Describe the appearance of an ECG in hypercalcemia.

• A. Prolonged PR interval
• B. Shortened QT interval
• C. Inverted T waves
• D. Absent P waves

Answer: (B)

In the context of hypercalcemia, a key change observed in the ECG is a shortened QT interval. This condition affects the cardiac action potentials, specifically altering the duration of the ventricular repolarization phase.

Hypercalcemia increases the extracellular calcium concentration, which can accelerate myocardial depolarization and repolarization. As a result, the QT interval, which measures the time taken to depolarize the ventricles and then repolarize, becomes shorter.

The importance of recognizing a shortened QT interval in hypercalcemia lies in its implications for cardiac function. A shortened QT can lead to changes in myocardial excitability and may increase the risk of arrhythmias.

Thus, understanding the relationship between hypercalcemia and a shortened QT interval is crucial for interpreting ECG changes accurately in patients with this electrolyte disturbance.