Normal or increased PR interval and short QT interval on ECG indicate which electrolyte abnormality?

Normal or increased PR interval and short QT interval on ECG indicate which electrolyte abnormality?

• A. Hypokalemia
• B. Hyperkalemia
• C. Hyponatremia
• D. Hypercalcemia

Answer: (D)

Calcium levels shape both the QT interval and AV nodal conduction on the ECG. When calcium is elevated, ventricular repolarization happens more quickly, shortening the QT interval. At the same time, calcium can slow AV nodal conduction, which may keep the PR interval normal or even prolong it. So the pattern of a normal or prolonged PR interval with a short QT interval is most consistent with hypercalcemia. This helps distinguish from other electrolyte disorders: hypokalemia typically lengthens the QT interval; hyperkalemia causes changes such as peaked T waves and potential QRS widening rather than a short QT; hyponatremia doesn’t produce the classic short QT pattern.

Calcium levels shape both the QT interval and AV nodal conduction on the ECG. When calcium is elevated, ventricular repolarization happens more quickly, shortening the QT interval. At the same time, calcium can slow AV nodal conduction, which may keep the PR interval normal or even prolong it. So the pattern of a normal or prolonged PR interval with a short QT interval is most consistent with hypercalcemia.

This helps distinguish from other electrolyte disorders: hypokalemia typically lengthens the QT interval; hyperkalemia causes changes such as peaked T waves and potential QRS widening rather than a short QT; hyponatremia doesn’t produce the classic short QT pattern.