High-Resolution Mapping and Ablation of Atrial Tachycardias Involving the Lateral Left Atrium
Shinsuke Miyazaki1, Kanae Hasegawa1, Kazuya Yamao2
1Department of Cardiovascular Medicine University of Fukui Japan.
Journal of the American Heart Association
|September 28, 2021
Summary
This study characterizes atrial tachycardias (ATs) in the lateral left atrium (LA), focusing on the mitral isthmus (MI) and left atrial ridge. High-resolution mapping effectively identified and treated these complex ATs, leading to successful long-term outcomes.
Area of Science:
- Electrophysiology
- Cardiology
- Cardiac Anatomy
Background:
- The lateral left atrium (LA) presents complex anatomy often implicated in atrial tachycardia (AT) development.
- Understanding the specific anatomical substrates, such as the posterolateral mitral isthmus (MI) and left atrial ridge, is crucial for effective AT management.
Purpose of the Study:
- To characterize atrial tachycardias (ATs) associated with the lateral left atrium (LA), specifically involving the posterolateral mitral isthmus (MI) and left atrial ridge.
- To evaluate the efficacy of high-resolution mapping and ablation strategies for these complex ATs.
Main Methods:
- High-resolution mapping and entrainment pacing were employed to characterize 28 lateral LA-associated ATs.
- The vein of Marshall was specifically mapped using a 1.8-Fr catheter when feasible.
- Ablation strategies targeted critical isthmuses identified through mapping, including MI linear ablation and LA-ridge/Marshall bundle junction ablation.
Main Results:
- Eighteen ATs were associated with the posterolateral MI, with all successfully eliminated post-ablation, showing no recurrence during a median follow-up of 27 months.
- Ten ATs involved the left atrial ridge or Marshall bundle, with ablation at the LA-ridge or LA-Marshall bundle junction successfully terminating the tachycardia.
- All identified ATs were terminated during ablation, and patients remained free from atrial tachyarrhythmias during follow-up periods of 27 and 12 months, respectively.
Conclusions:
- Atrial tachycardias (ATs) in the lateral left atrium (LA), particularly those involving the mitral isthmus (MI) and left atrial ridge, are often associated with prior MI ablation.
- High-resolution mapping is a highly effective approach for identifying the mechanisms and critical isthmuses of these complex ATs.
- Targeted ablation guided by detailed mapping demonstrates excellent efficacy and long-term success in managing lateral LA ATs.
