Which ECG finding is characteristic of hyperkalemia?

Which ECG finding is characteristic of hyperkalemia?

• A. Prolonged QT
• B. Peaked T waves
• C. ST depression
• D. U waves

Answer: (B)

Hyperkalemia alters cardiac conduction by elevating extracellular potassium, which speeds up initial repolarization and produces tall, peaked T waves on the ECG. This is one of the earliest and most recognizable changes as potassium rises. If potassium continues to rise, you can later see PR prolongation, flattening of the P waves, and widening of the QRS complex, progressing toward a sine-wave pattern in severe cases. Among common ECG findings, the peaked T waves are the best clue for hyperkalemia. By contrast, prolonged QT is more typical of hypokalemia or other electrolyte disorders, ST depression suggests ischemia, and U waves are classically associated with hypokalemia rather than hyperkalemia.

Hyperkalemia alters cardiac conduction by elevating extracellular potassium, which speeds up initial repolarization and produces tall, peaked T waves on the ECG. This is one of the earliest and most recognizable changes as potassium rises. If potassium continues to rise, you can later see PR prolongation, flattening of the P waves, and widening of the QRS complex, progressing toward a sine-wave pattern in severe cases. Among common ECG findings, the peaked T waves are the best clue for hyperkalemia. By contrast, prolonged QT is more typical of hypokalemia or other electrolyte disorders, ST depression suggests ischemia, and U waves are classically associated with hypokalemia rather than hyperkalemia.