Ventricular flow Dynamic past Bileaflet Prosthetic Heart Valves

1995 ◽  
Vol 18 (7) ◽  
pp. 380-391 ◽  
Author(s):  
V. Garitey ◽  
T. Gandelheid ◽  
J. Fuseri ◽  
R. PÉlissier ◽  
R. Rieu
Keyword(s):  
Heart Valves ◽  
Prosthetic Heart Valves ◽  
Septal Wall ◽  
Jude Medical ◽  
Anatomical Position ◽  
Mitral Inflow ◽  
Mitral Position ◽  
Significant Difference ◽  
Axis Parallel ◽  
Cardiovascular Simulator

To characterise hydrodynamic properties of prosthetic heart valves in mitral position, ultrasonic velocity measurements were performed using a cardiovascular simulator. A Duromedics and a Saint-Jude Medical bileaflet heart valve were tested. The Saint-Jude valve was oriented first in an anatomical position, i.e. the tilt axis parallel to the septal wall, and then in an anti-anatomical position. In the anti-anatomical position, from mid diastole to mid systole, two contrarotative vortices are generated in the ventricle by the interaction between the flow directed by the leaflets downstream from the lateral orifices and the ventricular wall motions. In the anatomical position, the mitral flow penetrates the ventricle principally through the lateral orifice proximal to the septal wall, due to the vortex in the atrial chamber. The mitral inflow then circulates along the septal wall to the apex, and produces a large ventricular vortex during systole. In the anatomical position, the Saint-Jude thus provides a better ventricular washout during this phase. The mitral inflow through the Duromedics in the anti-anatomical position produces two contrarotative vortices in the ventricle, but in the opposite sense than downstream the Saint-Jude valve; the flows that penetrate through the lateral orifices are directed to the ventricular walls and then recirculate to the centre of the ventricle, providing a very fluctuating flow near the apex. Thus, a slight difference in valve design produces a significant difference in the ventricular flow fields.

Highly resolved pulsatile flows through prosthetic heart valves using the entropic lattice-Boltzmann method

2014 ◽  
Vol 754 ◽  
pp. 122-160 ◽  
Author(s):  
B. Min Yun ◽  
L. P. Dasi ◽  
C. K. Aidun ◽  
A. P. Yoganathan
Keyword(s):  
Lattice Boltzmann Method ◽  
Pulsatile Flow ◽  
Lattice Boltzmann ◽  
Heart Valves ◽  
Prosthetic Heart Valves ◽  
Spatiotemporal Resolution ◽  
Jude Medical ◽  
High Spatiotemporal Resolution ◽  
Flow Through ◽  
Boltzmann Method

AbstractProsthetic heart valves have been widely used to replace diseased or defective native heart valves. Flow through bileaflet mechanical heart valves (BMHVs) have previously demonstrated complex phenomena in the vicinity of the valve owing to the presence of two rigid leaflets. This study aims to accurately capture the complex flow dynamics for pulsatile flow through a 23 mm St Jude Medical (SJM) Regent™ BMHV. The lattice-Boltzmann method (LBM) is used to simulate pulsatile flow through the valve with the inclusion of reverse leakage flow at very high spatiotemporal resolution that can capture fine details in the pulsatile BMHV flow field. For higher-Reynolds-number flows, this high spatiotemporal resolution captures features that have not been observed in previous coarse resolution studies. In addition, the simulations are able to capture with detail the features of leaflet closing and the asymmetric b-datum leakage jet during mid-diastole. Novel flow physics are visualized and discussed along with quantification of turbulent features of this flow, which is made possible by this parallelized numerical method.

Circulating Platelet Factors (Beta Thromboglobulin, Platelet Factor 4) In Patients With Prosthetic Heart Valves

1981 ◽  
Author(s):  
K Andrassy ◽  
H Zebe ◽  
J Koderisch ◽  
A Duczek ◽  
E Ritz
Keyword(s):  
Heart Valves ◽  
Prosthetic Heart Valves ◽  
Valve Prosthesis ◽  
Platelet Factor ◽  
Protein Levels ◽  
Platelet Protein ◽  
Mitral Valve Prosthesis ◽  
Significant Difference ◽  
Aortic Valve Prosthesis ◽  
Induced Aggregation

Despite anticoagulation, thromboembolic complications are frequent in patients with heart valve prosthesis (HVP). The present study was performed to investigate whether activation of platelets could be demonstrated in such patients. Platelet proteins in the circulation were measured as an index of platelet activation. Pat.: 33 pat. with mitral valve prosthesis (MVP) (19 with Bjφrk- Shiley (BS) and 14 pat. with Starr Edwards type (SE)) and 54 pat. with aortic valve prosthesis (35 BS; 10 SE; 9 bioprosthesis (BP). All pat. were anticoagulated (Dicumarol). Results : In MVP, a significant difference between BS and SE was observed with respect to LDH (247±48 vers. 474± 246) (p<0.05) but not with regard to Beta-TG and PF 4. There was no difference of platelet protein levels in presence/absence of atrial fibrillation. In 35% Beta TG (> 53 ng/ml) and PF 4 ( > 11 ng/ml) were above X±2 SD of CO. ADP and collagen induced aggregation (MA) was unchanged in all pat. (collagen 401 12; ADP 32±11; CO: collagen 39±7; ADP 32±6). In pat. with demonstrable hemolysis (LDH >250 IU), a significant correlation was observed between LDH and Beta TG/PF 4 both in MVP and AVP. MVP and AVP differed with respect to LDH (higher in AVP, p<0.05) and PF 4 (higher in MVP (p<0.01) but not with respect to Beta TG (differences of elimination of TG and PF 4?). Comment : In a high proportion of patients with HVP platelets are activated. The observation of elevated platelet indicator proteins is in agreement with previous findings of decreased platelet survival in HVP (Weily, H., New Engl. J. Med. 290, 534, 1974). Elevated platelet prot.may identify risk of thromboembolism.

LDA Study of the Flow Associated With the Design Differences and Orientations of the Bileaflet Mechanical Prostheses

2000 ◽  
Author(s):  
Toshinosuke Akutsu ◽  
Daiki Higucchi ◽  
Tomohiro Taguchi
Keyword(s):  
Flow Field ◽  
Pulsatile Flow ◽  
Heart Valves ◽  
Flow Fields ◽  
Flow Conditions ◽  
Jude Medical ◽  
Mitral Position ◽  
Highly Sensitive ◽  
Mechanical Prostheses ◽  
Two Component

Abstract Four typical mechanical bileaflet heart valves (St. Jude Medical, Advancing The Standard, Carbomedics, and Jyros valves) have been tested in the mitral position under pulsatile flow conditions. Measurements of velocity and turbulent stresses were conducted at five downstream locations using a sophisticated cardiac simulator in conjunction with a highly sensitive two-component LDA. Comparison of these flow fields associated with the opening and subsequent accelerating phase of the flow revealed similarity and dissimilarity of the flow field associated with the different valve designs and helped established visualizing the effect of the valve designs and orientations on the flow.

How Do Transcatheter Heart Valves Fit in Mitral Annuloplasty Rings and Which Combination Can be Recommended?

2018 ◽  
Vol 67 (04) ◽  
pp. 257-265
Author(s):  
Roya Ostovar ◽  
Ralf-Uwe Kuehnel ◽  
Michael Erb ◽  
Martin Hartrumpf ◽  
Thomas Claus ◽  
...  
Keyword(s):  
High Speed ◽  
Visual Inspection ◽  
Heart Valves ◽  
Mitral Annuloplasty ◽  
Jude Medical ◽  
Pulse Duplicator ◽  
Round Shape ◽  
Mitral Position ◽  
Transcatheter Heart Valve ◽  
Edwards Sapien

Background Transcatheter heart valve (THV) as valve-in-ring is increasingly used in the mitral position. Semi-rigid rings may serve as a more appropriate scaffold for proper anchoring of a THV as they may change from their oval to a round shape thereby fitting to the implanted THV. Methods One rigid and five semi-rigid rings of four manufacturers, Edwards Physio I and II, Sorin 3D Memo, Medtronic Simulus, and St. Jude Medical (SJM) Saddle and SJM Sequin, with sizes 28 to 36 mm and Edwards Sapien III THV 23, 26, and 29 mm were used. Preevaluation comprised insertion/inflation of the THV into the ring and visual inspection for the paravalvular gap ≥ 4 mm2. Only valves not showing paravalvular gap were then submitted to hemodynamic evaluation with a pulse duplicator. Cusp movement was assessed with a high-speed-camera. Mean transvalvular gradients (TVGs) were measured. Results SJM Saddle ring of all sizes and SJM Sequin ring 34 showed marked gaps combined with all THV sizes, thus not undergoing hemodynamic testing. It was further shown that ring sizes ≥ 36 mm did not allow for a proper fit of even the largest THV into the ring of all the manufacturers and were consequently not hemodynamically evaluated. The 23 mm THV was too small for any ring size. The lowest gradients were achieved with the 26 mm THV in 30 and 32 mm and the 29 mm THV in 32 and 34 mm rings. Conclusion Not all currently available annuloplasty rings are ideal scaffolds for THV placement. It appears that a more proper fit can be achieved with semi-rigid rings than with rigid ones. Note that 23 mm THV appeared to be too small for an adequate anchoring in even the smallest available ring. Thus, 26 mm as well as 29 mm THV fit properly in ring sizes between 28 and 34 mm. Surgeons may consider to choose from those ring brands and sizes which allow for good placement of a THV in view of possible valve degeneration in the later course.

Hydrodynamic Advantages and Disadvantages of Mechanical Bileaflet Valves and Tilting Disc Valves No. 29

1987 ◽  
Vol 16 (2) ◽  
pp. 77-85 ◽  
Author(s):  
R Heiliger
Keyword(s):  
Heart Valves ◽  
Efficiency Index ◽  
Mechanical Heart Valves ◽  
Orifice Area ◽  
Pressure Drops ◽  
Jude Medical ◽  
Advantages And Disadvantages ◽  
Mock Circulation ◽  
Mitral Position ◽  
Bileaflet Valves

In order to determine the effectiveness of mechanical heart valves two different types of mechanical heart valves, three tilting disc valves (BS–SD, BS–CCD, BS–M) and two bileaflet valves (St Jude Medical, Duromedics) with the same size of annulus diameter dA = 29 mm have been investigated in the mitral position of a mock circulation under pulsatile flow conditions. Flow, pressure and orifice area have been measured. Insufficiency, mean orifice area, discharge coefficient, performance index, and efficiency index have been calculated. The investigated tilting disc valves show smaller reflux volume and smaller insufficiency when comparing with the bileaflet valves. The bileaflet valves show higher values of orifice areas—that is to say smaller pressure drops—than the tilting disc valves. The St Jude Medical shows the biggest orifice areas, but also the highest reflux volume and insufficiency. Insufficiency of the Duromedics is slightly higher than that of the tilting disc valves. The orifice area of the Duromedics is bigger than that of the tilting disc valves and smaller than that of the St Jude Medical. The different pivot and the different profile of the disc of the BS–CCD and the BS–M are responsible for the more constant behaviour of the opening of these tilting disc valves when comparing with the BS–SD. Though the bileaflet valves show the better efficiency index, none of the valve types is superior in all hydrodynamic criteria. Both valve types, the bileaflet valves and the tilting disc valves, show different hydrodynamic advantages and disadvantages.

Optimal Intensity for Oral Anticoagulation in Patients with Prosthetic Heart Valves

1997 ◽  
Vol 17 (03) ◽  
pp. 158-160
Author(s):  
Alexander Turpie
Keyword(s):  
Risk Factors ◽  
Clinical Trials ◽  
Heart Valves ◽  
Oral Anticoagulants ◽  
Prosthetic Heart Valves ◽  
Additional Risk ◽  
Mitral Position ◽  
Mechanical Prostheses ◽  
Patients At Risk ◽  
Optimal Intensity

SummaryAntithrombotic therapy in patients with heart valve replacement has been placed on a firm scientific footing based on a number of prospective clinical trials. Patients with bioprostheses in the mitral position require a minimal of 3 months oral anticoagulants at a target INR of 2.0-3.0. Patients with bioprostheses with additional risk factors should receive oral anticoagulants indefinitely. Patients with mechanical prostheses require life-long anticoagulants at a target INR of 2.5-3.5. The addition of antiplatelet drugs to anticoagulants improves the outcome particularly in patients at risk of vascular disease.

Comparison between two different regimens of anticoagulants for pregnant women with prosthetic heart valves

2017 ◽  
Vol 6 (6) ◽  
pp. 2158
Author(s):  
Mustafa Bahloul ◽  
Armia Michael ◽  
Mansour Y. Kandeel ◽  
Ahmed M. Abbas
Keyword(s):  
Pregnant Women ◽  
Heart Valves ◽  
Oral Anticoagulants ◽  
Prosthetic Heart Valves ◽  
Fetal Outcomes ◽  
Warfarin Group ◽  
Group I ◽  
Significant Difference ◽  
Sequential Regimen ◽  
Group Ii

Background: The current study aims to assess the maternal and fetal outcomes of pregnant females with prosthetic heart valves receiving oral anticoagulants only versus the sequential regimen of heparin and OA throughout pregnancy.Methods: An observational was carried out at Assiut Women's Health Hospital, Egypt between February and December 2016. All pregnant women with prosthetic heart valves attending the emergency department during the study period were enrolled in the study. All included patients were classified into two groups; women who receive low molecular weight heparin (LMWH) during the first trimester then shift to warfarin till 36 weeks of gestation then continue on LMWH till delivery (Group I) and those who continue the all period of pregnancy on warfarin (Group II). The primary outcome of the study was the difference in the rate of maternal cardiac complications during labor between both groups.Results: The study included 72 patients have prosthetic valve replacement and on anticoagulants. Twenty-one were on oral anticoagulant; warfarin (Group II) and 51 pregnant women were on sequential regimen. Both groups were comparable in their basic and clinical data on admission. No difference between both groups in the mode of delivery (p=0.52), postpartum hemorrhage (0.09), sub rectal hematomas (p=0.08), the need for postpartum admission to ICU (p=0.93) and the duration of hospital stay (p=0.47). Additionally, no statistical significant difference between both groups as regard the mean birth weight (p=0.97), Apgar score (p=0.62), fetal sex (p=0.92) and congenital anomalies (p=0.08).Conclusions: The use of sequential LMWH and oral anticoagulants appears to be a safe option for those women although there is no difference in maternal and fetal outcomes with the use of continuous oral anticoagulants throughout the pregnancy.

Echocardiographic Appearance of Normally Functioning Sorin Bicarbon Valve Prostheses

1996 ◽  
Vol 4 (4) ◽  
pp. 217-221
Author(s):  
Attilio Renzulli ◽  
Nicola Vitale ◽  
Gennaro Ismeno ◽  
Giovanni Dialetto ◽  
Domenico Paparella ◽  
...  
Keyword(s):  
Heart Valves ◽  
Color Doppler ◽  
Early Postoperative Period ◽  
Prosthetic Heart Valves ◽  
Gastric Bleeding ◽  
Jude Medical ◽  
Echocardiographic Study ◽  
Valve Prostheses ◽  
Bicarbon Valve

A clinical and echocardiographic study was carried out to evaluate the performance of the Sorin Bicarbon bileaflet valve. From December 1990 to December 1994, 100 patients underwent isolated mitral (64) or aortic (36) valve replacement. There were 39 males and 61 females, with ages ranging from 21 to 73 years (mean 62 ± 9.6 years). Forty-three patients underwent a transthoracic continuous pulsed color Doppler echocardiogram at 3 and 6 months postoperatively. For mitral prostheses, the parameters calculated were valve area, pressure half-time and mean gradient; for aortic prostheses, peak and mean gradients were measured. Results were compared by analysis of variance to those obtained in patients matched for sex, body surface area, cardiac rhythm, site, and size of the prosthesis who had St. Jude Medical or CarboMedics valves implanted. No statistically significant differences were found among the 3 prosthetic heart valves. The operative mortality was 7%; 3 cases of fatal cerebral hemorrhage occurred in the early postoperative period. There was 1 late mortality, 1 case of transient cerebral ischemia, and 1 of gastric bleeding, all occurring inpatients with mitral prostheses. Midterm follow-up was satisfactory, although a larger series is required to confirm these results.

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