Coronary artery

From Ganfyd

The coronary artery anatomy is well described including its common variations, as a result of its importance in ischaemic heart disease. Above the aortic valve, the left coronary and right coronary cusp give rise to sinuses from which their respective coronary arteries lead from. The left is larger although perhaps 25% of the left ventricle is typically supplied by the right. Rare abnormalities such as a high right coronary artery origin, left circumflex or coronary artery from the right coronary cusp can occur.

Left coronary artery (LCA)

Left coronary artery
An anterior view of normal coronary artery anatomy
System:	Arterial system
Function:
Origin:	Aorta
Branches:	Left anterior descending artery, Left circumflex artery, Ramus intermedius
Insertion:
Arterial supply:	Aorta (Left coronary cusp)
Venous drainage:	coronary sinus
Lymphatic drainage:
Innervation:
Vertebral levels:
Search for Coronary artery in Gray's.

This starts out as the left main stem (LMCA, left main coronary artery) and is rather variable as to length, indeed double or triple artery starting effectively from the left coronary sinus are possible

Branches

• Left anterior descending artery (LAD)
  • Supplies interventricular septum and much adjacent heart to this. Reaches apex and may even supply posterior apex
  • Septal perforators
  • Diagonals
    • These are numbered as they arise
• Left circumflex artery (LCx)
  • In the interventricular sulcus (lateral or left atrio-ventricular groove) supplying left ventricle and left atrium. May supply branches to the SA and AV nodes and posterior aspect heart
  • Obtuse marginals
    • These are numbered as they arise
  • Lateral branches
    • Named (if exist) based on the segment of the lateral wall they supply
      • High lateral artery
      • Lateral artery
      • Posterior lateral artery
  • About 15% Posterior descending artery in posterior grove
• Ramus intermedius in about 35%

Right coronary artery (RCA)

Right coronary artery
An anterior view of normal coronary artery anatomy
System:	Arterial system
Function:
Origin:	Aorta
Branches:	Sinus atrial node artery, Conus artery, Right marginal artery, Posterior descending artery, Posterolateral artery
Insertion:
Arterial supply:	Aorta (Right coronary cusp)
Venous drainage:	coronary sinus
Lymphatic drainage:
Innervation:
Vertebral levels:
Search for Coronary artery in Gray's.

• Supplies the right atrium and right ventricle

Branches

• SA node artery
  • From the stem of the RCA and supplies the right atrium, SA node and part of the left atrium in 60%
• Conus artery which supplies the right ventricular outflow tract
• Right marginal
  • Largest of the branches supplying right ventricle and can sometimes reach apex
• Posterior descending artery (posterior interventricular artery) in 85%
  • This lies on the interventricular groove and sends branches into the interventricular septum (whether RC or Cx artery origin)
  • AV node artery
    • From the descending artery as the posterior septal artery supplying the AV node and interventrucular septum in well over 85%
• Posterolateral artery (PLA) in 85%
  

  

  This schematic picture, reflecting to some degree the necessity for several views in coronary angiograpy to fully view the right and left coronary trees respectively, illustrates the main variations. These are in the source of the posterior descending artery supply, the sino-atrial node artery supply and whether a ramus intermedius exists

Variants

• The RCA supplies the sino-atrial node in about 60% of the population
• The LCx supplies the sino-atrial node in about 40% of the population
• The ramus intermedius is found in about 35%
• With right dominance the RCA supplies the posterior descending artery, AV node artery and any PLA as in 70%
• With left dominance the LCx supplies the posterior descending artery, AV node artery and any PLA as in 10%
• With co-dominance the RCA supplies the PDA and the CX supplies the PLA. This happens in about 20%