Pulmonary Blood Flow In Children Research Articles

Pulmonary blood flow in children with univentricular heart and unilateral diaphragmatic paralysis.

Spontaneous breathing has an important effect on pulmonary arterial blood flow in patients with Glenn/Fontan circulation. Unilateral diaphragmatic paralysis (DP) is a frequent complication after heart surgery in congenital heart disease. The aim of this study was to investigate the influence of unilateral DP on blood flow distribution in the pulmonary arteries with Glenn/Fontan circulation. Magnetic resonance phase-contrast imaging was used to evaluate stroke volume index (SVI) in the left and right pulmonary arteries in patients with Glenn/Fontan circulation with unilateral DP. Data for 18 patients with univentricular heart and unilateral DP were analysed, 8 in the Glenn stage and 10 in the Fontan stage. Ten patients had right-sided DP, and 8 had left-sided DP. A diaphragmatic plication was performed in 7 patients. The control group consisted of 36 patients with Glenn (n = 16)/Fontan (n = 20) circulation without DP. In both left- and right-sided DP, the SVI to the ipsilateral side was significantly lower than in controls [2.81 (1.45-4.50) ml/m2 left vs 11.97 (7.36-16.37) ml/m2 in controls, P < 0.0002; 8.2 (4.49-12.64) ml/m2 with right vs 12.64 (9.66-16.61) ml/m2 in controls; P = 0.0284]. The SVI to the contralateral side showed a slight but non-significant increase in the presence of unilateral DP. Unilateral DP in patients with Glenn/Fontan circulation has a negative impact on pulmonary arterial SVI on the side of the paralysis.

Comparison of phase contrast magnetic resonance imaging and scintigraphy for determination of split pulmonary blood flow in children and young adults with congenital heart disease.

Measurement of differential blood flow to the lungs is important to understanding flow dynamics in the setting of congenital heart disease. Split blood flow via the pulmonary arteries guides and demonstrates the effect of interventions. Minimally invasive imaging of pulmonary blood flow can be achieved with scintigraphy or magnetic resonance imaging (MRI). To assess agreement of pulmonary blood flow measurements obtained by scintigraphy and MRI in children and young adults. We performed a retrospective review of patients < 21years of age who had undergone both nuclear medicine pulmonary perfusion scans (Tc-99m MAA) and cardiac MRI examinations from January 2012 to August 2021 at our tertiary pediatric hospital. Patient demographics, medical/surgical information, and estimates of split blood flow by both modalities were recorded. Pearson's correlation coefficient was used to determine the relationship between split blood flow measured by the two examinations. Agreement was calculated using interclass correlation coefficient (ICC) for absolute agreement and Bland-Altman difference analysis. Correlation between split blood flow measured by scintigraphy and MRI using net flow was 0.90 (95% CI: 0.83-0.94, P< 0.001) and the ICC for agreement on split blood flow was 0.90 (95% CI: 0.84-0.94). Mean difference in split blood flow by Bland-Altman analysis was 0.79% with 95% limits of agreement (-11.2 to 12.8%). There is excellent agreement between Tc-99m scintigraphy and phase contrast MRI for quantification of split pulmonary blood flow in children and young adults with congenital heart disease.

Accuracy of pulmonary ultrasound versus chest radiography for detecting pulmonary congestion resulting from increased pulmonary blood flow in children with congenital heart disease and left-to-right shunting

Introduction: Congenital heart diseases are a set of simple or complex dynamic heterogeneous malformations that originate in the embryo, progress through the pregnancy, and considerably change throughout the course of extrauterine life. They are the most common congenital defect, with a global prevalence estimated at 1.8 cases per 100 live births. These diseases can be classified by the cardiovascular segment affected and the impact on blood oxygenation and pulmonary flow. One of their most feared repercussions is pulmonary hypertension, which can result from lung exposure to increased blood flow, which changes vascular tone and causes medial hypertrophy and vascular remodeling. The advent of echocardiography has revolutionized healthcare for these children; however, chest radiography is still the most commonly used method for detecting increased blood flow and pulmonary edema. Objectives: Thus, this study compared the accuracy of ultrasound and chest radiography in detecting congestion resulting from increased pulmonary blood flow in children with congenital heart disease and left-to-right shunting. Methods: This is an observational longitudinal analytical prospective study comparing lung ultrasounds and chest radiographs of patients with congenital heart disease. Results: Our results suggest that ultrasound, which is a noninvasive diagnostic method that emits no radiation, has a discriminatory capacity similar to that of radiography, and has 92.59 % accuracy, 89.47 % sensitivity, and 100 % specificity. Conclusions: Pulmonary ultrasound is highly accurate, sensitive, and specific, and can be used to assess pulmonary congestion and edema resulting from increased blood flow in patients with heart disease.

Transcatheter occlusion of antegrade pulmonary blood flow in children with univentricular heart.

This study aims to evaluate the results of transcatheter occlusion of antegrade pulmonary blood flow in children with univentricular heart. Medical data of a total of seven patients (4 females, 3 males; median age 11.7 years; range, 1 to 24 years) who underwent transcatheter occlusion of the antegrade pulmonary blood flow following Glenn shunt or Fontan operation between September 2014 and January 2017 were retrospectively analyzed. Data including demographic and clinical characteristics of the patients, type of surgery, echocardiographic and cardiac catheterization findings were recorded. Four patients had a previous pulmonary artery banding operation, while three had pulmonary stenosis. Two patients had facial and upper extremity edema after Glenn operation, one had prolonged pleural effusion, one had prolonged pleural effusion after Fontan operation, and one developed dyspnea and effort intolerance several years after Fontan operation. In two patients, antegrade pulmonary blood flow was occluded to decrease systemic ventricular load before surgery. The Amplatzer Septal Occluder was used in five patients and the Amplatzer Vascular Plug-2 was used in two patients. Two patients developed transient, complete atrioventricular block during the procedure and the procedure was terminated early in one of these patients. Transient hemolysis was observed in one patient following the operation. Transcatheter occlusion of antegrade pulmonary blood flow is an effective alternative to surgery in patients with hemodynamic compromise after Glenn shunt or Fontan operation.

Noninvasive Investigation of Pulmonary Blood Flow in Children with Pulmonary Hypertension Using the TRV/RVOT VTI Ratio

Noninvasive Investigation of Pulmonary Blood Flow in Children with Pulmonary Hypertension Using the TRV/RVOT VTI Ratio

Elevated Low-Shear Blood Viscosity is Associated with Decreased Pulmonary Blood Flow in Children with Univentricular Heart Defects

After the Fontan procedure, patients with univentricular hearts can experience long-term complications due to chronic low-shear non-pulsatile pulmonary blood flow. We sought to evaluate hemorheology and its relationship to hemodynamics in children with univentricular hearts. We hypothesized that low-shear blood viscosity and red blood cell (RBC) aggregation would be associated with increased pulmonary vascular resistance (PVR) and decreased pulmonary blood flow (PBF). We performed a cross-sectional analysis of 62 children undergoing cardiac catheterization-20 with isolated atrial septal defect (ASD), 22 status post Glenn procedure (Glenn), and 20 status post Fontan procedure (Fontan). Shear-dependent blood viscosity, RBC aggregation and deformability, complete blood count, coagulation panel, metabolic panel, fibrinogen, and erythrocyte sedimentation rate were measured. PVR and PBF were calculated using the Fick equation. Group differences were analyzed by ANOVA and correlations by linear regression. Blood viscosity at all shear rates was higher in Glenn and Fontan, partially due to normocytic anemia in ASD. RBC aggregation and deformability were similar between all groups. Low-shear viscosity negatively correlated with PBF in Glenn and Fontan only (R (2) = 0.27, p < 0.001); it also negatively correlated with pulmonary artery pressure in Glenn (R (2) = 0.15, p = 0.01), and positively correlated with PVR in Fontan (R (2) = 0.28, p = 0.02). Our data demonstrate that elevated low-shear blood viscosity is associated with negative hemodynamic perturbations in a passive univentricular pulmonary circulation, but not in a pulsatile biventricular pulmonary circulation.

Echocardiographic Assessment of the Alterations in Pulmonary Blood Flow Associated with Ketamine and Etomidate Administration in Children with Tetralogy of Fallot.

Despite widespread uses of ketamine, the clinical studies determining its effect on pulmonary blood flow in children with tetralogy of Fallot (TOF) are lacking. Furthermore, the quantification of pulmonary blood flow is not possible in these patients, because pulmonary artery catheter is contraindicated. Therefore, the purpose of this study was to evaluate the changes in pulmonary blood flow by intra-operative transesophageal echocardiography after ketamine or etomidate administration in children with TOF. Eleven children each in the two clinical variants of TOF (group A-moderate to severe cyanosis; group B-mild to minimal cyanosis) undergoing intracardiac repair were prospectively studied after endotracheal intubation. A single bolus dose of ketamine (2mg/kg) and etomidate (0.3mg/kg) was administered in a random order after 15minute interval. Hemodynamic, arterial blood gas, and echocardiographic measurements were obtained at 7 consecutive times (T) points (baseline, 1, 2, 4, 6, 8, and 15minutes after drug administration). Ketamine produced a significant reduction in VTI-T (velocity time integrals total of left upper pulmonary vein), RVOT-PG (right ventricular outflow tract peak gradient), and MG (mean gradient) in group A while those in group B had a significant increase in VTI-T, RVOT-PG, and RVOT-MG at time (T1, T2, T4, and T6; P=0.00). This divergent behavior, however, was not observed with etomidate. Etomidate does not change pulmonary blood flow. However, ketamine produces divergent effects; it increases pulmonary blood flow in children with minimal cyanosis and decreases pulmonary blood flow in children with moderate to severe cyanosis.

Right Ventricular Outflow Tract Velocity Time Integral Determination in 570 Healthy Children and in 52 Pediatric Atrial Septal Defect Patients.

Determination of the right ventricular outflow tract velocity time integral (RVOT VTI) is an important part of the noninvasive investigation of pulmonary blood flow in adults; however, age-related pediatric reference data are lacking. We examined growth-related changes of RVOT VTI values in children and the predictive value of RVOT VTI values in identifying enhanced pulmonary blood flow in children with secundum type atrial septal defect (ASD). A prospective study was conducted in a group of 570 healthy children and 52 children with a moderate-sized to large ASD. We determined the effects of age, body length (BL), body weight (BW), and body surface area (BSA) on RVOT VTI values. The predictive value of normal values stratified for age, BW, BL, and BSA was tested in our 52 ASD children. RVOT VTI values ranged from mean 9.7±1.2cm in neonates to 23.3±2.7cm in children with 18years of age and showed a positive correlation with age, BL, BSA, and BW. In our population, RVOT VTI z-scores showed a high specificity for detecting ASD patients (>97%) with sensitivity up to 71%. We provide normal ranges and calculated z-scores of pediatric RVOT VTI values. Normal RVOT VTI z-scores might be additional predictors in identifying increased pulmonary blood flow in patients with ASD.

Importance of plasma endothelin-1 level in the evaluation of heart failure severity in infants with ventricular septal defect

Haemodynamic disturbances due to ventricular septal defect (VSD) can lead to heart failure (HF) and cause neurohormonal activation. Endothelin-1 (ET-1) clearance takes place mainly in the pulmonary circulation. We hypothesized that increased pulmonary blood flow in children with VSD could influence ET-1 level and reflect haemodynamic disturbances in these patients. To analyse usefulness of plasma ET-1 level in the evaluation of HF severity in infants with VSD without pulmonary hypertension. The study group included 34 children (aged 38-338 days, mean 130 ± 81 days) with VSD. Evaluation included history, physical examination, ET-1 level measurement, standard 12-lead electrocardiogram, chest X-ray, and transthoracic echocardiography in all children. The control group consisted of 31 healthy children. Mean plasma ET-1 level was significantly (p < 0.01) higher in the study group compared to the control group. We found no significant difference (p > 0.05) in mean plasma ET-1 level between children with or without HF. No significant correlation was found between plasma ET-1 level and the severity of HF. Infants with VSD show higher ET-1 level compared to healthy children. Plasma ET-1 level does not reflect the severity of HF in infants with VSD.

Abstract 9577: Non-Invasive Estimation of Pulmonary Blood Flow Using Photoacoustic Spectroscopy in Patients with Congenital Heart Disease

Background: Measurements of pulmonary blood flow (PBF) using inert gas rebreathing technology have recently been enhanced by the introduction of photoacoustic spectroscopy (PAS). PAS is non-invasive, non-toxic, and can estimate PBF in &lt;5 min. It has been employed successfully in adults with structurally normal hearts. Experience in patients with congenital heart disease (CHD) is, however, limited and its validity in patients with intracardiac shunts has not been evaluated. We compared estimates of PBF obtained with PAS technology to those obtained at cardiac catheterization. Methods: Fick-based estimates of PBF (using assumed oxygen consumption) were compared to PAS estimates in 50 CHD patients; 28 without intracardiac shunts, 10 with right to left (R--&gt;L) shunts and 12 with left to right (L--&gt;R) shunts. PAS estimates were acquired 1 day prior to catheterization while the patients were conscious, in a recumbent position. Fick-based estimates were acquired by individuals blinded to the PAS results. Results: Median age was 18.5 yrs (range 8-78). Among subjects without shunts or with R--&gt;L shunts, Fick and PAS-based estimates of PBF correlated reasonably well (r=0.59 and 0.75, respectively; p&lt;0.01 for both groups; r=0.72, p&lt;0.0001 combined). Bland-Altman analysis revealed good agreement (mean bias 0.3±0.5 l/min/m 2 ; 95% limits of agreement -0.8 - +1.3 l/min/m 2 ), similar to historical comparisons of Fick and thermodilution techniques. In contrast, the correlation between PBF estimates among subjects with L--&gt;R shunts was poor (r=0.24; p&gt;0.05). Conclusion: PAS provides accurate, rapid estimates of PBF in children and adults with CHD who have no residual shunt, as well as those with R--&gt;L shunts. Measurements in subjects with L--&gt;R shunts are less reliable, likely due to early re-circulation. Algorithms that take this phenomenon into account may improve the reliability of PAS measurements in patients with L--&gt;R shunts.

Multidetector-row Computed Tomography Evaluation of Bilateral Bronchial Narrowing Associated with Increased Pulmonary Blood Flow in Children with Congenital Heart Disease

Quantitative assessment of bilateral bronchial narrowing in children with congenital heart disease (CHD) with a left-to-right shunt has not yet been reported. In the present study, main bronchial size was evaluated bilaterally in normal subjects using multidetector-row computed tomography (MDCT), and the feasibility for diagnosis of bronchial narrowing in children with CHD associated with increased pulmonary blood flow was investigated. The short-axis diameter, long-axis diameter, and the cross-sectional area of the bilateral bronchi were measured immediately proximal to the origin of the superior lobar branch in 86 children aged 1-52 months. Subjects were divided into three groups as follows: group 1 (normal subjects; n = 52), group 2 (asymptomatic left-to-right shunt group; n = 25), and group 3 (symptomatic left-to-right shunt group with respiratory insufficiency; n = 9). Age, height, weight, and body surface area were significantly correlated with short- and long-axis bronchial diameters, and bronchial cross-sectional area in group 1. In group 2, the left bronchial cross-sectional area was significantly lower than group 1 (P < .001), whereas the right bronchial area was not significantly different. In group 3, the right bronchial area was significantly lower than that in groups 1 and 2 (P < .05). Although the left bronchial area in group 3 was significantly lower than in group 1 (P < .001), it was not significantly different from that in group 2. Our study suggests that MDCT can be used to quantify bilateral bronchial narrowing. Left main bronchial obstruction develops during the early stage of heart failure, followed by the development of right bronchial narrowing.

Computer and Physical Modeling of Blood Circulation Pump Support for a New Field of Application in Palliative Surgery

One of the most popular palliative procedures performed to increase pulmonary blood flow in children with congenital heart defects is a shunt operation (Blalock-Taussig graft or Glenn procedure), which creates the new blood channel to the pulmonary artery. The main problem with this kind of surgery is poor shunt effectiveness and the lack of possibility to regulate the flow. The aim of this work is to use advanced computer simulation methods to study the effectiveness of a new idea to introduce a small axial blood pump into a Blalock-Taussig (B-T) or Glenn shunt in order to control the blood flow and prevent any increase in the graft stenosis. Physical and computer 3-D simulation based on a finite element mesh (FEM) model was applied. Studies for optimization of the shunt and hybrid shunt with pump were performed for different stages of the disease. The graft with the axial pump creates good conditions for the vascular system and pulmonary artery blood flow as well as regulating blood pressure under variable conditions caused by palliative procedures. Its use permits the afterload of the left heart ventricle to be decreased. A palliative procedure is only a temporary solution. When a child grows, while the graft size is fixed, the blood flow through this graft may be not sufficient under changing hemodynamic conditions. The use of an axial pump for regulating the blood flow volume, during palliative procedures, allows to obtain the optimal flow conditions in pulmonary artery and safely wait on the final cardiac surgery correction later. However, the use of a pump mounted inside the graft increased hemodynamic resistance, which caused the flow to decrease up to 70% in the graft when the axial pump was not working.

Application of homologous conduits with valves in the treatment of complex congenital heart disease with insufficient pulmonary blood flow in children

To investigate the effects of homologous conduits with valves in the treatment of complex congenital heart disease with insufficient pulmonary blood flow in children. Homologous conduits with valves were used in the right ventricular outflow tract reconstruction among 212 pediatric patients with complex congenital heart disease with insufficient pulmonary blood flow, aged 2.6 (0.5 - 15). The patients were followed up for 2.6 years (6 months to 7 years) and underwent echocardiography to assess the degree of pulmonary insufficiency and calcification of blood vessel. The success rate of operation was 96.5% (204/212). The ratio of right ventricle to aortic pressure was less then 0.55. During the follow-up, echocardiography showed valvular regurgitation and calcification of the blood vessel in 34 patients, 23 (11.2%) being mild, 7 (3.42%) being moderate, and 4 (1.96%) being sever. 170 patients did not show obvious pulmonary insufficiency. Application of homologous conduits with valves in the treatment of complex congenital heart disease with insufficient pulmonary blood flow in children shows excellent early results in preventing pulmonary insufficiency.

Physical and Computer Modelling of Blood Flow in a Systemic-to-pulmonary Shunt

The aim of this work was the application of computer and physical in vitro simulation methods for estimating surgery procedure hemodynamics. The modified Blalock-Taussig (mB-T) palliative surgical procedure is performed to increase the pulmonary blood flow in children with congenital heart defects. Such a systemic-to-pulmonary shunt yields substantial modification in the blood flow within the large blood vessels. The objective of the present study was to investigate basic characteristics of the flow, flow pattern and pressure-flow efficiency, before and after opening of the mB-T graft. The model was based on the vessel geometry obtained from the Visible Human Project and included the arch of aorta, the three arteries branching from the arch, the pulmonary trunck, and the left and right pulmonary arteries. The graft was added between the left subclavian artery and the left pulmonary artery. The glass model of the vessels was produced and investigated in a physical model of the cardiovascular system with an artificial ventricular device as the blood pump. Flow rate and hydrostatic pressure were measured at the inlet to and outlets from the glass model and in a few points within the system. Laser flow visualization was also performed. Computer simulations were done using the boundary conditions from the physical model. The opening of the mB-T graft changed flow distribution in all branches (including inflow). A complex flow pattern with large eddies and channelling of the flow in the vicinity of the graft and within it was observed in flow visualization and in computer simulations. Because of that complexity the local measurements of hydrostatic pressure at the vessel wall could not predict the average flow rate. The reversed flow in the graft was observed during the systole. The complex flow pattern developed in the physical model of the mB-T graft. The channelling of the flow and the formation of large eddies may yield high shear stress and modify blood properties. The rigid wall model can describe only some flow characteristics observed in vivo. Computer simulation is a very fast and accurate method which permits earlier qualification of cardiac surgeons on how to change cardiac vascular blood flow after operations.

Quantitative angiographic assessment of pulmonary blood flow in children with congenital heart defects

Quantitative angiographic assessment of pulmonary blood flow in children with congenital heart defects

Effective pulmonary blood flow in children with acute asthma attack requiring hospitalization

In children with acute obstructive lung disease gas exchange is affected by ventilation-perfusion mismatch and the degree of bronchoconstriction. Standard lung function measurements do not reflect the impairment in gas exchange. Alternatively, the effective pulmonary blood flow (EPBF), that is, the proportion of the cardiac output that is supplying well-ventilated lung units, can give accurate and noninvasive estimates of ventilation-perfusion mismatch. We measured EPBF with the argon freon-22 rebreathing technique in children with acute severe asthma to assess their response to nebulized salbutamol and to determine whether induced changes in the EPBF could be predicted from baseline measurements. Twenty-four children admitted with an acute asthma attack had spirometry and triplicate EPBF measurements before and after nebulized salbutamol. Eighteen patients had repeated tests 50 days later when fully recovered; 4 patients were taking methylxanthines on at least one occasion. The mean forced expiratory volume in 1 sec (FEV1) rose from 55% of predicted to 66% after salbutamol and to 83% with recovery. The mean coefficients of variation for EPBF measurements on the three test occasions were 11.3%, 8.2%, and 9%. Except in children on methylxanthines, the EPBF values were reduced during the acute asthma attack (median, 2.53 L/min/m2; range, 1.99-3.60 L/min/m2) compared with paired values obtained after recovery (median, 2.89 L/min/m2; range, 2.28-4.04 L/min/m2) (P = 0.009). Salbutamol caused a highly significant increase in EPBF from 2.88 L/min/m2 (range, 1.86-3.80) before treatment to 3.34 L/min/m2 (range, 2.26-4.65) immediately afterwards (P = 0.0003).(ABSTRACT TRUNCATED AT 250 WORDS)

Local pulmonary blood flow in children with stenosis of pulmonary artery.

Local pulmonary blood flow in children with stenosis of pulmonary artery.

Interrelationships between pulmonary blood flow and bronchomotor tone: Po2 and Pco2.

ArticleInterrelationships between pulmonary blood flow and bronchomotor tone: Po2 and Pco2.M Samanek, and D M AviadoM Samanek, and D M AviadoPublished Online:01 Apr 1967https://doi.org/10.1152/jappl.1967.22.4.719MoreSectionsPDF (3 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByRegional CO2 tension quantitatively mediates homeostatic redistribution of ventilation following acute pulmonary thromboembolism in pigsJohn Y. C. Tsang, Wayne J. E. Lamm, and Erik R. Swenson1 September 2009 | Journal of Applied Physiology, Vol. 107, No. 3THE USE OF VENTILATION AND PERFUSION LUNG SCANS TO DOCUMENT CHANGES FOLLOWING EXPERIMENTAL PULMONARY EMBOLISMANZ Journal of Surgery, Vol. 52, No. 3The influence of normalization of CO2 tension with positive end-expiratory pressure ventilation on severe hypoxemiaJournal of Surgical Research, Vol. 22, No. 4The effects of carbon dioxide on pulmonary mechanics in hyperventilating, normal volunteersThe Journal of Thoracic and Cardiovascular Surgery, Vol. 71, No. 2Differential ventilation in unilateral pulmonary artery occlusionThorax, Vol. 27, No. 4Ventilation-perfusion inequalities resulting from hypocapnic changes in lung mechanicsThe Journal of Thoracic and Cardiovascular Surgery, Vol. 63, No. 4Exercise-induced airways constrictionThorax, Vol. 27, No. 2DISTRIBUTION OF PULMONARY BLOOD FLOW IN CHILDREN WITH CYSTIC FIBROSISActa Paediatrica, Vol. 60, No. 2Distribution of pulmonary blood flow after cavopulmonary anastomosis (Glenn operation).Heart, Vol. 31, No. 4 More from this issue > Volume 22Issue 4April 1967Pages 719-30 https://doi.org/10.1152/jappl.1967.22.4.719PubMed6023185History Published online 1 April 1967 Published in print 1 April 1967 Metrics