Commonly used criteria for ECG left ventricular hypertrophy (LV)
| 25–50% sensitive1-150 |
| 95% specific1-150 |
| Chest lead |
| R wave in V5 or V6 exceeds 25 mm |
| S wave in V1 or V2 exceeds 25 mm |
| Tallest R wave in V5 or V6 + deepest S wave in V1 or V2 exceeds 35 mm |
| Ventricular activation time (onset of QRS to peak R) exceeds 0.04 s |
| Limb lead |
| R in aVL exceeds 11 mm |
| R in I exceeds 12 mm |
| R in aVF exceeds 20 mm |
| R in I + S in III exceeds 25 mm |
| R in aVL + S in V3 exceeds 13 mm |
| Repolarisation changes (see note) |
| Mildly abnormal: |
| ST-T segment flattening, isolated ST depression or T wave inversion |
| Severely abnormal: |
| ST depression with inverted or biphasic T waves |
| • V4 to V6(that is, leads facing left ventricle) |
| • 1 and aVL (facing left ventricle when heart horizontal) or |
| • 11 and aVF (facing left ventricle when heart vertical) |
| Additional points |
| LVH results in only slight shift to the left of the frontal plane QRS axis |
| Horizontal heart: axis = +30° to −30° |
| Vertical axis: axis = +60° to +90° |
| There is often counterclockwise rotation—that is, qR complexes appear in the chest leads before the usual V4 to V6 |
| Prominent u waves may be seen in the mid and right precordial leads in LVH |
| Remember digoxin can produce ST/T wave changes and u waves |
↵1-150 Vary with criteria used and population screened—see text.
Note: “strain” refers to the additionalpresence of ST/T wave changes, usually definite ST depression (1 mm) and T wave inversion or biphasic T wave, which are of particular prognostic importance in the presence ofvoltage changes—see text.