1
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Nguyen AQN, Denault AY, Théoret Y, Varin F. Inhaled milrinone in cardiac surgical patients: pharmacokinetic and pharmacodynamic exploration. Sci Rep 2023; 13:3557. [PMID: 36864229 PMCID: PMC9981759 DOI: 10.1038/s41598-023-29945-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 02/13/2023] [Indexed: 03/04/2023] Open
Abstract
Mean arterial pressure to mean pulmonary arterial pressure ratio (mAP/mPAP) has been identified as a strong predictor of perioperative complications in cardiac surgery. We therefore investigated the pharmacokinetic/pharmacodynamic (PK/PD) relationship of inhaled milrinone in these patients using this ratio (R) as a PD marker. Following approval by the ethics and research committee and informed consent, we performed the following experiment. Before initiation of cardiopulmonary bypass in 28 pulmonary hypertensive patients scheduled for cardiac surgery, milrinone (5 mg) was nebulized, plasma concentrations measured (up to 10 h) and compartmental PK analysis carried out. Baseline (R0) and peak (Rmax) ratios as well as magnitude of peak response (∆Rmax-R0) were measured. During inhalation, individual area under effect-time (AUEC) and plasma concentration-time (AUC) curves were correlated. Potential relationships between PD markers and difficult separation from bypass (DSB) were explored. In this study, we observed that milrinone peak concentrations (41-189 ng ml-1) and ΔRmax-R0 (- 0.12-1.5) were obtained at the end of inhalation (10-30 min). Mean PK parameters agreed with intravenous milrinone published data after correction for the estimated inhaled dose. Paired comparisons yielded a statistically significant increase between R0 and Rmax (mean difference, 0.58: 95% CI 0.43-0.73; P < 0.001). Individual AUEC correlated with AUC (r = 0.3890, r2 = 0.1513; P = 0.045); significance increased after exclusion of non-responders (r = 4787, r2 = 0.2292; P = 0.024). Individual AUEC correlated with ∆Rmax-R0 (r = 5973, r2 = 0.3568; P = 0.001). Both ∆Rmax-R0 (P = 0.009) and CPB duration (P < 0.001) were identified as predictors of DSB. In conclusion, both magnitude of peak response of the mAP/mPAP ratio and CPB duration were associated with DSB.
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Affiliation(s)
- Anne Quynh-Nhu Nguyen
- Faculty of Pharmacy, Université de Montréal, 2940 Chemin de la Polytechnique, Montreal, QC, H3T 1J4, Canada
| | - André Y Denault
- Department of Anesthesiology and Critical Care Division, Montreal Heart Institute, Université de Montréal, 5000 Belanger Street, Montreal, QC, H1T 1C8, Canada.
| | - Yves Théoret
- Clinical Pharmacology Unit, CHU Sainte-Justine, Montreal, Canada
| | - France Varin
- Faculty of Pharmacy, Université de Montréal, 2940 Chemin de la Polytechnique, Montreal, QC, H3T 1J4, Canada.
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2
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Bartolo MA, Qureshi MU, Colebank MJ, Chesler NC, Olufsen MS. Numerical predictions of shear stress and cyclic stretch in pulmonary hypertension due to left heart failure. Biomech Model Mechanobiol 2022; 21:363-381. [PMID: 35037114 PMCID: PMC10174274 DOI: 10.1007/s10237-021-01538-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 11/24/2021] [Indexed: 12/15/2022]
Abstract
Isolated post-capillary pulmonary hypertension (Ipc-PH) occurs due to left heart failure, which contributes to 1 out of every 9 deaths in the United States. In some patients, through unknown mechanisms, Ipc-PH transitions to combined pre-/post-capillary PH (Cpc-PH) and is associated with a dramatic increase in mortality. Altered mechanical forces and subsequent biological signaling in the pulmonary vascular bed likely contribute to the transition from Ipc-PH to Cpc-PH. However, even in a healthy pulmonary circulation, the mechanical forces in the smallest vessels (the arterioles, capillary bed, and venules) have not been quantitatively defined. This study is the first to examine this question via a computational fluid dynamics model of the human pulmonary arteries, arterioles, venules, and veins. Using this model, we predict temporal and spatial dynamics of cyclic stretch and wall shear stress with healthy and diseased hemodynamics. In the normotensive case for large vessels, numerical simulations show that large arteries have higher pressure and flow than large veins, as well as more pronounced changes in area throughout the cardiac cycle. In the microvasculature, shear stress increases and cyclic stretch decreases as vessel radius decreases. When we impose an increase in left atrial pressure to simulate Ipc-PH, shear stress decreases and cyclic stretch increases as compared to the healthy case. Overall, this model predicts pressure, flow, shear stress, and cyclic stretch that providing a way to analyze and investigate hypotheses related to disease progression in the pulmonary circulation.
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Affiliation(s)
- Michelle A Bartolo
- Department of Mathematics, North Carolina State University, Raleigh, NC, 27695, USA
| | - M Umar Qureshi
- Department of Mathematics, North Carolina State University, Raleigh, NC, 27695, USA
| | - Mitchel J Colebank
- Edwards Lifesciences Foundation Cardiovascular Innovation and Research Center, University of California, Irvine, CA, 92697, USA
| | - Naomi C Chesler
- Edwards Lifesciences Foundation Cardiovascular Innovation and Research Center, University of California, Irvine, CA, 92697, USA
| | - Mette S Olufsen
- Department of Mathematics, North Carolina State University, Raleigh, NC, 27607, USA.
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3
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Sahoo D, Kar N, Devi S, Dey A, Das DS. A Case of Paraquat Poisoning Presenting With Spontaneous Pneumothorax and Pneumomediastinum. Cureus 2020; 12:e11943. [PMID: 33425522 PMCID: PMC7785492 DOI: 10.7759/cureus.11943] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Paraquat (1,1’-dimethyl-4,4’-dipyridylium) is a liquid herbicide associated with accidental and suicidal ingestion, leading to fatal toxicity. It can lead to multiple organ dysfunction, including metabolic acidosis, acute kidney and liver injury, pulmonary fibrosis, and acute respiratory distress syndrome (ARDS). Very rarely, this can present with spontaneous pneumothorax or pneumomediastinum or both, which are poor prognostic markers with a mortality rate of almost 100%. Here, we present a young male presenting with paraquat poisoning followed by the development of both pneumothorax and pneumomediastinum and death from respiratory failure. Paraquat poisoning should always be considered in the differential diagnosis in patients presenting with spontaneous pneumothorax or pneumomediastinum in places with high paraquat poisoning prevalence.
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Winter MP, Sharma S, Altmann J, Seidl V, Panzenböck A, Alimohammadi A, Zelniker T, Redwan B, Nagel F, Santer D, Stieglbauer A, Podesser B, Sibilia M, Helbich T, Prager G, Ilhan-Mutlu A, Preusser M, Lang IM. Interruption of vascular endothelial growth factor receptor 2 signaling induces a proliferative pulmonary vasculopathy and pulmonary hypertension. Basic Res Cardiol 2020; 115:58. [PMID: 32880713 PMCID: PMC7471204 DOI: 10.1007/s00395-020-0811-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 07/16/2020] [Indexed: 11/28/2022]
Abstract
Pulmonary arterial hypertension is a severe and progressive disease characterized by a pulmonary vascular remodeling process with expansion of collateral endothelial cells and total vessel occlusion. Endothelial cells are believed to be at the forefront of the disease process. Vascular endothelial growth factor (VEGF) and its tyrosine kinase receptor, VEGF receptor-2 (VEGFR-2), play a central role in angiogenesis, endothelial cell protection, but also in the destabilization of endothelial barrier function. Therefore, we investigated the consequences of altered VEGF signaling in an experimental model, and looked for translational correlates of this observation in patients. We performed an endothelial cell-specific conditional deletion of the kinase insert domain protein receptor (kdr) gene, coding for VEGFR-2, in C57/BL6 mice (Kdr∆end) and held them in an environmental chamber with 10% FiO2 or under normoxia for 6 weeks. Kdr knockout led to a mild PH phenotype under normoxia that worsened under hypoxia. Kdr∆end mice exhibited a significant increase in pulmonary arterial wall thickness, muscularization, and VEGFR-3+ endothelial cells obliterating the pulmonary artery vessel lumen. We observed the same proliferative vasculopathy in our rodent model as seen in patients receiving anti-angiogenic therapy. Serum VEGF-a levels were elevated both in the experimental model and in humans receiving bevacizumab. Interrupted VEGF signaling leads to a pulmonary proliferative arteriopathy in rodents after direct ablative gene manipulation of Kdr. Histologically, similar vascular lesions can be observed in patients receiving anti-VEGF treatment. Our findings illustrate the importance of VEGF signaling for maintenance of pulmonary vascular patency.
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Affiliation(s)
- Max-Paul Winter
- Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Smriti Sharma
- Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Johanna Altmann
- Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Veronika Seidl
- Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Adelheid Panzenböck
- Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Arman Alimohammadi
- Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Thomas Zelniker
- Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Bassam Redwan
- Division of Thoracic Surgery and Lung Transplantation, Department of Cardiothoracic Surgery, University Hospital of Münster, Münster, Germany
| | - Felix Nagel
- Ludwig Boltzmann Cluster for Cardiovascular Research, Center of Biomedical Research, Vienna, Austria
| | - David Santer
- Ludwig Boltzmann Cluster for Cardiovascular Research, Center of Biomedical Research, Vienna, Austria
| | | | - Bruno Podesser
- Ludwig Boltzmann Cluster for Cardiovascular Research, Center of Biomedical Research, Vienna, Austria
| | - Maria Sibilia
- Department of Medicine I, Institute for Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Thomas Helbich
- Department of Radiology, Medical University of Vienna, Vienna, Austria
| | - Gerald Prager
- Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
| | - Aysegül Ilhan-Mutlu
- Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
| | - Matthias Preusser
- Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
| | - Irene M Lang
- Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
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5
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Nguyen AQN, Denault AY, Théoret Y, Perrault LP, Varin F. Inhaled milrinone in cardiac surgical patients: a pilot randomized controlled trial of jet vs. mesh nebulization. Sci Rep 2020; 10:2069. [PMID: 32034202 PMCID: PMC7005849 DOI: 10.1038/s41598-020-58902-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 01/22/2020] [Indexed: 11/09/2022] Open
Abstract
Inhaled milrinone administered before cardiopulmonary bypass (CPB) reduces the severity of pulmonary hypertension during cardiac surgery. However, milrinone pharmacokinetics has not been determined for this route of administration. The objective of this study was to investigate inhaled milrinone dosing in vitro and early plasma concentrations in vivo after jet and mesh nebulization. Twelve pulmonary hypertensive patients scheduled for cardiac surgery were randomized to receive milrinone (5 mg) by inhalation before CPB using a jet or mesh nebulizer. In vitro experiments were conducted to determine the inhaled dose delivered with either jet or mesh nebulization. In vivo experiments involved hemodynamic monitoring and blood samples drawn from patients for the first 15 min after the end of inhalation to determine early plasma concentrations. After mesh nebulization, the mean in vitro inhaled dose was almost 3-fold higher compared to jet nebulization (46.4% vs 16.6% for mesh and jet, respectively; mean difference, 29.8%; 95% CI, 14.1 to 45.5; P = 0.006). Consistent with this, the early plasma concentrations in vivo were also 2-3 fold higher after mesh nebulization (P = 0.002-0.005). After inhalation (jet or mesh nebulization), milrinone early plasma concentrations remained within the therapeutic range. No systemic hypotension was reported in our patients.
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Affiliation(s)
| | - André Y Denault
- Department of Anesthesiology and Critical Care Division, Montreal Heart Institute, Université de Montréal, Montreal, Canada.
| | - Yves Théoret
- Clinical Pharmacology Unit, CHU Sainte-Justine, Montreal, Canada
| | - Louis P Perrault
- Department of Cardiac Surgery, Montreal Heart Institute, Université de Montréal, Montreal, Canada
| | - France Varin
- Faculty of Pharmacy, Université de Montréal, Montreal, Canada.
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6
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Abstract
Pulmonary hypertension is an uncommon, yet devastating, syndrome with a complex underlying pathobiology. Hypoxia, inflammation, and increased shear stress appear to be the primary pathogenic events; however, mechanisms by which these processes lead to pulmonary hypertension remain incompletely understood. The ultimate increase in pulmonary vascular resistance is attributed to remodelling of the walls of resistance vessels, which can lead to encroachment on and reduction of the vascular lumen. The number of blood vessels per unit of cross-sectional area in the hypertensive lung is also reduced, which can contribute to increased vascular resistance. Regardless of its etiology, endothelial dysfunction underlies pulmonary hypertension, one manifestation of which is the attenuated production of bioactive nitric oxide. Nitric oxide administration can exert beneficial effects at various stages of the disease. Here we review the known pathobiology of pulmonary hypertension, with a principal focus on endothelial nitric oxide, and also summarize the data on nitric oxide replacement therapy and other novel therapies that relate to nitric oxide as one approach to treatment.
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Affiliation(s)
- Claudio Napoli
- Department of Medicine, University of Naples, Naples, Italy
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7
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Morris CR. New strategies for the treatment of pulmonary hypertension in sickle cell disease : the rationale for arginine therapy. ACTA ACUST UNITED AC 2016; 5:31-45. [PMID: 16409014 DOI: 10.2165/00151829-200605010-00003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Nitric oxide (NO) is inactivated in sickle cell disease (SCD), while bioavailability of arginine, the substrate for NO synthesis, is diminished. Impaired NO bioavailability represents the central feature of endothelial dysfunction, and is a key factor in the pathophysiology of SCD. Inactivation of NO correlates with the hemolytic rate and is associated with erythrocyte release of cell-free hemoglobin and arginase during hemolysis. Accelerated consumption of NO is enhanced further by the inflammatory environment of oxidative stress that exists in SCD. Based upon its critical role in mediating vasodilation and cell growth, decreased NO bioavailability has also been implicated in the pathogenesis of pulmonary arterial hypertension (PHT). Secondary PHT is a common life-threatening complication of SCD that also occurs in most hereditary and chronic hemolytic disorders. Aberrant arginine metabolism contributes to endothelial dysfunction and PHT in SCD, and is strongly associated with prospective patient mortality. The central mechanism responsible for this metabolic disorder is enhanced arginine turnover, occurring secondary to enhanced plasma arginase activity. This is consistent with a growing appreciation of the role of excessive arginase activity in human diseases, including asthma and PHT. Decompartmentalization of hemoglobin into plasma consumes endothelial NO and thus drives a metabolic requirement for arginine, whose bioavailability is further limited by arginase activity. New treatments aimed at maximizing both arginine and NO bioavailability through arginase inhibition, suppression of hemolytic rate, or oral arginine supplementation may represent novel therapeutic strategies.
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Affiliation(s)
- Claudia R Morris
- Department of Emergency Medicine, Children’s Hospital and Research Center at Oakland, Oakland, California, USA
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8
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Kumar S, Oishi PE, Rafikov R, Aggarwal S, Hou Y, Datar SA, Sharma S, Azakie A, Fineman JR, Black SM. Tezosentan increases nitric oxide signaling via enhanced hydrogen peroxide generation in lambs with surgically induced acute increases in pulmonary blood flow. J Cell Biochem 2013; 114:435-447. [PMID: 22961736 DOI: 10.1002/jcb.24383] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 08/30/2012] [Indexed: 12/23/2022]
Abstract
We have previously shown that acute increases in pulmonary blood flow (PBF) are limited by a compensatory increase in pulmonary vascular resistance (PVR) via an endothelin-1 (ET-1) dependent decrease in nitric oxide synthase (NOS) activity. The mechanisms underlying the reduction in NO signaling are unresolved. Thus, the purpose of this study was to elucidate mechanisms of this ET-1-NO interaction. Pulmonary arterial endothelial cells were acutely exposed to shear stress in the presence or absence of tezosentan, a combined ET(A) /ET(B) receptor antagonist. Shear increased NO(x) , eNOS phospho-Ser1177, and H(2) O(2) and decreased catalase activity; tezosentan enhanced, while ET-1 attenuated all of these changes. In addition, ET-1 increased eNOS phospho-Thr495 levels. In lambs, 4 h of increased PBF decreased H(2) O(2) , eNOS phospho-Ser1177, and NO(X) levels, and increased eNOS phospho-Thr495, phospho-catalase, and catalase activity. These changes were reversed by tezosentan. PEG-catalase reversed the positive effects of tezosentan on NO signaling. In all groups, opening the shunt resulted in a rapid increase in PBF by 30 min. In vehicle- and tezosentan/PEG-catalase lambs, PBF did not change further over the 4 h study period. PVR fell by 30 min in vehicle- and tezosentan-treated lambs, and by 60 min in tezosentan/PEG-catalase-treated lambs. In vehicle- and tezosentan/PEG-catalase lambs, PVR did not change further over the 4 h study period. In tezosentan-treated lambs, PBF continued to increase and LPVR to decrease over the 4 h study period. We conclude that acute increases in PBF are limited by an ET-1 dependent decrease in NO production via alterations in catalase activity, H(2) O(2) levels, and eNOS phosphorylation.
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Affiliation(s)
- Sanjiv Kumar
- Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta GA 30912
| | - Peter E Oishi
- Department of Pediatrics, University of California, San Francisco CA 94143.,Cardiovascular Research Institute, University of California, San Francisco CA 94143
| | - Ruslan Rafikov
- Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta GA 30912
| | - Saurabh Aggarwal
- Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta GA 30912
| | - Yali Hou
- Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta GA 30912
| | - Sanjeev A Datar
- Department of Pediatrics, University of California, San Francisco CA 94143
| | - Shruti Sharma
- Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta GA 30912
| | - Anthony Azakie
- Department of Surgery, University of California, San Francisco CA 94143
| | - Jeffrey R Fineman
- Department of Pediatrics, University of California, San Francisco CA 94143.,Cardiovascular Research Institute, University of California, San Francisco CA 94143
| | - Stephen M Black
- Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta GA 30912
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9
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Carreras A, Kayali F, Zhang J, Hirotsu C, Wang Y, Gozal D. Metabolic effects of intermittent hypoxia in mice: steady versus high-frequency applied hypoxia daily during the rest period. Am J Physiol Regul Integr Comp Physiol 2012; 303:R700-9. [PMID: 22895743 DOI: 10.1152/ajpregu.00258.2012] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Intermittent hypoxia (IH) is a frequent occurrence in sleep and respiratory disorders. Both human and murine studies show that IH may be implicated in metabolic dysfunction. Although the effects of nocturnal low-frequency intermittent hypoxia (IH(L)) have not been extensively examined, it would appear that IH(L) and high-frequency intermittent hypoxia (IH(H)) may elicit distinct metabolic adaptations. To this effect, C57BL/6J mice were randomly assigned to IH(H) (cycles of 90 s 6.4% O(2) and 90 s 21% O(2) during daylight), IH(L) (8% O(2) during daylight hours), or control (CTL) for 5 wk. At the end of exposures, some of the mice were subjected to a glucose tolerance test (GTT; after intraperitoneal injection of 2 mg glucose/g body wt), and others were subjected to an insulin tolerance test (ITT; 0.25 units Humulin/kg body wt), with plasma leptin and insulin levels being measured in fasting conditions. Skeletal muscles were harvested for GLUT4 and proliferator-activated receptor gamma coactivator 1-α (PGC1-α) expression. Both IH(H) and IH(L) displayed reduced body weight increases compared with CTL. CTL mice had higher basal glycemic levels, but GTT kinetics revealed marked differences between IH(L) and IH(H), with IH(L) manifesting the lowest insulin sensitivity compared with either IH(H) or CTL, and such findings were further confirmed by ITT. No differences emerged in PGC1-α expression across the three experimental groups. However, while cytosolic GLUT4 protein expression remained similar in IH(L), IH(H), and CTL, significant decreases in GLUT4 membrane fraction occurred in hypoxia and were most pronounced in IH(L)-exposed mice. Thus IH(H) and IH(L) elicit differential glucose homeostatic responses despite similar cumulative hypoxic profiles.
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Affiliation(s)
- Alba Carreras
- Dept. of Pediatrics, Univ. of Chicago, Chicago, IL 60637, USA
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10
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Peña E, Dennie C, Veinot J, Muñiz SH. Pulmonary Hypertension: How the Radiologist Can Help. Radiographics 2012; 32:9-32. [DOI: 10.1148/rg.321105232] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
The primary challenge in the care of the patient with advanced pulmonary arterial hypertension (PAH) is right ventricular dysfunction with concomitant right heart failure. Right heart function is closely tied to survival in this disease, and there is a growing interest in the study of this unique structure. While echocardiography and cardiac magnetic resonance (CMR) have augmented our ability to image the right ventricle (RV), the primary means of assessing right heart function remains right heart catheterisation. Several of the currently available treatments for PAH have been shown to have effects on the RV, not just the pulmonary vasculature, and, in future, therapies aimed at optimizing right ventricular function may allow better outcomes in this challenging disease. New directions in right ventricular assessment including measurement of pulmonary vascular impedance and more widespread availability of CMR may allow greater knowledge about this little studied, yet highly important, right side of the heart.
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Affiliation(s)
- A R Hemnes
- Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
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12
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Chemla D, Castelain V, Provencher S, Humbert M, Simonneau G, Hervé P. Evaluation of various empirical formulas for estimating mean pulmonary artery pressure by using systolic pulmonary artery pressure in adults. Chest 2008; 135:760-768. [PMID: 18849403 DOI: 10.1378/chest.08-0904] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Mean pulmonary artery pressure (mPAP) may be estimated by using the classic rule of thumb, namely 2/3 x dPAP + 1/3 x sPAP, where dPAP = diastolic PAP and sPAP = systolic PAP. Studies have suggested that mPAP may be also estimated from sPAP alone. Pulmonary hypertension (PH) is usually defined by an invasive mPAP > 25 mm Hg, but the corresponding sPAP threshold remains to be established. Our study evaluated the accuracy and precision of various empirical formulas relating mPAP and sPAP in resting adults. METHODS Five previously published studies with individual high-fidelity PAPs were analyzed (n = 166 individuals, 57% of whom had PH). The time-averaged mPAP was compared with formula one (F1), the classic rule of thumb; formula two (F2) = dPAP + 0.41 x pulse PAP; formula three (F3) = square root of (sPAP x dPAP); formula four (F4) = 0.61 x sPAP + 2 mm Hg; and formula five (F5) = 2/3 x sPAP (parabolic shape). RESULTS The mPAP ranged from 9 to 82 mm Hg and was related to sPAP (r(2) = 0.98). The most accurate formula was F4 (mean bias, 0.0 mm Hg). The most precise formula was F1 (SD of the bias, 1.6 mm Hg). Other formulas gave estimates of essentially similar accuracy, while F2 and F3 were more precise than F4 and F5. sPAP > 36 mm Hg could be used to diagnose PH (mPAP > 25 mm Hg) with a 97.9% sensitivity and 98.6% specificity. CONCLUSION In resting adults, the most accurate estimate of mPAP was obtained by using sPAP only, while the combination of sPAP and dPAP gave the most precise mPAP estimate. The sPAP threshold of 36 mm Hg could be used to diagnose PH with high sensitivity and high specificity.
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Affiliation(s)
- Denis Chemla
- Paris Sud University-EA4046-Medical Intensive Care Unit, Paris, France.
| | - Vincent Castelain
- Medical Care Unit, Hautepierre Hospital, Louis Pasteur University, Strasbourg, France
| | | | - Marc Humbert
- AP-HP, Clamart, Pneumology Department, Clamart, France
| | | | - Philippe Hervé
- Department of Thoracic and Vascular Surgery, Le Plessis-Robinson, France
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13
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Armigliato M, Paolini R, Aggio S, Zamboni S, Galasso MP, Zonzin P, Cella G. Hyperthyroidism as a cause of pulmonary arterial hypertension: a prospective study. Angiology 2006; 57:600-6. [PMID: 17067983 DOI: 10.1177/0003319706293131] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The authors assessed the prevalence of pulmonary arterial hypertension (PAH) in patients with hyperthyroidism and evaluated the response to treatment of the thyrotoxicosis. They assessed the pulmonary artery systolic pressure (PASP) at rest (estimated by echocardiography) in 23 consecutive patients diagnosed with hyperthyroidism due to Graves' disease or toxic multinodular goiter. Twelve of 23 patients (52%) did not show antithyroglobulin and antithyroperoxidase antibodies. Seventeen patients were followed up for at least 9 months after achieving a stable euthyroid status. Fifteen (65%) patients demonstrated PAH at admission. Four patients were lost to follow-up; therefore they were able to evaluate 17 patients serially with echocardiography. Sixteen patients normalized their PASP value: 13 after methimazole, 2 after total thyroidectomy, and 1 after (131)I treatment. In 1 patient no significant change in PASP was observed. This patient experienced an acute myocardial reinfarction during follow-up. They found a higher prevalence than that previously reported in observational studies. In addition, they demonstrated that the PAH reverses after correction of hyperthyroidism. Elevated PASP at rest on echocardiography may be considered a frequent finding of thyrotoxicosis. Moreover, the data seem not to support an autoimmune pathogenesis for PAH.
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Affiliation(s)
- Michela Armigliato
- Departments of Medicine, University of Padova Medical School, Padova, Italy, Rovigo and Padova, Italy
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14
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Denault AY, Chaput M, Couture P, Hébert Y, Haddad F, Tardif JC. Dynamic right ventricular outflow tract obstruction in cardiac surgery. J Thorac Cardiovasc Surg 2006; 132:43-9. [PMID: 16798301 DOI: 10.1016/j.jtcvs.2006.03.014] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Revised: 02/20/2006] [Accepted: 03/08/2006] [Indexed: 12/23/2022]
Abstract
BACKGROUND Right ventricular outflow tract obstruction can be a cause of hemodynamic instability but it has not been described in non-congenital cardiac surgery. METHODS The prevalence of right ventricular outflow tract obstruction was retrospectively studied in 670 consecutive patients undergoing cardiac surgery. Significant right ventricular outflow tract obstruction was diagnosed if the right ventricular systolic to pulmonary artery peak gradient was more than 25 mm Hg. The diagnosis was based on measurement of the right ventricular and pulmonary artery systolic pressure through the paceport and distal opening of the pulmonary artery catheter. To further validate the prevalence and the importance of right ventricular outflow tract obstruction, 130 patients were prospectively studied over a 12-month period. RESULTS In the retrospective cohort, 6 patients (1%) undergoing various types of cardiac surgical procedures were found to have significant dynamic right ventricular outflow tract obstruction with a mean gradient of 31 +/- 4 mm Hg (26 to 35 mm Hg). In the prospective study significant dynamic right ventricular outflow tract obstruction was identified in 5 patients (4%) (average peak: 37 +/- 15 mm Hg; range: 27 to 60 mm Hg). The typical transesophageal echocardiography finding was end-systolic obliteration of the right ventricular outflow tract. In patients with significant dynamic right ventricular outflow tract obstruction, hemodynamic instability was present in 10/11 patients (91%). CONCLUSIONS Right ventricular outflow tract obstruction is easily diagnosed using the paceport of the pulmonary artery catheter and should be considered as a potential cause of hemodynamic instability especially when transesophageal echocardiography reveals systolic right ventricular cavity obliteration.
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Affiliation(s)
- André Y Denault
- Department of Anesthesiology, Montreal Heart Institute and University of Montreal, Montreal, Quebec, Canada.
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15
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Sciomer S, Magrì D, Badagliacca R. Non-invasive assessment of pulmonary hypertension: Doppler-echocardiography. Pulm Pharmacol Ther 2006; 20:135-40. [PMID: 16753319 DOI: 10.1016/j.pupt.2006.03.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Accepted: 03/15/2006] [Indexed: 11/26/2022]
Abstract
Pulmonary hypertension (PH) is a clinical condition characterised by elevated pulmonary artery pressure (PAP) and vascular resistances. At the onset of the disease, symptoms are frequently atypical so that PH diagnosis is usually made when the disease is advanced, which often is too late for efficacious treatment. As a consequence the prognosis is poor. Echo-Doppler evaluation allows: (a) an early identification of patients with PH, (b) to establish a patient's prognosis and (c) to evaluate a proper patient's follow-up. In patients with PH echocardiography provides information about right heart dimensions, pulmonary artery pressures, right ventricle systolic and diastolic function and left and right ventricle interdependence. Most importantly Echo-Doppler evaluation has became a major diagnostic tool for PH allowing evaluation of changes with time and with different treatments which are aimed at reducing pulmonary artery pressure and right heart dimensions and at improving right heart function.
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Affiliation(s)
- Susanna Sciomer
- Dipartimento di Scienze Cardiovascolari, Respiratorie e Morfologiche, Policlinico Umberto I, Università "La Sapienza", Rome, Italy.
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16
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Cella G, Saetta M, Baraldo S, Turato G, Papi A, Casoni G, Rigno M. Endothelial cell activity in chronic obstructive pulmonary disease without severe pulmonary hypertension. Clin Appl Thromb Hemost 2006; 11:435-40. [PMID: 16244769 DOI: 10.1177/107602960501100410] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Pulmonary hypertension is common in patients with chronic obstructive pulmonary disease (COPD), but the precise mechanism of vascular impairment in these patients is unknown. We, therefore, decided to investigate whether endothelial cell dysfunction is present in patients with COPD with a wide range of chronic airflow obstruction before the development of severe pulmonary hypertension. Selected plasma markers of endothelial cell activity were studied: nitrate+nitrite (NO-(2)/NO-(3)), thrombomodulin (TM), tissue factor pathway inhibitor (TFPI), soluble selectins (endothelium sES, leukocyte sLS, platelet sPS), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble platelet endothelial cell adhesion molecule-1 (sPECAM-1). Twenty-five patients with COPD (forced expiratory volume in one second/vital capacity [FEV(1)/VC] < 88% predicted) and 29 healthy control subjects were recruited to the study. Among patients nine had a pulmonary artery systolic pressure (PASP) between 15 and 30 mmHg, 13 between 32 and 38 mmHg, 2 had a PASP of 41 and 42 mmHg, respectively. One patient had severe pulmonary hypertension with a PASP of 70 mmHg. The average FEV(1) of patients with COPD was 46 +/- 4% predicted. As compared to control subjects, patients with COPD showed a significant increase in plasma levels of TM and TFPI, indicating that their endothelial cells are still able to produce potent coagulation inhibitors. Levels of NO-(2)/NO-(3) were similar in the two groups of subjects examined, further suggesting preserved endothelial function in patients with COPD. In regard to adhesion molecules, patients with COPD showed a reduction in sLS, sPS, and sPECAM-1, and an increase in sICAM-1. This study shows that endothelial cell activity is largely preserved in patients with COPD without severe pulmonary hypertension, suggesting that these patients, despite quite severe airway obstruction, retain reasonably normal endothelial function until they develop severe pulmonary hypertension.
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Affiliation(s)
- Giuseppe Cella
- Department of Medical and Surgical Sciences, University of Padova, Italy.
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Fattouch K, Sbraga F, Sampognaro R, Bianco G, Gucciardo M, Lavalle C, Vizza CD, Fedele F, Ruvolo G. Treatment of pulmonary hypertension in patients undergoing cardiac surgery with cardiopulmonary bypass: a randomized, prospective, double-blind study. J Cardiovasc Med (Hagerstown) 2006; 7:119-23. [PMID: 16645371 DOI: 10.2459/01.jcm.0000203850.97890.fe] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Pulmonary hypertension can already be present in patients undergoing cardiac surgery or can be exacerbated by cardiopulmonary bypass. Postoperative treatment is still a challenge for physicians. The aim of this study was to evaluate the effects of inhaled prostacyclin (iPGI2) and nitric oxide (iNO) compared with those of intravenous vasodilators. METHODS This prospective, randomized, double-blind study included 58 patients affected by severe mitral valve stenosis and pulmonary hypertension with high pulmonary vascular resistance (> 250 dynes x s x cm(-5)) and a mean pulmonary artery pressure > 25 mmHg. All patients were monitored by central venous, radial arterial and Swan-Ganz catheters. Data were recorded at six different time points, before induction of anaesthesia, during and after surgery. Prostacyclin and nitric oxide were administered by inhalation 5 min before weaning from cardiopulmonary bypass and continued in the intensive care unit. Right ventricular function was evaluated by transoesophageal echocardiography. RESULTS Hospital mortality was 3.4%. After drug administration, the mean pulmonary artery pressure and pulmonary vascular resistance were significantly decreased in the iNO and iPGI2 groups with respect to the baseline values (P < 0.05) and such a decrease was maintained throughout the study; this was not observed in the control group. In the iNO and iPGI2 groups we demonstrated a significant increase in cardiac indices and right ventricular ejection fraction after drug administration with respect to baseline. Furthermore, patients in the inhaled drug groups were weaned easily from cardiopulmonary bypass (P = 0.04) and had a shorter intubation time (P = 0.03) and intensive care unit stay (P = 0.02) than the control group. CONCLUSIONS Our data suggest that both iNO and iPGI2 are effective in the treatment of pulmonary hypertension. iPGI2 has a number of advantages over iNO, including its easy administration and lower cost. Intravenous vasodilator treatment, on the other hand, is effective in terms of mortality but has a higher morbidity rate.
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Affiliation(s)
- Khalil Fattouch
- Unit of Cardiac Surgery, University of Palermo, Palermo, Italy.
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18
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Chemla D, Castelain V, Humbert M, Hébert JL, Simonneau G, Lecarpentier Y, Hervé P. New formula for predicting mean pulmonary artery pressure using systolic pulmonary artery pressure. Chest 2004; 126:1313-7. [PMID: 15486398 DOI: 10.1378/chest.126.4.1313] [Citation(s) in RCA: 321] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
STUDY OBJECTIVES Mean pulmonary artery pressure (MPAP) and systolic pulmonary artery pressure (SPAP) are used interchangeably to define pulmonary hypertension (PH). We tested the hypothesis that the measurement of MPAP and SPAP is redundant in resting humans over a wide pressure range. DESIGN Prospective, observational study. SETTING Catheterization laboratory in a university hospital. PATIENTS This study involved 31 patients, as follows: primary PH, nine patients; chronic pulmonary thromboembolism, seven patients; venous PH, six patients; and control subjects with normal pulmonary artery pressure, nine patients. INTERVENTIONS None. MEASUREMENTS AND RESULTS High-fidelity pulmonary artery pressures were obtained when patients were at rest. Over the wide MPAP range that was under study (10 to 78 mm Hg), MPAP and SPAP were strongly related (r(2) = 0.98). Regression analysis performed on the first 16 subjects (test sample) allowed us to propose a formula (MPAP = 0.61 SPAP + 2 mm Hg), the accuracy of which was confirmed in the remaining 15 subjects (validation sample bias, 0 +/- 2 mm Hg). If PH was defined by an SPAP in excess of 30 or 40 mm Hg, this corresponded to an MPAP in excess of 20 or 26 mm Hg. If PH was defined by an MPAP of > 25 mm Hg, this corresponded to an SPAP of > 38 mm Hg. CONCLUSIONS In resting humans, MPAP can be accurately predicted from SPAP over a wide pressure range. The new formula may help to refine the threshold pressure values used in the diagnosis of PH. Further studies are needed to test the hypothesis that our formula may allow the noninvasive prediction of MPAP from Doppler-derived SPAP values.
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Affiliation(s)
- Denis Chemla
- Service EFCR, Broca 7, Hôpital de Bicêtre, 78 Rue du Général Leclerc 94, 275 Le Kremlin Bicêtre Cedex, France.
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19
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Gan CT, Noordegraaf AV, Marques KMJ, Bronzwaer JGF, Postmus PE, Boonstra A. A review of pulmonary arterial hypertension: Part 1. Novel insights and classification. Neth Heart J 2004; 12:287-294. [PMID: 25696347 PMCID: PMC2497135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is a disease characterised by an increased pulmonary artery pressure. The precapillary pulmonary arteries show distinct pathobiological changes, i.e. medial hypertrophy, intimal fibrosis, microthrombi and plexiform lesions. Although the pathogenesis is not completely understood, pulmonary vascular proliferation and remodelling, due to a variety of mediators, is believed to play the pathogenetic key role. Genetic research reveals molecular deformities and gene mutations associated with phenotypic PAH. This article covers novel insights into pathobiology, pathogenesis and genes of PAH, which led to a novel classification system and a diagnostic work-up, emanated from the World Health Organisation Symposium on Pulmonary Hypertension in Venice in June 2003.
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20
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Haché M, Denault A, Bélisle S, Robitaille D, Couture P, Sheridan P, Pellerin M, Babin D, Noël N, Guertin MC, Martineau R, Dupuis J. Inhaled epoprostenol (prostacyclin) and pulmonary hypertension before cardiac surgery. J Thorac Cardiovasc Surg 2003; 125:642-9. [PMID: 12658208 DOI: 10.1067/mtc.2003.107] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Pulmonary hypertension is commonly found in patients undergoing valvular surgery and can be worsened by cardiopulmonary bypass. Inhaled epoprostenol (prostacyclin) has been used for the treatment of pulmonary hypertension, but its effects compared with those of placebo on hemodynamics, oxygenation, echocardiographic examination, and platelet function have not been studied during cardiac surgery. METHODS Twenty patients with pulmonary hypertension undergoing cardiac surgery were randomized in a double-blind study to receive inhaled epoprostenol (60 microg) or placebo. The inhalation occurred after induction of anesthesia and before surgical incision. The effects on left and right systolic and diastolic cardiac functions evaluated by means of pulmonary artery catheterization and transesophageal echocardiography, as well as oxygenation and platelet aggregation, were studied. RESULTS Inhalation of epoprostenol significantly reduced indexed right ventricular stroke work from 10.7 +/- 4.57 g. m. m(-2) to 7.8 +/- 3.94 g. m. m(-2) (P =.003) and systolic pulmonary artery pressure from 48.4 +/- 18 mm Hg to 38.9 +/- 11.9 mm Hg (P =.002). The effect was correlated with the severity of pulmonary hypertension (r = 0.76, P =.01) and was no longer apparent after 25 minutes. There was no significant effect on systemic arterial pressures, left ventricular function, arterial oxygenation, platelet aggregation, and surgical blood loss. CONCLUSION Inhaled epoprostenol reduces pulmonary pressure and improves right ventricular stroke work in patients with pulmonary hypertension undergoing cardiac surgery. A dose of 60 microg is hemodynamically safe, and its effect is completely reversed after 25 minutes. We did not observe any evidence of platelet dysfunction or an increase in surgical bleeding after administration of inhaled epoprostenol.
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Abstract
Because of its high diffusing capacity through the alveolar-blood barrier and its high selectivity for the pulmonary vasculature, inhaled nitric oxide (NO) has been recently shown to be a viable and efficient approach to restore pulmonary NO deficiency. The most relevant applications of inhaled NO are in infants with primary pulmonary hypertension or hypoxia. In these patients, inhaled NO improves gas exchange and ventilation-perfusion matching, reduces the length of hospitalization and is without severe detrimental effects. The use of inhaled NO has also been extended to adults with pulmonary hypertension and the acute respiratory distress syndrome. In addition, recent clinical evidence supported by data from animal models, shows beneficial extra-pulmonary effects of inhaled NO, including protection against myocardial ischaemia-reperfusion injury.
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Affiliation(s)
- J Gianetti
- Ospedale G. Pasquinucci, CNR Institute of Clinical Physiology and G. d'Annunzio University, Chieti, Italy.
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22
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Scorza R, Caronni M, Bazzi S, Nador F, Beretta L, Antonioli R, Origgi L, Ponti A, Marchini M, Vanoli M. Post-menopause is the main risk factor for developing isolated pulmonary hypertension in systemic sclerosis. Ann N Y Acad Sci 2002; 966:238-46. [PMID: 12114278 DOI: 10.1111/j.1749-6632.2002.tb04221.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In scleroderma patients, isolated pulmonary hypertension (PHT) has been associated with selected HLA haplotypes, severe impairment of the diffusing capacity for carbon monoxide and the diagnosis of CREST. Most patients with CREST have a late-age onset of the disease, corresponding to the perimenopausal or postmenopausal period. We conducted a retrospective cohort study to determine the role of post-menopause and of the other known clinical and biological markers in the development of isolated pulmonary hypertension in Italian patients with systemic sclerosis. 189 female patients with scleroderma who had no ecographic signs of pulmonary hypertension (PHT) and radiographic signs of lung fibrosis at the first visit and did not develop significant pulmonary fibrosis during the observation time were included. Sixty-three out of 189 patients (33.3%) presented isolated pulmonary hypertension. A severe impairment of diffusing capacity for carbon monoxide at admission was found to be an early predictive element for its development. An increased risk was associated with postmenopausal condition (RR = 5.2, p = 0.000), CREST syndrome (RR = 2.8, p = 0.001) and haplotype HLA-B35 (RR = 2.8; p = 0.002). A significant positive interaction between postmenopausal condition and either HLA-B35 (RR = 15.2; p = 0.000) or the diagnosis of CREST (RR = 14.1; p = 0.000) was found. Postmenopausal condition alone or in combination with HLA-B35 and CREST syndrome is the main risk-factor for developing primary pulmonary hypertension in scleroderma patients. This suggests that hormonal replacement therapy could play a role in preventing isolated PHT in patients with systemic sclerosis.
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Affiliation(s)
- Raffaella Scorza
- Clinical Immunology and Allergology Unit, IRCCS Ospedale Maggiore and University of Milan, Milan, Italy.
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23
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Abstract
Primary pulmonary hypertension (PPH) is a rare disorder of the lung vasculature characterised by an increase in pulmonary artery pressure. Although the aetiology of this disease remains unknown, knowledge of the pathophysiology of the disease has advanced considerably. Diagnosis of PPH is largely by exclusion. The clinical symptoms associated with PPH are aspecific and similar to those seen in other cardiovascular and pulmonary diseases. Electrocardiography, echocardiography, pulmonary function tests, and a lung perfusion scan are necessary to exclude secondary forms of pulmonary hypertension and also help to confirm the diagnosis of PPH. A definite diagnosis of PPH is established by right-heart catheterisation which gives a precise measure of the blood pressure in the right side of the heart and the pulmonary artery, right ventricular function and cardiac output. Once a diagnosis of PPH is established, treatment involving drug therapy or surgery is commenced on the basis of the New York Heart Association functional class. Conventional treatment consists of lifetime administration of anticoagulants, oxygen, diuretics, and digoxin. Vasodilator therapy with calcium channel antagonists is indicated in patients who are 'vasoreactive' to acute vasodilator challenge as assessed by right-heart catheterisation. Promising results are obtained by continuous intravenous administration of epoprostenol (prostacyclin). Newer therapies for PPH include prostacyclin analogues, endothelin receptor antagonists, nitric oxide, phosphodiesterase-5 inhibitors, elastase inhibitors, and gene therapy. Surgical treatment consists of atrial septostomy, thromboendarterectomy, and lung or heart-lung transplantation.
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Affiliation(s)
- T L De Backer
- Department of Cardiology, Thoraxcentre, Erasmus Medical Centre Rotterdam, Rotterdam, The Netherlands.
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24
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Bright-Thomas RJ, Webb AK. The heart in cystic fibrosis. J R Soc Med 2002; 95 Suppl 41:2-10. [PMID: 12216270 PMCID: PMC1308632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023] Open
Affiliation(s)
- Rowland J Bright-Thomas
- Manchester Adult Cystic Fibrosis Unit, North West Lung Centre, Wythenshawe Hospital, Manchester M23 9LT, UK.
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25
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Reynolds PN, Nicklin SA, Kaliberova L, Boatman BG, Grizzle WE, Balyasnikova IV, Baker AH, Danilov SM, Curiel DT. Combined transductional and transcriptional targeting improves the specificity of transgene expression in vivo. Nat Biotechnol 2001; 19:838-42. [PMID: 11533642 DOI: 10.1038/nbt0901-838] [Citation(s) in RCA: 173] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The promise of gene therapy for health care will not be realized until gene delivery systems are capable of achieving efficient, cell-specific gene delivery in vivo. Here we describe an adenoviral system for achieving cell-specific transgene expression in pulmonary endothelium. The combination of transductional targeting to a pulmonary endothelial marker (angiotensin-converting enzyme, ACE) and an endothelial-specific promoter (for vascular endothelial growth factor receptor type 1, flt-1) resulted in a synergistic, 300,000-fold improvement in the selectivity of transgene expression for lung versus the usual site of vector sequestration, the liver. This combined approach should be useful for the design of other gene delivery systems.
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Affiliation(s)
- P N Reynolds
- Division of Human Gene Therapy, Departments of Medicine, Surgery and Pathology, and Gene Therapy Center, University of Alabama at Birmingham, USA.
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26
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Tuder RM, Cool CD, Yeager M, Taraseviciene-Stewart L, Bull TM, Voelkel NF. The pathobiology of pulmonary hypertension. Endothelium. Clin Chest Med 2001; 22:405-18. [PMID: 11590837 DOI: 10.1016/s0272-5231(05)70280-x] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Dysfunctional endothelial cells have a central and critical role in the initiation and progression of severe pulmonary hypertension. The elucidation of the mechanisms involved in the control of endothelial cell proliferation and cell death in the pulmonary vasculature, therefore, is fundamentally important in the pathogenesis of severe pulmonary hypertension and of great interest for a better understanding of endothelial cell biology. Because the intravascular growth of endothelial cells resulting in tumorlets is unique to severe pulmonary hypertension, this phenomenon can teach researchers about the factors involved in the formation and maintenance of the normal endothelial cell monolayer. Clearly, in severe pulmonary hypertension, the "law of the endothelial cell monolayer" has been broken. The ultimate level of such a control is at the altered gene expression pattern that is conducive to endothelial cell growth and disruption of pulmonary blood flow. Secondary pulmonary hypertension certainly also is associated with proliferated pulmonary endothelial cells and plexiform lesions that are histologically indistinguishable from those in PPH. What is then the difference in the mechanisms of endothelial cell proliferation between primary and secondary pulmonary hypertension? The authors believe that PPH is a disease caused by somatic mutations in key angiogenesis- or apoptosis-related genes such as the TGF-beta receptor-2 and Bax. The loss of these important cell growth control mechanisms allows for the clonal expansion of endothelial cells from a single cell that has acquired a selective growth advantage. On the other hand, the proliferated endothelial cells in secondary pulmonary hypertension are polyclonal. It follows from this finding that local (vascular) factor(s) (such as increased shear stress), rather than mutations, play a major role in triggering endothelial cell proliferation. In PPH and secondary pulmonary hypertension, the researcher can postulate that the pulmonary vascular bed contains progenitor-like cells with the capacity of dysregulated growth. The main difference in the pathogenesis of primary and secondary pulmonary endothelial cell proliferation therefore may be the initial mechanism involved in the recruitment of an endothelial progenitor-like cell. In PPH, anorexigen-associated, and familial PPH, the proliferation of endothelial cells occurs from a mutated single cell, whereas in secondary pulmonary hypertension, several progenitor-like cells would be activated to grow. The abnormal endothelial cells in both forms of severe pulmonary hypertension expand because of the expression of angiogenesis-related molecules such as VEGF, VEGFR-2, HIF-1 alpha, and HIF-beta. Also important for the expansion of these cells is the down-regulation of expression of apoptosis-related mediators such as TGF-beta receptor-2 or Bax. The success of any therapy for severe pulmonary hypertension requires that the underlying process of endothelial cell proliferation could be controlled or reversed.
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Affiliation(s)
- R M Tuder
- Departments of Pathology, and Medicine, University of Colorado Health Sciences Center, Denver, Colorado, USA.
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27
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Tilton RG, Brock TA, Dixon RA. Therapeutic potential of endothelin receptor antagonists and nitric oxide donors in pulmonary hypertension. Expert Opin Investig Drugs 2001; 10:1291-308. [PMID: 11772252 DOI: 10.1517/13543784.10.7.1291] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Pulmonary hypertension can occur idiopathically as a primary disorder of the pulmonary circulation or more commonly, it can exist as a haemodynamic manifestation of a wide variety of pulmonary and cardiovascular diseases, including acute lung injury, chronic obstructive lung disease, congenital heart disease, mitral stenosis, chronic left-sided congestive heart failure and connective tissue diseases such as scleroderma. Pulmonary hypertension is associated with changes in vascular tone as well as vascular structure, with the relative contribution of each dependent upon the aetiology of the increased pulmonary vascular resistance. Most currently available treatments utilise anticoagulants as well as vasodilator drugs that only attenuate the vasoconstrictive component of the disease. The latter category includes oral calcium channel blockers, iv. and aerosolised prostacyclin analogues and inhaled nitric oxide but all three classes of vasodilators have disadvantages and limitations. Treatment with vasodilators is often ineffective in patients with longstanding pulmonary hypertension in which structural changes contribute significantly to the pulmonary hypertension, blood flow obstruction and right heart failure. In view of the immense clinical need, new therapies are being developed by pharmaceutical companies to treat pulmonary hypertension. This update will focus on the current development status of endothelin receptor antagonists and nitric oxide donors for the treatment of pulmonary hypertension.
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Affiliation(s)
- R G Tilton
- Department of Pharmacology, Texas Biotechnology Corporation, Houston, Texas, TX 77030, USA.
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28
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Reynolds PN, Zinn KR, Gavrilyuk VD, Balyasnikova IV, Rogers BE, Buchsbaum DJ, Wang MH, Miletich DJ, Grizzle WE, Douglas JT, Danilov SM, Curiel DT. A targetable, injectable adenoviral vector for selective gene delivery to pulmonary endothelium in vivo. Mol Ther 2000; 2:562-78. [PMID: 11124057 DOI: 10.1006/mthe.2000.0205] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adenoviral (Ad) vectors are promising gene therapy vehicles due to their in vivo stability and efficiency, but their potential utility is compromised by their restricted tropism. Targeting strategies have been devised to improve the efficacy of these agents, but specific targeting following in vivo systemic administration of vector has not previously been demonstrated. The distinct aim of the current study was to determine whether an Ad-targeting strategy could maintain fidelity upon systemic vascular administration. We used a bispecific antibody to target Ad infection specifically to angiotensin-converting enzyme (ACE), which is preferentially expressed on pulmonary capillary endothelium and which may thus enable gene therapy for pulmonary vascular disease. Cell-specific gene delivery to ACE-expressing cells was first confirmed in vitro. Administration of retargeted vector complex via tail vein injection into rats resulted in at least a 20-fold increase in both Ad DNA localization and luciferase transgene expression in the lungs, compared to the untargeted vector. Furthermore, targeting led to reduced transgene expression in nontarget organs, especially the liver, where the reduction was over 80%. Immunohistochemical and immunoelectron microscopy analysis confirmed that the pulmonary transgene expression was specifically localized to endothelial cells. Enhancement of transgene expression in the lungs as a result of the ACE-targeting strategy was also confirmed using a new noninvasive imaging technique. This study shows that a retargeting approach can indeed specifically modify the gene delivery properties of an Ad vector given systemically and thus has encouraging implications for the further development of targetable, injectable Ad vectors.
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Affiliation(s)
- P N Reynolds
- Division of Human Gene Therapy, University of Illinois at Chicago, Birmingham, Alabama, 35294-3300, USA
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Muggenburg BA, Tilley L, Green FH. Animal models of cardiac disease: potential usefulness for studying health effects of inhaled particles. Inhal Toxicol 2000; 12:901-25. [PMID: 10989368 DOI: 10.1080/08958370050123225] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Cardiac disease is one of the major causes of morbidity and mortality worldwide and is the leading cause of death in the United States. Epidemiologic studies have shown a close association between morbidity and mortality from cardiac disease, primarily in persons already affected, and with modest increases in levels of air pollution. At present, no mechanisms are known by which inhaled air pollutants interact with the heart to cause death. Thus, animal models of cardiac disease are needed to study possible interactions between inhaled pollutants and the heart and the resultant morbidity and mortality. Very little research in animals has been conducted in this area, and appropriate animal models must be carefully selected. The purpose of this review is to examine several potential animal models and to discuss their advantages and disadvantages in the study of cardiac disease and air pollution.
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Affiliation(s)
- B A Muggenburg
- Lovelace Respiratory Research Institute, PO Box 5890, Albuquerque, NM 87185, USA.
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30
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Bradford KK, Deb B, Pearl RG. Combination therapy with inhaled nitric oxide and intravenous dobutamine during pulmonary hypertension in the rabbit. J Cardiovasc Pharmacol 2000; 36:146-51. [PMID: 10942154 DOI: 10.1097/00005344-200008000-00002] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Combination therapy with an intravenous inovasodilator and inhaled nitric oxide (NO) may be appropriate in patients with pulmonary hypertension and associated right ventricular failure. We examined whether dobutamine and inhaled NO would have additive pulmonary vasodilator effects in experimental pulmonary hypertension. Pulmonary hypertension was produced in anesthetized, mechanically ventilated rabbits by infusion of U46619, a thromboxane analogue. Dobutamine was administered in increasing doses (2.5-20 microg/kg/min) with and without inhaled NO (40 ppm). Dobutamine produced dose-dependent decreases in pulmonary vascular resistance (PVR) and mean arterial pressure (MAP) and increases in cardiac output (CO). Inhaled NO alone decreased pulmonary artery pressure (PAP) and PVR with no effect on MAP or CO. The effects of dobutamine and inhaled NO were additive, so that at each dose of dobutamine, inhaled NO decreased PAP and PVR with no effect on systemic hemodynamics. This study suggests that the combination of dobutamine and inhaled NO should produce additive pulmonary vasodilation in patients with pulmonary hypertension and associated right ventricular dysfunction.
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Affiliation(s)
- K K Bradford
- Department of Pediatrics, Stanford University Medical Center, California 94305-5117, USA
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Deb B, Bradford K, Pearl RG. Additive effects of inhaled nitric oxide and intravenous milrinone in experimental pulmonary hypertension. Crit Care Med 2000; 28:795-9. [PMID: 10752832 DOI: 10.1097/00003246-200003000-00031] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine whether inhaled nitric oxide (IN0) and intravenous milrinone have additive pulmonary vasodilator effects in a rat model of pulmonary hypertension. DESIGN Prospective, experimental study. SETTING Animal laboratory of a university medical center. SUBJECTS Male New Zealand White rabbits. INTERVENTIONS Anesthetized rabbits were mechanically ventilated and instrumented for measurement of systemic mean arterial pressure (MAP), pulmonary artery pressure (PAP), left atrial pressure, and cardiac output (CO). After baseline measurements, the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (30 mg/kg iv) was administered. Pulmonary hypertension was produced by the continuous infusion of U46619, a thromboxane A2 mimetic. INO (40 ppm) was added to the inspired gas, and hemodynamic measurements were obtained before and after INO. Milrinone was administered sequentially as a 30-mg/kg bolus followed by a 3-microg/kg/min infusion, a 100-mg/kg bolus followed by a 10-microg/kg/min infusion, and a 300-mg/kg bolus followed by a 30-microg/kg/min infusion (M3). Hemodynamic measurements were obtained with and without INO at each dose of milrinone. MEASUREMENTS AND MAIN RESULTS During U46619-induced pulmonary hypertension, INO decreased PAP and pulmonary vascular resistance (PVR) but did not affect MAP, systemic vascular resistance (SVR), or CO. Milrinone dose dependently decreased PAP, PVR, MAP, and SVR and increased CO. At each dose of milrinone, INO further decreased PVR but not SVR. M3 decreased PVR 49%, and the addition of INO decreased PVR an additional 19% so that PAP and PVR decreased to baseline values. CONCLUSIONS Milrinone and INO both decrease pulmonary hypertension individually, and the combination produces additive effects. Combination therapy may produce potent and selective pulmonary vasodilation during the treatment of pulmonary hypertension.
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Affiliation(s)
- B Deb
- Department of Anesthesia, Stanford University Medical Center, CA 94305-5117, USA
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Liu M, Tanswell AK, Post M. Mechanical force-induced signal transduction in lung cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:L667-83. [PMID: 10516207 DOI: 10.1152/ajplung.1999.277.4.l667] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The lung is a unique organ in that it is exposed to physical forces derived from breathing, blood flow, and surface tension throughout life. Over the past decade, significant progress has been made at the cellular and molecular levels regarding the mechanisms by which physical forces affect lung morphogenesis, function, and metabolism. With the use of newly developed devices, mechanical forces have been applied to a variety of lung cells including fetal lung cells, adult alveolar epithelial cells, fibroblasts, airway epithelial and smooth muscle cells, pulmonary endothelial and smooth muscle cells, and mesothelial cells. These studies have led to new insights into how cells sense mechanical stimulation, transmit signals intra- and intercellularly, and regulate gene expression at the transcriptional and posttranscriptional levels. These advances have significantly increased our understanding of the process of mechanotransduction in lung cells. Further investigation in this exciting research field will facilitate our understanding of pulmonary physiology and pathophysiology at the cellular and molecular levels.
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Affiliation(s)
- M Liu
- Thoracic Surgery Research Laboratory, Toronto General Hospital, University Health Network, Toronto M5G 2C4, Ontario, Canada M5G 1X8.
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Bossone E, Duong-Wagner TH, Paciocco G, Oral H, Ricciardi M, Bach DS, Rubenfire M, Armstrong WF. Echocardiographic features of primary pulmonary hypertension. J Am Soc Echocardiogr 1999; 12:655-62. [PMID: 10441222 DOI: 10.1053/je.1999.v12.a99069] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Primary pulmonary hypertension (PPH) is essentially a diagnosis of exclusion and usually is made late because of the nonspecific nature of the early signs and symptoms. Echocardiography is a key screening test in the diagnostic algorithm of patients with suspected PPH. The purpose of this study was to define the echocardiographic Doppler features in patients with PPH at the time of diagnosis. From 1992 to 1997, 51 patients were diagnosed with PPH at our institution. All underwent a standardized transthoracic echocardiographic examination, including a contrast study and transthoracic echocardiographic examination if indicated. Pulmonary artery systolic pressure was calculated from the tricuspid regurgitation jet. The majority of patients had pulmonary artery systolic pressure greater than 60 mm Hg (96%) associated with systolic flattening of the interventricular septum (90%), enlarged right atrium (92%) and ventricle (98%), and reduced right ventricular systolic function (76%). There was an increase in the interventricular septal thickness (>1.2 cm) in 21 (43%) of 49 patients, accompanied by a septal/posterior wall ratio greater than 1.3 in 11 (22%) of 49. Although a reduction in both left ventricular systolic and diastolic volumes was noted, global left ventricular systolic function was preserved in all patients. Mitral E/A ratio was less than 0.7 in 7 (22%) patients studied. Color Doppler revealed moderate to severe tricuspid regurgitation and pulmonic insufficiency in 41 (80%) of 51 and 16 (31%) of 51 of cases, respectively. Pericardial effusion (7 small and 1 moderate) and patent foramen ovale (n = 12) were also frequently detected. At the time of initial diagnosis, PPH is associated with secondary cardiac abnormalities in the majority of patients.
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Affiliation(s)
- E Bossone
- Division of Cardiology, Department of Internal Medicine, University of Michigan, Ann Arbor, USA
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Yu AY, Shimoda LA, Iyer NV, Huso DL, Sun X, McWilliams R, Beaty T, Sham JS, Wiener CM, Sylvester JT, Semenza GL. Impaired physiological responses to chronic hypoxia in mice partially deficient for hypoxia-inducible factor 1alpha. J Clin Invest 1999; 103:691-6. [PMID: 10074486 PMCID: PMC408131 DOI: 10.1172/jci5912] [Citation(s) in RCA: 506] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Chronic hypoxia induces polycythemia, pulmonary hypertension, right ventricular hypertrophy, and weight loss. Hypoxia-inducible factor 1 (HIF-1) activates transcription of genes encoding proteins that mediate adaptive responses to hypoxia, including erythropoietin, vascular endothelial growth factor, and glycolytic enzymes. Expression of the HIF-1alpha subunit increases exponentially as O2 concentration is decreased. Hif1a-/- mouse embryos with complete deficiency of HIF-1alpha due to homozygosity for a null allele at the Hif1a locus die at midgestation, with multiple cardiovascular malformations and mesenchymal cell death. Hif1a+/- heterozygotes develop normally and are indistinguishable from Hif1a+/+ wild-type littermates when maintained under normoxic conditions. In this study, the physiological responses of Hif1a+/- and Hif1a+/+ mice exposed to 10% O2 for one to six weeks were analyzed. Hif1a+/- mice demonstrated significantly delayed development of polycythemia, right ventricular hypertrophy, pulmonary hypertension, and pulmonary vascular remodeling and significantly greater weight loss compared with wild-type littermates. These results indicate that partial HIF-1alpha deficiency has significant effects on multiple systemic responses to chronic hypoxia.
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Affiliation(s)
- A Y Yu
- Institute of Genetic Medicine, Division of Pulmonary and Critical Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-3914, USA
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Abstract
Pulmonary hypertension (mean pulmonary arterial pressure > 20mm Hg at rest or > 30mm Hg during exercise) occurs (i) as primary pulmonary hypertension (no known underlying cause), (ii) as persistent pulmonary hypertension of the newborn or (iii) secondary to a variety of lung and cardiovascular diseases. In the last 10 to 15 years there have been significant advances in the medical management of this debilitating and life-threatening disorder. The main drugs in current use are anticoagulants (warfarin, heparin) and vasodilators, especially oral calcium antagonists, intravenous prostacyclin (prostaglandin I2; epoprostenol) and inhaled nitric oxide. Calcium antagonists, (e.g. nifedipine, diltiazem) are used chiefly in primary pulmonary hypertension. They are effective in patients who give a pulmonary vasodilator response to an acute challenge with a short acting vasodilator (e.g. prostacyclin, nitric oxide or adenosine), and are used in doses greater than are usual in the treatment of other cardiovascular disorders. Prostacyclin, given by continuous intravenous infusion, is effective in patients even if they do not respond to an acute vasodilator challenge. The long term benefit in these patients is thought to reflect the antiproliferative effects of the drug and/or its ability to inhibit platelet aggregation. It is used either as long term therapy or as a bridge to transplantation. Inhaled nitric oxide, which is used mainly in persistent pulmonary hypertension of the newborn, has the particular benefit of being pulmonary selective, due to its route of administration and rapid inactivation. Anticoagulants have a specific role in the treatment of pulmonary thromboembolic pulmonary hypertension and are also used routinely in patients with primary pulmonary hypertension. Nondrug treatments for pulmonary hypertension include (i) supplemental oxygen (> or = 15 h/day), which is the primary therapy in patients with pulmonary hypertension secondary to chronic obstructive pulmonary disease and (ii) heart-lung or lung transplantation, which nowadays is regarded as a last resort. Different types of pulmonary hypertension require different treatment strategies. Future advances in the treatment of pulmonary hypertension may come from the use of drug combinations, the development of new drugs, such as endothelin antagonists, nitric oxide donors and potassium channel openers, or the application of gene therapy.
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Affiliation(s)
- J C Wanstall
- Department of Physiology and Pharmacology, University of Queensland, Brisbane, Australia.
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Krieg P, Wahlers T, Giess W, Rohde R, Hartrumpf M, Bund M, Haverich A. Inhaled nitric oxide and inhaled prostaglandin E1: effect on left ventricular contractility when used for treatment of experimental pulmonary hypertension. Eur J Cardiothorac Surg 1998; 14:494-502. [PMID: 9860206 DOI: 10.1016/s1010-7940(98)00210-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
OBJECTIVE Pulmonary hypertension (PHT) is a life-threatening complication after isolated heart and lung transplantation. Recent work has shown that inhaled nitric oxide (NO) in combination with inhaled prostaglandin E1 (PGE1) reduce pulmonary hypertension but their influence on cardiac contractility is less well defined. METHODS This study investigated left ventricular contractility as measured by the 'Preload Recruitable Stroke Work-Relation' (PRSW) in 24 anesthetized open chest pigs, 12 receiving in random order NO (50 ppm), PGE1 (20 microg/ml) and their combination compared to 12 controls. PHT was induced by embolization with glass beads (500 microm). Prior to induction of PHT, sonomicrometric crystals were placed on the heart to measure instantaneous cardiac dimensions. Instantaneous intraventricular pressure (micro-tip catheter) and intraventricular dimensions were recorded digitally, while intraventricular volumes were calculated from the intraventricular dimensions applying the cylindric ellipsoidal volume model for the left ventricle. PRSW was calculated from the instantaneous pressure and volume data during rapid vena caval occlusion by analysis of generated pressure-volume loops. All data were analyzed by MANOVA and corrected for heart rate (level of significance #: P < 0.05); PRSW-slope measures contractility, (PRSW-X-intercept did not change significantly). RESULTS PRSW-change +/- SEM (in percent of initial PRSW after induction of PHT) was -14.6% +/- 4.4% versus 1.6% +/- 4.4% for NO versus Control (P = 0.004), -8.8% +/- 4.6% versus 1% +/- 3.3% (P = 0.18) for PGE1 versus Control and -5.7% +/- 4.4% versus 2.5% +/- 4.2% for NO + PGE1 versus Control (P = 0.33), respectively. In summary, application of NO 50 ppm significantly reduced left ventricular contractility while PGE1 20 microg/ml and the combination of NO and PGE1 did not. CONCLUSION If NO is not available, the sole application of nebulized PGE1 (20 microg/ml) appears to be safe with respect to left ventricular contractility in the setting of PHT. The combination of NO and PGE1 for the treatment of pulmonary hypertension should be considered for clinical application in situations where a combination of pulmonary hypertension and decreased left ventricular function is present.
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Affiliation(s)
- P Krieg
- Department of Cardiothoracic and Vascular Surgery, Hannover Medical School, Germany.
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