Inflammation Case Studies


CASE 3: Acute myocardial infarction, acute renal infarction


Clinical History:

Following left anterior descending coronary artery thrombosis with an acute myocardial infarction involving most of the free wall of the left ventricle, a 73-year-old man experienced partial paralysis of his right side. He also developed acute renal failure and hematuria. He died a short time later. (image 3.1 is the gross appearance of the cardiac lesion; images 3.2 is the gross appearance of the renal lesion, and images 3.3 and 3.4 demonstrate the lesion's microscopic findings).
  1. Describe the lesion in the heart at autopsy.

    2. An area of coagulative necrosis is present in the anterior left ventricular free wall and septum.

  2. Diagnose and describe the lesion in the kidney removed at autopsy. What would be the typical gross appearance?

    3. The section of kidney shows a triangular-shaped zone, with its base at the capsular surface and its apex pointed at the medulla, that has loss of cellular detail: the nuclei are gone (karyolysis) and the cytoplasm shows enhanced red staining (eosinophilia).

    Note that the ghosts of tubules and glomeruli are preserved. One small branch of a renal artery actually show the cause, a thrombus in an artery near the apex of the area of necrosis. This necrosis is the result of ischemia, leading to an infarction (coagulative necrosis). It is very recent, so that little inflammatory infiltrate is present.

  3. How did the renal lesion result from the myocardial infarction?

    4. A mural thrombus developed on the endocardium overlying the area of myocardial infarction. A portion of this thrombus broke off and was sent out into the systemic circulation, eventually going out the renal artery and lodging in a small branch to occlude the blood supply to a cortical segment and cause an infarct.

  4. What was the probable cause of his paralysis?

    5. A thrombus probably travelled to a cerebral artery, leading to brain infarction (a "stroke").