Monday, May 13, 2013

Series of Prehospital ECGs Showing Reperfusion

Medics recorded this ECG at time 0 in a patient with chest pain:

There are inferior hyperacute T-waves, with reciprocally inverted hyperacute T-wave in aVL, and a biphasic (down-up) T-wave in V2 and V3, as well as ST depression in I and V4-V6.

"Down-up" biphasic T-waves should always be thought to be reciprocal of "up-down" (Wellens' type) reperfusion T-waves.  (Alternatively, if you see a down-up T-wave, it may actually be a down T-wave followed by an upright U-wave, if it happens very late.)  Thus, this is probably inferior-posterior STEMI, possibly with some degree of reperfusion.

The chest pain began to resolve after NTG (t = 2 minutes):

The inferior T-waves are slightly smaller, and there is less negativity to the T-waves in V2 and V3

Another was recorded at t = 4 minutes:
Now the inferior T-waves are not at all hyperacute and the precordial T-waves are mostly upright.  Clearly, this is a reperfusing inferoposterior MI.  There are down-up T-waves in V4-V6.

Here is t = 13 minutes, with posterior leads V7-V9:
Now there are inverted (reperfusion) T-waves in the inferior leads, with a reciprocally upright T-wave in aVL. The T-waves in V2 and V3 are upright.  There are mostly inverted T-waves in V7-V9, pretty much reciprocal  to (opposite of) V2 and V3.

Here is t = 14 minutes (simultaneous to previous):
T-waves are upright in V4-V6, reciprocal to the inverted T-waves in V7-V9, but not exactly because these are not 180 degrees opposite each other.    V2 and V3 are another example of posterior reperfusion T-waves.
Angiogram showed an open culprit artery supplying the inferior and posterior walls

3 comments:

  1. Awesome case. Really shows off the dynamicity of T-waves with respect to acute occlusional ischemia. I believe the T-waves are the most under-appreciated ECG findings/clues to occlusion- a beautiful thing really. In fact, we see here that you don't even need to look at the ST segments to make the diagnosis!
    Sam

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  2. Great read and some great examples.

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