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Archivos de Bronconeumologia Apr 2022
Topics: COVID-19; Humans; Pulmonary Circulation; Thrombosis
PubMed: 34054194
DOI: 10.1016/j.arbres.2021.05.007 -
Circulation May 2022In REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure), implantation of... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
In REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure), implantation of an atrial shunt device did not provide overall clinical benefit for patients with heart failure with preserved or mildly reduced ejection fraction. However, prespecified analyses identified differences in response in subgroups defined by pulmonary artery systolic pressure during submaximal exercise, right atrial volume, and sex. Shunt implantation reduces left atrial pressures but increases pulmonary blood flow, which may be poorly tolerated in patients with pulmonary vascular disease (PVD). On the basis of these results, we hypothesized that patients with latent PVD, defined as elevated pulmonary vascular resistance during exercise, might be harmed by shunt implantation, and conversely that patients without PVD might benefit.
METHODS
REDUCE LAP-HF II enrolled 626 patients with heart failure, ejection fraction ≥40%, exercise pulmonary capillary wedge pressure ≥25 mm Hg, and resting pulmonary vascular resistance <3.5 Wood units who were randomized 1:1 to atrial shunt device or sham control. The primary outcome-a hierarchical composite of cardiovascular death, nonfatal ischemic stroke, recurrent HF events, and change in health status-was analyzed using the win ratio. Latent PVD was defined as pulmonary vascular resistance ≥1.74 Wood units (highest tertile) at peak exercise, measured before randomization.
RESULTS
Compared with patients without PVD (n=382), those with latent PVD (n=188) were older, had more atrial fibrillation and right heart dysfunction, and were more likely to have elevated left atrial pressure at rest. Shunt treatment was associated with worse outcomes in patients with PVD (win ratio, 0.60 [95% CI, 0.42, 0.86]; =0.005) and signal of clinical benefit in patients without PVD (win ratio, 1.31 [95% CI, 1.02, 1.68]; =0.038). Patients with larger right atrial volumes and men had worse outcomes with the device and both groups were more likely to have pacemakers, heart failure with mildly reduced ejection fraction, and increased left atrial volume. For patients without latent PVD or pacemaker (n=313; 50% of randomized patients), shunt treatment resulted in more robust signal of clinical benefit (win ratio, 1.51 [95% CI, 1.14, 2.00]; =0.004).
CONCLUSIONS
In patients with heart failure with preserved or mildly reduced ejection fraction, the presence of latent PVD uncovered by invasive hemodynamic exercise testing identifies patients who may worsen with atrial shunt therapy, whereas those without latent PVD may benefit.
Topics: Cardiac Catheterization; Female; Heart Atria; Heart Failure; Humans; Male; Pulmonary Circulation; Stroke Volume; Treatment Outcome; Vascular Diseases
PubMed: 35354306
DOI: 10.1161/CIRCULATIONAHA.122.059486 -
Clinics in Perinatology Mar 2024Fetal lungs have fewer and smaller arteries with higher pulmonary vascular resistance (PVR) than a newborn. As gestation advances, the pulmonary circulation becomes more... (Review)
Review
Fetal lungs have fewer and smaller arteries with higher pulmonary vascular resistance (PVR) than a newborn. As gestation advances, the pulmonary circulation becomes more sensitive to changes in pulmonary arterial oxygen tension, which prepares them for the dramatic drop in PVR and increase in pulmonary blood flow (PBF) that occur when the baby takes its first few breaths of air, thus driving the transition from fetal to postnatal circulation. Dynamic and intricate regulatory mechanisms control PBF throughout development and are essential in supporting gas exchange after birth. Understanding these concepts is crucial given the role the pulmonary vasculature plays in the development of complications with transition, such as in the setting of persistent pulmonary hypertension of the newborn and congenital heart disease. An improved understanding of pulmonary vascular regulation may reveal opportunities for better clinical management.
Topics: Pregnancy; Infant, Newborn; Female; Humans; Lung; Fetus; Pulmonary Circulation; Prenatal Care; Vascular Resistance
PubMed: 38325936
DOI: 10.1016/j.clp.2023.11.003 -
American Journal of Respiratory and... Aug 2023
Topics: Humans; Hypertension, Pulmonary; Pulmonary Artery; Pulmonary Circulation
PubMed: 37348119
DOI: 10.1164/rccm.202306-0990ED -
Aerospace Medicine and Human Performance Aug 2019Changes in gravity or body position provoke changes in hydrostatic pressure in the arterial system and in venous return. Potential asymmetries between left (Q) and...
Changes in gravity or body position provoke changes in hydrostatic pressure in the arterial system and in venous return. Potential asymmetries between left (Q) and right ventricular (Q) cardiac output during transient gravity changes were investigated. It was hypothesized that blood volume is temporarily stored in the pulmonary vessels, with amount and duration depending on the level and directions of gravity. Eight healthy, male subjects (32 ± 3 yr, 182 ± 7 cm, 82 ± 6 kg) were tested on a tilt seat (TS), in a long arm human centrifuge (laHC), and during parabolic flights (PF). The gravitational changes during PF were reconstructed by changing gravity in a laHC and different body positions on a TS. All participants were tested in the seated, resting position. Heart rate and blood pressure were recorded continuously and Q was calculated, applying the Modelflow Algorithm. Gas exchange was measured breath-by-breath. Q was calculated from these data according to the Fick Principle. Four sequences were superimposed and analyzed by ANOVA with the factors Time, Ventricle (Q, Q), and Mode (TS, PF, laHC). After reductions in gravity Q and Q were transiently desynchronized. ANOVA showed no main effect for Mode, but significant changes were found for Time and Ventricle and all interactions. Phases of reduced gravity seem to lead to transiently increased storage of blood volume inside the pulmonary vascular system. A more detailed understanding of these mechanisms might help to describe the compliance of the pulmonary vascular system in diseases of the pulmonary circulation.
Topics: Adaptation, Physiological; Adult; Blood Pressure; Cardiac Output; Centrifugation; Healthy Volunteers; Heart Rate; Humans; Hypergravity; Male; Posture; Pulmonary Circulation; Space Flight
PubMed: 31331418
DOI: 10.3357/AMHP.5300.2019 -
European Heart Journal Nov 2022
Topics: Humans; Pulmonary Circulation; Pulmonary Edema; Lung; Hemodynamics
PubMed: 36104502
DOI: 10.1093/eurheartj/ehac499 -
Journal of Echocardiography Mar 2023Pulmonary transit time (PTT) and pulmonary blood volume (PBV) derived from non-invasive imaging correlate with pulmonary artery wedge pressure. The response of PBV to...
BACKGROUND
Pulmonary transit time (PTT) and pulmonary blood volume (PBV) derived from non-invasive imaging correlate with pulmonary artery wedge pressure. The response of PBV to exercise may be useful in the evaluation of cardiopulmonary disease but whether PBV can be obtained reliably following exercise is unknown. We therefore aimed to assess the technical feasibility of measuring PTT and PBV after exercise using contrast echocardiography.
METHODS
In healthy volunteers, PTT was calculated from time-intensity curves generated as contrast traversed the cardiac chambers before and immediately after participants performed sub-maximal exercise on the Standard Bruce Protocol. From the product of PTT and heart rate (HR) during contrast passage through the pulmonary circulation, PBV relative to systemic stroke volume (rPBV) was calculated.
RESULTS
The cohort consisted of 14 individuals (age: 46 ± 8 years; 2 female) without cardiopulmonary disease. Exercise time was 8 ¾ ± 1 ¾ minutes and participants reached 85 ± 9% of age-predicted maximal HR, which corresponded to a near-doubling of resting HR at the time of post-exercise contrast injection. Data sufficient to derive PTT and rPBV were obtained for all participants. With exercise, the change in PBV from baseline ranged from 56 to 138% of systemic stroke volume, consistent with rPBV and absolute PBV values obtained in prior studies.
CONCLUSIONS
Acquisition of PTT and rPBV using contrast echocardiography after exercise is achievable and the results are physiologically plausible. As the next step towards clinical implementation, validation of this technique against hemodynamic exercise studies appears reasonable.
Topics: Humans; Female; Adult; Middle Aged; Blood Volume; Pulmonary Circulation; Echocardiography; Pulmonary Wedge Pressure; Heart
PubMed: 35829996
DOI: 10.1007/s12574-022-00582-9 -
Journal of Cardiovascular Magnetic... Nov 2019Body position can be optimized for pulmonary ventilation/perfusion matching during surgery and intensive care. However, positional effects upon distribution of pulmonary... (Comparative Study)
Comparative Study
BACKGROUND
Body position can be optimized for pulmonary ventilation/perfusion matching during surgery and intensive care. However, positional effects upon distribution of pulmonary blood flow and vascular distensibility measured as the pulmonary blood volume variation have not been quantitatively characterized. In order to explore the potential clinical utility of body position as a modulator of pulmonary hemodynamics, we aimed to characterize gravitational effects upon distribution of pulmonary blood flow, pulmonary vascular distension, and pulmonary vascular distensibility.
METHODS
Healthy subjects (n = 10) underwent phase contrast cardiovascular magnetic resonance (CMR) pulmonary artery and vein flow measurements in the supine, prone, and right/left lateral decubitus positions. For each lung, blood volume variation was calculated by subtracting venous from arterial flow per time frame.
RESULTS
Body position did not change cardiac output (p = 0.84). There was no difference in blood flow between the superior and inferior pulmonary veins in the supine (p = 0.92) or prone body positions (p = 0.43). Compared to supine, pulmonary blood flow increased to the dependent lung in the lateral positions (16-33%, p = 0.002 for both). Venous but not arterial cross-sectional vessel area increased in both lungs when dependent compared to when non-dependent in the lateral positions (22-27%, p ≤ 0.01 for both). In contrast, compared to supine, distensibility increased in the non-dependent lung in the lateral positions (68-113%, p = 0.002 for both).
CONCLUSIONS
CMR demonstrates that in the lateral position, there is a shift in blood flow distribution, and venous but not arterial blood volume, from the non-dependent to the dependent lung. The non-dependent lung has a sizable pulmonary vascular distensibility reserve, possibly related to left atrial pressure. These results support the physiological basis for positioning patients with unilateral pulmonary pathology with the "good lung down" in the context of intensive care. Future studies are warranted to evaluate the diagnostic potential of these physiological insights into pulmonary hemodynamics, particularly in the context of non-invasively characterizing pulmonary hypertension.
Topics: Adult; Female; Gravitation; Healthy Volunteers; Hemodynamics; Humans; Magnetic Resonance Angiography; Magnetic Resonance Imaging, Cine; Male; Patient Positioning; Prone Position; Prospective Studies; Pulmonary Artery; Pulmonary Circulation; Pulmonary Veins; Supine Position; Young Adult
PubMed: 31707989
DOI: 10.1186/s12968-019-0577-9 -
Heart Failure Clinics Jan 2023Main pulmonary vascular diseases (PVD) with precapillary pulmonary hypertension (PH) are pulmonary arterial and chronic thromboembolic PH. Guidelines recommend... (Meta-Analysis)
Meta-Analysis Review
Main pulmonary vascular diseases (PVD) with precapillary pulmonary hypertension (PH) are pulmonary arterial and chronic thromboembolic PH. Guidelines recommend supplemental oxygen therapy (SOT) for severely hypoxemic patients with PH, but evidence is scarce. The authors performed a systematic review and where possible meta-analyses on the effects of SOT on hemodynamics and exercise performance in patients with PVD. In PVD, short-term SOT significantly improved mean pulmonary artery pressure and exercise performance. There is growing evidence on the benefit of long-term SOT for selected patients with PVD regarding exercise capacity and maybe even survival.
Topics: Humans; Pulmonary Circulation; Vascular Diseases; Hypertension, Pulmonary; Pulmonary Artery; Hemodynamics; Oxygen
PubMed: 36922056
DOI: 10.1016/j.hfc.2022.11.001 -
Cardiology in the Young Nov 2023The objective was to study the ductus arteriosus morphology in duct-dependent pulmonary circulation and its pattern in different ventricle morphology using CT...
BACKGROUND
The objective was to study the ductus arteriosus morphology in duct-dependent pulmonary circulation and its pattern in different ventricle morphology using CT angiography.
METHOD
From January 2013 to December 2015, patients aged 6 months and below with duct-dependent pulmonary circulation underwent CT angiography to delineate the ductus arteriosus origin, tortuosity, site of insertion, and pulmonary artery anatomy. The ductus arteriosus were classified into type I, IIa, IIb, and III based on its site of origin, either from descending aorta, distal arch, proximal arch, or subclavian artery, respectively.
RESULTS
A total of 114 patients and 116 ductus arteriosus (two had bilateral ductus arteriosus) were analysed. Type I, IIa, IIb, and III ductus arteriosus were seen in 13 (11.2 %), 71 (61.2%), 21 (18.1%), and 11 (9.5%), respectively. Tortuous ductus arteriosus was found in 38 (32.7%), which was commonly seen in single ventricular lesions. Ipsilateral and bilateral branch pulmonary artery stenosis was seen in 68 (59.6%) and 6 (5.3%) patients, respectively. The majority of patients with pulmonary atresia intact ventricular septum had type I (54.4%) and non-tortuous ductus arteriosus, while those with single and biventricular lesions had type II ductus arteriosus (84.9% and 89.7%, respectively). Type III ductus arteriosus was more common in biventricular lesions (77.8%).
CONCLUSIONS
Ductus arteriosus in duct-dependent pulmonary circulation has a diverse morphology with a distinct origin and tortuosity pattern in different types of ventricular morphology. CT may serve as an important tool in case selection and pre-procedural planning for ductal stenting.
Topics: Humans; Ductus Arteriosus; Pulmonary Circulation; Ductus Arteriosus, Patent; Pulmonary Atresia; Stents; Computed Tomography Angiography
PubMed: 36651340
DOI: 10.1017/S1047951122004218