A 64-year-old woman who was discharged from the hospital 4 days ago comes to the emergency department due to chest tightness and severe shortness of breath. During evaluation, the patient becomes unresponsive and goes into cardiac arrest. Despite appropriate lifesaving measures, there is no return of spontaneous circulation and she is pronounced dead. Autopsy examination is performed, and the myocardial findings are shown in the image below. Which of the following most likely predisposed this patient to the observed cardiac findings?

Question

A 64-year-old woman who was discharged from the hospital 4 days ago comes to the emergency department due to chest tightness and severe shortness of breath.  During evaluation, the patient becomes unresponsive and goes into cardiac arrest.  Despite appropriate lifesaving measures, there is no return of spontaneous circulation and she is pronounced dead.  Autopsy examination is performed, and the myocardial findings are shown in the image below.  Which of the following most likely predisposed this patient to the observed cardiac findings?

Quizplus · Accepted Answer

11ec160b_3a95_7fa9_9249_7b297670a2ef_MD0001_00 This patient's autopsy reveals a slitlike tear in the anterior left ventricular (LV) wall that is consistent with LV free-wall rupture, an uncommon but devastating mechanical complication of transmural myocardial infarction (MI) that occurs up to 2 weeks following the event (frequently within 5 days). She likely had significant coronary atherosclerosis and experienced a transmural (ST-segment elevation) MI during her previous hospitalization. Following MI, the infarcted myocardium becomes akinetic and does not move with the remaining healthy myocardium, creating additional shear stress on the myocardial wall. Coagulative necrosis and enzymatic lysis of connective tissue also weaken the myocardial wall to the extent that it may be unable to contain the high LV pressures. If rupture occurs, it leads to abrupt filling of the pericardial space with blood and rapid development of cardiac tamponade. Patients can experience chest pain and shortness of breath followed by hypotension and shock that can rapidly progress to cardiac arrest. (Choices B, C, and E) Prolonged alcohol consumption, recent viral infection, and repeated blood transfusions (ie, iron overload) are all potential causes of dilated cardiomyopathy. Dilated cardiomyopathy can lead to cardiac arrest and death via generation of a malignant arrhythmia (ie, ventricular tachycardia or fibrillation); however, autopsy is expected to reveal an enlarged heart with eccentric hypertrophy of the LV and no tears in the myocardium. (Choice D) Recurrent bacterial pharyngitis can lead to recurrent episodes of rheumatic fever, which can cause inflammatory damage to both the myocardium and valvular endocardium. Death most commonly results from decompensated heart failure caused by valvular dysfunction; gross findings on autopsy are expected to show an enlarged heart with degenerated valves. Educational objective: Left ventricular (LV) free-wall rupture is an uncommon but devastating mechanical complication of transmural myocardial infarction that occurs up to 2 weeks following the event (frequently within 5 days). Rupture leads to cardiac tamponade that causes hypotension and shock with rapid progression to cardiac arrest. Autopsy typically reveals a slitlike tear at the site of infarction in the LV wall.

A 64-Year-Old Woman Who Was Discharged from the Hospital 4