Molecular basis of thromboembolism in association with atrial fibrillation

Atrial fibrillation (AF), one of the most common arrhythmias, has grown to be an important medical problem in societies with an increasing number of aged people, because AF is strongly associated with the occurrence of severe thromboembolism. Although the processes underlying AF-associated thrombosis have long been believed to be mainly dependent upon the decreased blood flow in the left atrium induced by AF, revisiting the well known Virchow's triad from the basic approach has disclosed that this is too simplistic. Here, the role of 3 important components, abnormalities in the blood flow, blood coagulability, and the endocardial function of the atria, in thrombus formation in the fibrillating atria are discussed. Unraveling the molecular basis of thrombus formation in the atrium could open a new era of a wide variety of management of stroke prevention for AF patients.