The classic digitalis effect has 4 typical findings on ECG:
- Virtually any: flattening, inversion, other abnormal waveforms such as peaking of the terminal portion (seen in about 10% of patients)
3.Sagging or “scooped” ST-segment with concomitant ST-segment depression
- More pronounced in leads with tall R waves (e.g. lateral leads)
4.Increase in the U-wave amplitude
It is important to remember that these do not correlate with toxicity as they can be seen at levels well within normal therapeutic range.
For a good review on this and the other important arrythmias assiociated with digoxin toxixicy, see here.