A 32-year-old man dies suddenly in his sleep. An autopsy is performed and the heart is examined for signs of structural cardiac disease. The heart shows a left ventricle with a large area of apical thinning composed of fibrotic scar tissue. The mid and basal left ventricular segments show normal myocardial thickness. The coronary arteries show no evidence of obstructive atherosclerosis. The right ventricle appears normal in size. No apparent valve damage is present. Dilation and wall-thickening of the esophagus is also noted. Which of the following factors in this patient's medical history would be most helpful in determining the cause of death?

Question

A 32-year-old man dies suddenly in his sleep.  An autopsy is performed and the heart is examined for signs of structural cardiac disease.  The heart shows a left ventricle with a large area of apical thinning composed of fibrotic scar tissue.  The mid and basal left ventricular segments show normal myocardial thickness.  The coronary arteries show no evidence of obstructive atherosclerosis.  The right ventricle appears normal in size.  No apparent valve damage is present.  Dilation and wall-thickening of the esophagus is also noted.  Which of the following factors in this patient's medical history would be most helpful in determining the cause of death?

Quizplus · Accepted Answer

11ec160b_38c5_c835_9249_fdb7db1f677b_MD0001_00 This man with a large area of localized cardiac apical wall thinning likely died of chronic Chagas cardiomyopathy. Chagas disease is caused by infection with the protozoan Trypanosoma cruzi, which is transmitted by the triatomine "kissing" bug (Reduviid family) found throughout the Americas as far north as the southern United States. Infection is rare in developed regions, but the disease is endemic throughout Central and South America where widespread open-air and thatched-roof housing exposes individuals to routine contact with the triatomine vector. Years following initial infection, some individuals develop serious end-organ damage affecting the cardiac, gastrointestinal, and/or central nervous systems. Cardiac disease results from a chronic parasite-induced and immune-mediated myocarditis that leads to dilated cardiomyopathy (DCM). Chronic Chagas cardiomyopathy is relatively unique among DCMs in that there is characteristically localized apical wall thinning with the development of a large apical aneurysm. In addition to impairing ventricular systolic function, the aneurysm can harbor mural thrombus that may systemically embolize and cause stroke. Damage to the cardiac conduction system can also trigger ventricular arrhythmias (eg, ventricular tachycardia, ventricular fibrillation) that can lead to sudden cardiac death (the likely cause of death in this patient). The gastrointestinal manifestations of Chagas disease result from destruction of the myenteric plexus, which can lead to progressive dilation and dysfunction of the esophagus and, less commonly, the colon. (Choices A, C, D, and E) Excessive alcohol consumption can lead to DCM. Measles, mumps, and rubella are typically vaccinated against in childhood and are potential causes of viral DCM. Genetic mutations of the gene encoding for the cardiac sarcomere protein titin can lead to familial DCM. Miners and metal workers who are exposed to high levels of cobalt can develop DCM. These DCMs typically involve diffuse left ventricular wall thinning, unlike the characteristic localized apical wall thinning and aneurysm development that occurs in chronic Chagas cardiomyopathy. DCM due to ischemic heart disease may sometimes involve localized wall thinning with aneurysm development, but it is unlikely in this young man with no evidence of atherosclerotic coronary artery disease. Esophageal enlargement is also not expected with these other etiologies of DCM. Educational objective: Chagas disease is endemic to Central and South America and can lead to chronic Chagas cardiomyopathy, a dilated cardiomyopathy. Unlike the diffuse ventricular wall thinning that occurs in most dilated cardiomyopathies, chronic Chagas cardiomyopathy is characterized by localized apical wall thinning with large apical aneurysm development. __________ References: Chagas cardiomyopathy in Latin America review. (http://www.ncbi.nlm.nih.gov/pubmed/30747287) Pathology of chronic Chagas cardiomyopathy in the United States: a detailed review of 13 cardiectomy cases. (http://www.ncbi.nlm.nih.gov/pubmed/27425387)

A 32-Year-Old Man Dies Suddenly in His Sleep