T Waves
- T wave axis usually follows the QRS axis
- Ts are always inverted in aVR; usually inverted in V1; upright in most other leads
- Isolated T wave inversion in lead III is normal
- With vertical QRS axis, T wave inversion in aVL is normal
- If T axis is normal but T waves are narrow based and peaked: consider hyperkalemia
- T waves are usually smooth; sharp notches or “shoulders” on the upslope or downslope of Ts are suggestive of superimposed Ps (or artifact)