Surface ECG spectral analysis to predict atrial fibrillation catheter ablation long-term outcome

Catheter ablation (CA) has emerged recently as an effective tool to treat atrial fibrillation (AF), which is today the most common cardiac arrhythmia. However, the long-term AF recurrence rate is about 50% for patients in persistent AF. As a consequence the optimal selection of patients for the procedure remains as an interesting clinical challenge. To this respect, the dominant atrial frequency (DAF) analysis from the surface ECG has been widely studied in recent years, reporting promising results. In the present work two additional spectral metrics complementing the information provided by the DAF, such as its 3 dB bandwidth (BW) and the median frequency (MF), are for the first time studied. Results provided no statistically significant differences for the DAF as well as the BW between patients with and without freedom from AF after a mean follow-up of 12±7 months. In contrast, a statistically significant greater MF was observed in patients maintaining sinus rhythm (6.42±0.17 Hz) than for those who relapsed to AF during the folow-up (6.03±0.30 Hz). Moreover, the MF provided sensitivity, specificity and accuracy values of 83.33%, 100% and 91.67%, respectively. Hence, the MF could be considered as a more promising harbinger of long-term CA outcome than the DAF. Further studies in wider databases should validate this preliminar finding.