Coronary Circulation

Question 1

Describe the left coronary artery

Answer 1

Usually larger than right
Arises from aorta and passes between the pulmonary trunk and left auricle
Then enters AV groove, divides into anterior inter-ventricular branch and a circumflex branch

Question 2

Label this. What does it show?

Answer 2

Coronary Artery Distribution

Question 3

What are the coronary artery variations?

Answer 3

Most common= RIGHT DOMINANT: Posterior IV branch comes from the right artery and so supplies large portion of posterior wall of left ventricle

LEFT DOMINANT: posterior IV arises from the circumflex on the left.

CO-DOMINANT: branches from the R+L coronary artery. This indicates LV strength

Question 4

Coronary sinus receives 4 major tributaries: Great, middle, small and posterior cardiac veins.

Describe the great cardiac vein.

Answer 4

Aka the anterior interventricular vein
Largest vein that empties into the coronary sinus
Runs from apex to pass around the posterior surface of the heart
Gradually enlarges to ‘form’ the coronary sinus

Question 5

Coronary sinus receives 4 major tributaries: Great, middle, small and posterior cardiac veins.

Describe the small cardiac vein.

Answer 5

Located on the anterior surface of the heart, in a groove between the RA and RV

It travels within this groove onto the posterior surface of the heart, where it empties into the coronary sinus

Question 6

•Coronary sinus receives 4 major tributaries: Great, middle, small and posterior cardiac veins.

Describe the middle cardiac vein.

Answer 6

• Also known as the posterior interventricular vein
• Begins at the apex of the heart and ascends in the posterior interventricular groove to empty into the coronary sinus

Question 7

Describe the posterior cardiac vein

Answer 7

• Located on the posterior surface of the left ventricle
• It lies to the left of the middle cardiac vein and empties into the coronary sinus

Question 8

Describe the anterior and smallest cardiac vein

Answer 8

Anterior cardiac veins
Small; arise on anterior surface of right ventricle
Cross coronary sulcus and enter anterior wall of right atrium
Smallest cardiac veins (aka thebesian)
Valve-less, drain directly into right atrium and ventricle
Occasionally associated w left atrium

Question 9

Describe coronary artery occlusion

Answer 9

Left anterior descending artery is the most commonly occluded.
It’s the main supply to IV septum and the bundle branches.
Blockage infarcts the conduction system

Right coronary branches supply SAN and AVN; blockage= conduction abnormalities

Question 10

Describe Coronary Artery Bypass Graft

Answer 10