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High-resolution Optical Mapping of the Mouse Sino-atrial Node
Published on: December 2, 2016
Optical mapping of the isolated coronary-perfused human sinus node.
Vadim V Fedorov1, Alexey V Glukhov, Roger Chang
1Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130, USA.
Journal of the American College of Cardiology
|October 16, 2010
Summary
This study mapped human sinoatrial node (SAN) excitation, revealing it
Area of Science:
- Electrophysiology
- Cardiac Anatomy
- Cardiovascular Research
Background:
- The precise origin and spread of electrical excitation within the human sinoatrial node (SAN) remain uncharacterized.
- Direct mapping of human SAN electrical activity is crucial for understanding cardiac rhythm generation.
Purpose of the Study:
- To confirm the hypothesis of functional insulation of the human SAN from the atrium, with specific electrical exit pathways.
- To map the site of origin and pattern of excitation within the human SAN.
Main Methods:
- Optical mapping of the SAN in human heart preparations using Di-4-ANBDQBS dye and blebbistatin.
- 3D structural reconstruction of the SAN using histological analysis.
Main Results:
- Identified the leading pacemaker site in the middle of the SAN, with slow, anisotropic conduction (1-18 cm/s).
- Demonstrated distinct sinoatrial conduction pathways (superior, middle, inferior) bridging the SAN and atrial myocardium.
- Revealed functional insulation of the SAN by connective tissue, fat, and coronary arteries, except at these pathways.
Conclusions:
- First demonstration of the leading SAN pacemaker site, excitation pattern, and conduction pathways into the right atrium.
- These pathways explain atrial breakthroughs originating from areas larger than the anatomically defined SAN during normal sinus rhythm.
