Managing atrial fibrillation to prevent its major complication: ischemic stroke

Atrial fibrillation is an acute or chronic arrhythmia that occurs postoperatively or during intense emotional stress, exercise, or acute alcohol intoxication. More than 10% of Americans aged 75 and older have atrial fibrillation, which is common in elderly patients with cardiopulmonary disorders. During atrial fibrillation, uncoordinated electrical activity leads to ineffective atrial contraction, reduced atrial filling time, and decreasing cardiac output. Blood flow stasis may cause thrombi to form in the quivering atria. Cardioversion may be indicated to convert an unstable patient into sinus rhythm. However, if cardioversion converts the patient's status to sinus rhythm, thrombi may become dislodged and propelled into the bloodstream as emboli. Occlusion of a cerebral blood vessel often follows, leading to stroke. Because patients with longstanding atrial fibrillation are predisposed to stroke, anticoagulation therapy (usually with heparin, warfarin, or aspirin) should be initiated 3 weeks prior to cardioversion. Proper anticoagulation can usually prevent ischemic stroke.