Blood clot embolization

Pulmonary embolism. A blood clot trapped in the blood vessels of the lungs. 

Many serious health problems result from abnormally located blood clots heart attacks (clots in coronary arteries), pulmonary embolism (clots in the lungs), and peripheral arterial occlusion and deep vein thrombosis (clots in the limbs). Each year heart attacks alone afflict over a million people in the United States, and almost half of them die as a result. 

Embolism The sudden blockage of a vessel caused by a blood clot or foreign material that has been brought to the site by the flow of blood. 

Embolization The process by which a blood clot or foreign material dislodges from its site of origin, flows in the blood, and blocks a distant vessel. 

The most prescribed drugs for blood-related disorders are also summarized in Table 1.17. Blood clots can occur in the veins at extremities (especially after a long period of immobility). Those clots can subsequently become lodged in the blood vessels, the atria, the heart valves, and within the lungs, causing embolism and shortness of breath. Under severe conditions, the clots can also obstruct the flow of blood to the brain, leading to a stroke and paralysis. Coumadin (warfarin see chemical structure below) is one of the main hematological compounds that has been widely prescribed to counter these conditions... 

Normal hemostasis is a balance between excessive and inadequate blood clotting. Overactive blood clotting is harmful because of the tendency for thrombus formation and occlusion of arteries and veins. Vessels may become directly blocked by the thrombus, or a portion of the thrombus may break off and create an embolism that lodges elsewhere in the vascular system. The tendency for excessive thrombus formation in the venous system is usually treated with anticoagulant drugs such as heparin and warfarin. Platelet inhibitors such as aspirin help prevent arterial thrombogenesis. Thrombolytic drugs (streptokinase, t-PA) that facilitate the dissolution of harmful clots may successfully reopen... 

Increased clotting may occur in the presence of thrombosis (enhanced formation of fibrin), stasis, and phlebitis (diminished circulation), or embolism (dislocation and lodging of blood clots). Although heparin is an extremely effective anticoagulant, it has certain limitations that are not shared by the newer thrombin inhibitors. As a result, these novel inhibitors may have advantages over heparin for use in certain clinical settings. 

Embolism Sudden blocking of an artery with a blood clot or foreign material. 

Thrombotic (blood clot) events, and subsequent complications, are a leading cause of morbidity and mortality in the general population.1 In 2005, it was estimated that there were more than 900,000 total venous thromboembolism events in the United States,2 two thirds of which were acquired in hospital. More than 600,000 of those were nonfatal venous thromboembolism events. Nearly 300,000 were fatal events, including more than 2,200 cases of deep venous thrombosis and 294,000 cases of pulmonary embolism. The majority deaths (93%) were due to sudden fatal pulmonary embolism, or were a consequence of undiagnosed venous thromboembolism. It was estimated that 340,000 patients developed complications from venous thromboembolism, including 336,000 with postthrombotic syndrome and 3,300 with chronic thromboembolic pulmonary hypertension. 

Thrombosis (blood clot) - may occur up to six weeks after surgery. Rarely, a blood clot can pass to the lungs causing a pulmonary embolism and a medical emergency. Treatment may necessitate anticoagulants. 

Q6 A thrombus is a blood clot which is fixed to the blood vessel wall. When it detaches and is carried in the blood, it is known as an embolus. Both thrombi and emboli can block blood vessels and deprive tissues of oxygen. In arteries blood clots usually form because the inner surface has been altered by deposition of atheroma. In contrast venous thrombosis results from slow or stagnant blood flow in veins, or defects in mechanisms which normally oppose inappropriate coagulation. Three major risk factors for pulmonary embolism are (i) venous stasis, (ii) hypercoagulability ofblood and (iii) injury to vascular endothelium following trauma or plaque rupture. 

Raloxifene side effects include bloody or cloudy urine painful urination pain in chest, arm or leg (rare) coughing blood (rare) sore/dry throat trouble in swallowing body aches cramping skin rash vaginal itching migraine headache (rare) and loss of speech, vision or coordination (rare). There is also an increased risk of blood clot formation (i.e., deep vein thrombosis, pulmonary embolism, and retinal embolism) in patients with a history of these conditions if treated with Raloxifene. 

Such a cerebral thrombosis is believed to occur as a result of atherosclerotic damage in the arterial wall. Narrowing of the arterial lumen slows the blood flow. The projection of rough-surfaced deposits into what is by then a trickle of blood may serve as a nucleus around which the thrombus will form, thereby completing the occlusion. A variation is the wandering of a blood clot, or embolus, through the vasculature until finally it becomes wedged in a cerebral artery. This is a cerebral embolism. 

Alteplase aids in dissolution of blood clots. It is indicated in the lysis of thrombi in management of acute myocardial infarction (MI) or acute massive pulmonary embolism, and... 

Patients with chronic atrial fibrillation—a common supraventricular arrhythmia—routinely receive warfarin to prevent the development of blood clots in the poorly contracting atrium and to decrease the risk of embolism of such clots to the brain or other tissues. Such patients are also often treated with anti arrhythmic drugs. The primary goals of antiarrhythmic treatment are to slow the atrial rate and, most importantly, control the ventricular rate. 

Bleeding from injured blood vessels can be arrested by the activation of the hemostatic mechanism [24]. However, an artificial device surface placed in contact with blood can disturb the balance of this mechanism [24]. Excessive blood clotting with increased risk of embolization can occur due to the adhesion of platelets and lenkocytes to device surface and the formation of fibrin network following the... 

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