Multiphysics and Multiscale Simulation: Application to a Coupled Model of the Left Ventricle and a Mechanical Heart Valve

Recent groundbreaking work by Kilner et al. [1] demonstrated that a healthy functioning heart redirects the flow through the left ventricle (LV) in an asymmetric manner, which results in an energy conserving mechanism. Heart valve replacement alters the physiological operation of the heart significantly affecting its hemodynamic performance. As a result, orientation and valve design could play a significant role in the energy efficient operation of the heart; therefore, orienting MHVs so that flow disturbances are minimized enhances the hemodynamic performance of the LV.

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Flow characteristics in a model of a left ventricle in the presence of a dysfunctional mitral mechanical heart valve

Journal of Visualization ◽

10.1007/s12650-019-00611-3 ◽

2019 ◽

Vol 23 (1) ◽

pp. 1-8

Author(s):

Nasibeh Mirvakili ◽

Giuseppe Di Labbio ◽

Wael Saleh ◽

Lyes Kadem

Keyword(s):

Left Ventricle ◽

Heart Valve ◽

Mechanical Heart Valve ◽

Flow Characteristics

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Experimental and Computational Studies of the Aortic Bi-leaflet Mechanical Heart Valve (BMHV) Hemodynamics in an Idealized Left Ventricle

QScience Proceedings ◽

10.5339/qproc.2012.heartvalve.4.64 ◽

2012 ◽

Vol 2012 (4) ◽

pp. 64

Author(s):

Trung Bao Le ◽

Brandon Chaffin ◽

Lucia Mirabella ◽

Arvind Santhanakrishnan ◽

Ajit Yoganathan ◽

...

Keyword(s):

Left Ventricle ◽

Heart Valve ◽

Mechanical Heart Valve ◽

Computational Studies

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

ASME 2011 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2011-53769 ◽

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.

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A Comparison of a Moderate with Moderate-high Intensity Oral Anticoagulant Treatment in Patients with Mechanical Heart Valve Prostheses

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656064 ◽

1997 ◽

Vol 77 (05) ◽

pp. 0839-0844 ◽

Cited By ~ 34

Author(s):

Vittorio Pengo ◽

Fabio Barbero ◽

Alberto Banzato ◽

Elisabetta Garelli ◽

Franco Noventa ◽

...

Keyword(s):

Heart Valve ◽

High Intensity ◽

Oral Anticoagulant ◽

Oral Anticoagulants ◽

Mechanical Heart Valve ◽

Moderate Intensity ◽

Minor Bleeding ◽

Anticoagulant Treatment ◽

Oral Anticoagulant Treatment ◽

Valve Prostheses

SummaryBackground. The long-term administration of oral anticoagulants to patients with mechanical heart valve prostheses is generally accepted. However, the appropriate intensity of oral anticoagulant treatment in these patients is still controversial.Methods and Results. From March 1991 to March 1994, patients referred to the Padova Thrombosis Center who had undergone mechanical heart valve substitution at least 6 months earlier were randomly assigned to receive oral anticoagulants at moderate intensity (target INR = 3) or moderate-high intensity (target INR = 4). Principal end points were major bleeding, thromboembolism and vascular death. Minor bleeding was a secondary end-point.A total of 104 patients were assigned to the target 3 group and 101 to the target 4 group; they were followed for from 1.5 years to up 4.5 years (mean, 3 years). Principal end-points occurred in 13 patients in the target 3 group (4 per 100 patient-years) and in 20 patients in the target 4 group (6.9 per 100 patient-years). Major hemorrhagic events occurred in 15 patients, 4 in the target 3 group (1.2 per 100 patient-years) and 11 in the target 4 group (3.8 per 100 patient-years) (p = 0.019). The 12 recorded episodes of thromboembolism, 4 of which consisted of a visual deficit, were all transient ischemic attacks, 6 in the target 3 group (1.8 per 100 patient-years) and 6 in the target 4 group (2.1 per 100 patient- years). There were 3 vascular deaths in each group (0.9 and 1 per 100 patient-years for target 3 and target 4 groups, respectively). Minor bleeding episodes occurred 85 times (26 per 100 patient-years) in the target 3 group and 123 times (43 per 100 patient-years) in the target 4 group (p = 0.001).Conclusions. Mechanical heart valve patients on anticoagulant treatment who had been operated on at least 6 months earlier experienced fewer bleeding complications when maintained on a moderate intensity regimen (target INR = 3) than those on a moderate-high intensity regimen (target INR = 4). The number of thromboembolic events and vascular deaths did not differ between the two groups.

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