LMCA
Also written as: LMCA — Left Main Coronary Artery
Left main coronary artery, the short segment that bifurcates into the LAD and circumflex arteries.
Full Definition
The left main coronary artery (LMCA) is a short but critically important vessel that arises from the left aortic sinus and typically measures 10-15mm in length before bifurcating into the left anterior descending (LAD) and left circumflex (LCX) arteries. In some patients, an intermediate branch (ramus intermedius) may arise from the LMCA, creating a trifurcation. LMCA disease is particularly concerning because it jeopardizes blood supply to a large portion of the left ventricle. Significant LMCA stenosis (>50%) is considered an indication for urgent revascularization, typically with CABG, though percutaneous intervention may be appropriate in selected cases.
Usage
Usage note: LMCA disease severity classifications differ from other coronary vessels (>50% is considered significant).
In Context
- "Critical 80% stenosis of the LMCA was identified, requiring emergency surgical revascularization." — Emergency cardiac assessment
- "The LMCA appeared normal with no evidence of ostial or distal disease at the bifurcation." — Coronary angiography report