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Swiss Medical Weekly 2017The term pulmonary hypertension refers to a serious condition characterised by high pulmonary vascular pressure, mainly as a consequence of various cardiac and... (Review)
Review
The term pulmonary hypertension refers to a serious condition characterised by high pulmonary vascular pressure, mainly as a consequence of various cardiac and respiratory diseases. Current clinical classification of pulmonary hypertension considers five distinct groups. Transthoracic echocardiography represents the first and most important noninvasive screening tool for estimating the probability of pulmonary hypertension. The diagnostic approach to pulmonary hypertension is supported by a proposed algorithm, which identifies the underlying cause. The definitive diagnosis and classification of pulmonary hypertension requires invasive confirmation of an elevated pulmonary artery mean pressure during a right heart catheterisation at rest. Pulmonary artery wedge pressure assessment has a pivotal role in differentiating precapillary from postcapillary pulmonary hypertension. The correct acquisition and interpretation of invasive pulmonary haemodynamic variables play a central role, not only in confirming the diagnosis but also in prognostication and treatment decision-making. During right heart catheterisation correct zero levelling of the external pressure transducer and pressure tracing readings at end-expiration should be assured. Obese patients and patients with obstructive lung diseases require special attention, given that spontaneous positive end-expiratory intrathoracic pressures are frequently observed. Because pressure and flow determinations with a fluid-filled flow-directed thermodilution catheter are potentially insufficiently precise, it is recommended to average at least three measurements. Acute vasoreactivity testing is indicated only in selected patients. Recent data suggest that invasive pulmonary haemodynamic measurement during exercise may be more sensitive than resting haemodynamics for early diagnosis, for treatment response assessment and for prognostic purposes.
Topics: Cardiac Catheterization; Echocardiography; Hemodynamics; Humans; Hypertension, Pulmonary; Positive-Pressure Respiration; Pulmonary Artery; Pulmonary Circulation; Vascular Resistance; Ventricular Dysfunction, Right; Ventricular Function, Right
PubMed: 28722077
DOI: 10.4414/smw.2017.14445 -
Anesthesiology Apr 2015Hypoxic pulmonary vasoconstriction (HPV) represents a fundamental difference between the pulmonary and systemic circulations. HPV is active in utero, reducing pulmonary... (Review)
Review
Hypoxic pulmonary vasoconstriction (HPV) represents a fundamental difference between the pulmonary and systemic circulations. HPV is active in utero, reducing pulmonary blood flow, and in adults helps to match regional ventilation and perfusion although it has little effect in healthy lungs. Many factors affect HPV including pH or PCO2, cardiac output, and several drugs, including antihypertensives. In patients with lung pathology and any patient having one-lung ventilation, HPV contributes to maintaining oxygenation, so anesthesiologists should be aware of the effects of anesthesia on this protective reflex. Intravenous anesthetic drugs have little effect on HPV, but it is attenuated by inhaled anesthetics, although less so with newer agents. The reflex is biphasic, and once the second phase becomes active after about an hour of hypoxia, this pulmonary vasoconstriction takes hours to reverse when normoxia returns. This has significant clinical implications for repeated periods of one-lung ventilation.
Topics: Anesthetics, Inhalation; Animals; Humans; Hypoxia; Lung; Pulmonary Circulation; Vasoconstriction
PubMed: 25587641
DOI: 10.1097/ALN.0000000000000569 -
Circulation Research Apr 2022There is an increased appreciation for the importance of the right heart and pulmonary circulation in several disease states across the spectrum of pulmonary... (Review)
Review
There is an increased appreciation for the importance of the right heart and pulmonary circulation in several disease states across the spectrum of pulmonary hypertension and left heart failure. However, assessment of the structure and function of the right heart and pulmonary circulation can be challenging, due to the complex geometry of the right ventricle, comorbid pulmonary airways and parenchymal disease, and the overlap of hemodynamic abnormalities with left heart failure. Several new and evolving imaging modalities interrogate the right heart and pulmonary circulation with greater diagnostic precision. Echocardiographic approaches such as speckle-tracking and 3-dimensional imaging provide detailed assessments of regional systolic and diastolic function and volumetric assessments. Magnetic resonance approaches can provide high-resolution views of cardiac structure/function, tissue characterization, and perfusion through the pulmonary vasculature. Molecular imaging with positron emission tomography allows an assessment of specific pathobiologically relevant targets in the right heart and pulmonary circulation. Machine learning analysis of high-resolution computed tomographic lung scans permits quantitative morphometry of the lung circulation without intravenous contrast. Inhaled magnetic resonance imaging probes, such as hyperpolarized 129Xe magnetic resonance imaging, report on pulmonary gas exchange and pulmonary capillary hemodynamics. These approaches provide important information on right ventricular structure and function along with perfusion through the pulmonary circulation. At this time, the majority of these developing technologies have yet to be clinically validated, with few studies demonstrating the utility of these imaging biomarkers for diagnosis or monitoring disease. These technologies hold promise for earlier diagnosis and noninvasive monitoring of right heart failure and pulmonary hypertension that will aid in preclinical studies, enhance patient selection and provide surrogate end points in clinical trials, and ultimately improve bedside care.
Topics: Heart Failure; Humans; Hypertension, Pulmonary; Pulmonary Circulation; Xenon Isotopes
PubMed: 35482838
DOI: 10.1161/CIRCRESAHA.121.319990 -
Biomolecules Sep 2021A variety of cell types in pulmonary arteries (endothelial cells, fibroblasts, and smooth muscle cells) are continuously exposed to mechanical stimulations such as shear... (Review)
Review
A variety of cell types in pulmonary arteries (endothelial cells, fibroblasts, and smooth muscle cells) are continuously exposed to mechanical stimulations such as shear stress and pulsatile blood pressure, which are altered under conditions of pulmonary hypertension (PH). Most functions of such vascular cells (e.g., contraction, migration, proliferation, production of extracellular matrix proteins, etc.) depend on a key event, i.e., the increase in intracellular calcium concentration ([Ca]) which results from an influx of extracellular Ca and/or a release of intracellular stored Ca. Calcium entry from the extracellular space is a major step in the elevation of [Ca], involving a variety of plasmalemmal Ca channels including the superfamily of stretch-activated channels (SAC). A common characteristic of SAC is that their gating depends on membrane stretch. In general, SAC are non-selective Ca-permeable cation channels, including proteins of the TRP (Transient Receptor Potential) and Piezo channel superfamily. As membrane mechano-transducers, SAC convert physical forces into biological signals and hence into a cell response. Consequently, SAC play a major role in pulmonary arterial calcium homeostasis and, thus, appear as potential novel drug targets for a better management of PH.
Topics: Animals; Biomechanical Phenomena; Biophysical Phenomena; Calcium Channels; Humans; Hypertension, Pulmonary; Models, Biological; Pulmonary Circulation
PubMed: 34572602
DOI: 10.3390/biom11091389 -
International Journal of Molecular... Jun 2023Pulmonary hypertension (PH) associated with left heart diseases (PH-LHD), also termed group 2 PH, represents the most common form of PH. It develops through the passive... (Review)
Review
Pulmonary hypertension (PH) associated with left heart diseases (PH-LHD), also termed group 2 PH, represents the most common form of PH. It develops through the passive backward transmission of elevated left heart pressures in the setting of heart failure, either with preserved (HFpEF) or reduced (HFrEF) ejection fraction, which increases the pulsatile afterload of the right ventricle (RV) by reducing pulmonary artery (PA) compliance. In a subset of patients, progressive remodeling of the pulmonary circulation resulted in a pre-capillary phenotype of PH, with elevated pulmonary vascular resistance (PVR) further increasing the RV afterload, eventually leading to RV-PA uncoupling and RV failure. The primary therapeutic objective in PH-LHD is to reduce left-sided pressures through the appropriate use of diuretics and guideline-directed medical therapies for heart failure. When pulmonary vascular remodeling is established, targeted therapies aiming to reduce PVR are theoretically appealing. So far, such targeted therapies have mostly failed to show significant positive effects in patients with PH-LHD, in contrast to their proven efficacy in other forms of pre-capillary PH. Whether such therapies may benefit some specific subgroups of patients (HFrEF, HFpEF) with specific hemodynamic phenotypes (post- or pre-capillary PH) and various degrees of RV dysfunction still needs to be addressed.
Topics: Humans; Hypertension, Pulmonary; Heart Failure; Stroke Volume; Pulmonary Circulation; Hemodynamics
PubMed: 37373119
DOI: 10.3390/ijms24129971 -
Internal Medicine (Tokyo, Japan) Feb 2023
Topics: Humans; Hypertension, Pulmonary; Pulmonary Circulation; Thromboembolism; Pulmonary Embolism; Chronic Disease
PubMed: 35793955
DOI: 10.2169/internalmedicine.0017-22 -
The Journal of Thoracic and... Oct 2021
Topics: Fontan Procedure; Humans; Pulmonary Circulation; Pyrimidines; Sulfonamides
PubMed: 33451847
DOI: 10.1016/j.jtcvs.2020.11.121 -
Clinics in Perinatology Dec 2015Despite advances in the care of preterm infants, these infants remain at risk bronchopulmonary dysplasia (BPD), which results in prolonged need for supplemental oxygen,... (Review)
Review
Despite advances in the care of preterm infants, these infants remain at risk bronchopulmonary dysplasia (BPD), which results in prolonged need for supplemental oxygen, recurrent respiratory exacerbations, and exercise intolerance. Recent investigations have highlighted the important contribution of the developing pulmonary circulation to lung development, showing that these infants are also at risk for pulmonary vascular disease (PVD), including pulmonary hypertension (PH) and pulmonary vascular abnormalities. Several epidemiologic studies have delineated the incidence of PH in preterm infants and the impact on outcomes. These studies have also highlighted gaps in the understanding of PVD in BPD.
Topics: Administration, Inhalation; Bronchopulmonary Dysplasia; Echocardiography; Endothelium-Dependent Relaxing Factors; Humans; Hypertension, Pulmonary; Infant, Newborn; Infant, Premature; Nitric Oxide; Pulmonary Circulation; Vascular Diseases
PubMed: 26593082
DOI: 10.1016/j.clp.2015.08.010 -
Annals of the American Thoracic Society Dec 2018Chronic obstructive pulmonary disease (COPD) is one of the most important causes of death worldwide, and in addition to its impact on the patient's health, it poses a... (Review)
Review
Chronic obstructive pulmonary disease (COPD) is one of the most important causes of death worldwide, and in addition to its impact on the patient's health, it poses a major socioeconomic burden. Tobacco smoke, indoor cooking, and air pollution are major triggers of the disease. This article summarizes evidence for the concept that lung microvascular molecular alterations can be a driver of lung emphysema. If findings from preclinical models allow a transfer to the human situation, this concept can offer new approaches for curative treatment of lung emphysema.
Topics: Airway Remodeling; Animals; Comorbidity; Disease Models, Animal; Endothelium, Vascular; Humans; Hypertension, Pulmonary; Mice; Pulmonary Artery; Pulmonary Circulation; Pulmonary Disease, Chronic Obstructive; Pulmonary Emphysema; Tobacco Smoking; Vascular Diseases
PubMed: 30759003
DOI: 10.1513/AnnalsATS.201808-532MG -
Respirology (Carlton, Vic.) Aug 2016Chronic obstructive pulmonary disease (COPD) is characterized by airflow obstruction that results from an inflammatory process affecting the airways and lung parenchyma.... (Review)
Review
Chronic obstructive pulmonary disease (COPD) is characterized by airflow obstruction that results from an inflammatory process affecting the airways and lung parenchyma. Despite major abnormalities taking place in bronchial and alveolar structures, changes in pulmonary vessels also represent an important component of the disease. Alterations in vessel structure are highly prevalent and abnormalities in their function impair gas exchange and may result in pulmonary hypertension (PH), an important complication of the disease associated with reduced survival and worse clinical course. The prevalence of PH is high in COPD, particularly in advanced stages, although it remains of mild to moderate severity in the majority of cases. Endothelial dysfunction, with imbalance between vasodilator/vasoconstrictive mediators, is a key determinant of changes taking place in pulmonary vasculature in COPD. Cigarette smoke products may perturb endothelial cells and play a critical role in initiating vascular changes. The concurrence of inflammation, hypoxia and emphysema further contributes to vascular damage and to the development of PH. The use of drugs that target endothelium-dependent signalling pathways, currently employed in pulmonary arterial hypertension, is discouraged in COPD due to the lack of efficacy observed in randomized clinical trials and because there is compelling evidence indicating that these drugs may worsen pulmonary gas exchange. The subgroup of patients with severe PH should be ideally managed in centres with expertise in both PH and chronic lung diseases because alterations of pulmonary vasculature might resemble those observed in pulmonary arterial hypertension. Because this condition entails poor prognosis, it warrants specialist treatment.
Topics: Endothelium-Dependent Relaxing Factors; Humans; Hypertension, Pulmonary; Lung; Prognosis; Pulmonary Artery; Pulmonary Circulation; Pulmonary Disease, Chronic Obstructive
PubMed: 27028849
DOI: 10.1111/resp.12772