AUTOPSY FINDINGS: MICROSCOPIC
The anterior left ventricle showed pale myocytes with fading nuclei and markedly decreased cross-striations, with blood vessels containing basophilic debris, bordered by a thin subepicardial zone of acute inflammation, extravasation of blood and myocyte cytoplasmic contraction banding, leaving only a small subepicardial corner of normal myocytes above the zone of inflammation. There was diffuse interstitial edema. The cardiac apex also showed diffuse interstitial edema and pale myocytes with fading nuclei and decreased striations, with a thin subepicardial zone of acute inflammation, extravasation of blood and myocyte cytoplasmic contraction banding. The subepicardial myocardium is illustrated in Images 01, 02 and 03.
The base of the posterior papillary muscle showed diffuse interstitial edema, a small area of acute inflammation and extravasation of blood, focal myocyte cytoplasmic contraction banding and areas of subendocardial hypereosinophilic myocytes. The posterior left ventricle showed multifocal myocyte contraction banding, diffuse interstitial edema and focal acute inflammation. The septum had a large area of pale staining myocytes associated with a nearby necrotic small intramyocardial coronary artery and a border of moderate acute inflammation and extravasation of blood.
Three sections of the most proximal portion of the right coronary artery showed severe atherosclerotic intimal thickening with old sclerotic disease in the deepest portions of the intima and areas of superimposed young atheroma resulting in 80-85% lumenal narrowing; there was focal superimposed thrombus deposition adding approximately 5% more lumenal narrowing. Five sections of the next most proximal right coronary artery all showed severe sclerotic intimal thickening with superimposed atheroma producing 70-80% lumenal narrowing, one with superimposed condensing fibrin thrombus deposition adding approximately 20% more narrowing (for a total of 90% lumenal stenosis), but the others with mostly postmortem thrombus in their residual lumens. The balance of the proximal right coronary artery showed sclerotic disease with superimposed atheroma producing 70-80% lumenal narrowing, with primarily postmortem thrombus in the residual lumens.
The left circumflex artery showed severe intimal thickening with one section showing two-sided large young atheromas with numerous cholesterol clefts, numerous macrophages and lymphocytes, and a few multinucleated giant cells, resulting in approximately 95% luminal narrowing and a slit-like lumen. The proximal left anterior descending artery showed intimal thickening with calcification and areas of young atheroma resulting in lumenal narrowing of 60-80%. The coronary arteries are illustrated in Images 04, 05 and 06.