Impact of Aortic Prosthetic Heart Valve Dysfunction on Left Ventricular Afterload and on the Accuracy of Echo-Doppler Measurements

2011 ◽  
Author(s):  
Othman Smadi ◽  
Zahra Keshavarz-Motamed ◽  
Ibrahim Hassan ◽  
Philippe Pibarot ◽  
Lyes Kadem
Keyword(s):  
Left Ventricle ◽  
Heart Valve ◽  
Heart Valves ◽  
Mechanical Heart Valve ◽  
Prosthetic Heart Valve ◽  
Left Ventricular ◽  
Heart Valve Disease ◽  
Thromboembolic Events ◽  
Left Heart ◽  
Ventricular Afterload

Left heart side (left ventricle and left atrium) is responsible for delivering the oxygenated blood to all body organs, where a relatively strong left ventricle contraction is needed to deliver around 5 liters of blood per minute. As a consequence, the left heart side experiences a high pressure (∼150 mmHg). Therefore, the dysfunction (stenosis or incompetence) in the aortic and/or mitral heart valves in the left side of the heart is more common than the dysfunction in the pulmonary and tricuspid heart valves in the right side of the heart (Yoganathan et al., 2004). Heart valve surgical replacement is the most effective solution in severe functional heart valve disease (Pibarot and Dumesnil, 2009). Almost, half of the total implants of prosthetic heart valves (∼300,000) are mechanical (mainly bileaflet). In case of mechanical heart valve (MHV), a lifelong anti-coagulant should be taken to avoid thromboembolic events. Despite the significant improvement in valve design resulting in minimizing prosthetic valve complications (thromboembolic events or pannus formation), these complications are still possible with MHV Implantation.

Simulations of Flow Through Bileaflet Mechanical Heart Valves With Asymmetric Leaflet Motion

2012 ◽  
Author(s):  
B. Min Yun ◽  
Lakshmi P. Dasi ◽  
Cyrus K. Aidun ◽  
Ajit P. Yoganathan
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Mechanical Heart Valve ◽  
Prosthetic Heart Valve ◽  
Prosthetic Heart Valves ◽  
Thromboembolic Events ◽  
Complex Flow ◽  
Blood Damage ◽  
Flow Through ◽  
Leaflet Motion

Prosthetic heart valves have been used for over 50 years to replace diseased native valves but still lead to severe complications such as platelet aggregation and thromboembolic events. The most widely implanted design is the bileaflet mechanical heart valve (BMHV). Most modern BMHV designs have better flow hemodynamics and blood damage performance than earlier-generation counterparts. However, blood element trauma and thromboembolic events still remain as major complications of current BMHV designs. These problems have been linked to blood damage caused by non-physiological stresses. These stresses are caused by the complex flow fields that arise due to prosthetic heart valve design. In order to reduce the severity of these complications, the blood damage that occurs in flows through prosthetic heart valves must be well understood.

Simulations of Flow Through Bileaflet Mechanical Heart Valves to Assess Platelet Damage

2011 ◽  
Author(s):  
B. Min Yun ◽  
Jingshu Wu ◽  
Cyrus K. Aidun ◽  
Ajit P. Yoganathan
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Mechanical Heart Valve ◽  
Prosthetic Heart Valve ◽  
Prosthetic Heart Valves ◽  
Thromboembolic Events ◽  
Complex Flow ◽  
Valve Design ◽  
Blood Damage ◽  
Flow Through

Prosthetic heart valves have been used for over 50 years to replace diseased native valves but still lead to severe complications such as hemolysis, platelet aggregation, and thromboembolic events. The most widely implanted design is the bileaflet mechanical heart valve (BMHV). Most modern BMHV designs have better flow hemodynamics and blood damage performance than their earlier-generation counterparts. However, blood element trauma and thromboembolic events still remain as major complications of current BMHV designs. These problems have been linked to blood element damage caused by non-physiological stresses. These stresses are caused by the complex flow fields that arise due to prosthetic heart valve design, particularly in the leaflet hinge region. In order to reduce the severity of these complications, the blood damage that occurs in flows through prosthetic heart valves must be well understood.

scholarly journals Hemodynamic Performance of Dysfunctional Prosthetic Heart Valve with the Concomitant Presence of Subaortic Stenosis: In Silico Study

2020 ◽  
Vol 7 (3) ◽  
pp. 90
Author(s):  
Othman Smadi ◽  
Anas Abdelkarim ◽  
Samer Awad ◽  
Thakir D. Almomani
Keyword(s):  
Early Detection ◽  
Heart Valve ◽  
Heart Valves ◽  
Cfd Simulation ◽  
Treatment Plan ◽  
Mechanical Heart Valve ◽  
Prosthetic Heart Valve ◽  
Subaortic Stenosis ◽  
Prosthetic Heart Valves ◽  
The Impact

The prosthetic heart valve is vulnerable to dysfunction after surgery, thus a frequent assessment is required. Doppler electrocardiography and its quantitative parameters are commonly used to assess the performance of the prosthetic heart valves and provide detailed information on the interaction between the heart chambers and related prosthetic valves, allowing early detection of complications. However, in the case of the presence of subaortic stenosis, the accuracy of Doppler has not been fully investigated in previous studies and guidelines. Therefore, it is important to evaluate the accuracy of the parameters in such cases to get early detection, and a proper treatment plan for the patient, at the right time. In the current study, a CFD simulation was performed for the blood flow through a Bileaflet Mechanical Heart Valve (BMHV) with concomitant obstruction in the Left Ventricle Outflow Tract (LVOT). The current study explores the impact of the presence of the subaortic on flow patterns. It also investigates the accuracy of (BMHV) evaluation using Doppler parameters, as proposed in the American Society of Echocardiography (ASE) guidelines.

How to grow a heart: fibreoptic guided fetal aortic valvotomy

2006 ◽  
Vol 16 (S1) ◽  
pp. 43-46 ◽  
Author(s):  
Elsa Suh ◽  
James Quintessenza ◽  
James Huhta ◽  
Ruben Quintero
Keyword(s):  
Left Ventricle ◽  
Aortic Stenosis ◽  
Fetal Echocardiography ◽  
Left Ventricular ◽  
Left Heart ◽  
Endocardial Fibroelastosis ◽  
Fetal Diagnosis ◽  
Ventricular Afterload ◽  
Systolic And Diastolic Function ◽  
Additional Support

Various physiologic mechanisms have been proposed to account for the development of hypoplasia of the left heart. The mechanism thus far most widely accepted suggests that the entity starts as severe or critical aortic stenosis during fetal gestation. Obstruction at the level of the abnormal aortic valve is then held to increase left ventricular afterload, resulting in decreased systolic and diastolic function. Shunting across the patent oval foramen is then reversed, so that blood flows from left to right. This reversal of flow during fetal gestation decreases the volume of blood crossing the mitral valve, thus decreasing the further potential for growth of the left ventricle.1 Additional support for this postulated physiologic mechanism was provided with the advent of fetal echocardiography during the 1980s.2–4 It was the group of Allan, working at Guy's Hospital in London, which first documented the fetal development of hypoplasia of the left heart by serial echocardiographic observation.4 In their retrospective study of 7000 pregnancies, 462 fetuses were diagnosed to have a structural cardiac defect at the time of the initial echocardiogram. Among those, 28 patients had dilated and dysfunctional left ventricles and aortic valves. The majority of these patients were also found to have concomitant endocardial fibroelastosis. Out of 15 patients in the series who were followed with serial echocardiograms, five progressed to develop hypoplasia of the left heart. With echocardiographic technology undergoing refinement over the same period, it was during this era that the first fetal cardiac intervention was performed using echocardiographic guidance.2,5,6 With still further technologic advances, fetal diagnosis of hypoplasia of the left heart can now be made as early as 13 weeks gestational age.7 One entity which is frequently associated with the hypoplastic left ventricle and aortic stenosis is endocardial fibroelastosis. There is an overlap of pathology between these three entities.8–10 In this report, we describe our own experience in intervention in a fetus suspected of developing hypoplasia of the left heart.

Evaluation of Paravalvular Leakage in Novel Mechanical Heart Valve

2017 ◽  
Author(s):  
Ankit Saxena ◽  
Rohan Shad ◽  
Mrudang Mathur ◽  
Anwesha Chattoraj ◽  
Sujay Shad
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Cardiac Tissue ◽  
Mechanical Heart Valve ◽  
Prosthetic Heart Valve ◽  
3D Printed ◽  
Novel Method ◽  
Novel Devices ◽  
Careful Assessment ◽  
Unique Mechanism

We developed a new mechanical heart valve prototype with a unique mechanism for attachment to cardiac tissue. The development of novel prosthetic heart valve systems requires careful assessment of paravalvular leaks — leakage of fluid that takes place between the valve and the cardiac tissue it is attached to. Traditional methods of testing paravalvular leaks in flow chambers are not ideal for novel devices and may underestimate its true extent. In this paper we developed a novel method of quantifying paravalvular leaks involving the use of 3D printed prototype heart valves and cadaveric bovine hearts, and compared the results with those from commercially available Medtronic ATS mechanical bileaflet valves. The average leak in our final prototype heart valves were found to be 0.13 ml/sec, compared to 0.33 ml/sec in the ATS valve.

Simulations of the Hinge Flow Fields of a Bileaflet Mechanical Heart Valve Under Physiologic Pulsatile Aortic Conditions

2008 ◽  
Author(s):  
Hélène A. Simon ◽  
Liang Ge ◽  
Iman Borazjani ◽  
Fotis Sotiropoulos ◽  
Ajit P. Yoganathan
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Mechanical Heart Valve ◽  
Prosthetic Heart Valve ◽  
Prosthetic Heart Valves ◽  
Valve Design ◽  
Bileaflet Mechanical Heart Valve ◽  
Hinge Flow ◽  
Blood Elements

Native heart valves with limited functionality are commonly replaced by prosthetic heart valves. Since the first heart valve replacement in 1960, more than three million valves have been implanted worldwide. The most widely implanted prosthetic heart valve design is currently the bileaflet mechanical heart valve (BMHV), with more than 130,000 implants every year worldwide. However, studies have shown that this valve design can still cause major complications, including hemolysis, platelet activation, and thromboembolic events. Clinical reports and recent in vitro experiments suggest that these thrombogenic complications are associated with the hemodynamic stresses imposed on blood elements by the complex non-physiologic flow induced by the valve, in particular in the hinge region.

Development and Optimization of a Novel Polymeric Prosthetic Heart Valve Using the Device Thrombogenicity Emulation (DTE) Methodology

2012 ◽  
Author(s):  
Thomas E. Claiborne ◽  
Michalis Xenos ◽  
Jawaad Sheriff ◽  
Dinesh Peter ◽  
Yared Alemu ◽  
...  
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Mechanical Heart Valve ◽  
Prosthetic Heart Valve ◽  
Total Artificial Heart ◽  
Circulatory Support ◽  
Calcific Aortic Valve Disease ◽  
Structural Valve Deterioration ◽  
Transcatheter Valve ◽  
Valve Implantation

Calcific aortic valve disease (CAVD) is the most common and life threatening form of valvular heart disease, characterized by stenosis and regurgitation, which is currently treated at the symptomatic end-stages via open-heart surgical replacement of the diseased valve with typically either a xenograft tissue valve or mechanical heart valve. These options offer the clinician a choice between structural valve deterioration and anticoagulant therapy respectively, effectively replacing one disease with another [1]. Polymeric heart valves (PHV) offer the promise of reducing or eliminating these complications [2] and may be efficacious for patients who cannot tolerate cardiothoracic surgery by using instead transcatheter valve implantation (TAVI) [3], where there is evidence that tissue valves are damaged during implantation [4], and in pulsatile circulatory support devices such as the SynCardia Total Artificial Heart. But development of PHVs has been slow due to the lack of sufficiently durable and biocompatible formulations.

Echocardiographic assessment of the aortic valve and left ventricular outflow tract

2005 ◽  
Vol 15 (S1) ◽  
pp. 27-36 ◽  
Author(s):  
Alfred Asante-Korang ◽  
Robert H. Anderson
Keyword(s):  
Aortic Valve ◽  
Left Ventricle ◽  
Left Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Left Ventricular ◽  
Outflow Tract ◽  
Left Heart ◽  
Transesophageal Echocardiogram ◽  
Left Ventricular Outflow ◽  
Echocardiographic Assessment

The previous reviews in this section of our Supplement1,2 have summarized the anatomic components of the ventriculo-arterial junctions, and then assessed the echocardiographic approach to the ventriculo-arterial junction or junctions as seen in the morphologically right ventricle. In this complementary review, we discuss the echocardiographic assessment of the comparable components found in the morphologically left ventricle, specifically the outflow tract and the arterial root. We will address the echocardiographic anatomy of the aortic valvar complex, and we will review the causes of congenital arterial valvar stenosis, using the aortic valve as our example. We will also review the various lesions that, in the outflow of the morphologically left ventricle, can produce subvalvar and supravalvar stenosis. We will then consider the salient features of the left ventricular outflow tract in patients with discordant ventriculo-arterial connections, and double outlet ventricles. To conclude the review, we will briefly address some rarer anomalies that involve the left ventricular outflow tract, showing how the transesophageal echocardiogram is used to assist the surgeon preparing for repair. The essence of the approach will be to consider the malformations as seen at valvar, subvalvar, or supravalvar levels,1 but we should not lose sight of the fact that aortic coarctation or interruption, hypoplasia of the left heart, and malformations of the mitral valve are all part of the spectrum of lesions associated with obstruction to the left ventricular outflow tract. These additional malformations, however, are beyond the scope of this review.

Sign in / Sign up

Export Citation Format

Share Document