When a coronary artery is occluded, the specific region of the heart that loses blood supply determines both symptoms and clinical findings. Understanding which wall is affected is foundational for exams and understanding autopsy findings.
LAD Occlusion
Infarct Location:
- Anterior LV wall
- Anterior septum
- Apex
This is the most commonly occluded vessel which is why it is nicknamed the widowmaker. ☠️
LCx Occlusion
Infarct Location:
- Lateral LV wall
- Posterior LV wall if left-dominant
R dominant circulation shown above
RCA Occlusion
Infarct Location:
- RV free wall
- Posterior septum (in right dominant)
- Posterior LV (in right dominant)
R dominant circulation shown above
Dominance
Dominance is determined by which artery gives rise to the Posterior Descending Artery (PDA).
80% right-dominant → PDA comes off the RCA
10% left-dominant → PDA comes off the LCx
10% co-dominant → PDA comes off both the RCA and LCx
A Simple Rule of Thumb
- LAD = Anterior
- LCx = Lateral
- RCA = Rear (posterior)
Want the full set of cardiac diagrams, explanations, and exam-ready frameworks? You can download the complete Cardiac Study Guide in the Study Tools Hub here.