In viral myocarditis, inflammatory infiltrates are primarily located in which tissue, and bacterial endocarditis is characterized by what?

In viral myocarditis, inflammatory infiltrates are primarily located in which tissue, and bacterial endocarditis is characterized by what?

• A. In viral myocarditis, inflammatory infiltrates are within the myocardium; endocarditis has vegetations on valve leaflets with organisms and fibrin deposition.
• B. In viral myocarditis, inflammatory infiltrates are within the endocardium; endocarditis has infiltrates in the myocardium.
• C. Viral myocarditis has vegetations on valves; endocarditis has neutrophilic infiltration of myocardium.
• D. Viral myocarditis involves pericardial inflammation; endocarditis involves pericardial effusion.

Answer: (A)

Inflammation in viral myocarditis mainly targets the heart muscle itself, so the inflammatory infiltrates are within the myocardium and accompany myocyte injury. Bacterial endocarditis, on the other hand, produces vegetations on the valve leaflets formed by organisms enmeshed in fibrin and platelets on the endocardial surface. This combination—infiltration in the myocardium for viral myocarditis and vegetations on valve leaflets with organisms and fibrin for endocarditis—is the correct pairing. Other descriptions misplace where inflammation occurs or misidentify the hallmark lesion of endocarditis.

Inflammation in viral myocarditis mainly targets the heart muscle itself, so the inflammatory infiltrates are within the myocardium and accompany myocyte injury. Bacterial endocarditis, on the other hand, produces vegetations on the valve leaflets formed by organisms enmeshed in fibrin and platelets on the endocardial surface. This combination—infiltration in the myocardium for viral myocarditis and vegetations on valve leaflets with organisms and fibrin for endocarditis—is the correct pairing. Other descriptions misplace where inflammation occurs or misidentify the hallmark lesion of endocarditis.