Microvascular Pressures in Isolated Perfused Immature Lamb Lungs: Effects of Flow Rate, Left Atrial Pressure and Surfactant Therapy

Neonatology ◽  
1996 ◽  
Vol 70 (6) ◽  
pp. 349-358 ◽  
Author(s):  
M. Matsuda ◽  
J. Anderson-Morris ◽  
Usha Raj
Keyword(s):  
Flow Rate ◽  
Left Atrial ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Surfactant Therapy

Influence of heart rate and left atrial pressure on pulmonary venous flow pattern in dogs

1994 ◽  
Vol 266 (6) ◽  
pp. H2296-H2302 ◽  
Author(s):  
T. Steen ◽  
B. M. Voss ◽  
O. A. Smiseth
Keyword(s):  
Heart Rate ◽  
Flow Pattern ◽  
Flow Rate ◽  
Left Atrial ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Mean Flow ◽  
Venous Flow ◽  
Pulmonary Venous Flow ◽  
The Relationship

In six open-chest anesthetized dogs we investigated the effect of heart rate (HR) on the relationship between left atrial pressure (LAP) and pulmonary venous flow (QPV). QPV was measured by ultrasonic transit time during volume loading and right atrial pacing. Consistent with previous studies, we found a negative correlation between LAP and mean flow rate during atrial systole divided by mean flow rate in the R-R interval. However, this relationship was shifted upward by tachycardia. The QPV maximum amplitude divided by mean flow rate in the R-R interval increased with loading but decreased with tachycardia. mean flow rate during ventricular systole divided by mean flow rate during the R-R interval increased with both loading and tachycardia. Regression coefficients for HR and LAP as predictors of these indexes were all significantly different from zero (P = 0.0001). We conclude that HR significantly influences the relationship between the QPV pattern and LAP. This could be a limitation of the pulmonary venous flow pattern as an indicator of left ventricular diastolic function.

Effect of blood flow rate and blood flow history on newborn pulmonary microcirculation

1991 ◽  
Vol 261 (2) ◽  
pp. H271-H279 ◽  
Author(s):  
C. D. Fike ◽  
M. R. Kaplowitz
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Left Atrial ◽  
Total Pressure ◽  
Pulmonary Blood Flow ◽  
Blood Flow Rate ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Flow Rates ◽  
Pulmonary Arterial

The purpose of this study was to determine whether increased pulmonary blood flow and/or the history of pulmonary blood flow alters microvascular pressures in lungs of newborns. Using the direct micropuncture technique, we measured pressures in 20- to 60-microns-diameter arterioles and venules in isolated lungs of newborn rabbits at consecutive blood flow rates of 50 (baseline), 100, and/or 200 ml.min-1.kg-1. Then in some lungs we returned blood flow rate to baseline and repeated microvascular pressure measurements. We kept left atrial pressure the same at all blood flow rates. When blood flow rate increased and left atrial pressure was maintained constant, pulmonary arterial, 20- to 60-microns-diameter arteriolar, and 20- to 60-microns-diameter venular pressures increased such that the percentage of total pressure drop that occurred across veins increased. When we returned blood flow to baseline, venular pressure returned to baseline, but arteriolar and pulmonary arterial pressures returned to values less than baseline so that the percentage of the total pressure drop that occurred across microvessels decreased. Thus both blood flow rate and blood flow history are important determinants of the longitudinal distribution of pulmonary vascular pressures across newborn lungs. These findings also suggest that in newborn lungs venules greater than 60 microns diameter are poorly distensible such that higher blood flow rates result in increased microvascular pressures. Hence, under conditions of increased pulmonary blood flow, such as occurs with left to right shunts, the tendency for edema formation will increase in newborn lungs even if left atrial pressure does not increase.

Lymph flow from edematous dog lungs

1987 ◽  
Vol 62 (6) ◽  
pp. 2416-2420 ◽  
Author(s):  
R. E. Drake ◽  
S. J. Allen ◽  
J. P. Williams ◽  
G. A. Laine ◽  
J. C. Gabel
Keyword(s):  
Flow Rate ◽  
Left Atrial ◽  
Lymph Flow ◽  
Effective Resistance ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Base Line ◽  
Lymph Vessels ◽  
Lymph System ◽  
Lung Lymph

We measured the flow rate (QLV) from cannulated lung lymph vessels in anesthetized dogs. Low-resistance lymph cannulas were used and the vessels were cannulated at the lung hilus. When we increased left atrial pressure to 42.9 +/- 5.7 (SD) cmH2O (base line = 6.6 +/- 4.6 cmH2O), the lungs became edematous and QLV increased from a base line of 20.4 +/- 21.5 microliters/min to 388 +/- 185 microliters/min. QLV plateaued at the higher level. We also measured the relationship between lymph flow rate and the height of the outflow end of the lymph cannula. From this relationship, determined at the end of the period of elevated left atrial pressure, we calculated the effective resistance and pressure driving lymph from the lungs. We also cannulated lymph vessels in the downstream direction and estimated the effective resistance and pressure opposing flow into the part of the lymphatic system between the lung hilus and the veins (extrapulmonary lymph vessels). We found that the effective resistance of the extrapulmonary part of the lymph system (0.042 +/- 0.030 (SD) cmH2O X min X microliter-1) was large compared with the resistance of the lymph vessels from the lungs (0.026 +/- 0.027). These data indicate that the resistance of the extrapulmonary part of the lung lymph system limits the maximum flow of lymph from edematous lungs.

scholarly journals LEFT ATRIAL PRESSURE CORRELATION WITH PERSISTENT IATROGENIC ATRIAL SEPTAL DEFECT AFTER MITRACLIP IMPLANTATION

2021 ◽  
Vol 77 (18) ◽  
pp. 1200
Author(s):  
Prince Sethi ◽  
Nikhil Parimi ◽  
Prakash Acharya ◽  
Amandeep Goyal ◽  
Emmanuel Daon ◽  
...  
Keyword(s):  
Atrial Septal Defect ◽  
Left Atrial ◽  
Septal Defect ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Iatrogenic Atrial Septal Defect

scholarly journals The Effect of Furosemide on Left Atrial Pressure in Dogs with Mitral Valve Regurgitation

2011 ◽  
Vol 25 (2) ◽  
pp. 244-250 ◽  
Author(s):  
S. Suzuki ◽  
T. Ishikawa ◽  
L. Hamabe ◽  
D. Aytemiz ◽  
H. Huai-Che ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Left Atrial ◽  
Mitral Valve Regurgitation ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Valve Regurgitation

Relationship of Pulmonary Venous Flow Pattern to Mean Left Atrial Pressure and Phasic Pressure Change

Cardiology ◽  
1996 ◽  
Vol 87 (3) ◽  
pp. 224-229 ◽  
Author(s):  
Jer-Min Lin ◽  
Yi-Heng Li ◽  
Kwan-Lih Hsu ◽  
Juey-Jen Hwang ◽  
Yung-Zu Tseng
Keyword(s):  
Flow Pattern ◽  
Left Atrial ◽  
Pressure Change ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Venous Flow ◽  
Pulmonary Venous Flow ◽  
Relationship Of

scholarly journals Continuous Left Atrial Pressure Monitoring During MitraClip

2015 ◽  
Vol 8 (7) ◽  
pp. e117-e119 ◽  
Author(s):  
Mackram F. Eleid ◽  
Saurabh Sanon ◽  
Guy S. Reeder ◽  
Rakesh M. Suri ◽  
Charanjit S. Rihal
Keyword(s):  
Left Atrial ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Pressure Monitoring

Doppler echo evaluation of pulmonary venous-left atrial pressure gradients: human and numerical model studies

2000 ◽  
Vol 279 (2) ◽  
pp. H594-H600 ◽  
Author(s):  
Michael S. Firstenberg ◽  
Neil L. Greenberg ◽  
Nicholas G. Smedira ◽  
David L. Prior ◽  
Gregory M. Scalia ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Left Atrial ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
High Fidelity ◽  
Pressure Gradients ◽  
Bernoulli Equation ◽  
Venous Flow ◽  
Model Studies ◽  
Pulmonary Venous Flow

The simplified Bernoulli equation relates fluid convective energy derived from flow velocities to a pressure gradient and is commonly used in clinical echocardiography to determine pressure differences across stenotic orifices. Its application to pulmonary venous flow has not been described in humans. Twelve patients undergoing cardiac surgery had simultaneous high-fidelity pulmonary venous and left atrial pressure measurements and pulmonary venous pulsed Doppler echocardiography performed. Convective gradients for the systolic (S), diastolic (D), and atrial reversal (AR) phases of pulmonary venous flow were determined using the simplified Bernoulli equation and correlated with measured actual pressure differences. A linear relationship was observed between the convective ( y) and actual ( x) pressure differences for the S ( y = 0.23 x + 0.0074, r = 0.82) and D ( y = 0.22 x + 0.092, r = 0.81) waves, but not for the AR wave ( y = 0.030 x + 0.13, r = 0.10). Numerical modeling resulted in similar slopes for the S ( y = 0.200 x − 0.127, r = 0.97), D ( y = 0.247 x − 0.354, r= 0.99), and AR ( y = 0.087 x − 0.083, r = 0.96) waves. Consistent with numerical modeling, the convective term strongly correlates with but significantly underestimates actual gradient because of large inertial forces.

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