Saturday, March 21, 2015

Chest Pain, LVH with Incomplete LBBB, and ST Elevation

A middle aged male with history of bicuspid aortic valve and aortic stenosis complained of 30 minutes of chest pain and dyspnea.  He described it as tightness and pressure.  It resolved with nitroglycerine.   Vital signs were normal and he appeared well.

Here is the initial ECG:
There is profound LVH with incomplete LBBB, with a QRS of 118 ms.  There is marked ST elevation in precordial leads. Although this can be seen with this degree of LVH and incomplete LBBB, one must entertain the possibility of anterior STEMI.
The ST/S ratio is 5/28 in lead V2, for a ratio of 0.18.   

Though 0.18 is less than 0.25, and of course also less than 0.20, it is still quite a high ratio.   A mean maximal ST/S ratio for a cohort of patients with complete LBBB is 0.10 (95% CI: 0.9-0.11).  


Worried about STEMI, a bedside echo was immediately recorded. Here is the parasternal long axis:

There is profound LVH and good wall motion

Here is a still image:
The arrows highlight the wide aortic root

A parasternal short axis was done:


This shows profound LVH with overall good wall motion.  In particular, the anterior wall and septum have good wall motion.  This makes anterior STEMI very unlikely.

The aortic root was not initially noticed, but the physicians were confident there was no STEMI.



The initial troponin I returned elevated at 0.128 ng/mL, at which point another ECG was recorded:
No change, consistent with the interpretation that this is the baseline ECG

The on-call cardiologist was consulted for management of this patient with a positive troponin and worrisome ST segments.  Because of the history of bicuspid aortic valve, the cardiologist was concerned about possible Aortic Dissection and suggested a chest CT.

After a second look at the echo, there was more suspicion of dissection, and a CT was ordered.  Here is one image:
This shows a large aortic root aneurysm that also has a subtle dissection (low density thin lines in the midst of the contrast is a dissection flap)

A repeat ECG was essentially unchanged.

Consistent with massive LVH



The patient went to the Operating Room.

(I am not completely certain that there was no involvement of the coronary cusps, with resulting partial occlusion of the left main and resulting NonSTEMI, but the serial ECGs do not support this).

Learning points:

1) Massive LVH can evolve over time to incomplete, or complete, LBBB, and it can have ST elevation that mimics STEMI.
2) Use ED echo to confirm good wall motion when there is anterior ST elevation due to LVH
3) Don't forget aortic dissection!

4 comments:

  1. Steve, is there a flap seen in the root?

    ReplyDelete
    Replies
    1. Brooks,
      I think it is there, but I'm not sure how certain one would be of its presence from a prospective viewpoint.
      Steve

      Delete
  2. Great case, Steve! Highlights the utility of basic echo in the undifferentiated chest pain patient. The aortic root is EXTREMELY wide on the PSLA! The RVOT, Aortic Root, & LA should all be approximately the same width on this view. (Rule of "thirds"...1/3, 1/3, 1/3) The AR is wider than both the RVOT & LA combined! Flap or no flap, this is absolutely diagnostic of aneurysm/dissection.

    SG

    ReplyDelete
    Replies
    1. This was more interesting even than that. I found out later that there had been obstruction of the right coronary cusp, and that the main channel had broken through the flap and restored flow. So some of the chest pain was due to RCA ischemia, and resolution was due to restoration of flow!

      Delete

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