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Eiby YA, Wright IMR, Stark MJ, Lingwood BE. Red cell infusion but not saline is effective for volume expansion in preterm piglets. Pediatr Res 2022:10.1038/s41390-022-02403-2. [PMID: 36509847 DOI: 10.1038/s41390-022-02403-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/10/2022] [Accepted: 11/14/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND A common first-line treatment for supporting cardiovascular function in preterm infants is volume expansion using saline, but this does not improve outcomes. This study aimed to determine if volume expansion with saline increases blood volume, blood pressure and cerebral oxygenation; and if volume expansion with packed red blood cells (RBC) is more effective. We hypothesized that RBC infusion is more effective than saline for increasing blood volume and maintaining cardiovascular function and cerebral oxygenation. METHODS Five groups of preterm piglets (98/115d gestation) were infused with saline (10 or 20 mL/kg) or RBC (10 or 20 mL/kg) or no treatment. Blood volume, blood pressure, central venous pressure, heart rate, carotid flow, cerebral oxygenation, arterial pH, base excess, and lactate levels were assessed for 6 h after treatment started. RESULTS Both RBC groups had significant increases in blood volume, and improved measures of cardiovascular function, cerebral oxygenation and metabolic acidosis. Saline infusion did not increase blood volume or measures of cardiovascular function, cerebral oxygenation or metabolic acidosis. CONCLUSIONS The results suggest that the deteriorating cardiovascular function in the hours after birth in preterm piglets, and possibly in premature babies, may be reversed or halted by more effective support of blood volume. IMPACT Blood volume decreases after birth in preterm piglets and this decrease is associated with deteriorating cardiovascular function and cerebral oxygenation. Infusion of saline does not increase blood volume nor prevent deterioration in cardiovascular function. Infusion of packed red blood cells results in an increase in blood volume and improvements in cardiovascular function and cerebral oxygenation. Deteriorating cardiovascular function in the hours after birth in preterm piglets, and possibly in human preterm neonates, may be reversed or halted by more effective support of blood volume.
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Affiliation(s)
- Yvonne A Eiby
- Perinatal Research Centre and UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.
| | - Ian M R Wright
- Perinatal Research Centre and UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.,Australian Institute of Tropical Health and Medicine and The College of Medicine and Dentistry, James Cook University, Cairns, QLD, Australia
| | - Michael J Stark
- Department of Neonatal Medicine, Women's and Children's Hospital Adelaide, Adelaide, SA, Australia.,Robinson Research Institute, School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - Barbara E Lingwood
- Perinatal Research Centre and UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.,Department of Neonatology, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
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2
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Chang HY, Chang JH, Peng CC, Hsu CH, Ko MHJ, Hung CL, Chen MR. Subclinical Changes in Left Heart Structure and Function at Preschool Age in Very Low Birth Weight Preterm Infants. Front Cardiovasc Med 2022; 9:879952. [PMID: 35600491 PMCID: PMC9120602 DOI: 10.3389/fcvm.2022.879952] [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: 02/20/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
Background Survivors of preterm birth are at risk of long-term cardiovascular consequences. The objective of this prospective observational study was to assess left heart function at preschool age in preterm children with very low birth weight (VLBW). Methods We recruited children aged 5–6 years from preterm infants and full-term children. All subjects underwent conventional echocardiography and speckle-tracking echocardiography. The results were compared between the preterm and term groups. Results Eighty-seven VLBW preterm children and 29 term controls were included in the study. After adjusting for body surface area, the preterm group compared to the full-term group had significantly smaller left ventricular (LV) end-diastolic and end-systolic internal dimensions (31.2 vs. 33.5 mm, p = 0.048; and 20.0 vs. 21.6 mm, respectively; p = 0.024), lower LV end-diastolic and end-systolic volumes (38.8 vs. 46.3 mL, p = 0.024; and 12.8 vs. 15.6 mL, respectively; p = 0.008). Left atrial (LA) maximal and minimal volume were also significantly smaller in the preterm group (15.4 vs. 18.9 mL, p = 0.017; and 6.2 vs 7.5 mL, respectively; p = 0.018). LV global longitudinal strain (−21.4 vs. −23.2%, p < 0.0001) and systolic strain rate (−1.30 vs. −1.37 /s, p = 0.001) were significantly lower in the preterm group than in the term control group. LA longitudinal strain was decreased (43.9 vs. 52.8%, p < 0.0001) and left atrial stiffness index (0.17 vs. 0.14, p < 0.0001) was increased in preterm infants. However, all the measurements in both groups were within normal range. Conclusions Subclinical changes of left heart structure and function were found in VLBW infants at preschool age. Additional long-term follow-ups of the cardiovascular outcomes are needed in this vulnerable population.
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Affiliation(s)
- Hung-Yang Chang
- Department of Pediatrics, MacKay Children's Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Jui-Hsing Chang
- Department of Pediatrics, MacKay Children's Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Chun-Chih Peng
- Department of Pediatrics, MacKay Children's Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Chyong-Hsin Hsu
- Department of Pediatrics, MacKay Children's Hospital, Taipei, Taiwan
| | - Mary Hsin-Ju Ko
- Department of Pediatrics, MacKay Children's Hospital, Taipei, Taiwan
- Department of Pediatrics, Hsinchu MacKay Hospital, Hsinchu, Taiwan
| | - Chung-Lieh Hung
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
- Division of Cardiology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan
- Institute of Biomedical Sciences, MacKay Medical College, New Taipei City, Taiwan
- *Correspondence: Ming-Ren Chen
| | - Ming-Ren Chen
- Department of Pediatrics, MacKay Children's Hospital, Taipei, Taiwan
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
- Chung-Lieh Hung
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3
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Forbes EM, Bakrania BA, Steane SE, Moritz KM, Lingwood BE, Eiby YA. Expression of TRPM6 and TRPM7 in the preterm piglet heart. Front Pediatr 2022; 10:891722. [PMID: 36081632 PMCID: PMC9445433 DOI: 10.3389/fped.2022.891722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 08/01/2022] [Indexed: 11/13/2022] Open
Abstract
Preterm infants are at increased risk of death and disability, and cardiovascular instability after birth is a contributing factor. Immaturity of calcium handling in the preterm heart may limit myocardial contractility and cardiac output. Two transmembrane cation channels, TRPM6 and TRPM7, may regulate intracellular cardiac calcium in the neonatal period. The aim of this study was to determine TRPM6 and TRPM7 mRNA expression in piglet hearts in late gestation, and the effects of sex, maternal glucocorticoids, and the transition to extrauterine life. Left and right ventricular tissue was collected at a range of gestational ages from cesarean delivered piglets at birth and at 6 h old. Additional groups included piglets exposed to maternal glucocorticoid treatment and spontaneously born term piglets at 12-24 h old. TRPM6 and TRPM7 mRNA expression was measured using RT-qPCR. Males had significantly lower TRPM7 expression in the left ventricle across all gestational ages compared to females. At term, both ventricles had higher TRPM7 expression at 6 h old than at birth. In preterm piglets, TRPM7 expression only increased postnatally in the right ventricle following maternal glucocorticoid exposure. At 12-24 h old, TRPM7 expression in both ventricles was lower than levels in 6 h old term Caesar piglets (113 days). Male preterm piglets may have immature myocardial Ca2+ handling and this could contribute to their poorer outcomes. Increased TRPM7 expression is the mature response to birth that is missing in preterm neonates. TRPM7 could serve as a novel target to improve cardiac function in preterm neonates.
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Affiliation(s)
- Elizabeth M Forbes
- Queensland Children's Hospital, Brisbane, QLD, Australia.,UQ Centre for Clinical Research and Perinatal Research Centre, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Bhavisha A Bakrania
- UQ Centre for Clinical Research and Perinatal Research Centre, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Sarah E Steane
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Karen M Moritz
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia.,Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Barbara E Lingwood
- UQ Centre for Clinical Research and Perinatal Research Centre, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Yvonne A Eiby
- UQ Centre for Clinical Research and Perinatal Research Centre, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
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4
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Aldana-Aguirre JC, Deshpande P, Jain A, Weisz DE. Physiology of Low Blood Pressure During the First Day After Birth Among Extremely Preterm Neonates. J Pediatr 2021; 236:40-46.e3. [PMID: 34019882 DOI: 10.1016/j.jpeds.2021.05.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 04/09/2021] [Accepted: 05/11/2021] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To investigate the circulatory physiology of hypotension during the first day after birth among stable extremely preterm neonates. STUDY DESIGN Case-control study of neonates born at ≤276/7 weeks gestational age with hypotension, defined as mean blood pressure in mmHg less than gestational age in weeks for at least 1 hour during the first 24 hours after birth, who underwent comprehensive echocardiography assessment before commencement of cardiovascular drugs. Neonates with hypotension (n = 14) were matched by gestational age and intensity of respiratory support with normotensive neonates (n = 27) who underwent serial echocardiography during the first day after birth, and relatively contemporaneous echocardiography assessments were used for comparison. RESULTS Neonates with hypotension had a higher frequency of patent ductus arteriosus ≥1.5 mm (71% vs 15%; P < .001) and ductal size (median diameter, 1.6 mm [IQR, 1.4-2.1] vs 1.0 mm [IQR, 0-1.3]; P = .002), higher echocardiography indices of left ventricular systolic function (mean shortening fraction, 34 ± 7% vs 26 ± 4%; P < .001; mean longitudinal strain, -16 ± 5% vs -14 ± 3%; P = .04; and mean velocity of circumferential fiber shortening, 1.24 ± 0.35 circ/s vs 1.01 ± 0.28 circ/s; P = .03), lower estimates of left ventricular afterload (mean end-systolic wall stress, 20 ± 7 g/cm2 vs 30 ± 9 g/cm2; P < .001 and mean arterial elastance, 43 ± 19 mmHg/mL vs 60 ± 22 mmHg/mL; P = .01), without significant difference in stress-velocity index z-score (-0.42 ± 1.60 vs -0.88 ± 1.30; P = .33). Neonates with hypotension had higher rates of any degree of intraventricular hemorrhage (71% vs 22%; P = .006). CONCLUSIONS Low blood pressure in otherwise well extremely low gestational age neonates was associated with low systemic afterload and larger patent ductus arteriosus, but not left ventricular dysfunction.
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Affiliation(s)
| | - Poorva Deshpande
- Department of Pediatrics, Mount Sinai Hospital, Toronto, Ontario, Canada; Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Amish Jain
- Department of Pediatrics, Mount Sinai Hospital, Toronto, Ontario, Canada; Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Dany E Weisz
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada; Department of Newborn and Developmental Pediatrics, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
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5
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Effect of Preterm Birth on Cardiac and Cardiomyocyte Growth and the Consequences of Antenatal and Postnatal Glucocorticoid Treatment. J Clin Med 2021; 10:jcm10173896. [PMID: 34501343 PMCID: PMC8432182 DOI: 10.3390/jcm10173896] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/26/2021] [Accepted: 08/26/2021] [Indexed: 12/18/2022] Open
Abstract
Preterm birth coincides with a key developmental window of cardiac growth and maturation, and thus has the potential to influence long-term cardiac function. Individuals born preterm have structural cardiac remodelling and altered cardiac growth and function by early adulthood. The evidence linking preterm birth and cardiovascular disease in later life is mounting. Advances in the perinatal care of preterm infants, such as glucocorticoid therapy, have improved survival rates, but at what cost? This review highlights the short-term and long-term impact of preterm birth on the structure and function of the heart and focuses on the impact of antenatal and postnatal glucocorticoid treatment on the immature preterm heart.
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6
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Eiby YA, Lingwood BE, Wright IMR. Plasma Leak From the Circulation Contributes to Poor Outcomes for Preterm Infants: A Working Hypothesis. Front Neurol 2021; 12:636740. [PMID: 34408716 PMCID: PMC8364946 DOI: 10.3389/fneur.2021.636740] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 07/09/2021] [Indexed: 11/13/2022] Open
Abstract
Preterm infants are at high risk of death and disability resulting from brain injury. Impaired cardiovascular function leading to poor cerebral oxygenation is a significant contributor to these adverse outcomes, but current therapeutic approaches have failed to improve outcome. We have re-examined existing evidence regarding hypovolemia and have concluded that in the preterm infant loss of plasma from the circulation results in hypovolemia; and that this is a significant driver of cardiovascular instability and thus poor cerebral oxygenation. High capillary permeability, altered hydrostatic and oncotic pressure gradients, and reduced lymphatic return all combine to increase net loss of plasma from the circulation at the capillary. Evidence is presented that early hypovolemia occurs in preterm infants, and that capillary permeability and pressure gradients all change in a way that promotes rapid plasma loss at the capillary. Impaired lymph flow, inflammation and some current treatment strategies may further exacerbate this plasma loss. A framework for testing this hypothesis is presented. Understanding these mechanisms opens the way to novel treatment strategies to support cardiovascular function and cerebral oxygenation, to replace current therapies, which have been shown not to change outcomes.
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Affiliation(s)
- Yvonne A Eiby
- Faculty of Medicine, Perinatal Research Centre, Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
| | - Barbara E Lingwood
- Faculty of Medicine, Perinatal Research Centre, Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia.,Department of Neonatology, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Ian M R Wright
- Faculty of Medicine, Perinatal Research Centre, Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia.,The School of Medicine, Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia.,Australian Institute of Tropical Health and Medicine, The College of Medicine and Dentistry, James Cook University, Cairns, QLD, Australia
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7
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Mohamed A, Marciniak M, Williamson W, Huckstep OJ, Lapidaire W, McCance A, Neubauer S, Leeson P, Lewandowski AJ. Association of Systolic Blood Pressure Elevation With Disproportionate Left Ventricular Remodeling in Very Preterm-Born Young Adults: The Preterm Heart and Elevated Blood Pressure. JAMA Cardiol 2021; 6:821-829. [PMID: 33978675 PMCID: PMC8117059 DOI: 10.1001/jamacardio.2021.0961] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Question Are left ventricular structure and function in preterm-born adults more susceptible to remodeling in association with blood pressure elevation? Findings In this cross-sectional cohort study of 468 adults with cardiac magnetic resonance imaging, left ventricular mass index and mass to end-diastolic volume ratio were greater for each 1–mm Hg elevation in systolic blood pressure in preterm-born adults than in term-born adults, with the greatest rise in those born very and extremely preterm (<32 weeks’ gestation). Meaning The findings of this study show that adults born preterm demonstrate greater remodeling in response to systolic blood pressure elevation and may require earlier interventions to prevent cardiovascular disease progression. Importance Preterm-born individuals have higher blood pressure with an increased risk of hypertension by young adulthood, as well as potentially adverse cardiac remodeling even when normotensive. To what extent blood pressure elevation affects left ventricular (LV) structure and function in adults born preterm is currently unknown. Objective To investigate whether changes observed in LV structure and function in preterm-born adults make them more susceptible to cardiac remodeling in association with blood pressure elevation. Design, Setting, and Participants This cross-sectional cohort study, conducted at the Oxford Cardiovascular Clinical Research Facility and Oxford Centre for Clinical Magnetic Resonance Research, included 468 adults aged 18 to 40 years. Of these, 200 were born preterm (<37 weeks’ gestation) and 268 were born at term (≥37 weeks’ gestation). Cardiac magnetic resonance imaging was used to characterize LV structure and function, with clinical blood pressure readings measured to assess hypertension status. Demographic and anthropometric data, as well as birth history and family medical history information, were collected. Data were analyzed between January 2012 and February 2021. Main Outcomes and Measures Cardiac magnetic resonance measures of LV structure and function in response to systolic blood pressure elevation. Results The cohort was primarily White (>95%) with a balanced sex distribution (51.5% women and 48.5% men). Preterm-born adults with and without hypertension had higher LV mass index, reduced LV function, and smaller LV volumes compared with term-born individuals both with and without hypertension. In regression analyses of systolic blood pressure with LV mass index and LV mass to end-diastolic volume ratio, there was a leftward shift in the slopes in preterm-born compared with term-born adults. Compared with term-born adults, there was a 2.5-fold greater LV mass index per 1–mm Hg elevation in systolic blood pressure in very and extremely preterm-born adults (<32 weeks’ gestation) (0.394 g/m2 vs 0.157 g/m2 per 1 mm Hg; P < .001) and a 1.6-fold greater LV mass index per 1–mm Hg elevation in systolic blood pressure in moderately preterm-born adults (32 to 36 weeks’ gestation) (0.250 g/m2 vs 0.157 g/m2 per 1 mm Hg; P < .001). The LV mass to end-diastolic volume ratio per 1–mm Hg elevation in systolic blood pressure in the very and extremely preterm-born adults was 3.4-fold greater compared with those born moderately preterm (3.56 × 10−3 vs 1.04 × 10−3 g/mL per 1 mm Hg; P < .001) and 3.3-fold greater compared with those born at term (3.56 × 10−3 vs 1.08 × 10−3 g/mL per 1 mm Hg; P < .001). Conclusions and Relevance Preterm-born adults have a unique LV structure and function that worsens with systolic blood pressure elevation. Additional primary prevention strategies specifically targeting cardiovascular risk reduction in this population may be warranted.
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Affiliation(s)
- Afifah Mohamed
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, England.,Department of Diagnostic Imaging & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.,Oxford University Hospitals NHS Foundation Trust, Oxford, England
| | - Maciej Marciniak
- Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, England
| | - Wilby Williamson
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, England
| | - Odaro J Huckstep
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, England.,Department of Biology, United States Air Force Academy, Air Force Academy, Colorado
| | - Winok Lapidaire
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, England.,Oxford University Hospitals NHS Foundation Trust, Oxford, England
| | - Angus McCance
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, England.,Oxford University Hospitals NHS Foundation Trust, Oxford, England
| | - Stefan Neubauer
- Oxford University Hospitals NHS Foundation Trust, Oxford, England.,Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, England
| | - Paul Leeson
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, England.,Oxford University Hospitals NHS Foundation Trust, Oxford, England
| | - Adam J Lewandowski
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, England.,Oxford University Hospitals NHS Foundation Trust, Oxford, England.,Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, England
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8
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Fortin-Pellerin E, Khoo NS, Coe JY, Mills L, Cheung PY, Hornberger LK. Effects of Early Myocardial Postnatal Maturation on Tolerance to Atrial Tachycardia With Altered Loading Conditions: An in vivo Swine Model. Front Pediatr 2020; 8:346. [PMID: 32671005 PMCID: PMC7330128 DOI: 10.3389/fped.2020.00346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 05/26/2020] [Indexed: 11/16/2022] Open
Abstract
Post-natal maturation of the myocardium starts shortly after birth and could affect how clinicians should provide hemodynamic support during this transition. Our aim was to assess the impact of post-natal maturation on tolerance to tachycardia with altered loading condition in a piglet model. Methods: We report three series of experimentations. Six groups of landrace cross neonatal piglets (NP) (1-3 days) and young piglets (YP) (14-17 days) were assigned to tachycardia (NP, YP), tachycardia and hypervolemia (NPV, YPV) or tachycardia and increased afterload (NPA, YPA) groups (n = 7/group). Under anesthesia, a pressure catheter was placed in the left ventricle and pacing wire in the right atrium. NPV and YPV groups had 60 ml/kg of normal saline infused over 20 min. NPA and YPA had balloon sub-occlusion of the descending aorta. Heart rate was increased by 10 bpm increments to 300 bpm. Left ventricular output was measured by echocardiography. Results: NP maintained left ventricular output throughout the pacing protocol but it decreased in the YP (p < 0.001). With volume loading both NPV and YPV maintained their output with tachycardia. Although increased afterload resulted in reduced output during tachycardia in NPA (p = 0.005), there was no added impact on output in YPA. Interestingly, 4 of 7 NPV had significant desaturation at 300 bpm (baseline 99.7% vs. 300 bpm 87.9%, p = 0.04), associated with a right to left shunt through the patent foramen ovale which resolved immediately on cessation of pacing. Conclusions: Early post-natal maturation is associated with improved myocardial tolerance to increased afterload and poor tolerance of tachycardia, the latter of which may be alleviated by increasing intravascular volume. These data could translate into the development of better strategies to optimize cardiac output at these early development ages.
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Affiliation(s)
- Etienne Fortin-Pellerin
- Division of Neonatology, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Nee S Khoo
- Fetal and Neonatal Cardiology Program, University of Alberta, Edmonton, AB, Canada.,Division of Cardiology, University of Alberta, Edmonton, AB, Canada
| | - James Y Coe
- Division of Cardiology, University of Alberta, Edmonton, AB, Canada
| | - Lindsay Mills
- Fetal and Neonatal Cardiology Program, University of Alberta, Edmonton, AB, Canada
| | - Po-Yin Cheung
- Departments of Pediatrics & Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Lisa K Hornberger
- Fetal and Neonatal Cardiology Program, University of Alberta, Edmonton, AB, Canada.,Division of Cardiology, University of Alberta, Edmonton, AB, Canada
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9
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Liu B, Zhang TN, Knight JK, Goodwin JE. The Glucocorticoid Receptor in Cardiovascular Health and Disease. Cells 2019; 8:cells8101227. [PMID: 31601045 PMCID: PMC6829609 DOI: 10.3390/cells8101227] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/04/2019] [Accepted: 10/08/2019] [Indexed: 12/19/2022] Open
Abstract
The glucocorticoid receptor is a member of the nuclear receptor family that controls many distinct gene networks, governing various aspects of development, metabolism, inflammation, and the stress response, as well as other key biological processes in the cardiovascular system. Recently, research in both animal models and humans has begun to unravel the profound complexity of glucocorticoid signaling and convincingly demonstrates that the glucocorticoid receptor has direct effects on the heart and vessels in vivo and in vitro. This research has contributed directly to improving therapeutic strategies in human disease. The glucocorticoid receptor is activated either by the endogenous steroid hormone cortisol or by exogenous glucocorticoids and acts within the cardiovascular system via both genomic and non-genomic pathways. Polymorphisms of the glucocorticoid receptor are also reported to influence the progress and prognosis of cardiovascular disease. In this review, we provide an update on glucocorticoid signaling and highlight the critical role of this signaling in both physiological and pathological conditions of the cardiovascular system. With increasing in-depth understanding of glucocorticoid signaling, the future is promising for the development of targeted glucocorticoid treatments and improved clinical outcomes.
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Affiliation(s)
- Bing Liu
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA.
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Tie-Ning Zhang
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA.
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06520, USA.
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
| | - Jessica K Knight
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA.
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Julie E Goodwin
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA.
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06520, USA.
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10
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Song R, Hu XQ, Zhang L. Glucocorticoids and programming of the microenvironment in heart. J Endocrinol 2019; 242:T121-T133. [PMID: 31018174 PMCID: PMC6602534 DOI: 10.1530/joe-18-0672] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 04/24/2019] [Indexed: 12/11/2022]
Abstract
Glucocorticoids are primary stress hormones and can improve neonatal survival when given to pregnant women threatened by preterm birth or to preterm infants. It has become increasingly apparent that glucocorticoids, primarily by interacting with glucocorticoid receptors, play a critical role in late gestational cardiac maturation. Altered glucocorticoid actions contribute to the development and progression of heart disease. The knowledge gained from studies in the mature heart or cardiac damage is insufficient but a necessary starting point for understanding cardiac programming including programming of the cardiac microenvironment by glucocorticoids in the fetal heart. This review aims to highlight the potential roles of glucocorticoids in programming of the cardiac microenvironment, especially the supporting cells including endothelial cells, immune cells and fibroblasts. The molecular mechanisms by which glucocorticoids regulate the various cellular and extracellular components and the clinical relevance of glucocorticoid functions in the heart are also discussed.
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Affiliation(s)
- Rui Song
- Correspondence to: Rui Song, PhD, , Lubo Zhang, PhD,
| | | | - Lubo Zhang
- Correspondence to: Rui Song, PhD, , Lubo Zhang, PhD,
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11
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Gill AW. Postnatal cardiovascular adaptation. Arch Dis Child Fetal Neonatal Ed 2019; 104:F220-F224. [PMID: 30049726 DOI: 10.1136/archdischild-2017-314453] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/12/2018] [Accepted: 07/13/2018] [Indexed: 12/12/2022]
Abstract
The heart undergoes rapid transformations in function during the transition to extrauterine life. Our understanding of the adaptive physiology underlying this process is able to inform the clinical management of infants who are struggling to complete this complex transition. Much of our knowledge of the cardiac transition is derived from the preterm infant in whom the preparative adaptations are incomplete and clinical sequelae all too common. This review will re-examine the cardiac transition highlighting the physiology that drives it and suggest appropriate clinical intervention to support the process.
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Affiliation(s)
- Andrew William Gill
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
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12
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Dyson RM, Palliser HK, Wilding N, Kelly MA, Chwatko G, Glowacki R, Berry MJ, Ni X, Wright IMR. Microvascular circulatory dysregulation driven in part by cystathionine gamma-lyase: A new paradigm for cardiovascular compromise in the preterm newborn. Microcirculation 2018; 26:e12507. [PMID: 30276964 DOI: 10.1111/micc.12507] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 09/24/2018] [Accepted: 09/27/2018] [Indexed: 11/28/2022]
Abstract
OBJECTIVE H2 S may explain the dysregulation of microvascular tone associated with poor outcome following preterm birth. In adult vasculature, H2 S is predominantly produced by CSE. We hypothesized that vascular CSE activity contributes to microvascular tone regulation during circulatory transition. METHODS Preterm (GA62) and full-term (GA69) guinea pig fetuses and neonates were studied. Microvascular blood flow was assessed by laser Doppler flowmetry. Thiosulfate, primary urinary metabolite of H2 S, was determined by high-performance liquid chromatography. Real-time H2 S production was assessed using a microrespiration system in fetal and postnatal (10, 24 hours) skin and heart samples. CSE contribution was investigated by inhibition via propargylglycine. RESULTS In preterm animals, postnatal H2 S production capacity in peripheral vasculature increased significantly and was significantly reduced by the inhibition of CSE. Urinary thiosulfate correlated with both microvascular blood flow and capacity of the vasculature to produce H2 S. H2 S produced via CSE did not correlate directly with microvascular blood flow. CONCLUSIONS In preterm neonates, H2 S production increases during fetal-to-neonatal transition and CSE contribution to total H2 S increases postnatally. CSE-dependent mechanisms may therefore underpin the increase in H2 S production over the first 72 hours of life in preterm human neonates, associated with both central and peripheral cardiovascular instability.
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Affiliation(s)
- Rebecca M Dyson
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.,Department of Paediatrics and Child Health Research, Graduate Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia.,Mothers and Babies Research Centre, Hunter Medical Research Institute, New Lambton Heights, New South Wales, Australia.,Discipline of Paediatrics and Child Health, School of Medicine and Public Health, University of Newcastle, Callaghan, New South Wales, Australia.,Department of Paediatrics and Child Health, University of Otago Wellington, Wellington, New Zealand
| | - Hannah K Palliser
- Mothers and Babies Research Centre, Hunter Medical Research Institute, New Lambton Heights, New South Wales, Australia.,School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia
| | - Nicole Wilding
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.,Department of Paediatrics and Child Health Research, Graduate Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia
| | - Megan A Kelly
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.,Department of Paediatrics and Child Health Research, Graduate Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia.,School of Biological Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia
| | - Grazyna Chwatko
- Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, Lodz, Poland
| | - Rafal Glowacki
- Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, Lodz, Poland
| | - Mary J Berry
- Department of Paediatrics and Child Health, University of Otago Wellington, Wellington, New Zealand
| | - Xin Ni
- Department of Physiology, Second Military Medical University, Shanghai, China
| | - Ian M R Wright
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.,Department of Paediatrics and Child Health Research, Graduate Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia.,Mothers and Babies Research Centre, Hunter Medical Research Institute, New Lambton Heights, New South Wales, Australia.,Discipline of Paediatrics and Child Health, School of Medicine and Public Health, University of Newcastle, Callaghan, New South Wales, Australia
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13
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Lingwood BE, Eiby YA, Bjorkman ST, Miller SM, Wright IMR. Supporting preterm cardiovascular function. Clin Exp Pharmacol Physiol 2018; 46:274-279. [PMID: 30347457 DOI: 10.1111/1440-1681.13044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 09/04/2018] [Accepted: 10/15/2018] [Indexed: 11/30/2022]
Abstract
Preterm infants are at higher risk of adverse neurodevelopmental outcomes. Inadequate cerebral oxygen delivery resulting from poor cardiovascular function is likely to be a significant contributor to preterm brain injury. In this context, improved support of cardiovascular function is integral to improving preterm outcomes. Many of the treatments used to support preterm cardiovascular function are based on adult physiology and may not be appropriate for the unique physiology of the preterm infant. The preterm heart is structurally immature with reduced contractility and low cardiac output. However, there is limited evidence that inotropic support with dopamine and/or dobutamine is effective in preterm babies. Hypovolemia may also contribute to poor preterm cardiovascular function; there is evidence that capillary leakage results in considerable loss of plasma from the circulation of newborn preterm babies. In addition, the vasoconstrictor response to acute stimuli does not develop until quite late in gestation and is limited in the preterm infant. This may lead to inappropriate vasodilatation adding to functional hypovolemia. The first line treatment for hypotension in preterm infants is volume expansion with crystalloid solutions, but this has limited efficacy in the preterm infant. More effective methods of volume expansion are required. Effective support of preterm cardiovascular function requires better understanding of preterm cardiovascular physiology so that treatments can target mechanisms that are sufficiently mature to respond.
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Affiliation(s)
- Barbara E Lingwood
- UQ Centre for Clinical Research and Perinatal Research Centre, The University of Queensland, Brisbane, Australia
| | - Yvonne A Eiby
- UQ Centre for Clinical Research and Perinatal Research Centre, The University of Queensland, Brisbane, Australia
| | - Stella T Bjorkman
- UQ Centre for Clinical Research and Perinatal Research Centre, The University of Queensland, Brisbane, Australia
| | - Stephanie M Miller
- UQ Centre for Clinical Research and Perinatal Research Centre, The University of Queensland, Brisbane, Australia
| | - Ian M R Wright
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
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14
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Huckstep OJ, Williamson W, Telles F, Burchert H, Bertagnolli M, Herdman C, Arnold L, Smillie R, Mohamed A, Boardman H, McCormick K, Neubauer S, Leeson P, Lewandowski AJ. Physiological Stress Elicits Impaired Left Ventricular Function in Preterm-Born Adults. J Am Coll Cardiol 2018; 71:1347-1356. [PMID: 29566820 PMCID: PMC5864965 DOI: 10.1016/j.jacc.2018.01.046] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/11/2018] [Accepted: 01/16/2018] [Indexed: 01/01/2023]
Abstract
BACKGROUND Experimental and clinical studies show that prematurity leads to altered left ventricular (LV) structure and function with preserved resting LV ejection fraction (EF). Large-scale epidemiological data now links prematurity to increased early heart failure risk. OBJECTIVES The authors performed echocardiographic imaging at prescribed exercise intensities to determine whether preterm-born adults have impaired LV functional response to physical exercise. METHODS We recruited 101 normotensive young adults born preterm (n = 47; mean gestational age 32.8 ± 3.2 weeks) and term (n = 54) for detailed cardiovascular phenotyping. Full clinical resting and exercise stress echocardiograms were performed, with apical 4-chamber views collected while exercising at 40%, 60%, and 80% of peak exercise capacity, determined by maximal cardiopulmonary exercise testing. RESULTS Preterm-born individuals had greater LV mass (p = 0.015) with lower peak systolic longitudinal strain (p = 0.038) and similar EF to term-born control subjects at rest (p = 0.62). However, by 60% exercise intensity, EF was 6.7% lower in preterm subjects (71.9 ± 8.7% vs 78.6 ± 5.4%; p = 0.004) and further declined to 7.3% below the term-born group at 80% exercise intensity (69.8 ± 6.4% vs 77.1 ± 6.3%; p = 0.004). Submaximal cardiac output reserve was 56% lower in preterm-born subjects versus term-born control subjects at 40% of peak exercise capacity (729 ± 1,162 ml/min/m2 vs. 1,669 ± 937 ml/min/m2; p = 0.021). LV length and resting peak systolic longitudinal strain predicted EF increase from rest to 60% exercise intensity in the preterm group (r = 0.68, p = 0.009 and r = 0.56, p = 0.031, respectively). CONCLUSIONS Preterm-born young adults had impaired LV response to physiological stress when subjected to physical exercise, which suggested a reduced myocardial functional reserve that might help explain their increased risk of early heart failure. (Young Adult Cardiovascular Health sTudy [YACHT]; NCT02103231).
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Affiliation(s)
- Odaro J Huckstep
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Wilby Williamson
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Fernando Telles
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Holger Burchert
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Mariane Bertagnolli
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Charlotte Herdman
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Linda Arnold
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Robert Smillie
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Afifah Mohamed
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Henry Boardman
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Kenny McCormick
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Stefan Neubauer
- Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Paul Leeson
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Adam J Lewandowski
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
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15
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Influence of sympathetic activity in the control of peripheral microvascular tone in preterm infants. Pediatr Res 2016; 80:793-799. [PMID: 27497044 DOI: 10.1038/pr.2016.160] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 06/21/2016] [Indexed: 01/21/2023]
Abstract
BACKGROUND Microvascular dysregulation following preterm birth is associated with increased illness severity and hypotension, particularly in males. Sympathetic nervous vascular regulation is evident in females. We hypothesized that sympathetic dysfunction in male preterm infants may contribute to a failure of peripheral microvascular vasoconstriction. METHODS Microvascular blood flow of infants 24-43 wk gestational age was assessed at 6, 24, and 72 h of age by laser Doppler. Blood flow Fourier transformed frequency distribution spectra (low frequency/high frequency ratio) were used to assess the influence of sympathetic tone on microvascular regulation. Total sympathetic output was assessed as urinary normetanephrine. RESULTS Microvascular sympathetic activity at 24 h postnatal age decreased in early preterm males, but not females. Peripheral sympathetic activity increased with advancing postnatal age in females, but decreased in males. In early preterm infants, total normetanephrine outputs increase significantly with postnatal age, in both sexes. CONCLUSION Sympathetic activation following preterm birth is sexually dimorphic, with preterm males having reduced sympathetic tone and reduced upregulation of sympathetic tone following birth. There is evidence of a disconnect between central sympathetic activity and local peripheral microcirculatory sympathetic drive. This may relate to autonomic nervous immaturity and highlights the need to understand how preterm birth may affect autonomic function.
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16
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Inotropes do not increase cardiac output or cerebral blood flow in preterm piglets. Pediatr Res 2016; 80:870-879. [PMID: 27490740 DOI: 10.1038/pr.2016.156] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/10/2016] [Indexed: 01/26/2023]
Abstract
BACKGROUND The preterm newborn is at high risk of developing cardiovascular compromise during the first day of life and this is associated with increased risk of brain injury. Standard treatments are volume expansion and administration of inotropes, typically dopamine and/or dobutamine, but there is limited evidence that inotropes improve clinical outcomes. This study investigated the efficacy of dopamine and dobutamine for the treatment of cardiovascular compromise in the preterm newborn using a piglet model. METHODS Preterm and term piglets were assigned to either dopamine, dobutamine or control infusions. Heart rate, left ventricular contractility, cardiac output, blood pressure, and cerebral and regional blood flows were measured during baseline, low (10 µg/kg/h), and high (20 µg/kg/h) dose infusions. RESULTS At baseline, preterm piglets had lower cardiac contractility, cardiac output, blood pressure, and cerebral blood flow compared to term piglets. The response of preterm piglets to either dopamine or dobutamine administration was less than in term piglets. In both preterm and term piglets, cardiac output and cerebral blood flow were unaltered by either inotrope. CONCLUSION In order to provide better cardiovascular support, it may be necessary to develop treatments that target receptors with a more mature profile than adrenoceptors in the preterm newborn.
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17
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Determination of Lung Volume and Hemodynamic Changes During High-Frequency Ventilation Recruitment in Preterm Neonates With Respiratory Distress Syndrome. Crit Care Med 2015; 43:1685-91. [DOI: 10.1097/ccm.0000000000000967] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Hirose A, Khoo NS, Aziz K, Al-Rajaa N, van den Boom J, Savard W, Brooks P, Hornberger LK. Evolution of left ventricular function in the preterm infant. J Am Soc Echocardiogr 2014; 28:302-8. [PMID: 25533193 DOI: 10.1016/j.echo.2014.10.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Indexed: 10/24/2022]
Abstract
BACKGROUND The aim of this study was to evaluate left ventricular function in preterm infants from 28 days to near term using echocardiography. METHODS Thirty clinically stable preterm infants delivered at <30 weeks' gestational age were prospectively enrolled. At 28 days, conventional, tissue Doppler, and speckle-tracking echocardiography evaluations of left ventricular function were performed, with comparison made to findings in 30 healthy term infants of similar postnatal age. Sixteen preterm infants underwent repeat examinations near term. RESULTS Compared with controls, preterm infants at 28 days had decreased peak mitral valve (MV) E-wave velocities (P < .01), E/A ratios (P < .0001), annular e' velocities (P < .0001), and e'/a' ratios (P < .0001); increased MV E/e' ratios (P < .01); and lower basal circumferential early diastolic and higher late diastolic strain rates. No significant differences were found in fractional shortening, ejection fraction, and longitudinal or circumferential strain and strain rate between preterm infants and controls. Although preterm infants at 28 days had higher heart rates compared with controls (161 ± 15 vs 142 ± 16 beats/min), no significant correlations existed between heart rate and MV E, E/A ratio, e', e'/a' ratio, and E/e' ratio. Near term, the differences in diastolic function persisted, including decreased MV e'/a' ratio (P < .05), increased E/e' ratio (P < .01), and increased late diastolic strain rate. CONCLUSIONS Clinically stable preterm infants have normal left ventricular systolic function but altered diastolic function, with greater dependence on atrial contraction, the latter of which persists despite nearing term. These findings may be relevant to the management of preterm infants and may relate to the longer term myocardial dysfunction observed in affected adults.
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Affiliation(s)
- Akiko Hirose
- Fetal & Neonatal Cardiology Program, Department of Pediatrics, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada
| | - Nee S Khoo
- Fetal & Neonatal Cardiology Program, Department of Pediatrics, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada
| | - Khalid Aziz
- Department of Pediatrics, Division of Neonatology, University of Alberta, Edmonton, Alberta, Canada
| | - Najlaa Al-Rajaa
- Fetal & Neonatal Cardiology Program, Department of Pediatrics, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada
| | - Jutta van den Boom
- Fetal & Neonatal Cardiology Program, Department of Pediatrics, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada
| | - Winnie Savard
- Fetal & Neonatal Cardiology Program, Department of Pediatrics, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada
| | - Paul Brooks
- Fetal & Neonatal Cardiology Program, Department of Pediatrics, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada
| | - Lisa K Hornberger
- Fetal & Neonatal Cardiology Program, Department of Pediatrics, Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada; Department of Obstetrics and Gynecology, Women's & Children's Health Research Institute, Mazankowski Alberta Heart Institute, Cardiovascular Research Centre, University of Alberta, Edmonton, Alberta, Canada.
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19
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Eiby YA, Lumbers ER, Staunton MP, Wright LL, Colditz PB, Wright IMR, Lingwood BE. Endogenous angiotensins and catecholamines do not reduce skin blood flow or prevent hypotension in preterm piglets. Physiol Rep 2014; 2:2/12/e12245. [PMID: 25538149 PMCID: PMC4332223 DOI: 10.14814/phy2.12245] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Endocrine control of cardiovascular function is probably immature in the preterm infant; thus, it may contribute to the relative ineffectiveness of current adrenergic treatments for preterm cardiovascular compromise. This study aimed to determine the cardiovascular and hormonal responses to stress in the preterm piglet. Piglets were delivered by cesarean section either preterm (97 of 115 days) or at term (113 days). An additional group of preterm piglets received maternal glucocorticoids as used clinically. Piglets were sedated and underwent hypoxia (4% FiO2 for 20 min) to stimulate a cardiovascular response. Arterial blood pressure, skin blood flow, heart rate and plasma levels of epinephrine, norepinephrine, angiotensin II (Ang II), angiotensin‐(1–7) (Ang‐(1‐7)), and cortisol were measured. Term piglets responded to hypoxia with vasoconstriction; preterm piglets had a lesser response. Preterm piglets had lower blood pressures throughout, with a delayed blood pressure response to the hypoxic stress compared with term piglets. This immature response occurred despite similar high levels of circulating catecholamines, and higher levels of Ang II compared with term animals. Prenatal exposure to glucocorticoids increased the ratio of Ang‐(1‐7):Ang II. Preterm piglets, in contrast to term piglets, had no increase in cortisol levels in response to hypoxia. Preterm piglets have immature physiological responses to a hypoxic stress but no deficit of circulating catecholamines. Reduced vasoconstriction in preterm piglets could result from vasodilator actions of Ang II. In glucocorticoid exposed preterm piglets, further inhibition of vasoconstriction may occur because of an increased conversion of Ang II to Ang‐(1‐7). This study aimed to determine if immature hormonal control of the cardiovascular system contributes to preterm cardiovascular compromise. Physiological and hormonal responses of preterm piglets to hypoxia are immature compared with term piglets. This is not due to a lack of endogenous catecholamines or angiotensin II, but may be due to the differences in cardiovascular actions of the renin–angiotensin system.
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Affiliation(s)
- Yvonne A Eiby
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
| | - Eugenie R Lumbers
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia
| | - Michael P Staunton
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
| | - Layne L Wright
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
| | - Paul B Colditz
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
| | - Ian M R Wright
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia Graduate School of Medicine and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Barbara E Lingwood
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
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Dyson RM, Palliser HK, Lakkundi A, de Waal K, Latter JL, Clifton VL, Wright IMR. Early microvascular changes in the preterm neonate: a comparative study of the human and guinea pig. Physiol Rep 2014; 2:2/9/e12145. [PMID: 25350751 PMCID: PMC4270232 DOI: 10.14814/phy2.12145] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Dysfunction of the transition from fetal to neonatal circulatory systems may be a major contributor to poor outcome following preterm birth. Evidence exists in the human for both a period of low flow between 5 and 11 h and a later period of increased flow, suggesting a hypoperfusion–reperfusion cycle over the first 24 h following birth. Little is known about the regulation of peripheral blood flow during this time. The aim of this study was to conduct a comparative study between the human and guinea pig to characterize peripheral microvascular behavior during circulatory transition. Very preterm (≤28 weeks GA), preterm (29–36 weeks GA), and term (≥37 weeks GA) human neonates underwent laser Doppler analysis of skin microvascular blood flow at 6 and 24 h from birth. Guinea pig neonates were delivered prematurely (62 day GA) or at term (68–71 day GA) and laser Doppler analysis of skin microvascular blood flow was assessed every 2 h from birth. In human preterm neonates, there is a period of high microvascular flow at 24 h after birth. No period of low flow was observed at 6 h. In preterm animals, microvascular flow increased after birth, reaching a peak at 10 h postnatal age. Blood flow then steadily decreased, returning to delivery levels by 24 h. Preterm birth was associated with higher baseline microvascular flow throughout the study period in both human and guinea pig neonates. The findings do not support a hypoperfusion–reperfusion cycle in the microcirculation during circulatory transition. The guinea pig model of preterm birth will allow further investigation of the mechanisms underlying microvascular function and dysfunction during the initial extrauterine period. e12145 A period of high microvascular flow occurs after birth, however, no period of low flow (hypoperfusion stage) precedes this, suggesting that no hypoperfusion–reperfusion cycle exists during early extrauterine life. The data strongly support the use of the preterm guinea pig in future studies to allow further investigation of the interrelationship between cardiac output, preload, afterload, microvascular flow, and SVC flow. Elucidation of these processes may then aid clinicians in managing the circulatory dysfunction of preterm neonates, particularly those at greatest risk, preterm male neonates.
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Affiliation(s)
- Rebecca M Dyson
- Mothers and Babies Research Centre, Hunter Medical Research Institute, Newcastle, NSW, Australia (R.M.D., H.K.P., J.L.L., I.R.W.) Discipline of Paediatrics and Child Health, School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia (R.M.D., J.L.L., I.R.W.) Graduate School of Medicine and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia (R.M.D., I.R.W.)
| | - Hannah K Palliser
- Mothers and Babies Research Centre, Hunter Medical Research Institute, Newcastle, NSW, Australia (R.M.D., H.K.P., J.L.L., I.R.W.) School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, NSW, Australia (H.K.P.)
| | - Anil Lakkundi
- Kaleidoscope Neonatal Intensive Care Unit, John Hunter Children's Hospital, Newcastle, NSW, Australia (A.L., K.W., I.R.W.)
| | - Koert de Waal
- Kaleidoscope Neonatal Intensive Care Unit, John Hunter Children's Hospital, Newcastle, NSW, Australia (A.L., K.W., I.R.W.)
| | - Joanna L Latter
- Mothers and Babies Research Centre, Hunter Medical Research Institute, Newcastle, NSW, Australia (R.M.D., H.K.P., J.L.L., I.R.W.) Discipline of Paediatrics and Child Health, School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia (R.M.D., J.L.L., I.R.W.)
| | - Vicki L Clifton
- Robinson Institute, School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, SA, Australia (V.L.C.)
| | - Ian M R Wright
- Mothers and Babies Research Centre, Hunter Medical Research Institute, Newcastle, NSW, Australia (R.M.D., H.K.P., J.L.L., I.R.W.) Discipline of Paediatrics and Child Health, School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia (R.M.D., J.L.L., I.R.W.) Graduate School of Medicine and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia (R.M.D., I.R.W.) Kaleidoscope Neonatal Intensive Care Unit, John Hunter Children's Hospital, Newcastle, NSW, Australia (A.L., K.W., I.R.W.)
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Polglase GR, Miller SL, Barton SK, Kluckow M, Gill AW, Hooper SB, Tolcos M. Respiratory support for premature neonates in the delivery room: effects on cardiovascular function and the development of brain injury. Pediatr Res 2014; 75:682-8. [PMID: 24614803 DOI: 10.1038/pr.2014.40] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 12/16/2013] [Indexed: 02/02/2023]
Abstract
The transition to newborn life in preterm infants is complicated by immature cardiovascular and respiratory systems. Consequently, preterm infants often require respiratory support immediately after birth. Although aeration of the lung underpins the circulatory transition at birth, positive pressure ventilation can adversely affect cardiorespiratory function during this vulnerable period, reducing pulmonary blood flow and left ventricular output. Furthermore, pulmonary volutrauma is known to initiate pulmonary inflammatory responses, resulting in remote systemic involvement. This review focuses on the downstream consequences of positive pressure ventilation, in particular, interactions between cardiovascular output and the initiation of a systemic inflammatory cascade, on the immature brain. Recent studies have highlighted that positive pressure ventilation strategies are precursors of cerebral injury, probably mediated through cerebral blood flow instability. The presence of, or initiation of, an inflammatory cascade accentuates adverse cerebral blood flow, in addition to being a direct source of brain injury. Importantly, the degree of brain injury is dependent on the nature of the initial ventilation strategy used.
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Affiliation(s)
- Graeme R Polglase
- 1] The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia [2] Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Suzanne L Miller
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Samantha K Barton
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Martin Kluckow
- Department of Neonatalogy, Royal North Shore Hospital, University of Sydney, Sydney, New South Wales, Australia
| | - Andrew W Gill
- Centre for Neonatal Research and Education, The University of Western Australia, Western Australia, Australia
| | - Stuart B Hooper
- 1] The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia [2] Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Mary Tolcos
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
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22
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Kim MY, Eiby YA, Lumbers ER, Wright LL, Gibson KJ, Barnett AC, Lingwood BE. Effects of glucocorticoid exposure on growth and structural maturation of the heart of the preterm piglet. PLoS One 2014; 9:e93407. [PMID: 24676209 PMCID: PMC3968162 DOI: 10.1371/journal.pone.0093407] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 03/05/2014] [Indexed: 11/27/2022] Open
Abstract
Inadequate maintenance of systemic blood flow in neonates following preterm birth is associated with increased morbidity and mortality, and may be due in part to structural immaturity of the myocardium. Maternal glucocorticoid administration is associated with improved cardiovascular function, and possibly promotes structural maturation of the myocardium. This study assessed the structural maturity of the myocardium in male and female preterm and term piglets, and preterm piglets exposed to a regimen of maternal glucocorticoids as used clinically. In preterm, term and glucocorticoid exposed preterm piglets cardiomyocyte maturity was examined by measuring the proportion of binucleated myocytes and the volumes of single living ventricular cardiomyocytes with fluorescence microscopy. Ventricular apoptosis and proliferation were measured by immunohistochemistry. Preterm piglet hearts had fewer binucleated myocytes, smaller myocytes, and more proliferative and fewer apoptotic nuclei than term hearts. Maternal glucocorticoid treatment resulted in increased binucleation with no increase in myocyte volume, and levels of proliferation and apoptosis that were more similar to the term heart. Atrial weights were increased and in female piglets there was an increase in the ratio of left to right ventricular weight. The observed changes in atrial mass and myocyte structural maturation correlated with changes in cardiac function of isolated hearts of littermates. In conclusion, the association between increased myocardial maturation following glucocorticoid exposure, improved cardiac function in littermates, and clinical improvement in human neonatal cardiac function exposed to antenatal glucocorticoids, suggests that glucocorticoid exposure contributes to improved cardiovascular function in preterm infants by promoting myocardial structural maturity.
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Affiliation(s)
- Min Young Kim
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
| | - Yvonne A. Eiby
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
| | - Eugenie R. Lumbers
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
- Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia
| | - Layne L. Wright
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
| | - Karen J. Gibson
- Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Amanda C. Barnett
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
| | - Barbara E. Lingwood
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
- * E-mail:
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23
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Kim MY, Finch AM, Lumbers ER, Boyce AC, Gibson KJ, Eiby YA, Lingwood BE. Expression of adrenoceptor subtypes in preterm piglet heart is different to term heart. PLoS One 2014; 9:e92167. [PMID: 24670668 PMCID: PMC3966759 DOI: 10.1371/journal.pone.0092167] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 02/19/2014] [Indexed: 11/18/2022] Open
Abstract
Preterm delivery increases the risk of inadequate systemic blood flow and hypotension, and many preterm infants fail to respond to conventional inotrope treatments. If the profile of cardiac adrenoceptor subtypes in the preterm neonate is different to that at term this may contribute to these clinical problems. This study measured mRNA expression of β1, β2, α1A, α2A and α2B-adrenoceptor subtypes by real time PCR in term (113d), preterm (91d) and preterm piglets (91d) exposed to maternal glucocorticoid treatment. Abundance of β-adrenoceptor binding sites in the left ventricle was measured using saturation binding assays. Relative abundance of β1-adrenoceptor mRNA in untreated preterm hearts was ∼50% of term abundance in both left and right ventricles (P<0.001). Trends in receptor binding site density measurements supported this observation (P = 0.07). Glucocorticoid exposure increased β1-adrenoceptor mRNA levels in the right ventricle of preterm hearts (P = 0.008) but did not alter expression in the left ventricle (P>0.1). Relative abundance of α1A-adrenoceptor mRNA was the same in preterm and term piglet hearts (P = >0.1) but was reduced by maternal glucocorticoid treatment (P<0.01); α2A-adrenoceptor mRNA abundance was higher in untreated and glucocorticoid exposed preterm piglet hearts than in term piglets (P<0.001). There was no difference between male and female piglets in mRNA abundance of any of the genes studied. In conclusion, there is reduced mRNA abundance of β1-adrenoceptors in the preterm pig heart. If this lower expression of β-adrenoceptors occurs in human preterm infants, it could explain their poor cardiovascular function and their frequent failure to respond to commonly used inotropes.
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MESH Headings
- Animals
- Binding Sites
- Female
- Gene Expression Regulation, Developmental
- Heart/embryology
- Male
- Myocardium/metabolism
- Premature Birth/metabolism
- Receptors, Adrenergic/genetics
- Receptors, Adrenergic/metabolism
- Receptors, Adrenergic, alpha/genetics
- Receptors, Adrenergic, alpha/metabolism
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/metabolism
- Sus scrofa/embryology
- Term Birth/metabolism
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Affiliation(s)
- Min Young Kim
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
| | - Angela M. Finch
- Department of Pharmacology, School of Medical Sciences, The University of New South Wales, Sydney, Australia
| | - Eugenie R. Lumbers
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
- Department of Physiology, School of Medical Sciences, The University of New South Wales, Sydney, Australia
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia
| | - Amanda C. Boyce
- Department of Physiology, School of Medical Sciences, The University of New South Wales, Sydney, Australia
| | - Karen J. Gibson
- Department of Physiology, School of Medical Sciences, The University of New South Wales, Sydney, Australia
| | - Yvonne A. Eiby
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
| | - Barbara E. Lingwood
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
- * E-mail:
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Lee A, Nestaas E, Liestøl K, Brunvand L, Lindemann R, Fugelseth D. Tissue Doppler imaging in very preterm infants during the first 24 h of life: an observational study. Arch Dis Child Fetal Neonatal Ed 2014; 99:F64-9. [PMID: 24048254 DOI: 10.1136/archdischild-2013-304197] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND Very preterm newborn infants often need cardiovascular support. More knowledge about myocardial function and factors that influence the immature myocardium may be helpful for optimising cardiovascular support in these infants. OBJECTIVE Serial assessment of global myocardial function by means of colour tissue Doppler imaging (cTDI) in very and extremely preterm infants during the first 24 h of life. STUDY DESIGN One-centre, prospective, observational longitudinal cohort study in a third level Neonatal Intensive Care Unit. Sixty-five infants with median (range) gestational age (GA) 27 (24-31) weeks and birth weight (BW) 1049 (484-1620) g underwent echocardiographic examinations including cTDI at 5, 12 and 24 h after birth. MAIN OUTCOME MEASURES Peak systolic and peak diastolic annular velocity and peak annular displacement of the left and right ventricle. RESULTS There was a significant reduction in systolic and diastolic velocities and displacement of both ventricles from 5 to 12 h age. From 12 to 24 h, there was a non-significant increase in myocardial velocities and displacement. At 5 h, babies with haemodynamically significant patent ductus arteriosus (PDA) had significantly higher systolic and diastolic velocities in both ventricles than those with non-significant PDA. CONCLUSIONS Myocardial tissue velocities decrease significantly from 5 to 12 h after birth in very preterm infants. Further studies are needed to confirm these results and to determine their clinical implications.
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Affiliation(s)
- A Lee
- Faculty of Medicine, University of Oslo, , Oslo, Norway
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