Special Feature: Atrial Fibrillation Management Pearls.

Special Feature

Atrial Fibrillation Management Pearls

By William J. Brady, MD, FACEP, FAAEM Dr. Brady is Professor of Emergency Medicine and Internal Medicine, Vice Chair, Emergency Medicine, University of Virginia, Charlottesville Dr. Brady reports no financial relationships with companies having ties to this field of study.

Several years ago as a medical student, I was wisely taught that the clinician should approach the patient with atrial fibrillation in the acute setting with the following thoughts in mind: 1) the patient's hemodynamic state; 2) control of the ventricular rate; and 3) consideration of acute cardioversion. Certainly, nothing has changed regarding the consideration and classification of hemodynamic instability. The American Heart Association considers hemodynamic instability to be present if hypoperfusion is present on the examination..sup.1,2 Hypoperfusion is potentially manifested by systemic hypotension, altered mentation, ischemic chest pain, dyspnea due to pulmonary congestion, or other signs of inadequate perfusion of the organs. Two matters warrant further comment regarding hemodynamic instability.

Clinical Decisions Can Be Complex

As Pollock wisely points out in his review of atrial fibrillation,.sup.3 the issue of instability is not a yes /no phenomenon. Rather, stability must be considered along a clinical spectrum--an atrial fibrillation spectrum ranging from an asymptomatic patient in whom the dysrhythmia is discovered incidentally, to the individual with new onset tachydysrhythmia in profound shock due to a rapid ventricular response. The emergency physician must consider numerous factors in this situation, including the clinical data characterizing the specific presentation as well as the patient's comorbidity, particularly the presence of mitral valve disease, left atrial dilation, and left ventricular function..sup.1,2 These features will affect treatment decisions in two important areas: the appropriate choice of therapeutic agents for rate control and probability of success of cardioversion in those patients identified as candidates for such therapy.

In unstable patients with new-onset atrial fibrillation who are profoundly unstable, urgent electrical cardioversion is the most appropriate therapy; this scenario, however, is uncommon. More often, new-onset atrial fibrillation will present less dramatically; such presentations include atrial fibrillation with a rapid ventricular response and a potential range of symptoms, including weakness, dizziness, palpitations, chest discomfort, and dyspnea. Recall that both chest discomfort and dyspnea are instability markers as noted by the American Heart Association..sup.1,2 These complaints--if they are to be considered manifestations of true hemodynamic compromise, however--must be due to acute coronary ischemia and pulmonary edema, respectively. In situations where these symptoms are present, yet do not result from either process, the sensation of a rapid heart rate is the likely cause. In the stable though symptomatic patient, rate control is the primary management goal.