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An S-shaped atrial artery supplying the sinus node area. An anatomical study
Insights
A rare S-shaped sinus node artery (SSNA) variant, originating from the left circumflex artery, was identified in 8% of human hearts. This SSNA variant supplies the sinus node and surrounding atrial regions.
Area of Science:
- Anatomy
- Cardiovascular System
- Human Anatomy
Background:
- The sinus node artery (SNA) is crucial for cardiac rhythm.
- Variations in coronary artery anatomy can impact cardiac function.
- Detailed anatomical descriptions of coronary variants are essential for clinical practice.
Purpose of the Study:
- To describe the anatomical characteristics of the S-shaped sinus node artery (SSNA).
- To determine the prevalence of the SSNA originating from the left circumflex artery (LCir).
- To delineate the vascular supply territory of the SSNA.
Main Methods:
- Study of 300 human hearts using X-ray imaging and vessel casting.
- Identification and classification of SSNA originating from the LCir.
- Detailed anatomical dissection and mapping of vascular supply.
Main Results:
- The SSNA was found in 8% of all hearts studied and 21.5% of cases where the SNA originated from the LCir.
- The SSNA originated as a branch, divided LCir, or main continuation of the LCir in different cases.
- The SSNA supplied the sinus node, surrounding atrial areas, left atrium, interatrial septum, right atrium, and partially the atrioventricular node.
Conclusions:
- The S-shaped sinus node artery (SSNA) is a distinct anatomical variant with a significant prevalence.
- This SSNA variant has a broad vascular supply territory, including critical cardiac structures.
- Understanding SSNA anatomy is important for cardiac interventions and understanding potential arrhythmias.
Abstract:
An S-shaped sinus node artery (SSNA), originating in the posterolateral part of the left circumflex artery (LCir) below or behind the left auricle, is described in detail. The coronary vessels were studied in 300 human hearts by x-ray films or by casting of the vessels, and the SSNA was found in 24 (21.5 percent) of the 111 cases where the sinus node artery (SNA) arose from the LCir, (ie, 8 percent of all the hearts). The SSNA constituted a branch of the LCir in 15 cases, the upper part of a divided LCir in 6 cases, and the main continuation of this artery in 3 cases, always following basically the same route to the sinus node (SN) area. It was larger than the normal SNA, supplying the SN and surrounding area, almost the whole left atrium, a large part of the interatrial septum and right atrium, and partially supplying the atrioventricular node area.