In hypokalaemia all ECG changes are seen except: (A) Decreased T-wave amplitude, (B) Normal ST segment, (C) prolonged QT interval, (D) U-wave
Answer is B. 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)