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Study on atrial fibrillation recidivity after electrical cardioversion through fibrillatory waves time-frequency analysis

Electrical cardioversion (ECV) is a well-established therapy for atrial fibrillation (AF), which is the most common cardiac arrhythmia in clinical practice. However, conventional ECV protocols cannot manage whether to stop or to continue delivering shocks to the patient after an unsuccessful tentative. To this respect, the present contribution analyzes the ability of the fibrillatory waves amplitude (fWA) and the dominant atrial frequency (DAF), extracted non-invasively from the atrial activity (AA) signal, to predict the effectiveness of every single shock in ECV protocols. Results showed that the effects of the first ineffective shock were notably reflected in the fWA. Indeed, by considering the fWA values after, instead of before, the first ineffective attempt, the diagnostic ability was increased from 79.37% to 85.71%. For the remaining ECV attempts, non-significant changes for the analyzed time-frequency metrics were observed. As a consequence, fWA and DAF could provide valuable information to improve the effectiveness of conventional ECV protocols, in which the effect of the first unsuccessful shock is crucial to elucidate the procedure effectiveness.