In hypokalaemia all ECG changes are seen except
Electrocardiographic changes in hypokalemia include broad flat T waves, ST depression, u wave and QT prolongation. These are most marked when serum K+ is <2.7 mmol/L. (reference: harrisons principles of internal medicine,19E page-307)
Decreased T-wave amplitude
Normal ST segment
prolonged QT interval
U-wave
Fluid and electrolytes