• The anterior wall of the left ventricle is supplied by the left anterior descending (LAD) artery.
• The anterior wall is generally divided into 4 subregions anteroseptal, mid-anterior, anterolateral, and apical (as illustrated above).
• Electrical activity of the anterior wall of the left ventricle is detected by the anterior leads: V1-2 (anteroseptal), V3-4 (mid-anterior), V5-6 (anterolateral).
• Patterns of anterior STEMI, corresponding ECG leads exhibiting ST elevation, and culprit lesion(s) are listed below:
Extensive anterior --- V1-6 + aVL, I --- proximal LAD
Mid-anterior --- V2-4 --- mid LAD
Anterolateral --- V2-6 + aVL, I --- LAD or mid-distal LAD/LCx
Anteroseptal --- V1-3 --- septal perforator
Apical --- V1-4 --- mid-distal LAD
Anteroinferior --- II, III, aVF + V2-6 --- mid-distal "wraparound" LAD
• Extensive anterior MI is caused by an occlusion of the --
Proximal left anterior descending (LAD) artery
• ECG findings associated with extensive anterior MI include:
ST elevation in anteroseptal (V1-2), mid-anterior (V3-4), anterolateral (V5-6), and high lateral (I, aVL) leads
Reciprocal ST depression in inferior leads (II, III, aVF)
• On echocardiography, there is hypo/akinesis of the anterior wall (shaded in grey below) seen in apical 4 chamber and parasternal short axis views.
• Mid-anterior MI is caused by occlusion of the --
Mid left anterior descending (LAD) artery below the level of the septal branch take-off
• ECG findings associated with mid-anterior MI include:
ST elevation in leads V3-6 (sparing septal leads V1-2)
• On echocardiography, there is hypo/akinesis of the anterior wall sparing septal wall (shaded in grey below) seen in apical 4 chamber and parasternal short axis views.
• Anterolateral MI is caused by occlusion(s) of --
Proximal left anterior descending (LAD) and its branches including the diagonal artery supplying the lateral wall, or
Mid-distal LAD (supplying mid-anterior wall) and either the left circumflex (LCx) or ramus intermedius (RI) (supplying the lateral wall)
• ECG findings associated with anterolateral MI include:
ST elevation in mid-anterior (V3-4) and lateral (V5-6, I, aVL) leads
Reciprocal ST depression in inferior leads (II, III, aVF)
• On echocardiography, there are hypo/akineses of the mid-anterior and lateral walls (shaded in grey below) seen in apical 4- and 2- chamber, and parasternal long and short axis views.
• Isolated anteroseptal MI is very rare because the septal perforators supplying the anteroseptal wall branch off the left anterior descending (LAD) very proximally and an occlusion of the proximal LAD will cause both anteroseptal and anterolateral wall infarct (causing extensive anterior MI).
• Anteroseptal MI is caused by occlusion(s) of the --
Septal perforator(s) of the left anterior descending (LAD) artery
• ECG findings associated with apical MI include:
ST elevation in anteroseptal leads (V1-4)
• On echocardiography, there is hypo/akinesis of the anteroseptal wall (shaded in grey below) seen in apical 4 chamber and parasternal short axis views.
• Apical MI is caused by occlusion of the --
Mid-distal left anterior descending (LAD) artery below the level of the septal and diagonal branches take-offs
• ECG findings associated with apical MI include:
ST elevation in leads V1-4
• On echocardiography, there is hypo/akinesis of the apical wall (shaded in grey below) seen in apical 4 chamber and parasternal short axis views.
• Anteroinferior MI is caused by occlusion(s) of the --
Mid-distal wrap-around left anterior descending artery (LAD), or
Mid-distal LAD (supplying the mid-anterior wall) and the posterior ascending artery (PDA) (supplying the inferior wall)
• ECG findings associated with anteroinferior MI include:
ST elevation in anterior (V2-6) and inferior (II, III, aVF) leads
Reciprocal ST depression in lateral leads (I, aVL)
• On echocardiography, there are hypo/akineses of the inferior and anterior walls (shaded in grey below) seen in apical 4- and 2- chamber, and parasternal long and short axis views.
