• The lateral wall of the left ventricle is supplied by the left circumflex (LCx) artery, the diagonal branches of the left anterior descending (LAD) artery, or the ramus intermedius (RI).
• Electrical activity of the lateral wall of the left ventricle is detected by the lateral leads (V5-6, aVL, I).
• Patterns of lateral STEMI, corresponding ECG leads exhibiting ST elevation, and culprit lesion(s) are listed below:
Isolated lateral --- V5-6, aVL, I --- LCx, D1, or RI
High lateral --- aVL, I --- D1 or OM
Anterolateral --- V2-4 + V5-6, aVL, I --- LAD or mid-distal LAD/LCx
Inferolateral --- II, III, aVF + V5-6, aVL, I --- LCx/PDA or dominant LCx
Inferoposterolateral --- II, III, aVF + V7-9 + V5-6, aVL, I --- LCx/PDA or dominant LCx
• Isolated lateral MI is caused by an occlusion of the --
Left circumflex (LCx) artery,
First diagnonal (D1) branch of the left anterior descending (LAD) artery, or
Ramus intermedius (RI)
• ECG findings associated with isolated lateral MI include:
ST elevation in lateral leads (V5-6, I, aVL)
Reciprocal ST depression in inferior leads (II, III, aVF)
• On echocardiography, there is hypo/akinesis of the lateral wall (shaded in grey below) seen in apical 4 chamber and parasternal short axis views.
• High lateral MI is often caused by an occlusion of the --
First diagnonal (D1) branch of the left anterior descending (LAD) artery, or
Obtuse marginal (OM) branch of the left circumflex (LCx) artery
• ECG findings associated with high lateral MI are:
ST elevation in lateral leads I, aVL
ST elevation in lead V2
Reciprocal ST depression in inferior leads III (most often), II, aVF
• High lateral MI is one of the silent MIs that can be easily missed on the ECG, e.g. in cases where only one of 2 leads (I, aVL) exhibits ST elevation which wouldn't meet the criteria for STEMI.
• 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.
• Inferolateral MI is caused by occlusion(s) of the --
Proximal dominant left circumflex artery (LCx) and its branches including the posterior descending artery (PDA), or
PDA branch of the dominant right coronary artery (RCA) (supplying the inferior wall) and the LCx (supplying the lateral wall)
• ECG findings associated with inferolateral MI include:
ST elevation in inferior (II, III, aVF) and lateral (I, aVL) leads
• On echocardiography, there are hypo/akineses of the inferior and lateral walls (shaded in grey below) seen in apical 4- and 2- chamber, and parasternal long and short axis views.
• Inferoposterolateral MI is an extension of inferolateral MI, caused by occlusion(s) of the --
Proximal dominant left circumflex artery (LCx) and its branches including the posterior descending artery (PDA), or
PDA branch of the dominant right coronary artery (RCA) (supplying the inferior and posterior walls) and the LCx (supplying the lateral wall)
• ECG findings associated with inferoposterolateral MI include:
ST elevation in inferior (II, III, aVF), posterior (V7-9), and lateral (I, aVL) leads
Reciprocal ST depression with upright T waves in anteroseptal leads (V1-3).
• On echocardiography, there are hypo/akineses of the inferior, posterior, and lateral walls (shaded in grey below) seen in apical 4- and 2- chamber, and parasternal long and short axis views.
