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Distal left anterior descending artery (dLAD)

The distal left anterior descending (LAD) artery is the terminal segment of the LAD, a major branch of the left coronary artery (LCA). It runs in the anterior interventricular groove, extending beyond the mid-LAD to reach the apex of the heart, often wrapping around to the diaphragmatic surface.

The distal LAD gives off small septal perforators and diagonal branches in its proximal course, but in the distal segment, it primarily supplies the apex of the heart, the distal interventricular septum, and portions of the inferior wall when it wraps around the apex. Its perfusion territory makes it a critical vessel in ischemic heart disease. Occlusion of the distal LAD is associated with apical infarction, ischemic cardiomyopathy, and abnormalities in LV function and wall motion.

Synonyms

  • Apical LAD

  • Terminal segment of LAD

  • Distal anterior interventricular artery

Function

  • Supplies the apex of the left ventricle

  • Provides blood to the distal interventricular septum

  • May extend to supply part of the inferior wall of LV (when it wraps around the apex)

  • Critical in defining the extent of LAD perfusion territory

MRI Appearance

T1-weighted images:

  • Distal LAD lumen appears as a signal void (black) in the anterior interventricular groove toward the apex

  • Surrounded by fat planes that help delineation

T2-weighted images:

  • Blood flow appears as a signal void

  • Altered signal (intermediate/high) suggests slow flow or thrombus

T1 Post-Contrast (Gadolinium-enhanced MRI):

  • Enhances brightly along its course

  • Distal LAD perfusion defects are seen in ischemia or infarction with delayed enhancement showing apical scar

MRI Non-Contrast Coronary MRA (Cardiac-gated 3D):

  • Visualizes distal LAD as a bright continuous structure reaching the apex and sometimes wrapping to the diaphragmatic surface

  • Useful for evaluating LAD length, termination, and variants in patients who cannot receive gadolinium

CT Appearance

CT Pre-Contrast:

  • Distal LAD seen as tubular structure in anterior interventricular groove; coronary calcifications appear hyperdense

  • Coronary calcium scoring frequently quantifies LAD burden, especially in distal segments

CT Post-Contrast:

  • Distal LAD enhances but requires high-resolution coronary protocol to be clearly delineated

CT Coronary Angiography (CCTA):

  • Gold standard non-invasive modality for distal LAD

  • Depicts the artery’s course to the apex, any wrap-around supply to the inferior wall, and terminal branches

  • Multiplanar and 3D reconstructions show stenosis, plaque morphology, occlusion, and distal flow

  • Essential in diagnosing apical ischemia, infarction, or assessing grafts/stents involving distal LAD

CT images

(dLAD) ct axial anatomy image -img-00000-00000

CT images

(dLAD) ct axial anatomy image -img-00000-00000_00001