gavish
- Institute for Research in Military Medicine (IRMM), Faculty of Medicine, The Hebrew University of Jerusalem, 9112001, Israel, Institute for Medical Research (IMRIC), Faculty of Medicine, The Hebrew University of Jerusalem, 9112001, Israel
| | - Arik Eisenkraft
- Institute for Research in Military Medicine (IRMM), Faculty of Medicine, The Hebrew University of Jerusalem, 9112001, Israel
| | - Andrea De Gaetano
- National Research Council of Italy, Institute for Systems Analysis and Computer Science 'A. Ruberti', Biomathematics Laboratory, UCSC Largo A. Gemelli 8, 00168 Rome, Italy
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14
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Dobreva A, Brady-Nicholls R, Larripa K, Puelz C, Mehlsen J, Olufsen MS. A physiological model of the inflammatory-thermal-pain-cardiovascular interactions during an endotoxin challenge. J Physiol 2021; 599:1459-1485. [PMID: 33450068 DOI: 10.1113/jp280883] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 01/11/2021] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS Inflammation in response to bacterial endotoxin challenge impacts physiological functions, including cardiovascular, thermal and pain dynamics, although the mechanisms are poorly understood. We develop an innovative mathematical model incorporating interaction pathways between inflammation and physiological processes observed in response to an endotoxin challenge. We calibrate the model to individual data from 20 subjects in an experimental study of the human inflammatory and physiological responses to endotoxin, and we validate the model against human data from an independent study. Using the model to simulate patient responses to different treatment modalities reveals that a multimodal treatment combining several therapeutic strategies gives the best recovery outcome. ABSTRACT Uncontrolled, excessive production of pro-inflammatory mediators from immune cells and traumatized tissues can cause systemic inflammatory conditions such as sepsis, one of the ten leading causes of death in the USA, and one of the three leading causes of death in the intensive care unit. Understanding how inflammation affects physiological processes, including cardiovascular, thermal and pain dynamics, can improve a patient's chance of recovery after an inflammatory event caused by surgery or a severe infection. Although the effects of the autonomic response on the inflammatory system are well-known, knowledge about the reverse interaction is lacking. The present study develops a mathematical model analyzing the inflammatory system's interactions with thermal, pain and cardiovascular dynamics in response to a bacterial endotoxin challenge. We calibrate the model with individual data from an experimental study of the inflammatory and physiological responses to a one-time administration of endotoxin in 20 healthy young men and validate it against data from an independent endotoxin study. We use simulation to explore how various treatments help patients exposed to a sustained pathological input. The treatments explored include bacterial endotoxin adsorption, antipyretics and vasopressors, as well as combinations of these. Our findings suggest that the most favourable recovery outcome is achieved by a multimodal strategy, combining all three interventions to simultaneously remove endotoxin from the body and alleviate symptoms caused by the immune system as it fights the infection.
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Affiliation(s)
- Atanaska Dobreva
- Department of Mathematics, North Carolina State University, Raleigh, NC, USA.,School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ, USA
| | - Renee Brady-Nicholls
- Department of Integrated Mathematical Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Kamila Larripa
- Department of Mathematics, Humboldt State University, Arcata, CA, USA
| | - Charles Puelz
- Department of Pediatrics, Section of Cardiology, Texas Children's Hospital and Baylor College of Medicine, Houston, TX, USA
| | - Jesper Mehlsen
- Section for Surgical Pathophysiology, Rigshospitalet, Copenhagen, Denmark
| | - Mette S Olufsen
- Department of Mathematics, North Carolina State University, Raleigh, NC, USA
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15
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Saugel B, Kouz K, Scheeren TWL, Greiwe G, Hoppe P, Romagnoli S, de Backer D. Cardiac output estimation using pulse wave analysis-physiology, algorithms, and technologies: a narrative review. Br J Anaesth 2020; 126:67-76. [PMID: 33246581 DOI: 10.1016/j.bja.2020.09.049] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/23/2020] [Accepted: 09/10/2020] [Indexed: 01/18/2023] Open
Abstract
Pulse wave analysis (PWA) allows estimation of cardiac output (CO) based on continuous analysis of the arterial blood pressure (AP) waveform. We describe the physiology of the AP waveform, basic principles of PWA algorithms for CO estimation, and PWA technologies available for clinical practice. The AP waveform is a complex physiological signal that is determined by interplay of left ventricular stroke volume, systemic vascular resistance, and vascular compliance. Numerous PWA algorithms are available to estimate CO, including Windkessel models, long time interval or multi-beat analysis, pulse power analysis, or the pressure recording analytical method. Invasive, minimally-invasive, and noninvasive PWA monitoring systems can be classified according to the method they use to calibrate estimated CO values in externally calibrated systems, internally calibrated systems, and uncalibrated systems.
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Affiliation(s)
- Bernd Saugel
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Outcomes Research Consortium, Cleveland, OH, USA.
| | - Karim Kouz
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas W L Scheeren
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Gillis Greiwe
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Phillip Hoppe
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefano Romagnoli
- Department of Health Science, Section of Anesthesia and Critical Care, University of Florence, Florence, Italy; Department of Anesthesia and Critical Care, Careggi University Hospital, Florence, Italy
| | - Daniel de Backer
- Department of Intensive Care, CHIREC Hospitals, Université Libre de Bruxelles, Brussels, Belgium
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16
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Ramírez J, van Duijvenboden S, Young WJ, Orini M, Lambiase PD, Munroe PB, Tinker A. Common Genetic Variants Modulate the Electrocardiographic Tpeak-to-Tend Interval. Am J Hum Genet 2020; 106:764-778. [PMID: 32386560 PMCID: PMC7273524 DOI: 10.1016/j.ajhg.2020.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 04/08/2020] [Indexed: 02/06/2023] Open
Abstract
Sudden cardiac death is responsible for half of all deaths from cardiovascular disease. The analysis of the electrophysiological substrate for arrhythmias is crucial for optimal risk stratification. A prolonged T-peak-to-Tend (Tpe) interval on the electrocardiogram is an independent predictor of increased arrhythmic risk, and Tpe changes with heart rate are even stronger predictors. However, our understanding of the electrophysiological mechanisms supporting these risk factors is limited. We conducted genome-wide association studies (GWASs) for resting Tpe and Tpe response to exercise and recovery in ∼30,000 individuals, followed by replication in independent samples (∼42,000 for resting Tpe and ∼22,000 for Tpe response to exercise and recovery), all from UK Biobank. Fifteen and one single-nucleotide variants for resting Tpe and Tpe response to exercise, respectively, were formally replicated. In a full dataset GWAS, 13 further loci for resting Tpe, 1 for Tpe response to exercise and 1 for Tpe response to exercise were genome-wide significant (p ≤ 5 × 10-8). Sex-specific analyses indicated seven additional loci. In total, we identify 32 loci for resting Tpe, 3 for Tpe response to exercise and 3 for Tpe response to recovery modulating ventricular repolarization, as well as cardiac conduction and contraction. Our findings shed light on the genetic basis of resting Tpe and Tpe response to exercise and recovery, unveiling plausible candidate genes and biological mechanisms underlying ventricular excitability.
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Affiliation(s)
- Julia Ramírez
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK,Institute of Cardiovascular Science, University College London, London WC1E 6BT, UK
| | - Stefan van Duijvenboden
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK,Institute of Cardiovascular Science, University College London, London WC1E 6BT, UK
| | - William J. Young
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK,Barts Heart Centre, St Bartholomew’s Hospital, London EC1A 7BE, UK
| | - Michele Orini
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK,Institute of Cardiovascular Science, University College London, London WC1E 6BT, UK,Barts Heart Centre, St Bartholomew’s Hospital, London EC1A 7BE, UK
| | - Pier D. Lambiase
- Institute of Cardiovascular Science, University College London, London WC1E 6BT, UK,Barts Heart Centre, St Bartholomew’s Hospital, London EC1A 7BE, UK
| | - Patricia B. Munroe
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK,NIHR Barts Cardiovascular Biomedical Research Unit, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK,Corresponding author
| | - Andrew Tinker
- Clinical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK,NIHR Barts Cardiovascular Biomedical Research Unit, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK,Corresponding author
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17
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Lancaster G, Debevec T, Millet GP, Poussel M, Willis SJ, Mramor M, Goričar K, Osredkar D, Dolžan V, Stefanovska A. Relationship between cardiorespiratory phase coherence during hypoxia and genetic polymorphism in humans. J Physiol 2020; 598:2001-2019. [PMID: 31957891 PMCID: PMC7317918 DOI: 10.1113/jp278829] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 01/15/2020] [Indexed: 12/15/2022] Open
Abstract
Key points High altitude‐induced hypoxia in humans evokes a pattern of breathing known as periodic breathing (PB), in which the regular oscillations corresponding to rhythmic expiration and inspiration are modulated by slow periodic oscillations. The phase coherence between instantaneous heart rate and respiration is shown to increase significantly at the frequency of periodic breathing during acute and sustained normobaric and hypobaric hypoxia. It is also shown that polymorphism in specific genes, NOTCH4 and CAT, is significantly correlated with this coherence, and thus with the incidence of PB. Differences in phase shifts between blood flow signals and respiratory and PB oscillations clearly demonstrate contrasting origins of the mechanisms underlying normal respiration and PB. These novel findings provide a better understanding of both the genetic and the physiological mechanisms responsible for respiratory control during hypoxia at altitude, by linking genetic factors with cardiovascular dynamics, as evaluated by phase coherence.
Abstract Periodic breathing (PB) occurs in most humans at high altitudes and is characterised by low‐frequency periodic alternation between hyperventilation and apnoea. In hypoxia‐induced PB the dynamics and coherence between heart rate and respiration and their relationship to underlying genetic factors is still poorly understood. The aim of this study was to investigate, through novel usage of time–frequency analysis methods, the dynamics of hypoxia‐induced PB in healthy individuals genotyped for a selection of antioxidative and neurodevelopmental genes. Breathing, ECG and microvascular blood flow were simultaneously monitored for 30 min in 22 healthy males. The same measurements were repeated under normoxic and hypoxic (normobaric (NH) and hypobaric (HH)) conditions, at real and simulated altitudes of up to 3800 m. Wavelet phase coherence and phase difference around the frequency of breathing (approximately 0.3 Hz) and around the frequency of PB (approximately 0.06 Hz) were evaluated. Subjects were genotyped for common functional polymorphisms in antioxidative and neurodevelopmental genes. During hypoxia, PB resulted in increased cardiorespiratory coherence at the PB frequency. This coherence was significantly higher in subjects with NOTCH4 polymorphism, and significantly lower in those with CAT polymorphism (HH only). Study of the phase shifts clearly indicates that the physiological mechanism of PB is different from that of the normal respiratory cycle. The results illustrate the power of time‐evolving oscillatory analysis content in obtaining important insight into high altitude physiology. In particular, it provides further evidence for a genetic predisposition to PB and may partly explain the heterogeneity in the hypoxic response. High altitude‐induced hypoxia in humans evokes a pattern of breathing known as periodic breathing (PB), in which the regular oscillations corresponding to rhythmic expiration and inspiration are modulated by slow periodic oscillations. The phase coherence between instantaneous heart rate and respiration is shown to increase significantly at the frequency of periodic breathing during acute and sustained normobaric and hypobaric hypoxia. It is also shown that polymorphism in specific genes, NOTCH4 and CAT, is significantly correlated with this coherence, and thus with the incidence of PB. Differences in phase shifts between blood flow signals and respiratory and PB oscillations clearly demonstrate contrasting origins of the mechanisms underlying normal respiration and PB. These novel findings provide a better understanding of both the genetic and the physiological mechanisms responsible for respiratory control during hypoxia at altitude, by linking genetic factors with cardiovascular dynamics, as evaluated by phase coherence.
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Affiliation(s)
| | - Tadej Debevec
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia.,Department of Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Gregoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Mathias Poussel
- Department of Pulmonary Function Testing and Exercise Physiology, CHRU de Nancy, Nancy, France
| | - Sarah J Willis
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Minca Mramor
- University Children's Hospital, University Medical Center Ljubljana, Ljubljana, Slovenia
| | - Katja Goričar
- Pharmacogenetics Laboratory, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Damjan Osredkar
- University Children's Hospital, University Medical Center Ljubljana, Ljubljana, Slovenia
| | - Vita Dolžan
- Pharmacogenetics Laboratory, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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18
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Kaufmann T, Saugel B, Scheeren TWL. Perioperative goal-directed therapy - What is the evidence? Best Pract Res Clin Anaesthesiol 2019; 33:179-187. [PMID: 31582097 DOI: 10.1016/j.bpa.2019.05.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 05/08/2019] [Indexed: 01/27/2023]
Abstract
Perioperative goal-directed therapy aims at optimizing global hemodynamics during the perioperative period by titrating fluids, vasopressors, and/or inotropes to predefined hemodynamic goals. There is evidence on the benefit of perioperative goal-directed therapy, but its adoption into clinical practice is slow and incomprehensive. Current evidence indicates that treating patients according to perioperative goal-directed therapy protocols reduces morbidity and mortality, particularly in patients having high-risk surgery. Perioperative goal-directed therapy protocols need to be started early, should include vasoactive agents in addition to fluids, and should target blood flow related variables. Future promising developments in the field of perioperative goal-directed therapy include personalized hemodynamic management and closed-loop system management.
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Affiliation(s)
- Thomas Kaufmann
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB, Groningen, the Netherlands.
| | - Bernd Saugel
- Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
| | - Thomas W L Scheeren
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB, Groningen, the Netherlands.
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19
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Abstract
Mock circulatory test rig (MCTR) is the essential and indispensable facility in the cardiovascular in vitro studies. The system configuration and the motion profile of the MCTR design directly influence the validity, precision, and accuracy of the experimental data collected. Previous studies gave the schematic but never describe the structure and motion design details of the MCTRs used, which makes comparison of the experimental data reported by different research groups plausible but not fully convincing. This article presents the detailed structure and motion design of a sophisticated MCTR system, and examines the important issues such as the determination of the ventricular motion waveform, modelling of the physiological impedance, etc., in the MCTR designing. The study demonstrates the overall design procedures from the system conception, cardiac model devising, motion planning, to the motor and accessories selection. This can be used as a reference to aid researchers in the design and construction of their own in-house MCTRs for cardiovascular studies.
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Affiliation(s)
- Yuhui Shi
- a Northwest Institute of Mechanical and Electrical Engineering , Xianyang , Shaanxi Province , China
| | - Theodosios Korakianitis
- b Parks College of Engineering, Aviation and Technology , Saint Louis University , Saint Louis , MO , USA
| | - Zhongjian Li
- c College of Automation , Northwestern Polytechnical University , Xi'an , China
| | - Yubing Shi
- d Faculty of Arts, Science and Technology , University of Northampton , Northampton , UK
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20
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Arnold A, Battista C, Bia D, German YZ, Armentano RL, Tran H, Olufsen MS. Uncertainty Quantification in a Patient-Specific One-Dimensional Arterial Network Model: EnKF-Based Inflow Estimator. J Verif Valid Uncertain Quantif 2017; 2:0110021-1100214. [PMID: 35832352 PMCID: PMC8597574 DOI: 10.1115/1.4035918] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 01/31/2017] [Indexed: 11/09/2023]
Abstract
Successful clinical use of patient-specific models for cardiovascular dynamics depends on the reliability of the model output in the presence of input uncertainties. For 1D fluid dynamics models of arterial networks, input uncertainties associated with the model output are related to the specification of vessel and network geometry, parameters within the fluid and wall equations, and parameters used to specify inlet and outlet boundary conditions. This study investigates how uncertainty in the flow profile applied at the inlet boundary of a 1D model affects area and pressure predictions at the center of a single vessel. More specifically, this study develops an iterative scheme based on the ensemble Kalman filter (EnKF) to estimate the temporal inflow profile from a prior distribution of curves. The EnKF-based inflow estimator provides a measure of uncertainty in the size and shape of the estimated inflow, which is propagated through the model to determine the corresponding uncertainty in model predictions of area and pressure. Model predictions are compared to ex vivo area and blood pressure measurements in the ascending aorta, the carotid artery, and the femoral artery of a healthy male Merino sheep. Results discuss dynamics obtained using a linear and a nonlinear viscoelastic wall model.
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Affiliation(s)
- Andrea Arnold
- Department of Mathematics, North Carolina State University, 2108 SAS Hall, 2311 Stinson Drive, Box 8205, Raleigh, NC 27695-8205 e-mail:
| | - Christina Battista
- DILIsym Services, Inc., Six Davis Drive, Research Triangle Park, NC 27709 e-mail:
| | - Daniel Bia
- Department of Physiology, Universidad de la República, Montevideo 11800, Uruguay e-mail:
| | - Yanina Zócalo German
- Department of Physiology, Universidad de la República, Montevideo 11800, Uruguay e-mail:
| | - Ricardo L Armentano
- Department of Biological Engineering, CENUR Litoral Norte-Paysandú, Universidad de la República, Montevideo 11800, Uruguay e-mail:
| | - Hien Tran
- Department of Mathematics, North Carolina State University, 2108 SAS Hall, 2311 Stinson Drive, Box 8205, Raleigh, NC 27695-8205 e-mail:
| | - Mette S Olufsen
- Department of Mathematics, North Carolina State University, 2108 SAS Hall, 2311 Stinson Drive, Box 8205, Raleigh, NC 27695-8205 e-mail:
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21
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Shi Y, Brown AG, Lawford PV, Arndt A, Nuesser P, Hose DR. Computational modelling and evaluation of cardiovascular response under pulsatile impeller pump support. Interface Focus 2011; 1:320-37. [PMID: 22670203 DOI: 10.1098/rsfs.2010.0039] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 02/04/2011] [Indexed: 11/12/2022] Open
Abstract
This study presents a numerical simulation of cardiovascular response in the heart failure condition under the support of a Berlin Heart INCOR impeller pump-type ventricular assist device (VAD). The model is implemented using the CellML modelling language. To investigate the potential of using the Berlin Heart INCOR impeller pump to produce physiologically meaningful arterial pulse pressure within the various physiological constraints, a series of VAD-assisted cardiovascular cases are studied, in which the pulsation ratio and the phase shift of the VAD motion profile are systematically changed to observe the cardiovascular responses in each of the studied cases. An optimization process is proposed, including the introduction of a cost function to balance the importance of the characteristic cardiovascular variables. Based on this cost function it is found that a pulsation ratio of 0.35 combined with a phase shift of 200° produces the optimal cardiovascular response, giving rise to a maximal arterial pulse pressure of 12.6 mm Hg without inducing regurgitant pump flow while keeping other characteristic cardiovascular variables within appropriate physiological ranges.
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Affiliation(s)
- Yubing Shi
- Medical Physics Group, Department of Cardiovascular Science, Faculty of Medicine, Dentistry and Health , University of Sheffield , Sheffield S10 2RX , UK
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Schmidt JP, Delp SL, Sherman MA, Taylor CA, Pande VS, Altman RB. The Simbios National Center: Systems Biology in Motion. Proc IEEE Inst Electr Electron Eng 2008; 96:1266. [PMID: 20107615 PMCID: PMC2811325 DOI: 10.1109/jproc.2008.925454] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Physics-based simulation is needed to understand the function of biological structures and can be applied across a wide range of scales, from molecules to organisms. Simbios (the National Center for Physics-Based Simulation of Biological Structures, http://www.simbios.stanford.edu/) is one of seven NIH-supported National Centers for Biomedical Computation. This article provides an overview of the mission and achievements of Simbios, and describes its place within systems biology. Understanding the interactions between various parts of a biological system and integrating this information to understand how biological systems function is the goal of systems biology. Many important biological systems comprise complex structural systems whose components interact through the exchange of physical forces, and whose movement and function is dictated by those forces. In particular, systems that are made of multiple identifiable components that move relative to one another in a constrained manner are multibody systems. Simbios' focus is creating methods for their simulation. Simbios is also investigating the biomechanical forces that govern fluid flow through deformable vessels, a central problem in cardiovascular dynamics. In this application, the system is governed by the interplay of classical forces, but the motion is distributed smoothly through the materials and fluids, requiring the use of continuum methods. In addition to the research aims, Simbios is working to disseminate information, software and other resources relevant to biological systems in motion.
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Affiliation(s)
- Jeanette P. Schmidt
- Departments of Bioengineering, Stanford University, MC-5448, Stanford, CA 94305-5448 USA
| | - Scott L. Delp
- Departments of Bioengineering, Mechanical Engineering, and Orthopaedic Surgery, MC-5444, Stanford University, Stanford, CA 94305-5444 USA
| | - Michael A. Sherman
- Departments of Bioengineering, Stanford University, MC-5448, Stanford, CA 94305-5448 USA
| | - Charles A. Taylor
- Departments of Bioengineering, Mechanical Engineering and Radiology, MC-5431 Stanford University, Stanford, CA 94305-5431 USA
| | - Vijay S. Pande
- Departments of Chemistry and Structural Biology, Stanford University, MC-5080, Stanford, CA 94305-5080 USA
| | - Russ B. Altman
- Departments of Bioengineering, Genetics, Medicine and Computer Science, MC-5444, Stanford University, Stanford, CA 94305-5444 USA
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