<prompt> These ECG changes are seen inHyponatremiaHypernatremiaHypokalemiaHyperkalemia  <response>: Electrocardiographic changes in hypokalemia include broad flat T waves, ST depression, prominent U waves best seen in the precordial leads and QT prolongation; these are most marked when serum K is 2.7 mmolL. Ref: Harrison 19e pg: 307 