This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid and electrolytes, Subject name: Medicine
All of the following may occur due to hypokalemia, except- 
Select and explain. 
A. Prolonged PR Interval, B. Prolonged QRS Interval, C. Prolonged QT Interval, D. Ventricular asystole
B: Prolonged QRS Interval
Answer: B: Prolonged QRS Interval 
Explanation: ECG changes when K+ < 2.7 mmol/l Increased amplitude and width of the P wave Prolongation of the PR interval T wave flattening and inversion ST depression Prominent <a href=" waves</a> (best seen in the precordial leads) Apparent long QT interval due to fusion of the T and U waves (= long QU interval) With worsening hypokalaemia... Frequent supraventricular and ventricular ectopics Supraventricular tachyarrhythmias: AF, atrial flutter, atrial tachycardia Potential to develop life-threatening ventricular arrhythmias, e.g. VT, VF and Torsades de Pointes Ref Davidson 23rd edition pg 361