1. Definition
Coronary circulation is the blood supply system of the heart. It
consists of arteries and veins that deliver oxygenated blood to the heart
muscle (myocardium) and drain deoxygenated blood.
2. Origin of Coronary
Arteries
- Both right
and left coronary arteries arise from the ascending aorta just
above the aortic valve, from the right and left aortic sinuses.
3. Coronary Arteries
A. Right Coronary
Artery (RCA)
- Origin:
Right aortic sinus
- Branches:
- Conus
branch (to infundibulum of RV)
- Right
marginal artery (to right ventricle)
- Posterior
interventricular artery (in 85% of people)
- Supplies:
- Right atrium
& ventricle
- SA node
(in 60% cases)
- AV node
(in 80% cases)
- Posterior
part of interventricular septum
B. Left Coronary Artery
(LCA)
- Origin:
Left aortic sinus
- Short main
stem → divides into:
- Left
anterior descending (LAD) artery
- Supplies anterior 2/3 of interventricular
septum, anterior walls of ventricles
- Circumflex
artery
- Gives left marginal artery
- Supplies left atrium, lateral & posterior
walls of left ventricle
- SA node (in 40%
cases, via circumflex)
Mnemonic for Branches:
“LAD supplies the LADder (septum), Circumflex circles around.”
4. Coronary Artery
Dominance
|
Type |
Based on origin of posterior
interventricular artery |
|
Right dominant (85%) |
From RCA |
|
Left dominant (8%) |
From LCA (circumflex branch) |
|
Co-dominant (7%) |
From both RCA and LCA |
5. Venous Drainage of
Heart
Main vein: Coronary
Sinus
- Opens into
right atrium
- Receives:
- Great
cardiac vein (along LAD)
- Middle
cardiac vein (along posterior interventricular groove)
- Small
cardiac vein (along right margin)
- Posterior
vein of LV
- Oblique
vein of LA
Other veins:
- Anterior
cardiac veins → directly into right atrium
- Thebesian
veins → tiny veins draining directly into heart chambers
6. Functional Features
|
Feature |
Description |
|
End arteries |
Coronary arteries have poor anastomosis |
|
Max flow |
Occurs during diastole |
|
Autoregulated |
Adjusted based on myocardial O₂ demand |
7. Clinical Anatomy
|
Condition |
Description |
|
Angina pectoris |
Chest pain due to reduced coronary blood flow |
|
Myocardial infarction (MI) |
Death of heart tissue due to blockage |
|
Coronary artery bypass graft (CABG) |
Surgery to bypass blocked arteries |
|
Atherosclerosis |
Fatty plaque buildup in coronary vessels |
