Electrolyte Disorders
| Author(s) | J.S.S.G. de Jong | |
| Moderator | T.T. Keller | |
| Supervisor | ||
| some notes about authorship | ||
Hypercalcemia
Hypercalcemia, high blood calcium, speeds repolarization. Characteristics of hypercalcemia:
- Mild: broad based tall peaking T waves
- Severe: extremely wide QRS, low R wave, disappearance of p waves, tall peaking T waves.
Hypocalcemia
ECG-characteristics of hypocalcemia, low blood calcium:
- Narrowing of the QRS complex
- Reduced PR interval
- T wave flattening and inversion
- Prolongation of the QT-interval
- Prominent U-wave
- Prolonged ST and ST-depression
Hyperkalemia
ECG characteristics of hyperkalemia, high blood potassium:
- Tall peaked T waves
- Flattening p-waves. In extreme hyperkalemia p-waves may disappear altogether.
- Prolonged depolarization leading to QRS widening (nonspecific intraventricular conduction defect) sometimes > 0.20 seconds
At concentrations > 7.5 mmol/L atrial and ventricular fibrillation can occur.
Consecutive ECGs of a patient with hyperkalemia. ECG1
Consecutive ECGs of a patient with hyperkalemia. ECG2
Consecutive ECGs of a patient with hyperkalemia. After correction of potassium levels. ECG3
Another patient, potassium of 9.4 mmol/L
Hypokalemia
Hypokalemia, low blood potassium, results in:
- ST depression and flattening of the T wave
- Negative T waves
- A U-wave may be visible
patient A
patient A
patient B
Patient C, Potassiumlevel of 1.5
