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09:17
High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation
Published on: July 29, 2011
The mechanisms of atrial fibrillation
Peng-Sheng Chen1, Chung-Chuan Chou, Alex Y Tan
1Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA. chenp@cshs.org
Journal of Cardiovascular Electrophysiology
|November 24, 2006
Summary
Thoracic veins, particularly pulmonary veins, are key drivers of atrial fibrillation (AF). Targeting these veins through isolation or medication can effectively control AF by reducing arrhythmogenic triggers.
Area of Science:
- Cardiology
- Electrophysiology
- Thoracic Vein Research
Background:
- Atrial fibrillation (AF) mechanisms are complex, with thoracic veins emerging as critical arrhythmogenic sources.
- The pulmonary vein (PV)-left atrial (LA) junction and the vein of Marshall (VOM) exhibit unique structural and electrical properties contributing to AF.
- Discontinuous myocardial fibers, fibrosis, and specialized cells within thoracic veins promote abnormal electrical activity.
Purpose of the Study:
- To review the arrhythmogenic mechanisms of thoracic veins in atrial fibrillation.
- To emphasize the role of pulmonary veins and the vein of Marshall in AF generation and maintenance.
- To evaluate the impact of antiarrhythmic drugs and ablation techniques on thoracic vein activity.
Main Methods:
- Review of existing literature on thoracic vein structure and function in AF.
- Analysis of myocardial fiber arrangement, cellular composition, and electrical properties of thoracic veins.
- Examination of the effects of pharmacological agents and ablation on PV-LA interactions.
Main Results:
- Thoracic veins, especially PV-LA junctions, possess arrhythmogenic features like discontinuous fibers and anisotropy.
- The VOM contains muscle bundles interspersed with fibrosis and fat, potentially promoting reentrant circuits.
- Specialized PAS-positive cells in PV sleeves may act as focal discharge sources.
- Antiarrhythmic drugs (Class I and III) modulate electrical activity in PV muscle sleeves.
- Ablation techniques separating thoracic veins from the LA reduce PV-LA interaction.
Conclusions:
- Thoracic veins are significant contributors to the initiation and perpetuation of atrial fibrillation.
- Thoracic vein isolation is a crucial strategy for AF management.
- Pharmacological and interventional approaches targeting thoracic veins offer effective AF control by mitigating arrhythmogenic mechanisms.
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