A 38-year-old man dies suddenly at his workplace and cannot be resuscitated. He had experienced chest discomfort, shortness of breath, and fatigue in the week preceding the event. The man was overweight but otherwise had no significant medical history. He had no established primary care physician. He did not use alcohol, tobacco, or illicit drugs. Both parents are alive and healthy; a maternal uncle reportedly died of a heart attack at age 50. Autopsy was performed and myocardial findings are shown in the slide below. Which of the following is the most likely diagnosis?

Question

A 38-year-old man dies suddenly at his workplace and cannot be resuscitated.  He had experienced chest discomfort, shortness of breath, and fatigue in the week preceding the event.  The man was overweight but otherwise had no significant medical history.  He had no established primary care physician.  He did not use alcohol, tobacco, or illicit drugs.  Both parents are alive and healthy; a maternal uncle reportedly died of a heart attack at age 50.  Autopsy was performed and myocardial findings are shown in the slide below.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec160b_38de_0b4e_9249_cbd0209fde25_MD0001_00 This patient likely died from acute myocarditis, a condition most often caused by viral infection. Numerous viruses, including coxsackievirus, adenovirus, influenza, and HIV have been implicated. Histopathology of viral myocarditis typically shows myocyte necrosis or degeneration accompanied by an inflammatory mononuclear cell infiltrate primarily consisting of lymphocytes with some macrophages. Other less common etiologies of acute myocarditis, including bacterial, parasitic, and rheumatologic, can have a similar histologic appearance but may demonstrate additional findings (eg, granulomas in mycobacterial disease, visible organisms in parasitic disease). The clinical presentation of acute myocarditis can vary significantly; many patients remain asymptomatic with subclinical infection, but some experience severe complications including decompensated heart failure (eg, dyspnea, fatigue, peripheral edema) due to dilated cardiomyopathy. Ventricular arrhythmias leading to sudden cardiac death (SCD) can also occur. (Choice B) Cardiac amyloidosis involves deposition of abnormal proteins in myocardial tissue and typically manifests as restrictive cardiomyopathy initially. SCD can occur, but histopathology demonstrates pink amorphous material (amyloid) surrounding cardiomyocytes. (Choice C) Congenital long QT syndrome can trigger ventricular arrhythmias and lead to SCD; however, histopathology is generally unremarkable and would not demonstrate myocardial necrosis with inflammatory infiltrate. (Choice D) Coronary artery disease can lead to SCD by triggering ventricular arrhythmia, either in the setting of acute myocardial infarction or chronic ischemic heart disease. However, microscopic changes in the early stages of acute myocardial infarction include areas of coagulative necrosis and subsequent neutrophilic infiltrate, and chronic ischemic heart disease typically shows evidence of healed myocardial infarctions (eg, collagenous scars). In addition, this patient's relatively young age and short duration of preceding exertional symptoms make acute myocarditis more likely. (Choice E) Hypertrophic cardiomyopathy is characterized by cardiac myocyte disarray and interstitial fibrosis that can predispose to ventricular arrhythmia and SCD. An inflammatory infiltrate is not expected. Educational objective: Acute myocarditis is most commonly caused by a viral infection (eg, coxsackievirus, adenovirus, influenza). It often resolves without noticeable symptoms, but patients can develop serious complications, including decompensated heart failure due to dilated cardiomyopathy or sudden cardiac death due to ventricular arrhythmia. Histopathology typically demonstrates myocyte necrosis with inflammatory mononuclear infiltrate.

A 38-Year-Old Man Dies Suddenly at His Workplace and Cannot