scholarly journals Non-invasive Assessment of Pulmonary Artery Wave Reflection in Dogs With Suspected Pulmonary Hypertension

2021 ◽  
Vol 8 ◽  
Author(s):  
Tomohiko Yoshida ◽  
Katsuhiro Matsuura ◽  
Goya Seijirow ◽  
Akiko Uemura ◽  
Zeki Yilmaz ◽  
...  

Background: Pulmonary arterial wave reflection (PAWR) occurs when the forward blood flow out the right ventricle is reflected by the pulmonary arterial tree, generating a backward wave. PAWR assessed by cardiac catheterization has been used to obtain information regarding pulmonary artery hemodynamics in pulmonary hypertension (PH) in people. However, diagnostic cardiac catheterization is not commonly used in small animal medicine because it is invasive and requires anesthesia.Hypothesis/Objective: To investigate whether PAWR can be assessed non-invasively in dogs with suspected PH using Doppler echocardiography, based on wave intensity analysis (WIA). In addition, the method was validated in a dog model of acute pulmonary embolism.Animals: Fifty-one client-owned dogs with tricuspid valve regurgitation were included in the clinical study (35 with suspected PH and 16 without echocardiographic evidence of PH) and eight healthy beagle dogs were included in the validation study.Methods: PAWR was assessed by separating pulmonary artery pulse pressure waveforms, which were estimated from the flow profile of tricuspid regurgitation, into forward (Pf) and backward pressures (Pb) using WIA. Reflection coefficient (RC) was defined as the ratio of peak Pb to peak Pf. We investigated the relationships between RC, cause, and survival time in dogs with suspected PH. In addition, we performed a validation study to compare PAWR obtained by cardiac catheterization and PAWR by Doppler echocardiography in dogs with experimentally-induced PH.Results: RC was significantly higher in dogs with suspected PH than in dogs without echocardiographic evidence of PH (0.18 ± 0.13 vs. 0.59 ± 0.21, P < 0.001). A characteristic reflected waveform appeared depending on the cause of PH. Kaplan-Meier survival curves showed that dogs with RC > 0.48 had a significantly shorter survival time than dogs with RC <0.48 (x2 = 9.8, log-rank test, p = 0.0018, median survival time 353 days vs. 110 days). In the validation study, RC obtained by Doppler echocardiography was significantly correlated with RC obtained by cardiac catheterization (r = 0.81, P < 0.001).Conclusions: PAWR analysis performed by echocardiography seems feasible in dogs and could provide useful information for classification and prognosis in canine PH.

2019 ◽  
Vol 317 (3) ◽  
pp. H505-H516 ◽  
Author(s):  
Junjing Su ◽  
Alun D. Hughes ◽  
Ulf Simonsen ◽  
Jens Erik Nielsen-Kudsk ◽  
Kim H. Parker ◽  
...  

High wave speed and large wave reflection in the pulmonary artery have previously been reported in patients with chronic thromboembolic pulmonary hypertension (CTEPH). We assessed the impact of pulmonary endarterectomy (PEA) on pulmonary arterial wave propagation and reservoir function in patients with CTEPH. Right heart catheterization was performed using a combined pressure and Doppler flow sensor-tipped guidewire to obtain simultaneous pressure and flow velocity measurements in the pulmonary artery in eight patients with CTEPH before and 3 mo after PEA. Wave intensity and reservoir-excess pressure analyses were then performed. Following PEA, mean pulmonary arterial pressure (PAPm; ∼49 vs. ∼32 mmHg), pulmonary vascular resistance (PVR; ∼11.1 vs. ∼5.1 Wood units), and wave speed (∼16.5 vs. ∼8.1 m/s), i.e., local arterial stiffness, markedly decreased. The changes in the intensity of the reflected arterial wave and wave reflection index (pre: ∼28%; post: ∼22%) were small, and patients post-PEA with and without residual pulmonary hypertension (i.e., PAPm ≥ 25 mmHg) had similar wave reflection index (∼20 vs. ∼23%). The reservoir and excess pressure decreased post-PEA, and the changes were associated with improved right ventricular afterload, function, and size. In conclusion, although PVR and arterial stiffness decreased substantially following PEA, large wave reflection persisted, even in patients without residual pulmonary hypertension, indicating lack of improvement in vascular impedance mismatch. This may continue to affect the optimal ventriculoarterial interaction, and further studies are warranted to determine whether this contributes to persistent symptoms in some patients. NEW & NOTEWORTHY We performed wave intensity analysis in the pulmonary artery in patients with chronic thromboembolic pulmonary hypertension before and 3 mo after pulmonary endarterectomy. Despite substantial reduction in pulmonary arterial pressures, vascular resistance, and arterial stiffness, large pulmonary arterial wave reflection persisted 3 mo postsurgery, even in patients without residual pulmonary hypertension, suggestive of lack of improvement in vascular impedance mismatch.


2013 ◽  
Vol 305 (2) ◽  
pp. H259-H264 ◽  
Author(s):  
Robert V. MacKenzie Ross ◽  
Mark R. Toshner ◽  
Elaine Soon ◽  
Robert Naeije ◽  
Joanna Pepke-Zaba

This study analyzed the relationship between pulmonary vascular resistance (PVR) and pulmonary arterial compliance ( Ca) in patients with idiopathic pulmonary arterial hypertension (IPAH) and proximal chronic thromboembolic pulmonary hypertension (CTEPH). It has recently been shown that the time constant of the pulmonary circulation (RC time constant), or PVR × Ca, remains unaltered in various forms and severities of pulmonary hypertension, with the exception of left heart failure. We reasoned that increased wave reflection in proximal CTEPH would be another cause of the decreased RC time constant. We conducted a retrospective analysis of invasive pulmonary hemodynamic measurements in IPAH ( n = 78), proximal CTEPH ( n = 91) before (pre) and after (post) pulmonary endarterectomy (PEA), and distal CTEPH ( n = 53). Proximal CTEPH was defined by a postoperative mean pulmonary artery pressure (PAP) of ≤25 mmHg. Outcome measures were the RC time constant, PVR, Ca, and relationship between systolic and mean PAPs. The RC time constant for pre-PEA CTEPH was 0.49 ± 0.11 s compared with post-PEA-CTEPH (0.37 ± 0.11 s, P < 0.0001), IPAH (0.63 ± 0.14 s, P < 0.001), and distal CTEPH (0.55 ± 0.12 s, P < 0.05). A shorter RC time constant was associated with a disproportionate decrease in systolic PAP with respect to mean PAP. We concluded that the pulmonary RC time constant is decreased in proximal CTEPH compared with IPAH, pre- and post-PEA, which may be explained by increased wave reflection but also, importantly, by persistent structural changes after the removal of proximal obstructions. A reduced RC time constant in CTEPH is in accord with a wider pulse pressure and hence greater right ventricular work for a given mean PAP.


2000 ◽  
Vol 279 (4) ◽  
pp. H2013-H2016 ◽  
Author(s):  
Yves Allemann ◽  
Claudio Sartori ◽  
Mattia Lepori ◽  
Sébastien Pierre ◽  
Christian Mélot ◽  
...  

Exaggerated hypoxia-induced pulmonary hypertension is a hallmark of high-altitude pulmonary edema (HAPE) and plays a major role in its pathogenesis. Many studies of HAPE have estimated systolic pulmonary arterial pressure (SPAP) with Doppler echocardiography. Whereas at low altitude, Doppler echocardiographic estimation of SPAP correlates closely with its invasive measurement, no such evidence exists for estimations obtained at high altitude, where alterations of blood viscosity may invalidate the simplified Bernoulli equation. We measured SPAP by Doppler echocardiography and invasively in 14 mountaineers prone to HAPE and in 14 mountaineers resistant to this condition at 4,559 m. Mountaineers prone to HAPE had more pronounced pulmonary hypertension (57 ± 12 and 58 ± 10 mmHg for noninvasive and invasive determination, respectively; means ± SD) than subjects resistant to HAPE (37 ± 8 and 37 ± 6 mmHg, respectively), and the values measured in the two groups as a whole covered a wide range of pulmonary arterial pressures (30–83 mmHg). Spearman test showed a highly significant correlation ( r = 0.89, P < 0.0001) between estimated and invasively measured SPAP values. The mean difference between invasively measured and Doppler-estimated SPAP was 0.5 ± 8 mmHg. At high altitude, estimation of SPAP by Doppler echocardiography is an accurate and reproducible method that correlates closely with its invasive measurement.


2021 ◽  
Author(s):  
Siriwan Sakarin ◽  
Anudep Rungsipipat ◽  
Sirilak Disatian Surachetpong

Abstract Background: Degenerative mitral valve disease (DMVD) is the most common cause of pulmonary hypertension (PH) in dogs. Medial thickening of the pulmonary artery is a major histopathological change in PH. A decrease in apoptosis of pulmonary arterial smooth muscle cells (SMCs) may be the cause of medial thickening. This study aimed to demonstrate the expression of apoptosis molecules in the pulmonary artery of dogs affected with PH secondary to DMVD (DMVD+PH) compared to DMVD without PH (DMVD) and healthy dogs (control). Lung samples were collected from three groups including control (n=5), DMVD (n=7) and DMVD+PH (n=7) groups. Masson trichrome and apoptotic proteins including Bax, Bcl2 and caspase-3 and -8, were stained. Results: The medial thickness in the DMVD and DMVD+PH groups was greater than in the control group and it was greatest in the DMVD+PH group. Bax, Bcl2 and caspase-3 and -8 were expressed mainly in the medial layer of the pulmonary artery. The percentages of Bax and caspase-3 and -8 positive cells were higher in the DMVD group compared to the DMVD+PH group, whereas the percentage of Bcl2-positive cells was increased in the DMVD and DMVD+PH groups. These findings suggested that apoptosis of pulmonary arterial SMCs occurred mainly in the DMVD group and decreased dramatically in the DMVD+PH group. Conclusions: An increase in the medial thickness in dogs affected with PH secondary to DMVD may occur due to a decrease in apoptosis of pulmonary arterial SMCs.


2013 ◽  
Vol 304 (12) ◽  
pp. L894-L901 ◽  
Author(s):  
Cassidy Delaney ◽  
Jason Gien ◽  
Gates Roe ◽  
Nicole Isenberg ◽  
Jenai Kailey ◽  
...  

Although past studies demonstrate that altered serotonin (5-HT) signaling is present in adults with idiopathic pulmonary arterial hypertension, whether serotonin contributes to the pathogenesis of persistent pulmonary hypertension of the newborn (PPHN) is unknown. We hypothesized that 5-HT contributes to increased pulmonary vascular resistance (PVR) in a sheep model of PPHN and that selective 5-HT reuptake inhibitor (SSRI) treatment increases PVR in this model. We studied the hemodynamic effects of 5-HT, ketanserin (5-HT2A receptor antagonist), and sertraline, an SSRI, on pulmonary hemodynamics of the late gestation fetal sheep with PPHN caused by prolonged constriction of the ductus arteriosis. Brief intrapulmonary infusions of 5-HT increased PVR from 1.0 ± 0.07 (baseline) to 1.4 ± 0.22 mmHg/ml per minute of treatment ( P < 0.05). Ketanserin decreased PVR from 1.1 ± 0.15 (baseline) to 0.82 ± 0.09 mmHg/ml per minute of treatment ( P < 0.05). Sertraline increased PVR from 1.1 ± 0.17 (baseline) to 1.4 ± 0.17 mmHg/ml per minute of treatment ( P = 0.01). In addition, we studied 5-HT production and activity in vitro in experimental PPHN. Compared with controls, pulmonary artery endothelial cells from fetal sheep with PPHN exhibited increased expression of tryptophan hydroxylase 1 and 5-HT production by twofold and 56%, respectively. Compared with controls, 5-HT2A R expression was increased in lung homogenates and pulmonary artery smooth muscle cell lysates by 35% and 32%, respectively. We concluded that increased 5-HT contributes to high PVR in experimental PPHN through activation of the 5-HT2A receptor and that SSRI infusion further increases PVR in this model.


Metabolites ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 87 ◽  
Author(s):  
Abdulwahab Alamri ◽  
Abdulhadi Burzangi ◽  
Paul Coats ◽  
David Watson

Pulmonary arterial hypertension (PAH) is a multi-factorial disease characterized by the hyperproliferation of pulmonary artery smooth muscle cells (PASMCs). Excessive reactive oxygen species (ROS) formation resulted in alterations of the structure and function of pulmonary arterial walls, leading to right ventricular failure and death. Diabetes mellitus has not yet been implicated in pulmonary hypertension. However, recently, variable studies have shown that diabetes is correlated with pulmonary hypertension pathobiology, which could participate in the modification of pulmonary artery muscles. The metabolomic changes in PASMCs were studied in response to 25 mM of D-glucose (high glucose, or HG) in order to establish a diabetic-like condition in an in vitro setting, and compared to five mM of D-glucose (normal glucose, or LG). The effect of co-culturing these cells with an ideal blood serum concentration of cholecalciferol-D3 and tocopherol was also examined. The current study aimed to examine the role of hyperglycemia in pulmonary arterial hypertension by the quantification and detection of the metabolomic alteration of smooth muscle cells in high-glucose conditions. Untargeted metabolomics was carried out using hydrophilic interaction liquid chromatography and high-resolution mass spectrometry. Cell proliferation was assessed by cell viability and the [3H] thymidine incorporation assay, and the redox state within the cells was examined by measuring reactive oxygen species (ROS) generation. The results demonstrated that PASMCs in high glucose (HG) grew, proliferated faster, and generated higher levels of superoxide anion (O2·−) and hydrogen peroxide (H2O2). The metabolomics of cells cultured in HG showed that the carbohydrate pathway, especially that of the upper glycolytic pathway metabolites, was influenced by the activation of the oxidation pathway: the pentose phosphate pathway (PPP). The amount of amino acids such as aspartate and glutathione reduced via HG, while glutathione disulfide, N6-Acetyl-L-lysine, glutamate, and 5-aminopentanoate increased. Lipids either as fatty acids or glycerophospholipids were downregulated in most of the metabolites, with the exception of docosatetraenoic acid and PG (16:0/16:1(9Z)). Purine and pyrimidine were influenced by hyperglycaemia following PPP oxidation. The results in addition showed that cells exposed to 25 mM of glucose were oxidatively stressed comparing to those cultured in five mM of glucose. Cholecalciferol (D3, or vitamin D) and tocopherol (vitamin E) were shown to restore the redox status of many metabolic pathways.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
L Gargani ◽  
V Codullo ◽  
P Argiento ◽  
A Moreo ◽  
F Pieri ◽  
...  

Abstract Background Patients with systemic sclerosis (SSc) are at risk of developing pulmonary arterial hypertension (PAH), which is often diagnosed late when the benefits of vasoactive therapies are limited. The concept of exercise pulmonary hypertension as a possible transitional phase anticipating resting PAH has been assessed in several pathologies, but has not been endorsed by the latest European Guidelines, because not supported by sufficient data. Purpose To evaluate whether PASP values at rest and at peak exercise, estimated at echocardiography, could be predictors of further development of PAH. Methods Four hundred and twenty-nine SSc patients without a previous diagnosis of PAH, enrolled at 4 referral Centres, underwent standard exercise Doppler echocardiography with PASP estimation at rest and at peak stress. Patients were then followed-up to assess the development of PAH, as diagnosed by a complete diagnostic work-up including right heart catheterization. PAH was defined by pre-capillary pulmonary hypertension (mean pulmonary artery pressure ≥25 mmHg with pulmonary arterial wedge pressure ≤15 mmHg), without significant interstitial lung disease and/or left heart disease. Results During the median follow-up of 75 months (IQR 29–114), 16 patients developed PAH. A combined cut-off of ≥24 mmHg as resting PASP and ≥40 as peak PASP was identified as the best predictor of further development of PAH (see Figure). Both resting PASP and peak PASP were predictors of PAH at univariate analysis (resting PASP OR 1.13, 95% C.I. 1.07–1.19, p<0.0001; peak PASP OR 1.13, 95% C.I. 1.07–1.18, p<0.0001). At multivariate analysis, only peak PASP was independently associated to PAH development (OR 1.13, 95% C.I. 1.04–1.18, p<0.001). Only one patient among those with resting PASP <24 mmHg and peak PASP <40 mmHg (34.7% of the total population) developed PAH during the follow-up (after 10 years from normal exercise Doppler echocardiography). Kaplan-Meier curves Conclusions Exercise increase in PASP is an independent predictor of later development of PAH in SSc. An increase in exercise PASP is frequent and is not necessarily associated with a later development of PAH, whereas the very high negative predictive value of a normal PASP both at rest and at peak exercise can be used in the clinical practice to confidently rule out about one third of patients. Acknowledgement/Funding Italian Ministry of Health (Ricerca Finalizzata 2011-2012)


Author(s):  
George K Istaphanous ◽  
Andreas W Loepke

Pediatric pulmonary arterial hypertension (PAH) is characterized by a pathologically elevated pulmonary artery pressure in children. The etiology of PAH is multifactorial, and while its prognosis is closely related to the reversibility of the underlying disease process, much progress has recently been made in its diagnosis and treatment, significantly decreasing the associated morbidity and mortality.


1963 ◽  
Vol 204 (4) ◽  
pp. 619-625 ◽  
Author(s):  
John W. Hyland ◽  
George T. Smith ◽  
Lockhart B. McGuire ◽  
Donald C. Harrison ◽  
Florence W. Haynes ◽  
...  

Pulmonary embolism was produced in 30 closed-chest 8-kg dogs with polystyrene spheres, glass beads, or blood clots of precise graded size. The sizes matched selectively the internal diameter of pulmonary arteries from lobar branches (5–6 mm) down to atrial arteries (0.17 mm). Emboli were injected into the right atrium until the pressure in the pulmonary artery rose 5–10 mm Hg. The number of emboli of a given size required to produce this incipient pulmonary hypertension was compared with the number of vessels of that same size as determined from the literature as well as by postmortem injection with Schlesinger mass. The number of emboli bore a constant relation to the number of vessels of that same size. With each size, the majority of vessels had to be occluded before pulmonary hypertension appeared. This was true even in the absence of anesthesia. The results support the thesis that mechanical blockade rather than vasoconstriction is the mechanism by which pulmonary hypertension is produced by emboli occluding pulmonary arterial (as opposed to arteriolar) vessels.


Sign in / Sign up

Export Citation Format

Share Document