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== | ==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 | ||
* | |||
*T | |||
* | |||
* | |||
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|ventricular fibrillation]] can occur. | At concentrations > 7.5 mmol/L atrial and [[Ventricular Fibrillation|ventricular fibrillation]] can occur. | ||
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Image:KJcasu18-2.jpg|Consecutive ECGs of a patient with hyperkalemia. ECG2 | Image:KJcasu18-2.jpg|Consecutive ECGs of a patient with hyperkalemia. ECG2 | ||
Image:KJcasu18-1.jpg|Consecutive ECGs of a patient with hyperkalemia. After correction of potassium levels. ECG3 | Image:KJcasu18-1.jpg|Consecutive ECGs of a patient with hyperkalemia. After correction of potassium levels. ECG3 | ||
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 | Hypokalemia, low blood potassium, results in: | ||
*ST depression and flattening of the T wave | *ST depression and flattening of the T wave | ||
*Negative T waves | *Negative T waves | ||
*A U-wave may be visible | *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 | ||
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</gallery> | </gallery> | ||
{{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> |