In case of hyperparathyroidism, which of the following will be seen?

AIIMS M.Sc. Nsg Entrance exam-2026

Medical Surgical Nursing

Medium

Appeared in: AIIMS M.Sc. Nsg Entrance exam-2026

Explanation

Hyperparathyroidism involves excessive secretion of parathyroid hormone (PTH), which mobilizes calcium from bones and increases its absorption, leading to hypercalcemia (high blood calcium).
Hypercalcemia alters the cardiac action potential by shortening the plateau phase (Phase 2), which is dependent on calcium influx.
This acceleration of ventricular repolarization is visualized on an ECG as a shortening of the ST segment.
The direct consequence of a shortened ST segment is a shortened QT interval, which represents the total time for ventricular depolarization and repolarization.

Option A: ST-segment elevation is not caused by hypercalcemia. It indicates myocardial injury or inflammation.
Option B: A prolonged QT interval is the opposite of what is seen in hypercalcemia.
Option C: Tall, peaked T waves are related to potassium levels, not calcium levels.

Visual 1: ECG Strip Comparison - An image showing a normal ECG side-by-side with an ECG demonstrating a short QT interval, with the ST segment and QT interval clearly labeled to highlight the shortening in the context of hypercalcemia.
Visual 2: Diagram of Cardiac Action Potential - A diagram illustrating the phases of the ventricular action potential, showing how increased extracellular calcium shortens the duration of the Phase 2 plateau, thus accelerating repolarization.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain ECG manifestations of hyperparathyroidism and hypercalcemia as background academic context rather than a clinical decision trigger.
Recognizing the ECG changes associated with electrolyte imbalances is a critical nursing responsibility, as conditions like severe hypercalcemia can lead to life-threatening arrhythmias and require prompt intervention.
Nurses monitoring patients with known or suspected parathyroid disorders, certain cancers (which can cause hypercalcemia), or those on calcium supplements should be vigilant for ECG changes and symptoms like confusion, weakness, or palpitations.
What if? If the patient had undergone a thyroidectomy and accidentally had their parathyroid glands removed (iatrogenic hypoparathyroidism), the resulting hypocalcemia would cause the opposite ECG finding: a prolonged QT interval, which increases the risk for a dangerous ventricular arrhythmia called Torsades de Pointes.

How to Approach the Question

First, analyze the question to identify the core medical condition: hyperparathyroidism.
Second, recall the primary physiological consequence of this condition. Hyperparathyroidism leads to hypercalcemia (elevated blood calcium).
Third, access your knowledge of how electrolyte imbalances affect the heart's electrical activity. Specifically, how does high calcium impact the ECG?
Fourth, evaluate the given options. A short QT interval is the known ECG manifestation of hypercalcemia.
Finally, eliminate the other options by linking them to their correct causes: ST elevation (MI/pericarditis), prolonged QT (hypocalcemia), and tall T waves (hyperkalemia).

Concept Tested & Keywords

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