<prompt> Tall T waves are seen in: RepeatHyperkalemiaHypocalcemiaHypercalcemiaHypokalemia  <response>: Ans: A Hyperkalemia Ref: Harrison s Principles of Internal Medicine, 18ed.Explanation:ECG changes in HyperkalaemiaTall T waves Earliest signProlonged PR intervalWidened QRS intervalFlattened P wavesArrythmias including bradycardia, ventricular tachycardia or fibrillationSinus arrest or nodal rhythm with possible asystoleECG changes in HypokalaemiaFlattened T wavesST segment depressionProlonged QT intervalTall U wavesAtrial arrythmiasVentricular tachycardia or ventricular fibrillation 