Procedural Feasibility and Long-Term Efficacy of Catheter Ablation of Atypical Atrial Flutters in a Wide Spectrum of Heart Diseases: An Updated Clinical Overview

Abstract

Atypical atrial flutters (AAFL) are difficult-to-manage atrial arrhythmias, yet potentially amenable to effective radiofrequency catheter ablation (CA). However, data on CA feasibility are only sparingly reported in the literature in different clinical settings, such as AAFL related to surgical correction of congenital heart disease. The aim of this review was to provide an overview of the clinical settings in which AAFL may occur to help the cardiac electrophysiologist in the prediction of the tachycardia circuit location before CA. Moreover, the role and proper implementation of cutting-edge technologies in this setting were investigated as well as which procedural and clinical factors are associated with long-term failure to maintain sinus rhythm (SR) to find out which patients may, or may not, benefit from this procedure. Not only different surgical and non-surgical scenarios are associated with peculiar anatomical location of AAFL, but we also found that CA of AAFL is generally feasible. The success rate may be as low as 50% in surgically corrected congenital heart disease (CHD) patients but up to about 90% on average after pulmonary vein isolation (PVI) or in patients without structural heart disease. Over the years, the progressive implementation of three-dimensional mapping systems and high-density mapping tools has also proved helpful for ablation of these macro-reentrant circuits. However, the long-term maintenance of SR may still be suboptimal due to the progressive electroanatomic atrial remodeling occurring after cardiac surgery or other interventional procedures, thus limiting the likelihood of successful ablation in specific clinical settings.

High density mapping of complex atrial tachycardia in patients after cardiac surgery

“…Among patients with ATs after cardiac surgery for CHD, at least 58% were Cavo‐tricuspid isthmus‐dependent ATs, and up to 25% were intra‐atrial reentrant tachycardias (IART) 12 . And IART location are influenced by anatomical position 13 . The anatomical location of IART is difficult to predict due to the major hemodynamic abnormalities and the iatrogenic areas of conduction block in heavily remodeled right atrial chambers in CHD patients 14 .…”

“…12 And IART location are influenced by anatomical position. 13 The anatomical location of IART is difficult to predict due to the major hemodynamic abnormalities and the iatrogenic areas of conduction block in heavily remodeled right atrial chambers in CHD patients. 14 It is essential to understand every surgical incision involving the atrial chambers as they may potentially represent a fertile substrate for the development of re-entrant circuits.…”

“…14 It is essential to understand every surgical incision involving the atrial chambers as they may potentially represent a fertile substrate for the development of re-entrant circuits. 13…”

Hybrid ablation for persistent and long-standing persistent atrial fibrillation: is the grass really greener on the other side?

“…In fact, the completion of atrial lines and their electrophysiological assessment can be greatly difficult to achieve. 5 Furthermore, the feasibility of CFAE ablation is controversial due to the currently limited understanding in their pathophysiology.…”