Inferior (diaphragmatic) left ventricular wall and posterior third of the septum

Territory

The diaphragmatic surface of the left ventricle plus the posterior third of the septum and the posteromedial papillary muscle, supplied by the posterior descending artery from whichever vessel is dominant.

Traced from the start

  1. Right (anterior) aortic sinus
  2. Left (posterior) aortic sinus and left main stem
  3. Right coronary arteryLeft circumflex artery
  4. Posterior descending (posterior interventricular) artery
  5. Inferior (diaphragmatic) left ventricular wall and posterior third of the septum

Detail

Supplied by
Posterior descending artery: RCA in 80% of inferior STEMIs, circumflex in 18%, wraparound LAD rarely
Leads
II, III and aVF

When it goes wrong

Inferior STEMI with ST elevation in III greater than II and ST depression in I or aVL

RCA is the culprit; record V4R for RV infarction and expect bradycardia or AV block

Inferior STEMI with ST elevation in II equal to or greater than III, no depression in aVL and lateral involvement

Circumflex is the culprit

Practise this structure

1 question in the bank tagged Myocardial Oxygen Supply.