Which electrocardiogram change is the earliest sign of hyperkalemia?
Answer and explanation
Correct answer: C. Peaked, narrow T waves
- Step 1: High extracellular potassium speeds repolarization. Step 2. The first ECG sign is tall, narrow, peaked T waves, followed by a wider QRS and a sine-wave pattern. Answer: peaked T waves. Why not the others: prominent U waves occur in hypokalemia, and ST elevation and a short PR are not typical.
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