Approach to catheter ablation of left atrial flutters

Abstract

Left atrial tachycardias (ATs) most commonly occur after catheter or surgical ablation of atrial fibrillation and in patients with atrial myopathies. Pre‐existing scar in the left atrium (LA) can result in complex circuits, sometimes with narrow channels that can be detected with high‐resolution mapping. The most common forms of macroreentrant AT from the LA are variants of peri‐mitral and roof‐dependent reentry. Localized reentrant rhythms occur in the setting of fibrosis that gives rise to slow conduction and may occur adjacent to areas of prior ablation. The approach to treating these ATs involves first identifying the left atrial origin, defining the tachycardia circuit – which can be facilitated by ultrahigh density mapping and entrainment – and selecting a suitable isthmus to target for ablation. An important endpoint in ablating left atrial flutters is to establish and confirm bidirectional line of the block. Challenges in ablating these ATs include the presence of multiple tachycardias, defining circuits with complex activation patterns and achieving durable lines of block, particularly in the lateral mitral isthmus. Progress in treating these arrhythmias has come from new mapping technologies and the recognition of epicardial connections that allow for persistent conduction across ablation lesions. Also, advances in delivering energy to obtain complete transmural lesions promise to improve the long‐term success of ablating ATs from the LA.

Comparison of the Anterior Septal Line and Mitral Isthmus Line for Perimitral Atrial Flutter Ablation Using Robotic Magnetic Navigation

“…is is the first study to our knowledge to evaluate the utility of RMN guidance for catheter ablation of PMAFLs. fibrosis [2]. It has been reported to occur in 37% of patients as a result of AF ablations and result from focal or reentrant mechanisms in diverse locations [13].…”

“…Left atrial tachycardias (ATs) are primarily seen in patients after radiofrequency catheter ablation (RFCA) or surgical therapy in the left atrium (LA) and in patients with atrial myopathies [1]. e substrate for these ATs is often a scar with resultant conduction slowing [2]. ese slow conduction zones form a critical isthmus in the reentrant circuit, giving rise to multiple variants of AT.…”

Outcome after tailored catheter ablation of atrial tachycardia using ultra‐high‐density mapping

“…Still, catheter ablation of these ATs can be challenging as they can have a complex course. They can occur between prior ablation scars and fibrotic areas with multiple entrances, exits, dead ends, and most important areas of slow conduction, which results not only in various kinds of reentry circuits, but might also be key for future arrhythmias 10,14,24 . The use of ultra‐HDM facilitates a detailed analysis of complex atrial arrhythmias.…”

“…kinds of reentry circuits, but might also be key for future arrhythmias. 10,14,24 The use of ultra-HDM facilitates a detailed analysis of complex atrial arrhythmias. To optimally characterize the mechanism and origin of the clinical AT, entrainment mapping was only marginally used in our study to reduce the risk of modification, termination, or degeneration to AF.…”

Slow Conduction Regions as a Caluable Vectorcardiographic Parameter for the Non-Invasive Identification of Atrial Flutter Types

“…The increasing prevalence of AFL [1] and its usual treatment, catheter ablation [2], makes it an important issue to study. The physiological basis of AFL is an atrial macroreentrant circuit [3] sorrounding an obstacle, in either counterclockwise (CCW) or a clockwise (CW) direction.…”