Left Coronary Artery
Larger of the two coronaries.
Origin: posterior aortic sinus of the ascending
aorta.
Descends:
 Between the pulmonary trunk and the left
auricle.
 In the IV groove to the apex of the heart.
Right Coronary Artery
Origin: anterior aortic sinus of the ascending aorta.
Descends:
 In the right atrioventricular groove = coronary groove between the right
auricle and the pulmonary trunk

Divides into two terminal branches:
Anterior Interventricular & Circumflex arteries.
Supplies the greater part of the left atrium, left
ventricle and ventricular septum.
Branches:
 Anterior Interventricular
Descends in the anterior interventricular groove
to the apex of the heart (in most individuals it
passes around the apex to anastomose with
terminal branches of the right coronary, in 1\3 it
ends at the apex).
Supplies the right and left ventricles and anterior
part of ventricular septum
Branches
♡ Left conus artery for pulmonary conus
Branches:
 Right Conus artery:
 For infundibulum
 Upper part of anterior wall of the right ventricle

the sternocostal surface up to the apex.

Artery of Sinoatrial Node (40%)
Atrial branches:
♡ Supply anterior and lateral surfaces of the right atrium
♡ One branch supplies posterior surface of both atria:
(Artery of the Sinoatrial Node)
♡ Supplies the SAN and both atria
ventricular branches or may arise from
the trunk of left coronary artery)

Anterior ventricular branches:
♡ 2-3 branches supply the anterior surface of the right ventricle.
♡ Marginal artery is the largest branch, runs along the lower margin of
♡ Left diagonal artery (one of the
 Circumflex artery:
Winds around the left margin of the heart in the
atrioventricular groove.
♡ Left marginal branch:
Supplies the left ventricular margin up to
apex.
♡ Anterior and posterior ventricular
branches:
Supplies the left ventricle.
♡ Atrial branches:
Supplies the left atrium.
At the inferior border of the heart it continues posteriorly along the
atrioventricular groove
♡ Anastomoses with the left coronary artery in the posterior
interventricular groove
♡ In 60% it arises from the Rt coronary, 40% from the Lt coronary

Posterior ventricular branches:
♡ About 2
♡ Supply the diaphragmatic surface of the right ventricle

Posterior interventricular (descending) artery (90%)
♡ Runs towards apex in the posterior interventricular groove.
♡ Supplies the right & left ventricles, including its inferior wall.
♡ Supplies the posterior part of the ventricular septum (Excluding Apex).
♡ Large septal branch Supplies the Atrioventricular Node.
Supplies:
 Right atrium,
 Right ventricle,
 Part of Left Atrium,
 Left ventricle & Atrioventricular septum.
 Most of the conducting system
Variations of the Coronary Arteries
Left Dominance
Right Dominance
Blood Supply of the ♥
1
Tasneem Aldraye
In 10% of the population, the posterior
In 90 % of population, the posterior
interventricular artery arises from the
interventricular artery is a branch of the RCA
circumflex branch of the LCA
Coronary Anastomosis:
 In most of people, the terminal branches of the right and left coronaries anastomose in
the posterior part of the IV groove
 This anastomoses is enough to provide adequate blood supply in case of coronary
occlusion, (functional end arteries)
Arterial supply of the Conducting System of the Heart:
 S-A Node:
Nerve Supply:
♡ Right coronary artery (60%)
Cardiac plexus lies below the arch of aorta.
♡ Left coronary artery (40%)
 Sympathetic Supply:
 A-V Node and A-V Bundle:
♡ Cervical and upper thoracic spinal
♡ Right coronary artery
nerves
 Right Bundle branch:
 Parasympathetic Supply:
♡ Left coronary artery
♡ Vagus nerve
 Left Bundle branch:
♡ Right & Left coronary arteries
Venous Drainage of Heart:
 Coronary Sinus
♡ drains most of the venous blood of the heart.
♡ Runs in the coronary sulcus (posterior atrioventricular groove).
♡ Origin: It is the continuation of the Great Cardiac Vein.
♡ Tributaries:
(3) Cardiac Veins:
 Great
 Middle
 Small
 Oblique vein of left atrium (vein of Marshall)
♡ Termination:
 Empties into right atrium
 Its opening is inferior & to the left of the IVC opening.
 Guarded by a valve
Veins Draining outside Coronary Sinus:
Anterior cardiac veins:
 Open directly into the right atrium
 Venae Cordis minimie (small cardiac veins):
 Open into the heart chambers
Heart groove contents:
 Right atrioventricular groove = Coronary groove: RCA & Small cardiac vein
 Left anterior atrioventricular groove: LCA
 Left posterior atrioventricular groove: Coronary sinus
 Anterior interventricular groove: Anterior interventricular artery & Great cardiac vein
 Posterior interventricular groove: Posterior interventricular artery & Middle cardiac vein
Blood Supply of the ♥
2
Tasneem Aldraye