Coronary Artery Supply to Heart Walls
The coronary arterial supply to the heart walls follows a standardized anatomical pattern, with the LAD artery supplying the anterior and anterolateral walls, the left circumflex artery supplying the lateral wall, and the right coronary artery (in right-dominant systems) or left circumflex artery (in left-dominant systems) supplying the inferior and posterior walls, while the interventricular septum receives dual supply from both LAD and posterior descending arteries. 1
Left Anterior Descending (LAD) Artery Territory
The LAD artery and its branches supply:
Anterior wall: The LAD itself runs along the anterior interventricular groove and directly perfuses the anterior left ventricular wall 1
Anterolateral wall: The diagonal branches (first, second, and third) originate from the LAD and specifically supply the anterolateral wall of the left ventricle 1
Interventricular septum (anterior two-thirds): The anterior descending septal perforators arise from the LAD to supply the interventricular septum 1. Research confirms that 4-10 perforators and 1-2 long septal arteries from the LAD supply the anterior two-thirds of the septum in 94% of cases 2
Left Circumflex Artery Territory
The left circumflex artery and its branches supply:
Lateral wall: The obtuse marginal branches (first, second, and third) originate from the left circumflex artery and supply the lateral wall of the left ventricle 1
Inferior wall (in left-dominant systems): In left-dominant circulation (9.5% of cases), the left circumflex continues as the left atrioventricular artery and supplies the inferior wall 1, 3
Right Coronary Artery Territory
The right coronary artery supplies:
Inferior wall (in right-dominant systems): In right-dominant circulation (87.1% of cases), the right coronary artery gives rise to the posterior descending artery (PDA) and posterolateral branches that supply the inferior wall 1, 3
Posterior wall: The posterolateral segmental artery and its branches (first, second, and third right posterolateral branches) supply the posterior wall in right-dominant systems 1
Interventricular septum (posterior one-third): The posterior descending septal perforators from the PDA supply the posterior one-third of the septum 1. The cephalic part of the posterior septum receives blood from the posterior interventricular artery 2
Right ventricular wall: Right ventricular branches arise directly from the right coronary artery 1
Atrioventricular Node Supply
The AV node blood supply depends on coronary dominance:
In right-dominant systems (87% of cases): The AV node is supplied by branches from the right coronary artery at the crux cordis 1, 4
In left-dominant systems (9.5% of cases): The AV node is supplied by the left circumflex artery continuation 1, 4
In co-dominant systems (3.4% of cases): Both right coronary and left circumflex contribute 1
The anatomical location of the AV node within the inferior pyramidal space at the atrial walls makes it vulnerable to ischemia when the dominant artery supplying this region is compromised 5.
Clinical Significance of Dominance Patterns
Left coronary dominance is associated with worse outcomes in ischemic disease, conduction abnormalities, and valvular disease compared to right dominance 4. This has direct implications for risk stratification when interpreting coronary anatomy.
Important Anatomical Variations
Approximately 15% of individuals lack the interventricular septal branch from the right coronary artery, making them susceptible to larger infarctions if the LAD is occluded 2
The posterior interventricular sulcus demonstrates 25 distinct vascularization patterns on CT angiography, with the most common (31.3%) involving RCA supply to basal and mid-ventricular segments and LAD supply to the apical segment 3
Atrioventricular and ventriculoatrial branches exist in 95% of hearts, establishing vascular connections across the coronary sulcus 6