Thursday, June 13, 2013

Hyperkalemia and ST Segment Elevation, Post 1

Case 1.

A male in his 60's presented with weakness.  Here is his initial ECG.  He had no chest pain:
Probable junctional rhythm, with wide QRS (162 ms) and peaked T-waves.  Obvious hyperkalemia.  But there is also ST elevation in III and aVF, with reciprocal ST depression in I and aVL, and ST depression in V2 and V3.  Is there also an infero-posterior STEMI?

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.

Case 2.

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.


  1. is there any predilection localization of ST elevation in hyperkalemia ?

    Lotfi Djilali Bensekrane

    1. It is most commonly found in precordial leads, especially V1 and V2.

  2. Any tips for differentiation between hyperacute Ts found in early STEMI vs hyperK related T wave changes when symptoms are generalized and non-specific? I suspect the 2 would present extremely similar.

    1. Read this post:

    2. Wow, great post! Thank you!

  3. What causes those small "bunny ears" in the P waves in the last image? Also, great post, ty.


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