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Functional morphology of the pig sinoatrial node
T Opthof1, B de Jonge, H J Jongsma
1Department of Physiology, University of Amsterdam, The Netherlands.
Journal of Molecular and Cellular Cardiology
|December 1, 1987
Summary
The porcine sinoatrial node generates impulses from a specific area with fewer myofilaments. Impulse propagation favors the crista terminalis over the interatrial septum.
Area of Science:
- Cardiovascular Physiology
- Cardiac Electrophysiology
Background:
- The sinoatrial node (SAN) is the primary pacemaker of the heart.
- Understanding SAN structure and function is crucial for cardiac rhythm research.
Purpose of the Study:
- To characterize the impulse generation and propagation in the porcine sinoatrial node.
- To investigate the cellular composition and electrical properties of the SAN.
Main Methods:
- Isolated right atrium preparation in pigs.
- Analysis of impulse generation sites and propagation pathways.
- Histological examination of SAN cellular composition.
Main Results:
- The porcine SAN exhibits unifocal impulse generation from a region with low myofilament content.
- Impulse propagation is anisotropic, favoring the crista terminalis over the interatrial septum.
- A significant zone of low excitability exists on the interatrial septal side of the SAN.
Conclusions:
- The porcine SAN's structure, with its elongated shape and specific cellular makeup, influences impulse generation and conduction.
- Anisotropic conduction properties are a key feature of the porcine SAN, impacting atrial activation patterns.