Electrocardiographic changes associated with hyperkalemia include which of the following?

Electrocardiographic changes associated with hyperkalemia include which of the following?

• A. Increased P wave amplitude
• B. Shortened PR interval
• C. Narrowed QRS complex
• D. Narrowed and peaked T waves

Answer: (D)

Hyperkalemia speeds up ventricular repolarization, so the most characteristic ECG change is tall, narrow‑tipped (peaked) T waves. This reflects the heart’s faster repolarization as extracellular potassium rises. The QT interval may appear shortened because the T waves become prominent earlier in the cycle. As potassium levels rise further, AV conduction slows, the PR interval lengthens, and P waves may flatten or disappear, with QRS complexes widening due to delayed ventricular depolarization. In severe cases, a sine‑wave pattern can occur and rhythm complications become life‑threatening. The other patterns don’t fit hyperkalemia: increased P wave amplitude would be atypical and is more associated with other conditions; a shortened PR interval is not the usual progression (PR tends to prolong); a narrowed QRS complex would not occur as potassium rises (QRS widens with higher levels).

Hyperkalemia speeds up ventricular repolarization, so the most characteristic ECG change is tall, narrow‑tipped (peaked) T waves. This reflects the heart’s faster repolarization as extracellular potassium rises. The QT interval may appear shortened because the T waves become prominent earlier in the cycle. As potassium levels rise further, AV conduction slows, the PR interval lengthens, and P waves may flatten or disappear, with QRS complexes widening due to delayed ventricular depolarization. In severe cases, a sine‑wave pattern can occur and rhythm complications become life‑threatening.

The other patterns don’t fit hyperkalemia: increased P wave amplitude would be atypical and is more associated with other conditions; a shortened PR interval is not the usual progression (PR tends to prolong); a narrowed QRS complex would not occur as potassium rises (QRS widens with higher levels).