Heart valves, artificial

Polymers are a fundamental part of the modem world, showing up in everything from coffee cups to cars to clothing. In medicine, too, their importance is growing for purposes as diverse as cardiac pacemakers, artificial heart valves, and biodegradable sutures. 

Short-acting dipyridamole (Persantine). Do not consider the long-acting dipyridamole (which has better properties than the short-acting in older adults) except with patients with artificial heart valves May cause orthostatic hypotension Low... 

Pyrolytic Carbon Coating Artificial Heart Valves Pyrolytic Carbon Coatings Spinal Surgery Bloactive Glass-Ceramic HA... 

Andersen HR, Knudsen LL, HasenkamJM. Transluminal implantation of artificial heart valves. Description of a new expandable aortic valve and initial results with implantation by catheter technique in closed chest pigs. Eur Heart J 1992 13(5) 704-708. 

Re-endothelialization promoting coating. When designing and applying permanent (whole life) implants like artificial vascular grafts, artificial hearts, or artificial heart valves, more attention and effort has been paid to... 

Pretreatment of patients undergoing dental extractions who have implanted prosthetic devices, such as artificial heart valves, to prevent seeding of prosthesis. 

Synthetic polymers are perhaps more vital to the fabric of modern society than any other group of compounds prepared in the laboratory. Nylon backpacks and polyester clothing, car bumpers and CD cases, milk jugs and grocery bags, artificial heart valves and condoms—all these products and innumerable others are made of synthetic polymers. Since 1976, the U.S. production of synthetic polymers has exceeded its steel production. Figure 30.1 illustrates several consumer products and the polymers from which they are made. 

In patients with artificial heart valves, management in pregnancy is problematic, because the efficacy of heparin has not been established. Two approaches have been recommended. One can use heparin in a therapeutic dosage throughout pregnancy or use heparin until the 13th week, followed by an oral anticoagulant until the middle of the third trimester, and then heparin until delivery. 

Iturbe-Alessio I, Fonseca MC, Mutchinik O, Santos MA, Zaj arias A, Salazar E. Risks of anticoagulant therapy in pregnant women with artificial heart valves. N Engl J Med 1986 315(22) 1390-3. 

Electrode Assembly. This device consists of a specially machined Teflon electrode holder, two disc electrodes (only one is energized), and a clamp machined from acrylic plastic (Figure 3). The electrode discs are of low-temperature isotropic carbon alloyed with SiC (Carbo-metics, Austin, TX). They were originally developed for use in artificial heart valves (14), and are approximately 1.6 cm in diameter and 1.25 mm thick, and have the surface properties of glassy carbon. Treatment of the discs requires only polishing to a high lustre with diamond grinding compounds of 14,000 and 50,000 mesh. 

The physiological inertness of silicone rubber enables its use in the manufacture and packaging of food, as disposable articles for contact with the body e.g. teats for babies and implants in the human body, e.g. artificial heart valves. 

The more serious events include massive hemorrhage with shock, intracranial bleeding and stroke, and pericardial tamponade. Plasma warfarin levels are not routinely done. The effect of warfarin is best followed by the PT and International Normalized Ratio (INR). Under therapeutic conditions the INR is maintained at 2.0-3.0, except for prophylaxis after artificial heart valve replacement when it may be 2.0-3.5. Specific assays of factor activity can be measured although this is not usually necessary. 

Ceramics Alumina Femoral balls, inserts of acetabular cups, artificial heart valves, dental roots, bone screws, endoscope Bioinert Heness and Ben-Nissan (2004)... 

EFE is immobilized in a Korean type total artificial heart valve by photoreaction polyallylamine is used as a photoreactive linker [86-88]. The proteolytic activity of the treated valves is three times higher than that of untreated valves using the azocasein method. These data show that an EFE-treated polyurethane valve leads to decreasing thrombus formation in vivo and that their biocompatibility is therefore greater than that of untreated valve. It is expected that EFE could be applied as a novel accessory in the artificial organs implanted into human body. 

Shear stress levels encountered during hemodialysis and use of several common blood pumps range from 10 to 250 dyn/cm2 for periodic exposures of between 1 s and 1 min. These levels are well within the range of shear stress exposures used in this investigation. In addition, extremely high shear stresses (4000 dyn/cm2) of short (millisecond) duration may occur in the presence of mechanical valves, including artificial heart valves (15, 16). 

In the manufacture of meshes used in the repair of wounds and in the production of artificial heart valves ... 

Warfarin (Coumadin) Antagonize vitamin K. Interfere with the synthesis of vitamin K-dependent clotting factors (II, VII, IX, X). Deep venous thrombosis, ischemic heart disease (selected patients), rheumatic heart disease, pulmonary embolism. Lifelong use in patients with artificial heart valves. Bleeding, hemorrhage, necrosis, Gl upset. 

Anticoagulants are given to patients who are at risk for deep venous thrombosis and pulmonary embolism. These patients may have had a myocardial infarction (MI, heart attack), a cerebrovascular accident (CVA or stroke), or have an artificial heart valve. 

Fifty patients with artificial heart valves taking acenocoumarol had no changes in their prothrombin times while taking ditazole 800 mg daily. Nevertheless, as with other antiplatelet drugs, combined use with oral anticoagulants might increase the risk or intensity of bleeding. Some caution is therefore appropriate on concurrent use. 

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