Persistent Atrial Fibrillation Ablation: Ongoing Challenges Defining the Target Population and Substrate

Abstract

Purpose of Review Catheter ablation (CA) is a well-established treatment for paroxysmal atrial fibrillation (AF), but outcomes in persistent AF can be suboptimal. This review summarises recent evidence relating to the ideal patient population and target substrate for CA, and the techniques available. Recent Findings Risk scores can identify individuals with persistent AF who are more likely to benefit from CA. Pulmonary vein isolation (PVI) remains the most important ablation technique but non-pulmonary vein triggers explain the high recurrence rates in persistent AF. Novel electroanatomic mapping technologies, hybrid approaches, ethanol vein of Marshall ablation and thoracoscopic epicardial ablation are promising recent developments. Pulsed field ablation (PFA) is a new ablation modality with an excellent safety profile in trials to date; its role in persistent AF remains an area of study. Summary Improving outcomes of CA in persistent AF remains a significant research focus, with several encouraging directions for future study.

Combination of frequency- and time-domain characteristics of the fibrillatory waves for enhanced prediction of persistent atrial fibrillation recurrence after catheter ablation

“…Spectral analysis of f -waves has been the focal point of several recent studies dealing with preoperative CA success prediction [23] . Hence, in the present work the extracted 6 s-length intervals of f -waves were characterized in the frequency-domain through common features, but also using novel parameters that have been introduced here for the first time.…”

“…Well-known time and frequency parameters of these waves, including their amplitude and dominant frequency (DF), are today considered as surrogate markers of remodeling in the atrial substrate and have proven to be effective in predicting the success of different AF treatments [24] , [25] . In the particular case of CA, they have reported a higher performance than clinical parameters and scores, but there is still room for improvement [23] . Moreover, predictive models based only on traditional statistical approaches have been mainly studied to combine detachedly frequency [26] or time [27] , [28] features, largely leaving unexplored the possible complementary information between both domains of the f -waves.…”

“…In the last years, there is a growing focus on analyzing f -waves extracted from the ECG signal to preoperatively anticipate CA outcome [23] . Well-known time and frequency parameters of these waves, including their amplitude and dominant frequency (DF), are today considered as surrogate markers of remodeling in the atrial substrate and have proven to be effective in predicting the success of different AF treatments [24] , [25] .…”