A male in his 60's presented with weakness. Here is his initial ECG. He had no chest pain:
The K returned at 9.4 mEq/L. He was treated with 5 g of calcium gluconate, 20 units of insulin and 100 ml of 50% dextrose and 100 mL of 8.4% bicarbonate. Here is the second ECG 60 minutes later, with a concurrent K of 7.4 mEq/L:
|Sinus rhythm with a normal QRS at 94 ms, with hardly any change in the serum potassium. All the difference is in calcium administration. The ST elevation is gone.|
The troponin was normal. All ST elevation was due to hyperkalemia.
A woman in her 40's was found down:
|Sinus rhythm with wide QRS at 133 ms and obvious Peaked T-waves with obvious hyperkalemia. But there is also significant ST elevation in V1-V3. Is there anterior STEMI?|
The K = 8.1.
After treatment with 3 g of calcium gluconate, 10 units of insulin, and 50mL of 8.4% bicarbonate (at 100 minutes), the K was measured again and was 6.5 mEq/L and this ECG was recorded:
|QRS = 88 ms and ST elevation is now normal, not excessive.|
The troponin was normal.
Hyperkalemia can cause ST segment shifts that mimic STEMI. Here is a post with two more cases.
My next post will be a similar dramatic presentation in which the diagnosis is a mystery.