Left Anterior Descending Artery (LAD): Anatomy and Myocardial Supply

The left anterior descending artery (LAD) is the largest coronary artery and supplies the majority of the left ventricle.

Origin & Course

• Branch of left main coronary artery (LMCA)
• Runs in the anterior interventricular sulcus (groove between left and right ventricles)
• Also called the "anterior interventricular artery"

Major Branches & Supply

• Septal perforators: Anterior 2/3 of interventricular septum (including bundle branches)
• Diagonal branches (D1, D2...): Anterolateral left ventricle
• Distal LAD: Apex of heart

Clinical Significance

• "Widow-maker" lesion: Proximal LAD occlusion → large anterior MI, high mortality
• Supplies ~45–55% of left ventricular mass
• Critical for LV systolic function
• Primary target for CABG (LIMA-LAD graft has best long-term patency)

LAD disease is the most prognostically significant coronary lesion.