Abstract 19522: Spectral Analysis of Baseline Electrocardiogram During Atrial Fibrillation Predicts Response to Antiarrhythmic Drug Therapy in Patients With Persistent Atrial Fibrillation
Introduction: The response of persistent atrial fibrillation (AF) to antiarrhythmic drug therapy is variable and cannot be predicted by clinical characteristics.
Hypothesis: We aimed to evaluate the ability of power spectral analysis of the baseline ECG during AF to predict the response of persistent AF to antiarrhythmic drug therapy.
Methods: Patients with persistent AF who were admitted for antiarrhythmic drug (dofetilide or sotalol) loading were prospectively enrolled in the study. Atrial activity was extracted from the ECG using an Independent Component Analysis method, which provides a composite representation of atrial activity. The extracted composite atrial signal was bandpass filtered between 3.5 and 40 Hz. The filtered data were then subjected to a Modified Periodogram, which was computed based on a Fast Fourier Transform. The regularity index was computed as the ratio of the power in the dominant frequency and all its harmonics to the total power in the spectrum. Patients were followed at 1 month, 3 months and every 3 months thereafter.
Results: Thirty two patients were enrolled in the study. Dofetilide was used in 28 (88%) patients. Fifteen (47%) patients converted spontaneously to sinus rhythm during the 3-day hospital loading period. The clinical and echocardiographic characteristics of patients with and without acute conversion were similar. The regularity index was significantly higher in those who converted to sinus rhythm compared to those who did not (0.71±0.20 vs. 0.38±0.13, respectively; p<0.0001). A regularity index ≥0.58 had a 70% sensitivity and 93% specificity to predict acute conversion (area under ROC curve=0.91; 95% confidence interval 0.81 to 1.0; p=0.0003) and was associated with a 5-fold increase in the acute conversion rate (odds ratio=5.63; 95% confidence interval 1.94 to 16.32; p=0.004). The regularity index was the only independent predictor of acute conversion. Neither acute conversion, nor the regularity index predicted sinus rhythm maintenance, after a median follow-up of 9 months (interquartile range 4 to 20 months).
Conclusions: Increased regularity index predicts acute conversion of persistent AF during antiarrhythmic therapy, but does not predict long-term sinus rhythm maintenance.
Author Disclosures: S. Stavrakis: None. J.W. Dyer: None. E. Koomson: None. B.J. Scherlag: None. B. Bhardwaj: None. R. Lazzara: None. S.S. Po: None.
- © 2016 by American Heart Association, Inc.