Thrombosis and thromboembolism

Abstract

Thrombosis is of enormous importance in human disease. It may occur at any point in the circulation, from the lumen of the left ventricle to the capillary microcirculation. The effects may vary from a transient, very localized and essentially harmless interruption of blood flow to catastrophic infarction of the brain or myocardium or fatal circulatory obstruction at the pulmonary trunk. The specific pathologies are described in detail in other chapters, but some idea of the range of possible events is given by the following, far from comprehensive, list:

• intracardiac mural thrombus following myocardial infarction;

• intra-atrial thrombus during atrial fibrillation leading to emboli (especially cerebrovascular);

• coronary artery thrombosis associated with atherosclerosis and causing myocardial infarction;

• thrombosis in the cerebrovascular circulation (carotid arterioles) causing stroke;

• thrombosis of iliac or femoral arteries, complicating atherosclerosis and endangering whole lower limb;

• thrombosis in deep veins of leg or pelvis, possibly giving rise to pulmonary emboli; and

• disseminated intravascular coagulation in the microcirculation, causing depletion of platelets and clotting factors.