BACKGROUND: Atrial fibrillation is the most common arrhythmia in patients hospitalized in intensive care units and emergency departments and is associated with an increased morbidity and mortality. In critically ill patients, atrial fibrillation can cause hemodynamic instability and cardiogenic shock. The mechanisms and the management of atrial fibrillation are significantly different in critically ill patients compared to outpatients.
DIAGNOSIS AND TREATMENT: The initial management includes the evaluation of the hemodynamic consequences of new-onset atrial fibrillation and the optimization of reversible causes. In patients with hemodynamic instability the rapid restoration of an adequate perfusion pressure is the initial goal. Often, a rapid conversion in sinus rhythm is required to achieve hemodynamic stabilization. Electrical cardioversion, if possible performed after pretreatment with an antiarrhythmic drug to increase the success rate, frequently plays a central role in the conversion to sinus rhythm of hemodynamically unstable patients. Stable patients are initially treated with a short-acting intravenous β-blocker to achieve heart rate control. A conversion to sinus rhythm may be achieved pharmacologically with vernakalant, an atrial-specific multichannel blocker.
EVALUATION: All patients with atrial fibrillation lasting more than 48 h should be evaluated for anticoagulation in order to reduce cardio-embolic complications. After recovering from the acute illness, atrial fibrillation persists only in a minority of patients.