Coronary supply to Conduction System

Ramus interventricularis posterior (RIP)

• 70% of people have dominant right coronary artery, because RIP arises from it

• The dominant right artery through RIP supplies

  • Inferior wall of the heart
  • Posterior third of the ventricular septum
  • AV node
  • Bundle of His

• 10% of people → left dominance; 20% of people → codominance

• Proximal occlusion of the dominant right coronary artery (RCA)

  • causes ischemic damage to the AV node
  • Results in first-degree AV block

Ramus nodi sinuatrialis

• Supplies the SA node
  • 30% of people have ramus nodi sinuatrialis originating from the left coronary artery
  • 70% of people have ramus nodi sinuatrialis originating from the right coronary artery