scholarly journals Foramen ovale blood flow and cardiac function after main pulmonary artery occlusion in fetal sheep

2019 ◽  
Vol 104 (2) ◽  
pp. 189-198 ◽  
Author(s):  
Juulia Lantto ◽  
Tiina Erkinaro ◽  
Mervi Haapsamo ◽  
Heikki Huhta ◽  
Hanna-Marja Voipio ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Artery ◽  
Cardiac Function ◽  
Main Pulmonary Artery ◽  
Artery Occlusion ◽  
Foramen Ovale ◽  
Fetal Sheep

Endothelin-1 vasoactive responses in lambs with pulmonary hypertension and increased pulmonary blood flow

1995 ◽  
Vol 269 (6) ◽  
pp. H1965-H1972 ◽  
Author(s):  
J. Wong ◽  
V. M. Reddy ◽  
K. Hendricks-Munoz ◽  
J. R. Liddicoat ◽  
R. Gerrets ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Hypertension ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Pulmonary Blood Flow ◽  
Heart Diseases ◽  
Main Pulmonary Artery ◽  
Similar Degree ◽  
Fetal Sheep ◽  
Endothelin 1

Increased concentrations of endothelin-1 (ET-1) are found in children with congenital heart diseases that produce increased pulmonary blood flow and pulmonary hypertension, but the role of ET-1 in the pathophysiology of pulmonary hypertension is unclear. Therefore, we investigated ET-1-induced vasoactive responses and ET-1 concentrations in an animal model of pulmonary hypertension and increased pulmonary blood flow. Vascular shunts were placed between the ascending aorta and main pulmonary artery in seven late-gestation fetal sheep. Four weeks after spontaneous delivery, ET-1 increased pulmonary vascular resistance by 29.7 +/- 34.4% (P < 0.05), the ETb-receptor agonist [Ala1,3,11,15]ET-1 (4AlaET-1) had no effect, and the ETa-receptor antagonist cyclo(D-Asp-L-Pro-D-Val-L-Leu-D-Trp) (BQ-123) decreased pulmonary vascular resistance by -16.0 +/- 5.6% (P < 0.05). In contrast, in six control lambs with a similar degree of pulmonary hypertension induced by U-46619, ET-1 and 4AlaET-1 decreased pulmonary vascular resistance by 24.8 +/- 17.6, and 20.0 +/- 13.8%, respectively (P < 0.05). In addition, systemic arterial concentrations of immunoreactive ET-1 were elevated in lambs with pulmonary hypertension (29.2 +/- 9.6 vs. 15.2 +/- 10.7 pg/ml, P < 0.05). Pulmonary hypertension and increased pulmonary blood flow alters the response of ET-1 from pulmonary vasodilation to vasoconstriction. These altered responses suggest a role for ET-1 and its receptors in the pathogenesis of pulmonary hypertension secondary to increased pulmonary blood flow.

A Computational Pulsatile Model of the Bidirectional Cavopulmonary Anastomosis: The Influence of Pulmonary Forward Flow

1996 ◽  
Vol 118 (4) ◽  
pp. 520-528 ◽  
Author(s):  
Francesco Migliavacca ◽  
Marc R. de Leval ◽  
Gabriele Dubini ◽  
Riccardo Pietrabissa
Keyword(s):  
Blood Flow ◽  
Pulmonary Artery ◽  
Superior Vena Cava ◽  
Superior Vena ◽  
Main Pulmonary Artery ◽  
Vena Cava ◽  
Similar Distribution ◽  
Pulsatile Blood Flow ◽  
Cavopulmonary Anastomosis ◽  
Bidirectional Cavopulmonary Anastomosis

The bidirectional cavopulmonary anastomosis (BCPA or bidirectional Glenn) is an operation to treat congenital heart diseases of the right heart by diverting the systemic venous return from the superior vena cava to both lungs. The main goal is to provide the correct perfusion to both lungs avoiding an excessive increase in systemic venous pressure. One of the factors which can affect the clinical outcome of the surgically reconstructed circulation is the amount of pulsatile blood flow coming from the main pulmonary artery. The purpose of this work is to analyse the influence of this factor on the BCPA hemodynamics. A 3-D finite element model of the BCPA has been developed to reproduce the flow of the surgically reconstructed district. Geometry and hemodynamic data have been taken from angiocardiogram and catheterization reports, respectively. On the basis of the developed 3-D model, four simulations have been performed with increasing pulsatile blood flow rate from the main pulmonary artery. The results show that hemodynamics in the pulmonary arteries are greatly influenced by the amount of flow through the native main pulmonary artery and that the flow from the superior vena cava allows to have a similar distribution of the blood to both lungs, with a little predilection for the left side, in agreement with clinical postoperative data.

Altered endothelium-dependent responses in lambs with pulmonary hypertension and increased pulmonary blood flow

1996 ◽  
Vol 271 (2) ◽  
pp. H562-H570 ◽  
Author(s):  
V. M. Reddy ◽  
J. Wong ◽  
J. R. Liddicoat ◽  
M. Johengen ◽  
R. Chang ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Hypertension ◽  
Endothelial Function ◽  
Pulmonary Blood Flow ◽  
Main Pulmonary Artery ◽  
Plasma Concentrations ◽  
Phosphodiesterase Inhibitor ◽  
No Synthase ◽  
Late Gestation ◽  
Fetal Sheep

To investigate early endothelial function associated with increased pulmonary blood flow, vascular shunts were placed between the ascending aorta and main pulmonary artery in 18 late-gestation fetal sheep. Four weeks after delivery, the lambs were instrumented to measure vascular pressures and blood flows, and blood was collected to measure plasma concentrations of guanosine 3',5'-cyclic monophosphate [cGMP, the second messenger to nitric oxide (NO)-mediated vasodilation] and L-arginine (the precursor for NO synthesis). The responses to the endothelium-dependent vasodilators acetylcholine (ACh, 1.0 microgram/kg) and ATP (0.1 mg.kg-1.min-1), the endothelium-independent vasodilators M & B-22948 (a cGMP-specific phosphodiesterase inhibitor, 2.5 mg/kg) and inhaled NO (40 ppm), and N omega-nitro-L-arginine (an inhibitor of NO synthase, 5 mg/kg) were then compared with responses in 12 age-matched controls. Vasodilator responses in control lambs were determined during pulmonary hypertension induced by U-46619 (a thromboxane A2 mimic). Shunted lambs displayed a selective impairment of endothelium-dependent pulmonary vasodilation, an augmented pulmonary vasoconstricting response to NO synthase inhibition, increased plasma cGMP concentrations, and decreased L-arginine concentrations. Taken together, these data suggest that lambs with pulmonary hypertension and increased pulmonary blood flow have early aberrations in endothelial function, as manifested by increased basal NO activity, that cannot be further increased by agonist-induced endothelium-dependent vasodilators.

Bronchial circulation in pulmonary artery occlusion and reperfusion

1990 ◽  
Vol 68 (1) ◽  
pp. 125-129 ◽  
Author(s):  
T. F. Kowalski ◽  
S. Guidotti ◽  
M. Deffebach ◽  
P. Kubilis ◽  
M. Bishop
Keyword(s):  
Blood Flow ◽  
Pulmonary Artery ◽  
Morphological Changes ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Arterial Blood Flow ◽  
Lung Edema ◽  
Base Line ◽  
Bronchial Circulation ◽  
Arterial Blood

Obstruction of pulmonary arterial blood flow results in minimal biochemical and/or morphological changes in the involved lung. If the lung is reperfused, a syndrome of leukopenia and lung edema occurs. We used the radiolabeled microsphere technique to measure the response of the bronchial circulation in rabbits to acute pulmonary artery occlusion (PAO) and to pulmonary artery reperfusion. We found that the bronchial blood flow (Qbr) decreased from a base line of 0.37 +/- 0.10 to 0.09 +/- 0.04 (SE) ml.min-1.g dry lung-1 (P less than or equal to 0.05) after 4 h of PAO. In a separate group of animals, Qbr 24 h after PAO remained low (0.20 +/- 0.07 ml.min-1.g dry lung-1, P = 0.06). Qbr during PAO was inversely correlated with the wet-to-dry ratio after reperfusion (r = -0.68, P = 0.06). Qbr did not change during 4 h of reperfusion. We speculate that a critical level of Qbr may be necessary during PAO to prevent ischemia/reperfusion injury from occurring.

Understanding the Hybrid Stage I Approach for Hypoplastic Left Heart Syndrome

2016 ◽  
Vol 36 (5) ◽  
pp. 48-55
Author(s):  
Sharon L. Cheatham ◽  
Grace M. Deyo
Keyword(s):  
Blood Flow ◽  
Pulmonary Artery ◽  
Hypoplastic Left Heart Syndrome ◽  
Main Pulmonary Artery ◽  
Median Sternotomy ◽  
Stage I ◽  
Left Heart ◽  
Hypoplastic Left Heart ◽  
Cavopulmonary Anastomosis ◽  
Left Heart Syndrome

Hybrid stage I palliation combines cardiothoracic surgery and interventional transcatheter procedures for treatment of hypoplastic left heart syndrome. The approach is an alternative to the Norwood procedure, the traditional first stage of surgical palliation. Hybrid stage I palliation involves placing bilateral branch pulmonary artery bands and a patent ductus arteriosus stent through a median sternotomy, performed without cardiopulmonary bypass. The purpose of the bands is to control blood flow to the lungs and protect the pulmonary bed while the stent sustains systemic cardiac output. A balloon atrial septostomy is performed to create an atrial septal defect for unobstructed blood flow from the left atrium to the right atrium. The second stage of palliative surgery is the comprehensive stage II, which incorporates removal of the stent and pulmonary artery bands, atrial septectomy, anastomosis of the diminutive ascending aorta to the main pulmonary artery, aortic arch augmentation, and bidirectional cavopulmonary anastomosis. The traditional Fontan procedure completes the series of palliation.

Results of Additional Pulsatile Pulmonary Blood Flow with Bidirectional Glenn Cavopulmonary Anastomosis: Positive Effect on Main Pulmonary Artery Growth and Less Need for Fontan Conversion

2013 ◽  
Vol 16 (1) ◽  
pp. 30 ◽  
Author(s):  
Orhan Saim Demirtürk ◽  
Murat Güvener ◽  
İsa Coşkun ◽  
Selman Vefa Yıldırım
Keyword(s):  
Blood Flow ◽  
Pulmonary Artery ◽  
Oxygen Pressure ◽  
Pulmonary Blood Flow ◽  
Main Pulmonary Artery ◽  
Bidirectional Glenn ◽  
Cavopulmonary Anastomosis ◽  
Cavopulmonary Shunt ◽  
Partial Oxygen

<strong>Background</strong>: Additional antegrade pulsatile pulmonary blood flow obtained by leaving the main pulmonary artery patent during bidirectional cavopulmonary shunt has been shown to give additional benefits to the bidirectional Glenn cavopulmonary anastomosis. We retrospectively evaluated our 20-patient pulsatile Glenn series in order to find out whether these salutary effects were valid or not.<br /><strong>Methods</strong>: Between June 2007 and November 2011, 20 patients (11 girls and 9 boys) with single-ventricle physiology underwent bidirectional cavopulmonary anastomosis. The additional source of blood flow was through the unligated main pulmonary artery in all patients. A retrospective review of our surgical experience was performed focusing on the role of additional pulmonary flow. Medical records and perioperational and postoperative follow-up data including clinical outcomes were retrospectively retrieved and analyzed.<br /><strong>Results</strong>: Two patients died in the early postoperative period. One patient died in the follow-up period. Mean follow-up time was 23.9 ± 15.7 months. No superior vena cava syndrome and no increase in pulmonary vascular resistance were observed. Improvement of partial oxygen pressure after pulsatile Glenn has been shown in all patients (P = .00). At a mean interval of 22.9 months, main pulmonary artery size continued to increase after pulsatile Glenn cavopulmonary anastomosis (P = .028). Only 1 patient was converted to Fontan type circulation after pulsatile Glenn cavopulmonary anastomosis.<br /><strong>Conclusions</strong>: The pulsatile cavopulmonary shunt is a useful procedure in the early and intermediate term management of patients with a functional univentricular heart. It improves partial oxygen pressure and the impact of pulsatility on the main pulmonary artery.

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