Abstract: Objectives: To investigate whether acute atrial fibrillation (AF) creates a prothrombotic state in hypertensive patients, and to assess the evolution in research indices after cardioversion. Design and methods: Plasma levels of von Willebrand factor (vWf), soluble P-selectin and fibrin D-dimers were measured in hypertensive patients with acute AF pre-cardioversion and at 1, 7, 14, and 30days post-cardioversion. The results were compared with hypertensive controls and healthy controls. Results: Pre-cardioversion plasma vWf levels in acute AF patients were similar to those of controls; however, post-cardioversion, the vWf levels increased significantly and only returned to baseline levels 14days later. Compared with controls, acute AF patients had higher levels of fibrin D-dimers, which lasted at least 14days after cardioversion. Conclusions: This study demonstrated that hypertensive patients with acute AF have an abnormal prothrombotic state, which persists for up to 14days after cardioversion. [ABSTRACT FROM AUTHOR]