Clinical History:

Two days prior to admission this 78-year-old female developed severe acid indigestion and felt nauseated.  One hour prior to hospitalization she complained of severe chest pain and collapsed.  She was dead on arrival at the hospital.

-  Figure 1 is a transverse section of her left ventricle.

-  Figure 2 is a higher magnification of the area between arrows in Figure 1.  In Figure 2, the tip of the arrow is at the junction between myocardium and endocardium.

Questions:

1. Name the lesion (between the arrows) in Figure 1.  A close up view is seen in Figure 2.  Is this the expected appearance given the history (i.e. time of onset)? Does the thinness of the wall in this area have functional significance?

2. Where should you look for the cause of this tissue injury (see Figure 3)? What acute and chronic processes might be going on in the blockage seen in Figure 3? Does such blockage always produce myocardial damage?

3. From your discussions of injury and inflammation, predict the histology of the myocardial damage (Figure 4). How would this lesion evolve with time, and would the result be functional muscle?

4. Figure 5 shows an endocardial lesion adjacent to the myocardial injury. Name, pathogenesis, possible complications?

5. Speculate briefly on possible causes for the sudden decompensation.