Physical and physiological determinants of pulmonary venous flow: numerical analysis

1997 ◽  
Vol 272 (5) ◽  
pp. H2453-H2465 ◽  
Author(s):  
J. D. Thomas ◽  
J. Zhou ◽  
N. Greenberg ◽  
G. Bibawy ◽  
P. M. McCarthy ◽  
...  
Keyword(s):  
Systolic Function ◽  
Systolic Dysfunction ◽  
Pulmonary Veins ◽  
Pulmonary Arteries ◽  
Lumped Parameter Model ◽  
Physiological Data ◽  
Venous Flow ◽  
Pulmonary Venous Flow ◽  
Atrial Contraction ◽  
Before And After

To study the physical and physiological determinants of transmitral and pulmonary venous flow, a lumped-parameter model of the cardiovascular system has been created, modeling the instantaneous pressure, volume, and influx/efflux of the pulmonary veins, left atrium and ventricle, systemic arteries and veins. right atrium and ventricle, and pulmonary arteries. Initial validation has been obtained by direct comparison with transesophageal echocardiographic recordings of mitral and pulmonary venous velocity for the following clinical situations: normal diastolic function, delayed ventricular relaxation, restrictive filling due to severe systolic dysfunction, severe mitral regurgitation before and after valve repair surgery, and premature atrial contraction occurring during ventricular systole. Sensitivity analysis has been performed with a Jacobian matrix, representing the proportional change in a group of output indexes (yi) in response to isolated changes in input parameters (xj), [(delta yi/yi)/ ([delta xj/xj)], demonstrating the complementary nature of mitral and pulmonary venous A-wave velocity for predicting ventricular stiffness and atrial systolic function. This unified numerical-experimental programming environment should facilitate model refinement and physiological data exploration, in particular guiding more accurate interpretations of Doppler echocardiographic data.

Pattern of blood flow in the pulmonary veins of the dog

1965 ◽  
Vol 20 (6) ◽  
pp. 1118-1128 ◽  
Author(s):  
Eugene Morkin ◽  
John A. Collins ◽  
Harold S. Goldman ◽  
Alfred P. Fishman
Keyword(s):  
Blood Flow ◽  
Pulmonary Circulation ◽  
Pulmonary Veins ◽  
Electromagnetic Flowmeter ◽  
Sine Wave ◽  
Left Ventricular ◽  
Mean Flow ◽  
Venous Flow ◽  
Pulmonary Venous Flow ◽  
Atrial Contraction

The pattern of blood flow in the large pulmonary veins was studied in dogs by chronic implantation of sine-wave electromagnetic flowmeters and cineangiographic observations. These revealed that: 1) pulmonary venous flow is continuous and pulsatile with peak rate of flow of approximately twice the mean flow; 2) the initial rapid increase in venous flow occurs 0.10 sec after the onset of ventricular systole, reaching a peak at the time of closure of the A-V valves; 3) left atrial contraction produces a fleeting slowing or reversal of flow; and 4) respiratory variations in pulmonary venous flow follow those in pulmonary arterial flow, beat by beat. The genesis of phasic pulmonary venous flow was investigated by analysis of pressure and flow curves from the two sides of the heart, by consideration of the energy required for left ventricular filling, and by reconstruction of the pulmonary venous flow pulse using a mathematical model of the pulmonary circulation. These three lines of evidence are consistent in indicating that the transmitted right ventricular pressure is the major determinant of the pulmonary venous flow pattern in the dog. pulsatile pulmonary venous flow; pulmonary venous flow; pulmonary circulation; ventricular suction; respiration on pulmonary circulation; pulmonary venous angiography; pulmonary veno-atrial junctions; electromagnetic flowmeter; cineangiography Submitted on November 16, 1964

Normal patterns of flow in the superior caval, hepatic and pulmonary veins as measured using Doppler echocardiography during childhood

2003 ◽  
Vol 13 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Canan Ayabakan ◽  
Süheyla Özkutlu
Keyword(s):  
Body Mass Index ◽  
Heart Rate ◽  
Doppler Echocardiography ◽  
Pulmonary Veins ◽  
Age Groups ◽  
Caval Vein ◽  
Normal Children ◽  
Venous Flow ◽  
Superior Caval Vein ◽  
Pulmonary Venous Flow

To date, no reference values have been provided for right and left atrial filling in normal children. The aim of our study, therefore, was to characterize measurements of superior caval, hepatic, and pulmonary venous flow using Doppler echocardiography in a large group of normal children to reflect the effects of age, body mass index, sex, heart rate and respiration.Doppler echocardiographic examinations of the superior caval, hepatic and pulmonary veins were performed during inspiration and expiration in 72 healthy children with a mean age of 6.73 ± 5.10 years. The subjects were segregated into four age groups, namely infants <2 years, preschool children between the ages of 2 and 7 years, children of school age between 7 and 11 years, and adolescents older than 11 years.Age has significant effect on the systolic and reverse atrial flows within the superior caval vein (p < 0.05). No change in the Doppler velocities was observed related to body mass index or sex. All peak systolic velocities decreased significantly during expiration (p < 0.05). This decrease was most prominent in the hepatic vein (26%), but less remarkable in the superior caval vein (5.7%) and the pulmonary veins (3.9%). During expiration, the peak diastolic flow in the superior caval and the hepatic veins decreased, while the reverse atrial flow in the hepatic vein increased (p < 0.05). Pulmonary venous velocities were similar in all age groups (p > 0.05). Except for the systolic pulmonary venous velocities, these parameters were not influenced by respiration (p > 0.05). The diastolic time, the interval between reverse atrial flow and ventricular systole reflected by the R wave on the electrocardiogram, and the interval between ventricular systole and diastolic flow, were negatively correlated with heart rate (p < 0.05; r = −0.35, −0.85, and −0.8 respectively), and positively correlated with age (p < 0.05; r = 0.3, 0.8, and 0.7 respectively). They were not influenced by respiration.Our study provides data of the patterns and the normal ranges of velocities of superior caval, hepatic, and pulmonary venous flow in a series of normal children. The results can now be used for comparison with the patterns found in the setting of disease.

Mathematical model that characterizes transmitral and pulmonary venous flow velocity patterns

1995 ◽  
Vol 268 (1) ◽  
pp. H476-H489 ◽  
Author(s):  
Y. Sun ◽  
B. J. Sjoberg ◽  
P. Ask ◽  
D. Loyd ◽  
B. Wranne
Keyword(s):  
Mitral Valve ◽  
Flow Velocity ◽  
Physiological State ◽  
Pulmonary Veins ◽  
Space Representation ◽  
Analog Model ◽  
Venous Flow ◽  
Integration Model ◽  
State Space Representation ◽  
Pulmonary Venous Flow

The transmitral and pulmonary venous flow velocity (TMFV and PVFV, respectively) patterns are related to the physiological state of the left heart by use of an electrical analog model. Filling of left ventricle (LV) through the mitral valve is characterized by a quadratic Bernoulli's resistance in series with an inertance. Filling of the left atrium (LA) through the pulmonary veins is represented by a lumped network of linear resistance, capacitance, and inertance. LV and LA are each represented by a time-varying elastance. A volume dependency is incorporated into the LV model to produce physiological pressure-volume loops and Starling curves. The state-space representation of the analog model consists of 10 simultaneous differential equations, which are solved by numerical integration. Model validity is supported by the following. First, the expected effects of aging and decreasing LV compliance on TMFV and PVFV are accurately represented by the model. Second, the model-generated TMFV and PVFV waveforms fit well to pulsed-Doppler recordings in normal and postinfarct patients. It is shown that the TMFV deceleration time is prolonged by the increase in LV compliance and, to a lesser extent, by the increase in LA compliance. A shift from diastolic dominance to systolic dominance in PVFV occurs when LA compliance or pulmonary perfusion pressure increases or when LV compliance or mitral valve area decreases. The present model should serve as a useful theoretical basis for echocardiographic evaluation of LV and LA functions.

scholarly journals Myocardial stunning in patients with coronary artery disease before and after treatment by method of coronary artery bypass grafting (own studies)

2022 ◽  
Vol 12 (1) ◽  
pp. 43-54
Author(s):  
V. Kundina ◽  
T. Babkina
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Postoperative Period ◽  
Systolic Function ◽  
Systolic Dysfunction ◽  
Early Postoperative Period ◽  
Inferior Wall ◽  
Before And After ◽  
Artery Disease

Aim of the study: Determination of quantitative radiological indicators of myocardial revascularization effectiveness in patients with coronary artery disease in the early postoperative period. Materials and methods of research: For the implementation of the clinical objectives, 62 patients with coronary artery disease, heart failure, with preserved systolic function and systolic dysfunction were examined in the early postoperative period (up to 7 days). The patients' age ranged from 40 to 79 years, the average age of the examined was 59.6 ± 8.2 years. 35 (56%) patients had HF with LV systolic dysfunction with EF of 49% or less. 27 (44%) patients had preserved systolic function - ejection fraction greater than or equal to 50%. Results: In the group before treatment, the average value ​​of MV was 69.4% CI 95% [65.3%; 73.5%], and after treatment the value of MV was 75.0% CI 95% (70.8%; 79.3%], p = 0.0000. Percentage of RFP inclusion in the anterior wall was 69.5% CI [66.2%; 72.8%] before treatment and significantly improved to 72.3% CI [69.1%; 75.4%] after treatment (p = 0.023). Lateral wall had a parameter value of 73.9% CI [70.7%; 77.1%] before treatment and improved perfusion up to 77.2% CI [74.3%; 80.2%] (p = 0.018). Parameter values for the intraventricular septum were 64.5% CI [60.7%; 68.3%] before treatment and 69% CI [65.2%; 72.8%] after treatment (p = 0.000034) and for the inferior wall those were 54.0% CI (49.7%; 58.3%] and 61.7% CI (57.9%); 65.6%] before and after treatment respectively (p = 0.000032). Conclusion: The determination of quantitative radiological parameters proposed as a result of this study is extremely important for the early postoperative period (7-10 days) for determination of stunned myocardial reserve and late stage of patients` management (1-1.5 years) for determination of hibernation reserve and final assessment of CABG effectiveness.

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