Tall 'T' waves are seen in: (Repeat): (A) Hyperkalemia, (B) Hypocalcemia, (C) Hypercalcemia, (D) Hypokalemia
Answer is A. Ans: A (Hyperkalemia) Ref: Harrison 's Principles of Internal Medicine, 18ed.Explanation:ECG changes in HyperkalaemiaTall T waves (Earliest sign)Prolonged 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