The first prosthetic valve was implanted by Hufnagel in 1952 in a patient with aortic insufficiency. Since then, prosthetic valves have evolved into various mechanical and bioprosthetic shapes and sizes. Despite the excitement surrounding the current development of prosthetic heart valves, surgically implanted valves remain the mainstay of current practice, and this article discusses the hemody...

Timing diagrams are useful for capturing temporal specifications in which all mentioned events are required to occur. We first show that translating timing diagrams with both partial orders on events and don’t-care regions to LTL potentially yields exponentially larger formulas containing several non-localized terms corresponding to the same event. This raises a more fundamental question: which...

To determine the appropriate timing for surgical intervention in infective endocarditis (IE), we evaluated 24 patients (17 males, 6 females, with one included twice) who underwent surgical intervention for IE of native valves (NVE, n = 21) and prosthetic valves (PVE, n = 3) between January 1989 and September 1994. The mean age was 41 +/- 13 years (range 6 to 64 years). The most common infective...

Valvetrain flexibility enables the optimization of the engine’s ability to breathe across the operating range, resulting in more efficient operation. The authors have shown the merit of improving volumetric efficiency via valvetrain flexibility to improve fuel efficiency at elevated engine speeds in the previous work. This study focuses on production viable solutions targeting similar volumetri...

BACKGROUND The two most common causes of aortic stenosis are primary "degenerative" calcification of tricuspid aortic valves and secondary calcification of congenital bicuspid valves. T lymphocyte infiltration occurs in stenotic tricuspid aortic valves, indicating an inflammatory component, but it has not been shown whether it also occurs in stenotic bicuspid valves. OBJECTIVE To compare non-...

Background: The two most common causes of aortic stenosis are primary “degenerative” calcification of tricuspid aortic valves and secondary calcification of congenital bicuspid valves. T lymphocyte infiltration occurs in stenotic tricuspid aortic valves, indicating an inflammatory component, but it has not been shown whether it also occurs in stenotic bicuspid valves. Objective: To compare non-...

1. Permanent therapy with oral anticoagulants offers the most consistent protection in patients with mechanical heart valves. 2. Antiplatelet agents alone do not consistently protect patients with mechanical prosthetic heart valves, including patients in sinus rhythm with St. Jude Medical valves in the aortic position. 3. Levels of oral anticoagulants that prolong the INR to 2.0 to 3.0 appear s...

transcatheter aortic valve replacement (tavr) is a novel therapeutic intervention for the replacement of severely stenotic aortic valves in high-risk patients for standard surgical procedures. since the initial partner trial results, use of tavr has been on the rise each year. new delivery methods and different valves have been developed and modified in order to promote the minimally invasive p...

Although porcine aortic valves or pericardial tissue mounted on a stent have made implantation techniques easier, these valves sacrifice orifice area and increase stress at the attachment of the stent, which causes primary tissue failure. Optimizing hemodynamics to prevent patient-prosthetic mismatch and improve durability, stentless bioprostheses use was revived in the early 1990s. The purpose...

BACKGROUND AND OBJECTIVES The aim of this study was to assess mechanical valve function using 64-slice multidetector computed tomography (MDCT). SUBJECTS AND METHODS In 20 patients (mean age, 50+/-12 years; male-to-female ratio, 10:10), 30 St. Jude bileaflet mechanical valves (15 aortic and 15 mitral valves) were evaluated using MDCT. We selected images vertical and parallel to the mechanical...