Tailoring the Ablative Strategy for Atrial Fibrillation: A State-of-the-Art Review

Abstract

In spite of technological progress and the improving skills of operators, atrial fibrillation (AF) ablation results appear to date to be at a plateau. In any case, the superiority of ablation over pharmacological therapy in terms of effectiveness, reduction of hospitalizations, and improvement has been well demonstrated in recent randomized trials. Triggers, substrate, and modulating factors (elements of Coumel’s triangle) play different roles in paroxysmal and persistent AF, so induction and perpetuation mechanisms of arrhythmia may be different in each patient. Although effective ablative strategies are available for the treatment of paroxysmal AF triggers and persistent AF substrates, an adequate clinical evaluation of the patient is crucial in order to increase the chances of success. Recognizing triggers allows not only performing an effective ablation but also to avoid unnecessary lesions and at the same time reducing the risk of complications. AF beginning and triggers could be recorded by 12-lead ECG, continuous Holter monitoring, or implantable devices. In case of an unsuccessful noninvasive evaluation, nonpulmonary vein triggers should be investigated with an electrophysiological study. Persistent AF needs more effort to perform an accurate substrate characterization. Among the many methods proposed, recently the use of high-density mapping and multipolar catheters seems of particular benefit in order to clarify the arrhythmia mechanisms. Surgical and hybrid techniques allow to treat regions such as the posterior wall or Bachmann’s bundle, which is fundamental for an ablative strategy that goes beyond just pulmonary vein isolation. Too often, patients are referred to electrophysiology laboratories without adequate preprocedural screening and planning in order to submit them to a standard “ready-made” procedure. The accurate search for triggers in paroxysmal AF and the correct recognition of the link between a possible underlying heart disease and the substrate in persistent AF could allow us to tailor the interventional approach in order to overcome the current plateau, increasing ablative procedure success and minimizing complications.

Optimal Catheter Ablation Strategy for Patients with Persistent Atrial Fibrillation and Heart Failure: A Retrospective Study

“…It is well known that arrhythmogenic mechanisms beyond the pulmonary veins are often involved in patients with PeAF. The prevailing CA strategies beyond PVI for PeAF include targeting mechanisms and anatomical ablation, and recently, Zefferino Palam et al have well summarized the current CA strategies in this article [ 21 ]. CFAEs and rotor ablation have been developed in the past ten years to eliminate PeAF, but did not demonstrate more benefits than PVI alone.…”

Intermittent ventricular pre‐excitation in symptomatic adults: Always a marker of low risk?

“…Furthermore, the evolution of the APs properties over time is not absolutely predictable and, moreover, we must not forget that the presence of an AP in itself can increase the risk of AF since it increases the intra-atrial refractoriness dispersion 25 ; thus, APs represent an excellent ablative target in the context of tailored AF treatment. 26 So far we have made some speculations on the pediatric population on which we have considerable studies, which however are lacking on the adult population. For the latter, we have only reports showing cases of patients with intermittent ventricular pre-excitation and APs with high-risk characteristics or even cardiac arrest from VF.…”

Will the blooming of artificial intelligence modify our approach to atrial fibrillation cure?

“…To this goal, we tried to evaluate whether an ablative approach, tailored on the patho-physiological mechanisms of the arrhythmia could provide optimal results, minimizing the procedural risks for patients. We demonstrated that some forms of paroxysmal atrial fibrillation can be triggered by other kind of arrhythmias with focal (atrial tachycardia) or reentrant mechanism (WPW syndrome or nodal reentrant tachycardia) (7)(8) . On the other hand, in patients with vagally-mediated AF we also investigated the possibility of using right atrial ganglion ablation to modify the influence of the autonomic nervous system on the heart, in order to prevent atrial fibrillation episodes (9) .…”