Download Left Coronary Artery

Blood supply of the
Heart
Dr. Sama ul Haque
Dr Rania Gabr
Objectives
 Enlist the arteries and veins supplying heart.
 Describe the origin and branches of the right and left
coronary arteries.
 Define coronary artery anastomosis.
 Describe the arterial supply of the conducting system
of heart.
 Discuss the venous drainage and nerve supply of the
heart.
 Delineate the surface anatomy of the heart and
valves.
 Explain the radiological anatomy of the heart.
Arterial supply of Heart
 Right coronary artery
 Left coronary artery
RCA
LCA
Origin of
Coronary
Arteries
AA
They arise from the 
initial part of the
Ascending Aorta
(Aortic Sinuses),
immediately above
the aortic valve.
Right Coronary Artery
Arises from the anterior
aortic sinus of the
ascending aorta.
Descends in the right
atrioventricular groove =
Coronary groove between
the Right Auricle and the
Pulmonary trunk.
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.
Right Coronary Artery
Branches of the Right Coronary artery
1- Right Conus artery:
For infundibulum and upper
part of anterior wall of the
right ventricle.
Right conus
2- Anterior ventricular
branches:
2-3 branches supply
anterior surface of the right
ventricle.
Marginal artery is the
largest branch, runs along
the lower margin of the
sternocostal surface up to
the apex.
Anterior ventricular
brs
3- 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
In 60% it arises from the
Rt coronary, 40% from the
Lt coronary
4- Posterior ventricular
branches;
About 2, supply the
diaphragmatic surface of
the right ventricle.
5- 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.
(RCA ) Supplies:
Right atrium,
Right ventricle,
Part of Left
Atrium,
Left ventricle &
Atrioventricular
septum.
Most of the
conducting system
Right Coronary Artery
Right Coronary Artery
Left Coronary Artery
The Larger of the two
coronaries.
Arises from the left
posterior aortic sinus of
the ascending aorta.
Descends:
1. Between the pulmonary
trunk and the left auricle.
2. In the IV groove to the
apex of the heart.
Divides into two terminal
branches:
Anterior Interventricular & Supplies the greater part of the
left Atrium, left ventricle and
Circumflex arteries.
ventricular septum.
1- 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 ). It supplies the right and
left ventricles and anterior part
of ventricular septum
Branches
1) Left conus artery for
pulmonary conus.
2) Left diagonal artery
one of the ventricular branches
or may arise from the trunk of
left coronary,
Branches
2. Circumflex artery:
Winds around the left margin of
the heart in the atrioventricular
groove.
1) Left marginal branch:
Supplies the left ventricular margin
up to Apex.
2) Anterior and posterior
ventricular branches:
Supplies the left ventricle.
3) Atrial branches:
Supplies the left atrium.
3. Artery of Sinoatrial Node
(40%)
Left Coronary Artery
Variations of the Coronary Arteries
 Right Dominance:
 In (90 %) of
population, the
Posterior
Interventricular
artery is a branch of
the Right Coronary.
 Left Dominance:
 In the rest (10%),
the Posterior
Interventricular
artery arises from
the Circumflex
branch of the Left
Coronary A
Coronary Anastomosis
In MOST of people, the
terminal branches of the
right and left coronaries
anastomose in the
posterior part of the IV
groove
However this
anastomoses is not large
enough to provide
adequate blood supply in
case of coronary
occlusion, (Functional
End arteries)
Arterial supply of the Conducting
system of Heart
 S-A Node:
Right coronary artery (60%)
Left coronary artery (40%)
 A-V Node and A-V
Bundle: Right coronary
artery
 Right Bundle branch: Left
coronary artery
 Left Bundle branch:
Right & Left coronary
arteries
Venous Drainage of Heart
1-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:
 A. Great.
 B. Middle.
 C. Small.
 D. Oblique vein of left atrium (vein
of Marshall).
Termination:
It empties into
Right Atrium.
Its opening is
inferior & to
the left of the
IVC opening.
It is guarded
by a valve.
Veins Draining outside Coronary Sinus
2- Anterior
cardiac veins:
Open directly
into the Right
Atrium.
3- Venae Cordis
minimie (small
cardiac veins):
Open into the
heart chambers.
Contents of Heart grooves
1. Right atrioventricular groove =
Coronary groove:
Right coronary artery
Small cardiac vein
2. Left anterior atrioventricular
groove:
Left coronary artery
3. Left posterior atrioventricular
groove:
Coronary sinus
4. Anterior interventricular groove:
Anterior interventricular artery
Great cardiac vein
5. Posterior interventricular
groove:
Posterior interventricular artery
Middle cardiac vein
Cardiac Veins (Sternocostal Surface)
Anterior cardiac veins
Cardiac Veins (Diaphragmatic Surface)
Nerve supply of the Heart
Cardiac plexus lies below the arch of Aorta.
1. Sympathetic Supply:
Cervical and upper thoracic spinal nerves
2. Parasympathetic Supply:
Vagus nerve
Location of Heart
Surface anatomy of the heart
 The upper limit of the
heart :
 The 3rd costal cartilage on
the right side of the
sternum and the 2nd
intercostal space on the
left side of the sternum.
 The right margin of the
heart:
 extends from the right
third costal cartilage to
near the right 6th costal
cartilage.
Surface anatomy of the heart
Surface anatomy of the heart
 The left margin of the heart:
 Descends laterally from the
2nd intercostal space to the
apex located near the
midclavicular line in the 5th
intercostal space.
 The lower margin of the
heart:
 Extends from the sternal
end of the right 6th costal
cartilage to the apex in the
5th intercostal space near
the midclavicular line.
Surface anatomy of the heart valves
 Pulmonary Valve:
Lies behind the medial
end of the 3rd left costal
cartilage and the adjoining
part of the sternum.
 Aortic Valve:
Lies behind the left half
of the sternum
opposite the 3rd
intercostal space.
Surface anatomy of the heart valves
Tricuspid Valve:
Lies behind the right half
of the sternum
opposite the 4th
intercostal space.
Mitral Valve:
Lies behind the left half
of the sternum
opposite the 4th costal
cartilage.
Left
Auscultation Areas
Surface Anatomy