Internal capacitance and resistance allow prediction of right ventricle outflow

1982 ◽  
Vol 243 (1) ◽  
pp. H99-H112 ◽  
Author(s):  
K. B. Campbell ◽  
J. A. Ringo ◽  
Y. Wakao ◽  
P. A. Klavano ◽  
J. E. Alexander
Keyword(s):  
Right Ventricle ◽  
Series Resistance ◽  
Predictive Performance ◽  
Ventricular Volume ◽  
Right Atrial ◽  
Model Structure ◽  
Time Varying ◽  
Predictive Capability ◽  
Elementary Model ◽  
Marginal Improvement

The relationship between right ventricle afterloading pressure (P) and outflow (Q) was studied in three isolated canine right ventricle (RV) preparations. Right atrial pressure was held constant while graded elevations in P were induced with stepwise occlusions of the right and left branches of the pulmonary artery. P and Q signals were collected and analyzed using a digital computer system. Data were analyzed by assuming a model structure for the RV and comparing resultant model predictions of Q with actual observations. The model structure was modified in accordance with the discrepancy between prediction and observation to improve the model's predictive capability. The initial model tested was the time-varying linear relationship between ventricular volume and pressure. Utilizing this model, accurate predictions of RV outflow in the face of varying pressure afterloads could not be made. The addition of a series resistance to this elementary model resulted in marked improvement in predictive performance. The addition of greater complexity to the model gave only marginal improvement to the model's predictive capability. It was concluded that a time-varying capacitance and series resistance adequately model internal properties of the RV that relate outflow to afterloading pressure.

scholarly journals Comparison of pretherapeutic osseous tumor volume and standard hematology for prediction of hematotoxicity after PSMA-targeted radioligand therapy

2021 ◽  
Author(s):  
Liam Widjaja ◽  
Rudolf A. Werner ◽  
Tobias L. Ross ◽  
Frank M. Bengel ◽  
Thorsten Derlin
Keyword(s):  
Multivariate Analysis ◽  
Tumor Volume ◽  
Predictive Performance ◽  
Castration Resistant Prostate Cancer ◽  
Operating Characteristics ◽  
Predictive Capability ◽  
Radioligand Therapy ◽  
Castration Resistant ◽  
Pet Ct ◽  
Late Stages

Abstract Purpose Hematotoxicity is a potentially dose-limiting adverse event in patients with metastasized castration-resistant prostate cancer (mCRPC) undergoing prostate-specific membrane antigen (PSMA)-directed radioligand therapy (RLT). We aimed to identify clinical or PSMA-targeted imaging-derived parameters to predict hematological adverse events at early and late stages in the treatment course. Methods In 67 patients with mCRPC scheduled for 177Lu-PSMA-617 RLT, pretherapeutic osseous tumor volume (TV) from 68Ga-PSMA-11 PET/CT and laboratory values were assessed. We then tested the predictive capability of these parameters for early and late hematotoxicity (according to CTCAE vers. 5.0) after one cycle of RLT and in a subgroup of 32/67 (47.8%) patients after four cycles of RLT. Results After one cycle, 10/67 (14.9%) patients developed leukocytopenia (lymphocytopenia, 39/67 [58.2%]; thrombocytopenia, 17/67 [25.4%]). A cut-off of 5.6 × 103/mm3 for baseline leukocytes was defined by receiver operating characteristics (ROC) and separated between patients with and without leukocytopenia (P < 0.001). Baseline leukocyte count emerged as a stronger predictive factor in multivariate analysis (hazard ratio [HR], 33.94, P = 0.001) relative to osseous TV (HR, 14.24, P = 0.01). After four cycles, 4/32 (12.5%) developed leukocytopenia and the pretherapeutic leukocyte cut-off (HR, 9.97, P = 0.082) tended to predict leukocytopenia better than TV (HR, 8.37, P = 0.109). In addition, a cut-off of 1.33 × 103/mm3 for baseline lymphocytes separated between patients with and without lymphocytopenia (P < 0.001), which was corroborated in multivariate analysis (HR, 21.39, P < 0.001 vs. TV, HR, 4.57, P = 0.03). After four cycles, 19/32 (59.4%) developed lymphocytopenia and the pretherapeutic cut-off for lymphocytes (HR, 46.76, P = 0.007) also demonstrated superior predictive performance for late lymphocytopenia (TV, HR, 5.15, P = 0.167). Moreover, a cut-off of 206 × 103/mm3 for baseline platelets separated between patients with and without thrombocytopenia (P < 0.001) and also demonstrated superior predictive capability in multivariate analysis (HR, 115.02, P < 0.001 vs.TV, HR, 12.75, P = 0.025). After four cycles, 9/32 (28.1%) developed thrombocytopenia and the pretherapeutic cut-off for platelets (HR, 5.44, P = 0.048) was also superior for the occurrence of late thrombocytopenia (TV, HR, 1.44, P = 0.7). Conclusions Pretherapeutic leukocyte, lymphocyte, and platelet levels themselves are strong predictors for early and late hematotoxicity under PSMA-directed RLT, and are better suited than PET-based osseous TV for this purpose.

scholarly journals Non invasive ventilation and right ventricle function in cardiogenic pulmonary edema: an echocardiographic perspective to select the "right" ventilatory support

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
D Pedicino ◽  
A Angelini ◽  
G Russo ◽  
A D"aiello ◽  
E Rocco ◽  
...  
Keyword(s):  
Right Ventricle ◽  
Pulmonary Edema ◽  
Longitudinal Strain ◽  
Global Longitudinal Strain ◽  
Cardiogenic Pulmonary Edema ◽  
Right Atrial ◽  
Controlled Study ◽  
Free Wall ◽  
Non Invasive ◽  
Rv Function

Abstract Funding Acknowledgements Type of funding sources: None. Background High-flow nasal cannulae oxygen therapy (HFNCOT) represents a better tolerated alternative to non-invasive pressure support ventilation (NIPSV) for acute cardiogenic pulmonary edema (ACPE) treatment. However, there are still few data on the effect of HFNCOT on cardiac function and hemodynamic. Purpose To assess and compare the effects of NIPSV and HFNCOT in ACPE setting on right ventricular (RV) systolic function and on indices of cardiac filling and output, as measured by echocardiography.  Methods  This is a cross-over controlled study, enrolling 15 consecutive patients admitted to our Cardiovascular Intensive Care Unit for ACPE and hypoxaemic, normo/hypocapnic acute respiratory failure, with P/F ratio &lt; 200. Each patient received NIPSV, followed by HFNCOT. Full echocardiographic assessment and blood gas analysis (BGA) were performed 40 minutes from onset of each ventilation modality, respectively before NIPSV to HFNCOT switch and before HFNCOT interruption. In particular, RV function parameters, together with RV and atrial strain, were prospectively collected. Results  In spite of not significant changes in BGA, RV function was significantly improved under HFNCOT, as compared to NIPSV, as assessed by the following parameters: tricuspid annular plane excursion (TAPSE) (P = 0.001), RV S’ wave (P = 0.007), RV fractional area change (RVFAC) (P = 0.006). Strain analysis confirmed the significant improvement in RV function, with free wall global longitudinal strain (GLS) and free wall and septum GLS significantly higher under HFNCOT, as compared to NIPSV (-21% vs -18% P &lt; 0.001, and -15% vs -19% P = 0.008, respectively,), and a significant increase in right atrial positive longitudinal strain (P &lt; 0.001).  Conclusions NIPSV significantly affect RV function making more complex the management of patients presenting with ACPE. In this setting, HFNCOT represents a valuable alternative, providing similar respiratory outcomes while preserving good right ventricle performance.

scholarly journals P686 Right atrial, right ventricular and pulmonary cement embolism: a rare complication of percutaneous vertebroplasty

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
S Akhunova ◽  
R Khayrullin ◽  
N Stekolshchikova ◽  
M Samigullin ◽  
V Padiryakov
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricle ◽  
Right Atrium ◽  
Percutaneous Vertebroplasty ◽  
Rare Complication ◽  
Clinical Manifestations ◽  
Stable Condition ◽  
Right Atrial ◽  
Cement Embolism ◽  
The Right

Abstract A 68-year-old man was admitted to the hospital with complaints of pain in the lumbar spine. He had L5 disc herniation, Spinal stenosis of the L5 root canal - S1 on the right in the past medical history. Percutaneous vertebroplasty at the level of L3 and Th8 vertebral bodies was performed six months ago due to painful vertebral hemangioma. The man is suffering from arterial hypertension, receives antihypertensive therapy. During routine transthoracic echocardiography, a hyperechoic structure with a size of 9.5 x 0.9 cm was found in the right atrium and right ventricle. Chest computed tomography with contrast enhancement revealed signs of bone cement in the right atrium and right ventricle, in the right upper lobe artery, in the branches of the upper lobe artery, in the paravertebral venous plexuses. Considering the duration of the disease, the stable condition, the absence of clinical manifestations and disorders of intracardiac hemodynamics, it was decided to refrain from surgical treatment. Antiplatelet therapy and dynamic observation were recommended. Conclusion Percutaneous vertebroplasty is a modern minimally invasive surgical procedure for the treatment of degenerative-dystrophic diseases of the spine. However, the cement can penetrate into the paravertebral veins and migrate to the right chambers of the heart and the pulmonary artery. This clinical case demonstrates asymptomatic cement embolism of the right chambers of the heart and pulmonary artery after percutaneous vertebroplasty, detected incidentally during routine echocardiography. Abstract P686 Figure.

scholarly journals External validation of the predictive performance of population pharmacokinetic models for phenobarbital in pediatric patients

2020 ◽  
Author(s):  
Sunae Ryu ◽  
Woo Jin Jung ◽  
Zheng Jiao ◽  
Jung Woo Chae ◽  
Hwi-yeol Yun
Keyword(s):  
External Validation ◽  
Predictive Performance ◽  
Validation Dataset ◽  
Therapeutic Drug ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Models ◽  
Bayesian Forecasting ◽  
Predictive Capability ◽  
Young Infants ◽  
Simulation Based

Aim: Several studies have reported population pharmacokinetic models for phenobarbital (PB), but the predictive performance of these models has not been well documented. This study aims to do external validation of the predictive performance in published pharmacokinetic models. Methods: Therapeutic drug monitoring data collected in neonates and young infants treated with PB for seizure control, was used for external validation. A literature review was conducted through PubMed to identify population pharmacokinetic models. Prediction- and simulation-based diagnostics, and Bayesian forecasting were performed for external validation. The incorporation of size or maturity functions into the published models was also tested for prediction improvement. Results: A total of 79 serum concentrations from 28 subjects were included in the external validation dataset. Seven population pharmacokinetic studies of PB were selected for evaluation. The model by Voller et al. [27] showed the best performance concerning prediction-based evaluation. In simulation-based analyses, the normalized prediction distribution error of two models (those of Shellhaas et al. [24] and Marsot et al. [25]) obeyed a normal distribution. Bayesian forecasting with more than one observation improved predictive capability. Incorporation of both allometric size scaling and maturation function generally enhanced the predictive performance, but with marked improvement for the adult pharmacokinetic model. Conclusion: The predictive performance of published pharmacokinetic models of PB was diverse, and validation may be necessary to extrapolate to different clinical settings. Our findings suggest that Bayesian forecasting improves the predictive capability of individual concentrations for pediatrics.

Cardiovascular Physical Examination

2016 ◽  
pp. 53-58
Author(s):  
Kyle W. Klarich ◽  
Lori A. Blauwet ◽  
Sabrina D. Phillips
Keyword(s):  
Physical Examination ◽  
Right Ventricle ◽  
Wave Amplitude ◽  
Venous Pressure ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Jugular Venous Pressure ◽  
Structural Disease ◽  
The Right ◽  
The Relationship

Jugular venous pressure reflects right atrial pressure and the relationship between right atrial filling and emptying into the right ventricle. Changes in wave amplitude may indicate structural disease and rhythm changes. Normal jugular venous pressure is 6 to 8 cm H2O. It is best evaluated with the patient supine at an angle of at least 45°. The right atrium lies 5 cm below the sternal angle, and thus the estimated jugular venous pressure equals the height of the jugular venous pressure above the sternal angle + 5 cm.

Pushmi-Pullyu and the Right Atrium

2011 ◽  
pp. 55-62
Author(s):  
James R. Munis
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Right Ventricle ◽  
Flow Rate ◽  
Blood Flow Rate ◽  
The Other ◽  
Right Atrial ◽  
The One ◽  
The Right ◽  
Point Of Intersection

What does right atrial pressure (PRA) do to cardiac output (CO)? On the one hand, we've been taught that PRA represents preload for the right ventricle. That is, the higher the PRA, the greater the right ventricular output (and, therefore, CO). This is simply an application of Starling's law to the right side of the heart. On the other hand, we've been taught that PRA represents the downstream impedance to venous return (VR) from the periphery. That is, the higher the PRA, the lower the VR, and therefore, the lower the CO. The point of intersection between the 2 curves defines a unique blood flow rate, which is both CO and VR at the same time.

scholarly journals Giant right atrial myxoma: A rare cause of cardiovascular collapse

2019 ◽  
Vol 7 ◽  
pp. 2050313X1984146
Author(s):  
Andres Beiras-Fernandez ◽  
Angela Kornberger ◽  
Hazem El-Beyrouti ◽  
Christian-Friedrich Vahl
Keyword(s):  
Heart Failure ◽  
Right Ventricle ◽  
Right Atrium ◽  
Heart Valves ◽  
Surgical Intervention ◽  
Atrial Myxoma ◽  
Right Atrial ◽  
Cardiovascular Collapse ◽  
Right Atrial Myxoma ◽  
The Right

We report the case of a patient with a giant right atrial myxoma that remained clinically silent until it almost completely obliterated the right atrium, prolapsed into the right ventricle and obstructed the tricuspid valve inflow. This case illustrates the importance of rapid surgical intervention in the setting of acute heart failure caused by tumor masses obliterating heart valves or cardiac chambers.

P4355Echocardiographic estimation of right ventricle wall tension: hemodynamic comparison and long term follow up

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
U Annone ◽  
P Omede' ◽  
F D'Ascenzo ◽  
A Montefusco ◽  
A Milan ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricle ◽  
Right Atrial ◽  
Stroke Work ◽  
Work Index ◽  
All Cause Mortality ◽  
Long Term Follow Up ◽  
Stroke Work Index

Abstract Introduction Prognosis in pulmonary hypertension (PH) is strictly linked to right ventricle (RV) failure, which results from uncoupling between RV and the superimposed pressure load; in first phases, coupling between these two actors still be preserved, at the price of augmented right ventricle wall tension (RVWT). Purpose We sought to describe how to estimate RVWT with echocardiography, how it correlates with RV hemodynamics and if it may predict prognosis. Methods A total of 190 patients without overt RV failure, with suspected pulmonary hypertension (PH) to a previous echocardiography, underwent to right heart catheterization (RHC) and nearly-simultaneous echocardiography. We estimated RVWT according to Laplace law (RV length × tricuspid regurgitation peak gradient [TRPG]), in order to predict initial RV stress, and was correlated with RV hemodynamic profile; its potential prognostic impact was tested along with canonical RV function parameters. Results In patients enrolled in our study, RVWT correlated significantly with invasive estimation of right ventricle end diastolic pressure (R 0.343, p<0.001); a significant relationship between RVWT and several hemodynamic variables was observed (mean pulmonary artery pressure, pulmonary artery compliance, transpulmonary gradient, pulmonary vascular resistance, RV telediastolic pressure, right atrial pressure, RV stroke work index; all p<0.001). At a mean follow up of five years and three months, only RVWT predicted all-cause mortality (p 0.036), while TAPSE, TAPSE/TRPG, RV fractional area change and RV S' wave did not. Correlation: RWVT and RV hemodynamic Hemodynamic variable R R2 p value Mean pulmonary artery pressure 0.742 0.550 <0.001 RV differential pressure 0.794 0.630 <0.001 Pulmonary artery pulsatory pressure 0.740 0.547 <0.001 Mean right atrium pressure 0.326 0.106 <0.001 Cardiac index/right atrial pressure 0.209 0.044 0.012 RV stroke work index 0.588 0.346 <0.001 Pulmonary artery compliance 0.449 0.202 <0.001 Pulmonary vascular resistance 0.531 0.282 <0.001 Prognosis: different RV variables Discussion We identified a novel bedside echocardiographic predictor of altered RV hemodynamic, which results precociously altered in patients without overt RV failure, and able to predict all cause mortality at a long term follow up. Further studies are needed to confirm its role in PH patients.

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