Normal ECG

Inferior myocardial infarction

• ST elevation in the inferior leads II, III and aVF
• reciprocal ST depression in the anterior leads

Acute anterior myocardial infarction

• ST elevation in the anterior leads V1 - 5, I and aVL
• reciprocal ST depression in the inferior leads

Acute posterior myocardial infarction

Old inferior myocardial infarction

• 2 contiguous q wave wider than 1 small box and 25% of QRS amplitude

Acute myocardial infarction in the presence of left bundle branch block

Modified Sgarbossa Criteria

• ≥ 1 lead with ≥1 mm of concordant ST elevation
• ≥ 1 lead of V1-V3 with ≥ 1 mm of concordant ST depression
• ≥ 1 lead anywhere with ≥ 1 mm STE and proportionally excessive discordant STE, as defined by ≥ 25% of the depth of the preceding S-wave.

Left ventricular hypertrophy (LVH)

• Sokolow + Lyon (Am Heart J, 1949;37:161)
  • S V1+ R V5 or V6 > 35 mm
• Cornell criteria (Circulation, 1987;3: 565-72)
  • SV3 + R avl > 28 mm in men
  • SV3 + R avl > 20 mm in women
• Framingham criteria (Circulation,1990; 81:815-820)
  • R avl > 11mm, R V4-6 > 25mm
  • S V1-3 > 25 mm, S V1 or V2 +
  • R V5 or V6 > 35 mm, R I + S III > 25 mm
• Romhilt + Estes (Am Heart J, 1986:75:752-58)
  • Point score system

Pericarditis

• Widespread concave ST elevation and PR depression throughout most of the limb leads (I, II, III, aVL, aVF) and precordial leads (V2-6).
• Reciprocal ST depression and PR elevation in lead aVR (± V1).
• Sinus tachycardia is also common in acute pericarditis due to pain and/or pericardial effusion.