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Coronary anatomy: Difference between revisions
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===''Anatomy''=== | ===''Anatomy''=== | ||
[[File: | [[File:Coronary_anatomy1.png]]<cite>Fauci</cite> | ||
The main coronary arteries may be considered to be located in two planes: the plane of the atrioventricular groove and the plane of the interventricular septum . | The main coronary arteries may be considered to be located in two planes: the plane of the atrioventricular groove and the plane of the interventricular septum<cite>Jukema4</cite>. | ||
The right coronary artery (RCA) originates in the right sinus of Valsalva and runs in the right ventricular side of the atrioventricular groove. At the crux the posterior descending artery (RDP) and atrioventricular node artery originate. If the RCA continues after the RDP to supply a portion of the posterior left ventricular wall (RPL), it is called a right dominant circulation (85% of people). If the LCA supplies the posterior left ventricular wall (LPL) the coronary circulation is called left dominant (5%), in 10% of people there is balanced system. The RDP runs in the posterior interventricular groove. In 60% the sinus node artery arises from the proximal portion of the RCA. | The right coronary artery (RCA) originates in the right sinus of Valsalva and runs in the right ventricular side of the atrioventricular groove. At the crux the posterior descending artery (RDP) and atrioventricular node artery originate. If the RCA continues after the RDP to supply a portion of the posterior left ventricular wall (RPL), it is called a right dominant circulation (85% of people). If the LCA supplies the posterior left ventricular wall (LPL) the coronary circulation is called left dominant (5%), in 10% of people there is balanced system. The RDP runs in the posterior interventricular groove. In 60% the sinus node artery arises from the proximal portion of the RCA. | ||
The left main coronary artery (LMCA) originated in the left sinus of Valsalva. Its length varies from 5-10mm. Sporadically the LMCA is absent, resulting in separated ostia of RCx and LAD. Sometimes there is a trifurcation, with a branch between the RCx and LAD called | The left main coronary artery (LMCA) originated in the left sinus of Valsalva. Its length varies from 5-10mm. Sporadically the LMCA is absent, resulting in separated ostia of RCx and LAD. Sometimes there is a trifurcation, with a branch between the RCx and LAD called intermediate artery. Usually the LAD runs in the anterior interventricular groove. The most important side branches are the septal branches and diagonal branches to the left ventricular wall. The RCx runs in the left atrioventricular groove. All branches to the left ventricular wall are classified as obtuse marginal or posterolateral branches. In 40% the sinus node artery arises from the proximal portion of the RCx. | ||
===''Nomenclature of segments''=== | |||
===''Recommended radiographic projections''=== | |||
Recommended projections for the RCA are: | |||
*LAO 45 Proximal and mid-RCA | |||
*RAO 30 Mid-RCA, RDPcollateral vessels to LAD | |||
*LAO 20 cranial 25 Crux, RDP and RPL | |||
[[File:RecommendedRadiographicProjections.png]] | |||
LAO 45 | |||
[[File:RecommendedRadiographicProjections2.png]] | |||
RAO 30 | |||
[[File:RecommendedRadiographicProjections3.png]] | |||
LAO 20 cranial 25 | |||
Recommended projections for the LCA are: | |||
*Cranial 40 (0- RAO 5) Left main and LAD proximal, mid and distal, diagonals | |||
*Caudal 40 (0- RAO 30) Left main, bifurcations, LAD proximal, RCx proximal, mid and distal, MO-bifurcations | |||
*LAO 50 caudal 25 (spider view) Left main, bifurcations LAD and RCx | |||
[[File:RecommendedProjectionsForTheLCA.png]] | |||
Cranial 40 (0-RAO 5) | |||
[[File:RecommendedProjectionsForTheLCA2.png]] | |||
Caudal 40 (0-RAO 30) | |||
[[File:RecommendedProjectionsForTheLCA3.png]] | |||
Spider view | |||
===''Blood supply cardiac conduction system''=== | |||
[[File:BloodSupplyCardiacConductionSystem.png]] | |||
===''Collateral circulation''=== | |||
Collateral connections between coronary arteries are present in every individual<cite>Jukema5</cite>. Because of the higher perfusion pressures in major arteries, there is normally no flow in collateral connections. In case of a coronary obstruction of more than 70% diameter reduction, blood starts to flow to the artery distal of the obstruction. These pre-existent collaterals are called recruitable collaterals. Collaterals can also be newly formed and can be intra- or intercoronary. Cardiac ischemia stimulates formation of new collaterals and growth of recruitable collaterals. Recruitable vessels have a corkscrew aspect. Filling can be retrograde or antegrade (as by bridge collaterals: intracoronary collaterals). Coronary steal means that the flow through the epicardial coronary artery is diminished by the flow to collaterals that it is causing cardiac ischemia. | |||
For collateral connections, it is necessary to make longer angiographic projections. In a RCA obstruction, intercoronary collaterals can form between the septal branches of the LAD and the RDP through the interventricular septum. Collaterals connecting distal portions of two arteries are frequently observed, p.e. connections between the distal RCx and RCA in the interventricular groove and between diagonal branches of the LAD. A collateral between the conus branch of the RCA to the proximal LAD is called a ring of Vieussens. Atrial branches from the RCA or the Kugel’s artery (mostly an small artery arising from proximal RCA anastomosing with branches of sinus node artery) can form connections between the proximal and distal RCA. | |||
== References == | == References == | ||
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#Genereux pmid=22157475 | #Genereux pmid=22157475 | ||
#Fauci Fauci AS, Kasper DL, Braunwald E, Hauser SL, Longo DL. Harrison’s Principles of Internal Medicine, 17th edition: http://www.accessmedicine.com | #Fauci Fauci AS, Kasper DL, Braunwald E, Hauser SL, Longo DL. Harrison’s Principles of Internal Medicine, 17th edition: http://www.accessmedicine.com | ||
Jukema JW, Vliegen HW, Bruschke AVG. Coronary angiography: principles, technique and interpretation. 1e druk, Leiden, the Netherlands, 2009. Chapter 3: 23-34. | |||
#Jukema4 Jukema JW, Vliegen HW, Bruschke AVG. Coronary angiography: principles, technique and interpretation. 1e druk, Leiden, the Netherlands, 2009. Chapter 3: 23-34. | |||
#Jukema5 Jukema JW, Vliegen HW, Bruschke AVG. Coronary angiography: principles, technique and interpretation. 1e druk, Leiden, the Netherlands, 2009. Chapter 4: 35-40. | |||
</biblio> | </biblio> | ||