Anatomy - Cardio

Question 1

What supplies the SA & AV nodes?

Answer 1

• SA & AV nodes:
  
  • supplied by branchs of the right coronary artery (R.C.A.)
• Infarct:
  
  • may be cause nodal dysfunction
    
    • bradycardia (slow heart rate)
    • heart block (long PR interval)

Question 2

Explain dominant circulation.

Answer 2

Circulation Dominance:

• Right-dominant circulation (85%)
  
  • PDA arises from RCA (right coronary artery)
• Left-dominant circulation (8%)
  
  • PDA arises from LCX (left circumflex coronary artery)
• Codominant circulation (7%)
  
  • PDA arises from both LCX & RCA

Notes:

• Coronary artery occlusion = most common in LAD (left anterior descending artery)
  
  • supplies:
    
    • 2/3 of interventricular septum
    • anterolateral papillary muscle
    • anterior surface of left ventricle
• Coronary blood flow peaks in early diastole

Question 3

Important cardiovascular arteries

Answer 3

Right:

1. Right coronary artery (RCA)
2. Right (acute) marginal artery
   
   • supplies R.V.
3. Posterior Descending/Interventricular artery (PDA)
   
   • can be right/left/codominant
   • supplies:
     
     • AV node
     • posterior 1/3 of interventricular septum
     • posterior 2/3 wall of ventricles
     • posteromedial papullary muscles

Left:

1. Left main coronary artery (LCA)
2. Left circumflex coronary artery (LCX)
   
   • supplies:
     
     • lateral & posterior walls of L.V.
     • anterolateral papillary muscle
3. Left anterior descending artery (LAD)
   
   • supplies:
     
     • anterior 2/3 of interventricular septum
     • anterolateral papillary muscle
     • anterior surface of L.V.