ECG changes in hypomagnesaemia is characterized by

(C). ECG changes in hyperkalemia include peaking of the T waves, this is followed, as the potassium level increases, by ST-segment depression, an increased PR interval, flattening of the P wave, and widening of the QRS complex. In hypokalemia a flattened T wave, a depressed ST segment, and the appearance of a U wave. In hypermagnesemia ECG changes include prolonged PR, QRS, and QT intervals