Examples of ECG Abnormalities in Electrolyte Emergencies (Hyperkalemia, Hypokalemia)

📚 Quick Study Guide

• ⚡ Hyperkalemia (High Potassium): ECG changes often occur in a predictable sequence as potassium levels rise. Look for:
• 📈 Peaked T waves (especially in the precordial leads)
• 📉 Flattened P waves
• ↔️ Prolonged PR interval
• widening QRS complex
• 💀 Sine wave pattern (severe hyperkalemia)
• 💧 Hypokalemia (Low Potassium): Hypokalemia causes different but equally important ECG changes:
• 📉 Flattened T waves or T wave inversion
• ⬆️ Prominent U waves (best seen in precordial leads)
• ⬇️ ST segment depression
• ⬆️ Increased risk of arrhythmias (e.g., atrial fibrillation, ventricular tachycardia)
• 🔢 Important Potassium Levels:
• Normal Potassium: 3.5-5.0 mEq/L
• Hyperkalemia: >5.0 mEq/L
• Hypokalemia: <3.5 mEq/L
• 🧪 Remember: ECG changes may not always correlate perfectly with potassium levels. Clinical context is crucial!

Practice Quiz

1. What is the earliest ECG finding typically seen in hyperkalemia?
   1. A. Prolonged QRS complex
   2. B. Peaked T waves
   3. C. Prominent U waves
   4. D. ST segment depression
2. Which ECG change is most characteristic of hypokalemia?
   1. A. Peaked T waves
   2. B. Shortened PR interval
   3. C. Prominent U waves
   4. D. Widened QRS complex
3. A patient with severe hyperkalemia is likely to exhibit which ECG abnormality?
   1. A. Flattened T waves
   2. B. Sine wave pattern
   3. C. Shortened QT interval
   4. D. Tall R waves
4. What effect does hypokalemia typically have on the T wave?
   1. A. Increases T wave amplitude
   2. B. Inverts or flattens the T wave
   3. C. Has no effect on the T wave
   4. D. Causes T wave peaking
5. Which of the following ECG changes suggests a *life-threatening* hyperkalemia?
   1. A. Peaked T waves in leads II, III, aVF
   2. B. Flattened P waves and widened QRS complex
   3. C. Prominent U waves in V1-V3
   4. D. ST segment elevation in V2-V4
6. ST segment depression coupled with prominent U waves is most indicative of which electrolyte abnormality?
   1. A. Hypercalcemia
   2. B. Hypokalemia
   3. C. Hyperkalemia
   4. D. Hyponatremia
7. A patient's ECG shows flattened P waves, a prolonged PR interval, and a widening QRS complex. What electrolyte imbalance is MOST likely?
   1. A. Hypokalemia
   2. B. Hypercalcemia
   3. C. Hyperkalemia
   4. D. Hypocalcemia