U wave that occurs just after the T wave and is usually of smaller amplitude than the T wave. Flattening of the T wave. ST depression on occasion, which can mimic ischemia.

The differential diagnosis of a U-wave includes hypokalemia, cardiac ischemia ... potassium level less than 2.5 mEq/mL, concerning ECG changes, or significant muscle weakness.

An ST depression is a possible outcome of an electrocardiogram (ECG) test. It can indicate health conditions such as hypokalemia ... graph represent different waves of electrical activity.

Diffuse T wave inversion is stage III of the ECG changes in pericarditis ... but negative QRS in lead I). Hypokalemia causes U waves in the ECG seen as a positive wave just after the T wave.