Thrombolysis Health Dictionary

A channel for venous blood placed either side of the sphenoid bone at the base of the SKULL behind the eye sockets. Blood drains into it from the eye, the nose, the brain and part of the cheek, and leaves via the internal jugular and facial veins. Sometimes the sinus becomes blocked by a blood clot (thrombus), usually a complication of a nearby bacterial infection. A potentially serious condition, it should be treated with thrombolysis and antibiotics.... cavernous sinus

A natural PROTEIN that occurs in the body. It has the property of breaking down a THROMBUS in a blood vessel (see THROMBOLYSIS). It is e?ective only in the presence of FIBRIN and activates plasminogen, which occurs normally on the surface of the ?brin. TPA is an important thrombolytic treatment immediately after a myocardial infarction (see HEART, DISEASES OF).... tissue plasminogen activator (tpa, tpa)

Urokinase is an ENZYME obtained from URINE which dissolves blood clots. It is used to treat THROMBOLYSIS in the EYE, in arteriovenous shunts (see SHUNT) and deep-vein THROMBOSIS. It has the advantage over other ?brinolytic drugs of not causing immunological reactions.... urokinase

n. the introduction of a *catheter into a hollow organ or vessel. In urethral catheterization a catheter is introduced into the bladder through the urethra to relieve obstruction to the outflow of urine (see also intermittent self-catheterization). Catheters can also be passed above the pubis through the anterior abdominal wall (suprapubic catheterization) directly into a full bladder if urethral catheterization is not possible. Cardiac catheterization entails the introduction of special catheters into the chambers of the heart. This allows the measurement of pressures in the chambers and pressure gradients across the heart valves, as well as the injection of contrast medium for visualization of structures using X-rays (see coronary angiography). Vascular catheterization enables the introduction into the arteries or veins of: (1) contrast medium for angiography or venography; (2) drugs to constrict or expand vessels or to dissolve a thrombus (see thrombolysis); (3) metal coils or other solid materials to block bleeding vessels or to thrombose *aneurysms (see embolization); (4) devices for monitoring pressures within important vessels (e.g. *Swan-Ganz catheters for monitoring pulmonary artery pressure in critically ill patients); or (5) balloons and *stents to relieve obstruction.... catheterization

n. the condition in which an embolus becomes lodged in an artery and obstructs its blood flow. The most common form of embolism is *pulmonary embolism, in which a blood clot is carried in the circulation to lodge in the pulmonary artery. An embolus in any other artery constitutes a systemic embolism. In this case a common source of the embolus is a blood clot within the heart in mitral valve disease or following *myocardial infarction. The clinical features depend upon the site at which an embolus lodges (for example, a stroke may result from a cerebral embolism and gangrene caused by a limb embolism). Treatment is by *anticoagulant therapy with heparin and warfarin. Major embolism is treated by *embolectomy or *thrombolysis to remove or dissolve the embolus. See also air embolism.... embolism

death of a segment of heart muscle, which follows interruption of its blood supply (see coronary thrombosis). Myocardial infarction is usually confined to the left ventricle. The patient experiences a ‘heart attack’: sudden severe chest pain, which may spread to the arms and throat. Although severe chest pain is the most widely recognized symptom of myocardial infarction, many patients – especially women – do not have chest pain. Other presenting symptoms include abdominal pain, nausea, vomiting, sweating, shortness of breath, and dizziness. The main danger is that of ventricular *fibrillation, which accounts for most of the fatalities. Other *arrhythmias are also frequent. Other complications include heart failure, rupture of the heart, phlebothrombosis, pulmonary embolism, pericarditis, shock, mitral regurgitation, and perforation of the septum between the ventricles.

Patients with myocardial infarction are best cared for in a specialized coronary care unit with facilities for the early detection, prevention, and treatment of arrhythmias and *cardiac arrest. Blockage of a major coronary artery is detected by elevation of the *S–T segment on the *electrocardiogram (STEMI or S–T elevation myocardial infarction). It is relieved by emergency *coronary angioplasty (commonly called primary *percutaneous coronary intervention) or the intravenous infusion of a drug to dissolve thrombus (*thrombolysis). Most survivors of myocardial infarction are able to return to a full and active life, including those who have been successfully resuscitated from cardiac arrest. Lesser degrees of coronary obstruction may not be seen on the electrocardiogram but are revealed by the detection of raised *troponin levels in the blood (NSTEMI or non-S–T elevation myocardial infarction). Treatment is with *antiplatelet drugs and early percutaneous coronary intervention.... myocardial infarction

(PCI) treatment of coronary artery disease delivered by cardiac *catheterization. This usually means *coronary angioplasty followed by insertion of a coronary *stent, but also includes more specialized procedures, such as rotational *atherectomy (rotablation). Primary PCI refers to the use of PCI as the first-line treatment to relieve coronary obstruction in S-T elevation *myocardial infarction, rather than *thrombolysis. Rescue PCI is used in the event of unsuccessful thrombolysis.... percutaneous coronary intervention

n. restoration of blood flow to a tissue that follows relief of an arterial occlusion, most commonly following the correction of acute coronary artery occlusion by coronary *stenting or *thrombolysis in the context of heart attack.... reperfusion

the avoidance or alleviation of disease by early detection and appropriate management. Secondary prevention approaches include population *screening tests that identify disease in asymptomatic people, enabling timely treatment; and *thrombolysis in people who have had a heart attack (*myocardial infarction) or ischaemic *stroke. See also preventive medicine; primary prevention; tertiary prevention.... secondary prevention

n. an enzyme produced by some haemolytic bacteria of the genus *Streptococcus that is capable of liquefying blood clots (see also fibrinolytic). It is given to treat blockage of blood vessels, including deep vein thrombosis, myocardial infarction, and pulmonary embolism (see thrombolysis). Side-effects may include digestive upsets, haemorrhage, and fever.... streptokinase

(tPA, TPA) a natural protein, found in the body and able to be manufactured by genetic engineering, that can break up a thrombus (see thrombolysis). It requires the presence of *fibrin as a cofactor and is able to activate *plasminogen on the fibrin surface, which distinguishes it from the other plasminogen activators, *streptokinase and *urokinase. tPAs include reteplase and tenecteplase, given to treat acute myocardial infarction, and *alteplase.... tissue-type plasminogen activator