Posterior Lateral Branch of the RCA

ramus posterior lateralis arteriae coronariae dextrae

The posterior lateral branches arise from the right coronary artery in its course along the diaphragmatic surface of the right ventricle and extend to the posterior and lateral walls of the left ventricle in right-dominant coronary systems. They supply the inferior left ventricular wall and are responsible for the myocardial territory affected in inferior myocardial infarction from RCA occlusion.

Region: Chest

Clinical Relevance

Clinical Notes

In right-dominant coronary anatomy (85% of individuals), the posterior descending artery and the posterior lateral branches arise from the RCA. Inferior ST-elevation myocardial infarction (STEMI) from RCA occlusion affects the inferior wall supplied by these branches. Right ventricular infarction from proximal RCA occlusion (before the RV branches) requires specific management with volume loading rather than nitrates. Revascularisation targets the culprit vessel with primary PCI restoring flow to both the posterior descending and the posterior lateral branches.

Pathology

Common Injuries & Conditions

Inferior STEMI from RCA Occlusion of Posterior Lateral Branch

Acute RCA occlusion proximal to the posterior lateral branches produces inferior wall STEMI with ST elevation in leads II, III, and aVF and reciprocal changes in the lateral leads; primary PCI of the RCA restores flow to both the posterior descending and posterior lateral branches, and right-sided ECG leads are applied to detect concomitant right ventricular infarction.