scholarly journals Retinal venous pressure: the role of endothelin

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Josef Flammer ◽  
Katarzyna Konieczka
Keyword(s):  
Venous Pressure ◽  
Retinal Venous Pressure

scholarly journals Retinal venous pressure is decreased after anti-VEGF therapy in patients with retinal vein occlusion–related macular edema

2021 ◽  
Author(s):  
Teruyo Kida ◽  
Josef Flammer ◽  
Katarzyna Konieczka ◽  
Tsunehiko Ikeda
Keyword(s):  
Macular Edema ◽  
Intravitreal Injection ◽  
Retinal Vein Occlusion ◽  
Venous Pressure ◽  
Decisive Role ◽  
Retinal Venous Pressure ◽  
Vein Occlusion ◽  
Anti Vegf ◽  
Significant Difference ◽  
Endothelial Growth Factor

Abstract Purpose The pathomechanism leading to retinal vein occlusion (RVO) is unclear. Mechanical compression, thrombosis, and functional contractions of veins are discussed as the reasons for the increased resistance of venous outflow. We evaluated changes in the retinal venous pressure (RVP) following intravitreal injection of anti-vascular endothelial growth factor (VEGF) agent to determine the effect on RVO-related macular edema. Methods Twenty-six patients with RVO-related macular edema (16 branch RVOs [BRVOs] and 10 central RVOs [CRVOs], age 72.5 ± 8.8 years) who visited our hospital were included in this prospective study. Visual acuity (VA), intraocular pressure (IOP), central retinal thickness (CRT) determined by macular optical coherence tomography, and RVP measured using an ophthalmodynamometer were obtained before intravitreal injection of ranibizumab (IVR) and 1 month later. Results Comparison of the BRVOs and CRVOs showed that VA was significantly improved by a single injection in BRVOs (P < 0.0001; P = 0.1087 for CRVOs), but CRT and RVP were significantly decreased without significant difference in IOP after the treatment in both groups (P < 0.0001). Conclusion The anti-VEGF treatment resulted in a significant decrease in the RVP, but the RVP remained significantly higher than the IOP. An increased RVP plays a decisive role in the formation of macula edema, and reducing it is desirable.

Intra-ocular pressure changes during maximal isometric contraction: Does this reflect intra-cranial pressure or retinal venous pressure?

1999 ◽  
Vol 21 (3) ◽  
pp. 243-246 ◽  
Author(s):  
Rob D. Dickerman ◽  
Greg H. Smith ◽  
Len Langham-Roof ◽  
Walter J. McConathy ◽  
John W. East ◽  
...  
Keyword(s):  
Isometric Contraction ◽  
Venous Pressure ◽  
Retinal Venous Pressure ◽  
Intra Ocular Pressure ◽  
Ocular Pressure ◽  
Pressure Changes ◽  
Intra Cranial Pressure

Renal hemodynamic responses to increased renal venous pressure: role of angiotensin II

1982 ◽  
Vol 243 (3) ◽  
pp. F260-F264 ◽  
Author(s):  
P. R. Kastner ◽  
J. E. Hall ◽  
A. C. Guyton
Keyword(s):  
Angiotensin Ii ◽  
Filtration Rate ◽  
Enzyme Inhibitor ◽  
Venous Pressure ◽  
Renin Secretion ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Filtration Fraction ◽  
A Value

Studies were performed to quantitate the effects of progressive increases in renal venous pressure (RVP) on renin secretion (RS) and renal hemodynamics. RVP was raised in 10 mmHg increments to 50 mmHg. Renin secretion rate increased modestly as RVP was increased to 30 mmHg and then increased sharply after RVP exceeded 30 mmHg. Glomerular filtration rate (GFR), renal blood flow (RBF), and filtration fraction (FF) did not change significantly when RVP was elevated to 50 mmHg. GFR and RBF were also measured after the renin-angiotension system (RAS) was blocked with the angiotensin converting enzyme inhibitor (CEI) SQ 14225. After a 60-min CEI infusion, RBF was elevated (32%), GFR was unchanged, FF was decreased, and total renal resistance (TRR) was decreased. As RVP was increased to 50 mmHg, GFR and FF decreased to 36.3 and 40.0% of control, respectively, RBF returned to a value not significantly different from control, and TRR decreased to 44.8% of control. The data indicate that the RAS plays an important role in preventing reductions in GFR during increased RVP because blockade of angiotensin II (ANG II) formation by the CEI results in marked decreases in GFR at high RVPs. The decreases in GFR after ANG II blockade and RVP elevation were not due to lack of renal vasodilation, since TRR was maintained below while RBF was maintained either above or at the pre-CEI levels.

The role of venous pressure variability during hemodialysis in the prediction of impending arteriovenous graft occlusion

2021 ◽  
pp. 112972982110573
Author(s):  
Yuan-Hsi Tseng ◽  
Min Yi Wong ◽  
Chih-Chen Kao ◽  
Chien-Chao Lin ◽  
Ming-Shian Lu ◽  
...  
Keyword(s):  
Operating Characteristic ◽  
Characteristic Curve ◽  
Venous Pressure ◽  
Blood Flow Rate ◽  
Curve Analysis ◽  
Graft Occlusion ◽  
Arteriovenous Graft ◽  
Significant Elevation ◽  
Operating Characteristic Curve

Background: Elevated venous pressure during hemodialysis (VPHD) is associated with arteriovenous graft (AVG) stenosis. This study investigated the role of VPHD variations in the prediction of impending AVG occlusion. Methods: Data were retrieved from 118 operations to treat AVG occlusion (occlusion group) and 149 operations to treat significant AVG stenosis (stenosis group). In addition to analyzing the VPHD values for the three hemodialysis (HD) sessions prior to the intervention, VPHD values were normalized to mean blood pressure (MBP), blood flow rate (BFR), BFR × MBP, and BFR2 × MBP to yield ratios for analysis. The coefficient of variation (CV) was used to measure relative variations. Results: The within-group comparisons for both groups revealed no significant differences in the VPHD mean and CV values among the three HD sessions prior to intervention. However, the CVs for VPHD/MBP, VPHD/(BFR × MBP), and VPHD/(BFR2 × MBP) exhibited significant elevation in the occlusion group during the last HD session prior to intervention compared with both the penultimate and antepenultimate within-group HD data ( p < 0.05). In the receiver operating characteristic curve analysis, the CV for VPHD/(BFR2 × MBP) was the only parameter able to discriminate between the last and the penultimate HD outcomes ( p < 0.001). According to a multivariate analysis, after controlling for covariates, CV for VPHD/(BFR2 × MBP) >8.76% was associated with a higher risk of AVG thrombosis (odds ratio: 3.17, p < 0.001). Conclusions: Increasing the variation in VPHD/(BFR2 × MBP) may increase the probability of AVG occlusion.

Muscle sympathetic nerve responses to dynamic one-legged exercise: effect of body posture

1993 ◽  
Vol 264 (1) ◽  
pp. H1-H7 ◽  
Author(s):  
C. A. Ray ◽  
R. F. Rea ◽  
M. P. Clary ◽  
A. L. Mark
Keyword(s):  
Sympathetic Nerve ◽  
Venous Return ◽  
Muscle Sympathetic Nerve Activity ◽  
Venous Pressure ◽  
Arm Exercise ◽  
Exercise Effect ◽  
Leg Exercise ◽  
Cardiac Filling ◽  
Cardiopulmonary Baroreceptors

Previous studies examining muscle sympathetic nerve activity (MSNA) during dynamic exercise have focused on upper extremity exercise. The present study was undertaken to investigate 1) MSNA responses to dynamic one-legged knee extensions (DLE) and 2) the role of the cardiopulmonary baroreflexes in the modulation of MSNA responses to DLE. MSNA was measured during 4 min of DLE at 20 (n = 10) and 30 W (n = 9) and during 3 min of DLE at 40 W (n = 9). DLE was performed in the upright (sitting) position and MSNA was recorded in the contralateral leg (peroneal nerve). DLE elicited significant increases in mean arterial pressure (MAP) and heart rate (HR; P < 0.05). In contrast to previous studies using dynamic arm exercise, MSNA (bursts/min) decreased by 25% (P < 0.05) during the first minute of DLE from resting control and remained suppressed during the remaining 3 min of DLE at 20 and 30 W. During the first minute of DLE at 40 W, MSNA (bursts/min) decreased by 18% (P < 0.05), but returned to control levels during the last minute of exercise. Because dynamic leg exercise in the upright position increases venous return, we postulated that upright DLE might increase cardiac filling pressures and stimulate the cardiopulmonary baroreceptors resulting in suppression of MSNA. To investigate this possibility, we measured MSNA and central venous pressure (CVP) during 4 min of both supine and upright DLE at 30 W. MAP, HR, and CVP increased and MSNA decreased from 30 +/- 3 to 22 +/- 3 bursts/min (mean exercise value; P < 0.05) during upright DLE.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Retinal venous pressure in the non-affected eye of patients with retinal vein occlusions

2014 ◽  
Vol 252 (10) ◽  
pp. 1569-1571 ◽  
Author(s):  
Maneli Mozaffarieh ◽  
M. Bärtschi ◽  
P. B. Henrich ◽  
A. Schoetzau ◽  
J. Flammer
Keyword(s):  
Venous Pressure ◽  
Retinal Venous Pressure ◽  
Retinal Vein Occlusions

Pulmonary and systemic blood pressure response to serotonin: role of chemoreceptors

1961 ◽  
Vol 201 (2) ◽  
pp. 369-374 ◽  
Author(s):  
K. Braun ◽  
S. Stern
Keyword(s):  
Pulmonary Artery ◽  
Blood Pressure Response ◽  
Pressor Response ◽  
Femoral Vein ◽  
Venous Pressure ◽  
Systemic Blood Pressure ◽  
Systemic Circulation ◽  
Ascending Aorta ◽  
Pulmonary Arterial

Large doses of serotonin (200 µg/ kg) in the anesthetized open-chest dog, administered into the femoral vein, right heart, pulmonary artery, left heart, ascending aorta or common carotid arteries, caused a marked pressor response in the systemic circulation. The latent period became shorter with the shift of the site of the injection toward the ascending aorta. After injection into the descending aorta a "double peak" pressor response was obtained. These observations, together with the demonstration of a much less pronounced pressor effect after elimination of the aortic and carotid chemoreceptors, indicate participation of chemoreceptor stimulation in the systemic pressor response. In the pulmonary artery the pressure rose markedly and consistently. A rise in the pulmonary venous pressure without any significant change in the left atrial pressure was observed, indicating pulmonary venous constriction. Chemoreceptor stimulation was shown to play a part also in the rise of both the pulmonary arterial and pulmonary venous pressures.

scholarly journals 1633 Final non-invasive echo-guided assessment of left atrial pressure after percutaneous edge-to-edge procedure for mitral regurgitation

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
M Gavazzoni ◽  
M Z Zuber ◽  
A P Pozzoli ◽  
M T Taramasso ◽  
F M Maisano
Keyword(s):  
Correlation Coefficient ◽  
Left Atrial ◽  
Continuous Wave ◽  
Venous Pressure ◽  
Right Atrial ◽  
Rater Reliability ◽  
Intra Class Correlation ◽  
Therapeutic Decisions ◽  
Intra Class Correlation Coefficient

Abstract Background/Introduction. Recently the central role of hemodynamic invasive monitoring during MitraClip (Abbott Vascular, Santa Clara, CA, USA) procedure has been raised. After removal of Steerable Guide Catheter (SGC) at the end of procedure, iatrogenic interatrial septum defect determines acute sub-clinical hemodynamic changes depending on right atrial (RA) and left atrial (LA) pressures. The possibility to assess LAP non-invasively by Doppler -echocardiography at the end of the procedure allows to quantify real hemodynamic impact of reduction of MR and leaves the door open to further therapeutic decisions (such as closure of iatrogenic IASd). Purpose This prospective study aimed to assess the role of evaluation of post-procedural mean trans-atrial gradient with continuous-wave (CW) Doppler (DPmean-IAS) in estimating final m-LAP after removal of SGC. Methods We prospectively performed the computation of trans-atrial CW- Doppler tracing for estimation of mean-transatrial gradient (meanGp-LA-RA) in patients treated with MitraClip; we added the estimation of central venous pressure (CVP) according to: i) dilatation of superior vena cava (IVC, mm); ii) presence or not of systolic excursion of IVC (end-inspiratory excursion was not evaluable in patients under sedation); iii) hepatic vein dilatation. The sum of CVP estimated and meanGp-LA-RA (mmHg) represents the m-LAP-Echo-measured at the end of procedure. This value has been compared with m-LAP measured invasively before removal of SGC. We tested the inter-rater reliability with the Intra-class Correlation Coefficient for comparing this method with the gold standard (invasive assessment of LAP). Results we included 19 patients; aetiology of MR was degenerative in 89% of cases. Basal m-LAP was 15 ± 13,3 mmHg and decreased by 32% by the end of procedure (mean-LAP at the end: 10,1 ± 3,3 mmHg, p &lt; 0.001). At the end of the procedure mean Gp-LA-RA was 2.5 ± 1.2 mmHg and CVP 7.5 ± 3.5; the m-LAP-Echo-measured was 9.6 ± 2.4. The delay in time of computation of m-LAP by echocardiography with respect to last invasive assessment available was computed and settled around 5 minutes (IQR 3-9 min). The inter-rater reliability with the Intra-class Correlation Coefficient was high: 0.8, (CI95% 0.647-0.948, p &lt; 0.01); with Bland-Altman test we could assess that bias of measures was acceptable for this clinical context with upper concordance limit of 2,7 mmHg and lower of 4,7 mmHg, with a bias of 0,9 mmHg, not relevant for this clinical purpose. Conclusions The present study represents the first validation of a Doppler-based method for non invasively assessing post-procedural LAP in percutaneous mitral valve interventions requiring transeptal approach. Follow up is needed for correlate this value with clinical outcomes.

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