<prompt> Following is indicative of hypercalcemia on ECGShort QT intervalBundle branch blocksProlonged PR intervalParoxysmal atrial tachycardia  <response>: A Short QT interval ECG OF HYPERCALCEMIAECG OF HYPOCALCEMIA Marked shortening of Q-T interval Prolongation of Q-T interval ST segment is eliminated Lengthening of ST segment ECG of HYPERCALCAEMIA: Short QT interval Serum calcium 15 mg occurs in malignancy. 200 mgday of urinary calcium suggest hypercalcaemia. 100 mgday Hypocalcaemia ECG shows a shortened QT interval, measurements of PTH and PTH-related protein PTHrP help distinguish between maligncmcy- associated by hypercalcaemia elevated PTHrP and hypoerparathyroidism elevated PTH. Q-T Interval: Measurement from the beginning of the Q wave to the end of the T wave. Normal Q-T interval: is from 0,32 to 0.4 sec. Shortened Q-T interval: Hyperkalemia; Hypercalcemia; Digitalis and Diphenyhydantoin sodium; Tachycardia. Prolonged Q-T interval: Bradycardia-complete A-V book Hypokalemia, Hypocalcaemia and hypomagnesemia Drugs--Quinidine, procainamide, phenothiazines, tricyclic antidepressants. IHD, Mitral valve prolapse, CNS disease. 