scholarly journals The impact of shape uncertainty on aortic‐valve pressure‐drop computations

2021 ◽  
Author(s):  
M. J. M. M. Hoeijmakers ◽  
W. Huberts ◽  
M. C. M. Rutten ◽  
F. N. Vosse
Keyword(s):  
Pressure Drop ◽  
Aortic Valve ◽  
Shape Uncertainty ◽  
The Impact ◽  
Valve Pressure

Steady Flow Hemodynamic and Energy Loss Measurements in Normal and Simulated Calcified Tricuspid and Bicuspid Aortic Valves

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Clara Seaman ◽  
A. George Akingba ◽  
Philippe Sucosky
Keyword(s):  
Pressure Drop ◽  
Aortic Valve ◽  
Energy Loss ◽  
Steady Flow ◽  
Flow Rate ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Type I ◽  
Orifice Area ◽  
The Impact

The bicuspid aortic valve (BAV), which forms with two leaflets instead of three as in the normal tricuspid aortic valve (TAV), is associated with a spectrum of secondary valvulopathies and aortopathies potentially triggered by hemodynamic abnormalities. While studies have demonstrated an intrinsic degree of stenosis and the existence of a skewed orifice jet in the BAV, the impact of those abnormalities on BAV hemodynamic performance and energy loss has not been examined. This steady-flow study presents the comparative in vitro assessment of the flow field and energy loss in a TAV and type-I BAV under normal and simulated calcified states. Particle-image velocimetry (PIV) measurements were performed to quantify velocity, vorticity, viscous, and Reynolds shear stress fields in normal and simulated calcified porcine TAV and BAV models at six flow rates spanning the systolic phase. The BAV model was created by suturing the two coronary leaflets of a porcine TAV. Calcification was simulated via deposition of glue beads in the base of the leaflets. Valvular performance was characterized in terms of geometric orifice area (GOA), pressure drop, effective orifice area (EOA), energy loss (EL), and energy loss index (ELI). The BAV generated an elliptical orifice and a jet skewed toward the noncoronary leaflet. In contrast, the TAV featured a circular orifice and a jet aligned along the valve long axis. While the BAV exhibited an intrinsic degree of stenosis (18% increase in maximum jet velocity and 7% decrease in EOA relative to the TAV at the maximum flow rate), it generated only a 3% increase in EL and its average ELI (2.10 cm2/m2) remained above the clinical threshold characterizing severe aortic stenosis. The presence of simulated calcific lesions normalized the alignment of the BAV jet and resulted in the loss of jet axisymmetry in the TAV. It also amplified the degree of stenosis in the TAV and BAV, as indicated by the 342% and 404% increase in EL, 70% and 51% reduction in ELI and 48% and 51% decrease in EOA, respectively, relative to the nontreated valve models at the maximum flow rate. This study indicates the ability of the BAV to function as a TAV despite its intrinsic degree of stenosis and suggests the weak dependence of pressure drop on orifice area in calcified valves.

Aortic Stenosis, Aortic Regurgitation and Arterial Hypertension

2019 ◽  
Vol 17 (2) ◽  
pp. 180-190 ◽  
Author(s):  
V. Katsi ◽  
G. Georgiopoulos ◽  
D. Oikonomou ◽  
C. Aggeli ◽  
C. Grassos ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Stenosis ◽  
Aortic Regurgitation ◽  
Antihypertensive Agents ◽  
Renin Angiotensin System ◽  
Aortic Disease ◽  
Review Of The Literature ◽  
Angiotensin System ◽  
The Impact ◽  
Worse Prognosis

Background: Hypertension (HT) is an important risk factor for cardiovascular disease and might precipitate pathology of the aortic valve. </P><P> Objective: To investigate the association of HT with aortic dysfunction (including both aortic regurgitation and stenosis) and the impact of antihypertensive treatment on the natural course of underlying aortic disease. </P><P> Methods: We performed a systematic review of the literature for all relevant articles assessing the correlation between HT and phenotype of aortic disease. </P><P> Results: Co-existence of HT with aortic stenosis and aortic regurgitation is highly prevalent in hypertensive patients and predicts a worse prognosis. Certain antihypertensive agents may improve haemodynamic parameters (aortic jet velocity, aortic regurgitation volume) and remodeling of the left ventricle, but there is no strong evidence of benefit regarding clinical outcomes. Renin-angiotensin system inhibitors, among other vasodilators, are well-tolerated in aortic stenosis. </P><P> Conclusion: Several lines of evidence support a detrimental association between HT and aortic valve disease. Therefore, HT should be promptly treated in aortic valvulopathy. Despite conventional wisdom, specific vasodilators can be used with caution in aortic stenosis.

scholarly journals THE IMPACT OF AORTIC ANGULATION ON CONTEMPORARY TRANSCATHETER AORTIC VALVE REPLACEMENT

2021 ◽  
Vol 77 (18) ◽  
pp. 1129
Author(s):  
Giorgio Medranda ◽  
Cheng Zhang ◽  
Brian Case ◽  
Charan Yerasi ◽  
Brian Forrestal ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Replacement ◽  
Valve Replacement ◽  
Transcatheter Aortic Valve Replacement ◽  
Transcatheter Aortic Valve ◽  
The Impact

The Impact of Aortic Angulation on Contemporary Transcatheter Aortic Valve Replacement Outcomes

2021 ◽  
Vol 14 (11) ◽  
pp. 1209-1215
Author(s):  
Giorgio A. Medranda ◽  
Anees Musallam ◽  
Cheng Zhang ◽  
Hank Rappaport ◽  
Paige E. Gallino ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Replacement ◽  
Valve Replacement ◽  
Transcatheter Aortic Valve Replacement ◽  
Transcatheter Aortic Valve ◽  
The Impact

scholarly journals IMPULSE: the impact of gender on the presentation and management of aortic stenosis across Europe

Open Heart ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. e001443
Author(s):  
Richard Paul Steeds ◽  
David Messika-Zeitoun ◽  
Jeetendra Thambyrajah ◽  
Antonio Serra ◽  
Eberhard Schulz ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Stenosis ◽  
Severe Aortic Stenosis ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Surgical Aortic Valve Replacement ◽  
Ventricular Ejection Fraction ◽  
Patient Profile ◽  
Transcatheter Aortic Valve ◽  
The Impact

AimsThere is an increasing awareness of gender-related differences in patients with severe aortic stenosis and their outcomes after surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI).MethodsData from the IMPULSE registry were analysed. Patients with severe aortic stenosis (AS) were enrolled between March 2015 and April 2017 and stratified by gender. A subgroup analysis was performed to assess the impact of age.ResultsOverall, 2171 patients were enrolled, and 48.0% were female. Women were characterised by a higher rate of renal impairment (31.7 vs 23.3%; p<0.001), were at higher surgical risk (EuroSCORE II: 4.5 vs 3.6%; p=0.001) and more often in a critical preoperative state (7.0vs 4.2%; p=0.003). Men had an increased rate of previous cardiac surgery (9.4 vs 4.7%; p<0.001) and a reduced left ventricular ejection fraction (4.9 vs 1.3%; p<0.001). Concomitant mitral and tricuspid valve disease was substantially more common among women. Symptoms were highly prevalent in both women and men (83.6 vs 77.3%; p<0.001). AVR was planned in 1379 cases. Women were more frequently scheduled to undergo TAVI (49.3 vs 41.0%; p<0.001) and less frequently for SAVR (20.3 vs 27.5%; p<0.001).ConclusionsThe present data show that female patients with severe AS have a distinct patient profile and are managed in a different way to males. Gender-based differences in the management of patients with severe AS need to be taken into account more systematically to improve outcomes, especially for women.

Two-Phase Flows in Mini-/Micro-Gas Flow Channels of PEM Fuel Cells

2013 ◽  
Author(s):  
Sung Chan Cho ◽  
Yun Wang
Keyword(s):  
Pressure Drop ◽  
Gas Flow ◽  
Fluid Model ◽  
Pem Fuel Cells ◽  
Two Phase ◽  
Micro Gas Flow ◽  
Two Fluid Model ◽  
The Impact ◽  
Two Fluid ◽  
Phase Pressure

In this paper, two-phase flow dynamics in a micro channel with various wall conditions are both experimentally and theoretically investigated. Annulus, wavy and slug flow patterns are observed and location of liquid phase on different wall condition is visualized. The impact of flow structure on two-phase pressure drop is explained. Two-phase pressure drop is compared to a two-fluid model with relative permeability correlation. Optimization of correlation is conducted for each experimental case and theoretical solution for the flows in a circular channel is developed for annulus flow pattern showing a good match with experimental data in homogeneous channel case.

Abstract 5857: Low Operative Mortality with implantation of a Continuous Flow LVAD and Impact of Concurrent Cardiac Procedures

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Jay D Pal ◽  
Charles T Klodell ◽  
Ranjit John ◽  
Francis Pagani ◽  
Joseph G Rogers ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Continuous Flow ◽  
Operative Mortality ◽  
Negative Impact ◽  
Venous Pressure ◽  
Heartmate Ii ◽  
Cardiac Procedures ◽  
Increased Risk ◽  
The Impact ◽  
Tricuspid Repair

Objective: Our goal was to determine the operative mortality of isolated implantation of the HeartMate II continuous flow LVAD and the impact of additional concurrent cardiac procedures on patient outcomes. Methods: In a multicenter trial, 279 patients at 33 clinical sites underwent implantation of the HeartMate II continuous flow LVAD as a bridge to transplantation from March 2005 to March 2007. HeartMate II implantation (HM II) was the only procedure required in 172 patients while 80 patients required concurrent cardiac procedures in conjunction with LVAD implantation (HM II+CCP). Results: Preoperative characteristics were similar, but central venous pressure (14.5 vs 11.6 mmHg) was greater for patients requiring concurrent cardiac procedures, suggesting worse right heart dysfunction. Mean cardiopulmonary bypass times increased from 97 to 120 minutes when a concurrent cardiac procedure was performed (p<0.001). Length of stay slightly increased from 23 to 26 days (p=0.17). Overall 30- and 180-day mortality was 5.8% and 13.3% for the HM II group, and 11.3% and 20.0% for the HM II+CCP group. Concurrent valvular procedures increased the risk to 8.5% and 19.1%. Patients who underwent an aortic valve replacement with cardioplegic arrest had a 30-day mortality of 25%, higher than for isolated concurrent mitral (0%) or tricuspid repair (3.3%). Other cardiac procedures were associated with a 30-day mortality of 27.8%. Survival at 180 days was 87% for HMII alone and 80% for HMII+CCP. Conclusion: There is a low 5.8% operative mortality for patients requiring uncomplicated HeartMate II implantation, with no apparent increased risk for concurrent PFO closure, mitral or tricuspid repair. However, concurrent aortic valve and other cardiac procedures are associated with a significantly decreased survival. The increased risk of these procedures must be balanced against the negative impact of uncorrected aortic insufficiency during VAD support.

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