Which of the following changes are seen in ECG reading, in patients with hyperkalemia?

Appeared in: Combined AIIMS - 2020 (Jodhpur, Bhopal, Patna, Raipur)

Explanation

Hyperkalemia causes a spectrum of progressive changes on the ECG as serum potassium levels increase.
Tall, peaked T waves and a shortened QT interval are typically the earliest signs, appearing in mild hyperkalemia.
As hyperkalemia becomes more severe, the PR interval becomes prolonged, indicating a delay in atrioventricular (AV) conduction.
Later, P waves may disappear and the QRS complex widens, which can progress to a sine wave pattern and cardiac arrest.
Because all the listed options (peaked T wave, shortened QT, prolonged PR) are documented findings in hyperkalemia, 'All of these' is the most comprehensive and correct answer.

Option A: This option is a correct finding in hyperkalemia, but it is not the only one. Selecting this option alone ignores other valid changes like a prolonged PR interval and shortened QT interval.
Option B: This is a valid, though less commonly emphasized, early change in hyperkalemia. However, it is not the only change that occurs.
Option C: A prolonged PR interval is a key finding in moderate hyperkalemia, but it is not the only ECG abnormality. The earliest change is typically the peaked T wave.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain ECG interpretation in electrolyte imbalances, specifically hyperkalemia as background academic context rather than a clinical decision trigger.
Recognizing the ECG changes of hyperkalemia is a critical nursing skill, as it allows for prompt identification and intervention before life-threatening arrhythmias occur.
Nurses should immediately report any ECG changes suggestive of hyperkalemia to the healthcare provider and prepare for emergency treatment, which may include IV calcium gluconate, insulin with dextrose, or sodium bicarbonate.
What if the patient had hypokalemia (low potassium)? The ECG would show different changes, such as ST depression, flattened T waves, and the appearance of a prominent U wave. This highlights the importance of correlating ECG findings with specific electrolyte imbalances.

How to Approach the Question

First, identify the core concepts in the question: 'ECG changes' and 'hyperkalemia'.
Recall the pathophysiology of how elevated potassium affects cardiac electrical conduction.
Systematically review the progression of ECG changes as hyperkalemia worsens: starting with repolarization (T wave), then AV conduction (PR interval), and finally depolarization (QRS complex).
Evaluate each option against this known progression. You should recognize that 'Tall and peaked T wave', 'Shortened QT interval', and 'Prolonged PR interval' are all valid findings.
When multiple options are individually correct, check for an 'All of these' option. In this case, it is the most complete and accurate answer.

Concept Tested & Keywords

Concept Tested: ECG interpretation in electrolyte imbalances, specifically hyperkalemia.
Stem keywords: ECG reading, hyperkalemia, changes
Lead-in keywords: Which of the following

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E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 542-544

E6 Gynecology Williams p. 64-85

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