Surface ECG f Wave Analysis at Initial Onset of Paroxysmal and Persistent Atrial Fibrillation
Atrial fibrillation (AF) affects over 20 million people worldwide and by 2050 over 15.9 million Americans will suffer from AF, more than doubling the current prevalence.1 Depending on age, 60–70% of emergency department (ED) visits for AF in the United States lead to hospitalization. Hospitalization for AF in the United States exceeds rates in both Canada and Europe; a modest reduction of 15% in hospitalization rates could reduce inpatient costs by 1 billion dollars annually.2 A great deal of regional and other inconsistencies exist in the management of AF in the ED.3 When patients with new onset AF present to the ED, it is unknown whether they have paroxysmal AF (PAF) that can be expected to terminate spontaneously or persistent AF (PeAF) that will require further treatment. Foreknowledge of this might help in the deployment of ED resources, specifically to avoid hospital admission for patients in whom AF will spontaneously terminate.
The surface electrocardiogram (ECG) is routinely performed in the ED. We and others4 have used frequency analysis of the ECG to measure the fibrillatory (f) wave frequency. Previous studies have shown higher f wave frequency among PeAF patients when compared to PAF patients.6 As such, we hypothesized that the ECG f wave frequency obtained in the ED could be a valuable diagnostic tool for predicting whether the patient has PeAF or PAF. This study was conducted at two centers with patients who presented to the ED with new onset AF. We specifically hypothesized that the higher dominant frequency (DF) values that have been noted in patients6 with PeAF versus PAF could be incorporated into a prediction tool to identify those patients in whom spontaneous reversion to sinus rhythm could be expected.