Phasic reflux of pulmonary blood flow in atelectasis: influence of systemic PO2

1976 ◽  
Vol 40 (6) ◽  
pp. 883-888 ◽  
Author(s):  
J. C. Newell ◽  
M. G. Levitzky ◽  
J. A. Krasney ◽  
R. E. Dutton

In 16 dogs ventilated with 100% O2, control blood flow to the left lung was 35 +/- 2% of aortic flow. When left lung atelectasis was induced, left pulmonary artery flow fell to 19 +/- 2% of aortic flow. A large retrograde component of flow developed in this pulmonary artery, suggesting that blood flows into the pulmonary arteries of both lungs during systole, but flows back out of the collapsed lung and into the uncollapsed lung during diastole. Systemic PaO2 remained above 78 mmHg. Subsequently, when the ventilation of the right lung was changed from oxygen to room air, systemic PaO2 fell to 64 +/- 3 mmHg and atelectatic left lung flow rose from 19 +/- 2% to 28 +/- 2% f aortic flow. This was associated with a reduction in reflux from the atelectatic lung. These results suggest that the attenuation of flow to an atelectatic lung is more pronounced if systemic normoxemia is maintained by adequate oxygenation of the normal lung.

1995 ◽  
Vol 117 (2) ◽  
pp. 237-241
Author(s):  
H. Katayama ◽  
G. W. Henry ◽  
C. L. Lucas ◽  
B. Ha ◽  
J. I. Ferreiro ◽  
...  

We studied the detailed profiles of blood flow in the right and left pulmonary arteries using 20 MHz pulsed Doppler ultrasound equipment in a lamb model. Fourteen lambs aged four to six weeks were selected. In six lambs, monocrotaline pyrrole was injected parenterally to create pulmonary hypertension (PH group). Eight other lambs served as unaltered controls (control group). The blood flow velocities were sampled in 1mm increments along the anterior—posterior axis of the branch arteries. The maximum velocity of the forward flow in the left pulmonary artery was higher than that in the right pulmonary artery in the control group (71.7 ± 15.9cm/s vs 60.2 ± 13.5; p < 0.05). The fastest backward flow was located at the posterior position of the vessel in the right pulmonary artery in the control group. No significant bias in location was shown in the left pulmonary artery. Using indices of P90, acceleration time, P90*AcT, the velocity waveforms in the PH group were compared with those in the control group. In the left pulmonary artery, every index in the control group showed a significantly greater value that in the PH group. On the other hand, no significant differences were found between either group in the right pulmonary artery.


1995 ◽  
Vol 5 (2) ◽  
pp. 199-201
Author(s):  
Dipak Kholwadwala ◽  
Vincent A. Parnell ◽  
Rubin S. Cooper

while preferential blood flow to the rightpulmonary artery has been described in transposition of the great arteries with or without obstruction of the left ventricular outflow tract, this disparity of pulmonary blood flow is not present in newborns.1We report a newborn with transposition in whom there was discontinuity of the pulmonary arteries and ductal blood supply to the left pulmonary artery. To our knowledge, this entity has not been described in newborns with transposition of the great arteries {S,D,D}.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Atsuko Kato ◽  
Christian Drolet ◽  
Shi-Joon Yoo ◽  
Andrew Redington ◽  
Lars Grosse-Wortmann

Introduction: The left pulmonary artery (LPA) contributes more than the right (RPA) to total pulmonary regurgitation (PR) in patients after tetralogy of Fallot (TOF) repair, but the mechanism of this difference is not well known. We hypothesized that unilaterally increased pulmonary vascular resistance (PVR), resulting from lung compression by the enlarged and levorotated heart leads to greater PR in the LPA. This study aimed to analyze the interplay between heart and lung size, mediastinal geometry, and differential PR. Methods: This is a single-center retrospective analysis of 50 magnetic resonance studies in patients after TOF repair. Patients with more than mild discrete branch pulmonary artery stenosis were excluded. Blood flow was measured by phase-contrast velocity encoding within the branch pulmonary arteries. On the axial image with the largest total cardiac surface area, cardiac angle (α) between the thoracic anterior-posterior line and the interventricular septum, right and left lung areas as well as right and left hemithorax areas were measured (Figure). Results: There was no difference in LPA and RPA diameters. The LPA showed significantly less total forward flow (p=0.04), smaller net forward flow (p=<0.001), and greater RF (p=0.001) than the RPA. Left lung area was smaller than the right (p<0.001). RVEDVi correlated with LPA RF (R=0.48, p<0.001), but not with RPA RF. Larger RVEDVi correlated with a larger α angle (R=0.46, p<0.001), i.e. a more leftward cardiac axis and with smaller left lung area (R=-0.58, p<0.001). LPA RF, but not RPA RF, correlated inversely with left lung area indexed to the left hemithorax area (R=-0.34, p=0.02). Conclusions: An enlarged and levorotated heart - as a result of PR - is associated with smaller left lung size, and augments diastolic flow reversal in the LPA, presumably via increased left PVR. By imposing a further volume load on the RV, LPA regurgitation may thus close a positive feed-back loop of PR and RV dilatation.


1981 ◽  
Vol 50 (1) ◽  
pp. 102-106 ◽  
Author(s):  
P. S. Barie ◽  
T. S. Hakim ◽  
A. B. Malik

We determined the effect of pulmonary hypoperfusion on extravascular water accumulation in anesthetized dogs by occluding the left pulmonary artery for 3 h and then reperfusing it for 24 h. The lung was reperfused either at normal left atrial pressure (Pla) or during increased Pla induced by a left atrial balloon. In each case the extravascular water content-to-bloodless dry weight ratio (W/D) of the left lung was compared with that of the right lung. The W/D of the left lung of 3.26 +/- 0.49 ml/g was not significantly different from the value of 2.87 +/- 0.37 for the right lung after the reperfusion at normal Pla. However, the W/D of the left lung of 5.10 +/- 0.38 ml/g was greater (P less than 0.05) than the value of 4.42 +/- 0.34 for the right lung after reperfusion at Pla of 25 Torr. This difference could not be prevented by pretreatment with heparin, suggesting that the increase in lung water content was not due to activation of intravascular coagulation secondary to stasis occurring during the occlusion. Because the left lung was more edematous than the right one, even though both lungs had been subjected to the same increase in Pla, the results suggest that a period of pulmonary hypoperfusion causes an increase in the interstitial protein concentration.


2007 ◽  
Vol 103 (2) ◽  
pp. 594-599 ◽  
Author(s):  
Jesús Sánchez ◽  
Aigul Moldobaeva ◽  
Jessica McClintock ◽  
John Jenkins ◽  
Elizabeth Wagner

We previously showed increased expression of the ELR+, CXC chemokines in the lung after left pulmonary artery obstruction. These chemokines have been shown in other systems to bind their G protein-coupled receptor, CXCR2, and promote systemic endothelial cell proliferation, migration, and capillary tube formation. In the present study, we blocked CXCR2 in vivo using a neutralizing antibody and also studied mice that were homozygous null for CXCR2. To estimate the extent of neovascularization in this model, we measured systemic blood flow to the left lung 14 days after left pulmonary artery ligation (LPAL). We found blood flow significantly reduced (67% decrease) with neutralizing antibody treatment compared with controls. However, blood flow was not altered in the CXCR2-deficient mice compared with wild-type controls after LPAL. To test for ligand availability, we measured macrophage inflammatory protein (MIP)-2 in lung homogenates after LPAL, because this is the predominant CXC chemokine previously shown to be increased after LPAL ( 22 ). MIP-2 protein was two- to fourfold higher in the left lung relative to the right lung in all treatment groups 4 h after LPAL and this increase did not differ among groups. We speculate that the CXCR2-deficient mice have compensatory mechanisms that mitigate their lack of gene expression and conclude that CXCR2 contributes to chemokine-induced systemic angiogenesis after pulmonary artery obstruction.


2000 ◽  
Vol 10 (4) ◽  
pp. 419-422 ◽  
Author(s):  
Astolfo Serra ◽  
Francisco Chamie ◽  
R.M. Freedom

AbstractMajor abnormalities of pulmonary circulation are uncommon in the patient with pulmonary atresia and intact ventricular septum. Non-confluent pulmonary arteries have only rarely been described in this setting. In this case report, we describe a patient in whom the pulmonary arteries are non-confluent, with the right pulmonary artery supplied through a right-sided arterial duct, and the left pulmonary artery most likely through a fifth aortic arch, thus providing a systemic-to-pulmonary arterial connection. We discuss the various forms of non-confluent pulmonary arteries in the setting of pulmonary atresia and intact ventricular septum.


2020 ◽  
Vol 10 ◽  
pp. 5
Author(s):  
Pierre D. Maldjian ◽  
Kevin R. Adams

We report a case of a partial anomalous left pulmonary artery sling in an adult patient as an incidental finding on computed tomography. There is a normal bifurcation of the pulmonary trunk into right and left pulmonary arteries with anomalous origin of the left upper lobe pulmonary artery from the right pulmonary artery. The anomalous vessel passes between the trachea and esophagus forming a partial left pulmonary artery sling without airway compression.


PEDIATRICS ◽  
1958 ◽  
Vol 22 (1) ◽  
pp. 48-48

The authors report three cases of respiratory embarrassment in infants from compression of the right bronchus and trachea by a "vascular sling" formed by an aberrant left pulmonary artery coursing anterior to the right main-stem bronchus and posterior to the trachea. Five similar cases have been described in earlier literature. The embryologic origin of this anomaly appears to be a disturbed time-sequence in the growth and union of the left pulmonary artery and the left lung bud. The clinical symptoms are those of respiratory distress in the neonatal period produced by tracheobronchial compression, associated with obstructive emphysema of the right lung. Bronchoscopic examination reveals extrinsic pressure on the right bronchus and posterior wall of the trachea. The esophagram does not reveal any posterior indentation and is thereby helpful in distinguishing this entity from the more common "vascular ring" which is a systemic arterial malformation causing constriction of the trachea and esophagus. Early recognition of an anomalous left pulmonary artery is particularly important in view of the fact that the condition can be corrected surgically.


2012 ◽  
Vol 23 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Goran Cuturilo ◽  
Danijela Drakulic ◽  
Aleksandar Krstic ◽  
Marija Gradinac ◽  
Tamara Ilisic ◽  
...  

AbstractMalposition of the branch pulmonary arteries is a rare malformation with two forms. In the typical form, pulmonary arteries cross each other as they proceed to their respective lungs. The “lesser form” is characterised by the left pulmonary artery ostium lying directly superior to the ostium of the right pulmonary artery, without crossing of the branch pulmonary arteries. Malposition of the branch pulmonary arteries is often associated with other congenital heart defects and extracardiac anomalies, as well as with 22q11.2 microdeletion. We report three infants with crossed pulmonary arteries and one adolescent with “lesser form” of the malformation. The results suggest that diagnosis of malposition of the branch pulmonary arteries could be challenging if based solely on echocardiography, whereas modern imaging technologies such as contrast computed tomography and magnetic resonance angiography provide reliable establishment of diagnosis. In addition, we performed the first molecular characterisation of the 22q11.2 region among patients with malposition of the branch pulmonary arteries and revealed a 3-megabase deletion in two out of four patients.


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