Electrical Isolation of the Left Atrial Appendage - A New Frontier in the Treatment for Atrial Fibrillation

Abstract

Atrial fibrillation is not only the most common clinical arrhythmia, it is also one of the most challenging conditions to treat in day-today clinical practice. In particular, the persistent form of this condition is not easily amenable to traditional forms of therapy, whereas, the paroxysmal form is far more responsive to standard modes of treatment. In our relentless quest to find better solutions to overcome persistent atrial fibrillation, arguably the most promising of these currently appears to be electrical isolation of the left atrial appendage. Whilst surgical amputation of the left atrial appendage for stroke prevention has been practiced for more than half a century, only recently has attention gradually been shifting to electrical isolation of the left atrial appendage for the treatment of persistent atrial fibrillation. In this review article, we present compelling pieces of evidence for the use of this strategy, and the various ways in which it can be achieved.

Persistent Atrial Fibrillation: The Role of Left Atrial Posterior Wall Isolation and Ablation Strategies

“…More recently, these studies have described outcomes using a subxiphoid approach to reach the posterior left atrium, and additional studies dedicated to this approach will be important. Concomitant application of the AtriClip ® , the most widely employed left atrial appendage exclusion device, is gaining popularity [ 4 ] and future studies should assess the precise impact on AF outcomes of including this technique. Another endpoint of interest for a hybrid approach is evaluating the length of stay for comparison with other minimally invasive surgical ablation approaches.…”

“…This typically takes form as standalone endocardial catheter ablation or as surgical ablation if performed concomitantly with a primary cardiac surgical procedure. In both cases, pulmonary vein isolation (PVI) is paramount, although other regions often emerge as potential substrates in PersAF [ 4 ]. One of these regions, arguably the most influential after the pulmonary veins (PVs), is the posterior wall of the left atrium, which is known to generate AF triggers and is subject to electrical and structural changes that occur with the persistence of AF.…”

A Chronicle of Hybrid Atrial Fibrillation Ablation Therapy: From Cox Maze to Convergent

“…Additionally, endocardial ablation focused on PV isolation does not address extra-PV triggers and substrates that become more prevalent in persistent and longstanding persistent AF, such as the left atrial posterior wall and left atrial appendage (LAA). [18][19][20][21] Although meta-analyses have reported a potential benefit of endocardial posterior wall ablation in PVI, and there is a growing trend to undertake such an approach, there is no absolute consensus on posterior wall ablation that is used routinely. 18,22 Measures to reduce thermal injury risk may in turn limit the ability to create durable, transmural lesions.…”

“…The LAA itself harbours electrical activity and is also the predominant site of thrombus formation in AF. 21 Some investigators have reported preliminary data on the addition of thoracoscopic LAA exclusion as part of hybrid convergent procedures, and this is an emerging area for further study. [74][75][76]…”

Hybrid Ablation of Nonparoxysmal Atrial Fibrillation: The Convergent and Totally Thoracoscopic Approaches

“…In addition to the pulmonary veins, the posterior wall of the left atrium is derived from the same embryologic tissues and is a common region for atrial fibrillation triggers [ 10 ]. Although recognized increasingly as a key component of NPAF management, endocardial CA in this region is often difficult due to the large area of substrate, and adjacent structures [ 10 , 11 ].…”