• Disturbances in serum calcium concentration often affect ventricular repolarization thus changes in QT intervals might be seen on ECG.
• Calcium imbalance often results in altered mental status, and in severe cases, coma and death.
• In hypocalcemia, QTc intervals are prolonged.
• Accordingly, there is an increased risk of Torsades de pointes and fatal tachyarrhythmia.
• In hypercalcemia, ECG might show shortened QTc intervals.
• In severe cases, Osborn waves might appear (also seen in hypothermia).
