This patient had a K of 8.1 mEq/L and a very low ionized Calcium of 2.4 mg/dl (normal: 4.4 – 5.2). Both were from a blood sample drawn 13 minutes prior to the following ECG (time zero):
ECG time zero:
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| There is a near sine wave which is pathognomonic for hyperkalemia. The QRS duration is 254 ms. |
3 g of Calcium gluconate was administered and another ECG was recorded 1 minute later:
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| The QRS is now 190 ms |
Another dose of Calcium was given and this ECG was recorded 2 minutes after the 2nd (3 min after the 1st):
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| The QRS is not 154 ms. |
4 minutes after this, another ECG was recorded:
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| The QRS is wider again, at 190 ms. |
There was rapid release of potassium from this very ill patient, and only a transient effect of Calcium
Learning Point:
Calcium has rapid but reversible effects on QRS width in Hyperkalemia.
