Complete interatrial block in a left-atrial dependent atrioventricular node
Javier Ramos Jiménez1, Álvaro Marco Del Castillo1, Daniel Rodríguez Muñoz1
1Arrhythmia and Electrophysiology Unit, Cardiology Department, University Hospital 12 de Octubre, Madrid, Spain.
Journal of Cardiovascular Electrophysiology
|July 1, 2021
Summary
Electrophysiologic study revealed interatrial dissociation during radiofrequency ablation for atypical atrial flutter. The atrioventricular node became dependent on a left atrial rhythm, highlighting anatomical considerations during ablation.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Ablation
Background:
- Recurrent atypical atrial flutter necessitates electrophysiologic study and potential ablation.
- Radiofrequency ablation is a common treatment for complex atrial arrhythmias.
Observation:
- During radiofrequency ablation of the cavotricuspid isthmus and anterior mitral line, unexpected findings occurred.
- Energy delivery on the anterior left atrial wall led to interatrial dissociation.
Findings:
- A complete block of sinus impulses to the atrioventricular (AV) node was observed.
- AV node activation became reliant on a subsidiary left atrial rhythm, indicating altered cardiac conduction.
Implications:
- Understanding intra- and inter-atrial connections is crucial for extensive ablation procedures.
- Prior cardiac surgeries may increase the complexity and risk of such interatrial conduction abnormalities.
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