2 main coronary arteries that arise from the aorta
Coronary artery origins/ostia
- RCA comes off of the RCC and heads anteriorly (towards the sternum)
- LM comes off of the LCC

Left coronary artery

Begins with the Left main stem and most often bifurcates into the LAD and LCx
Left anterior descending (LAD)
- Proximal, mid and distal segments
- Diagonal branches
- Septal branches
- “Diagonals go down”, i.e. branches on the inferior aspect of the LAD will be diagonal branches.
Left circumflex artery (LCx)
- Travels in the atrioventricular groove
- Proximal, atrioventricular and distal segments
- Obtuse marginal
  - The anterior marginal branches go “anteriorly” (i.e. towards the sternum), whereas the obtuse marginal branches run along the obtuse margin of the heart 🫀
- Sinoatrial node branch
  - often arises from the LCx, but can arise from the RCA as well
- +/- posterolateral branch

Right coronary artery