CD34+-enriched donor lymphocyte infusions in a case of pure red cell aplasia and late graft failure after major ABO-incompatible bone marrow transplantation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Increased life expectancy will result in a higher prevalence of AF. Treatment of AF constitutes a persistent medical dilemma. Different multicenter trials have confirmed that oral anticoagulant therapy is the best choice for the prevention of systemic embolism. It must be recognized, however, that the incidence of systemic embolism in patients with AF varies according to the presence and type of underlying heart disease. Advanced age increases the risk of emboli in patients with AF. At the same time, older patients have a higher risk of hemorrhage when treated with oral anticoagulants. Thus, careful titrated individual oral anticoagulant therapy targeted to a safe and effective INR must be considered in patients with AF. Another dilemma in AF patients is the convenience of restoring sinus rhythm and indicating permanent antiarrhythmic therapy versus the alternative of heart rate control plus oral anticoagulants. Several multicenter trials now in progress have addressed this issue and most likely will answer these questions. Identification of patients with paroxysmal AF and risk of systemic embolism constitutes another dilemma, since only a small proportion of these patients evolve to chronic arrhythmia. Advanced age, history of hypertension and left atrial enlargement in 2D Echo are well recognized risk factors for embolism in patients with non valvular paroxysmal AF. A history of previous embolism constitutes another risk factor and supports the hypothesis that AF may activate systemic coagulation factors and left atrial thrombus formation in some patients.