Difference between revisions of "Electrolyte Disorders"

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(Hyperkalemia)
m (Hypocalcemia)
 
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==Hypercalcemia==
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==Hyperkalemia==
Hypercalcemia results in a faster repolarization. Characteristics of hypercalcemia:
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ECG characteristics of hyperkalemia, high blood potassium:
*mild: broad based tall peaking T waves
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*P-waves are widened and of low amplitude due to slowing of conduction
*severe: extremely wide QRS, low R wave, disappearance of p waves, tall peaking T waves.
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*QRS complex:
 
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**QRS widening
==Hypocalcemia==
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**fusion of QRS-T
ECG-characteristics of hypocalcemia:
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**loss of the ST segment
*narrowing of the QRS complex
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*Tall tented T waves
*reduced PR interval
 
*T wave flattening and inversion
 
*prolongation of the QT-interval
 
*prominent U-wave
 
*prolonged ST and ST-depression
 
  
==Hyperkalemia==
+
The initial part of the QRS complex is often spared as purkinje fibers are less sensitive to hyperkalemia.
[[Image:ecg_hyperkaliemie.jpg|thumb| Extreme hyperkalemia. No p-waves, wide QRS, tall peaking T waves.]]
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These changes can also occur in acidosis (via the same mechanism) and during Class IC anti-arrhythmic intoxication.
[[Image:ecg_hyperkaliemie2.jpg|thumb| Same patient after partial correction of the potassium level. Still no p-waves visible, wide QRS, tall peaking T waves.]]
 
ECG characteristics of hyperkalemia:
 
*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|ventricular fibrillation]] can occur.
 
At concentrations > 7.5 mmol/L atrial and [[Ventricular Fibrillation|ventricular fibrillation]] can occur.
 
<gallery consecutive ECGs of a patient with severe hypokalemia>
 
<gallery consecutive ECGs of a patient with severe hypokalemia>
Image:KJcasu18-3.jpg|Consecutive ECGs of a patient with hypokalemia. ECG1
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Image:KJcasu18-3.jpg|Consecutive ECGs of a patient with hyperkalemia. ECG1
Image:KJcasu18-2.jpg|Consecutive ECGs of a patient with hypokalemia. ECG2
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Image:KJcasu18-2.jpg|Consecutive ECGs of a patient with hyperkalemia. ECG2
Image:KJcasu18-1.jpg|Consecutive ECGs of a patient with hypokalemia. After correction of potassium levels.
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Image:KJcasu18-1.jpg|Consecutive ECGs of a patient with hyperkalemia. After correction of potassium levels. ECG3
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File:DVA0578.jpg|Another patient, potassium of 9.4 mmol/L
 +
File:E000561.jpg|Potassium 7.5 mmol/L. [[Answer_-_Case_of_the_month_(Oct_2011)|More ECGs]]
 
</gallery>
 
</gallery>
 
{{clr}}
 
{{clr}}
  
 
==Hypokalemia==
 
==Hypokalemia==
 +
Hypokalemia, low blood potassium, results in:
 +
*ST depression and flattening of the T wave
 +
*Negative T waves
 +
*A U-wave may be visible
 
<gallery>
 
<gallery>
 +
Image:Hypokalemia.jpg| A patient with hypokalemia, prominent QT prolongation. Not the extrasystoles originating from the prolonged T/U wave. This patient definitely needs rhythm monitoring
 
Image:KJcasu17-1.jpg| patient A
 
Image:KJcasu17-1.jpg| patient A
 
Image:KJcasu17-2.jpg| patient A
 
Image:KJcasu17-2.jpg| patient A
 
Image:KJcasu17-3.jpg| patient B
 
Image:KJcasu17-3.jpg| patient B
 +
Image:JJ0003.jpg| Patient C, Potassiumlevel of 1.5
 
</gallery>
 
</gallery>
Hypokalemia is a low blood potassium level. This results in:
 
*ST depression and flattening of the T wave
 
*Negative T waves
 
*A U-wave may be visible
 
 
{{clr}}
 
{{clr}}
 +
 +
==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.
 +
<gallery>
 +
File:E000546.jpg|A patient with severe hypercalcemia: Calcium 4.6 mmol/L, albumin 37 g/L
 +
</gallery>
 +
 +
==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
 +
<gallery>
 +
File:E000800.jpg|An ECG of a patient with hypocalcemia
 +
</gallery>

Latest revision as of 12:23, 3 September 2014

Author(s) J.S.S.G. de Jong
Moderator T.T. Keller
Supervisor
some notes about authorship

Hyperkalemia

ECG characteristics of hyperkalemia, high blood potassium:

  • P-waves are widened and of low amplitude due to slowing of conduction
  • QRS complex:
    • QRS widening
    • fusion of QRS-T
    • loss of the ST segment
  • Tall tented T waves

The initial part of the QRS complex is often spared as purkinje fibers are less sensitive to hyperkalemia. These changes can also occur in acidosis (via the same mechanism) and during Class IC anti-arrhythmic intoxication.

At concentrations > 7.5 mmol/L atrial and ventricular fibrillation can occur.


Hypokalemia

Hypokalemia, low blood potassium, results in:

  • ST depression and flattening of the T wave
  • Negative T waves
  • A U-wave may be visible


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