In a hospital cardiac care unit, there are three patients with different cardiac conditions: a 52 year old man with dilated cardiomyopathy, an 18 year old girl with mitral valve prolapse, and a 30 year old man with infective endocarditis of the mitral valve. Which of the following features do all these patients most likely share?
Systemic thromboembolism may develop in each of these patients. Vegetations associated with infective endocarditis may undergo fragmentation and result in systemic thromboembolism. Stasis develops in dilated ventricles, which predisposes to formation of thrombi attached to the ventricular walls (mural thrombi). Mural thrombi may also form within the left atrium in the presence of mitral valve prolapse. Thromboemboli may originate from mural thrombi. Decreased compliance is a pathophysiologic alteration present in a variety of cardiac disorders in which there is impediment to expansion or relaxation of ventricular walls, such as restrictive cardiomyopathy, hyperophic cardiomyopathy, and constrictive pericarditis. This feature is not present in any of the conditions described in the question. Depressed myocardial contractility results from conditions that impair myocardial inotropism, such as dilated cardiomyopathy and ischemic hea disease. Depressed inotropism is not present in infective endocarditis or mitral valve prolapse. Of the three conditions in the question stem, only infective endocarditis is definitely related to an infectious etiology, usually bacteria. Recall that mitral valve prolapse is due to myxomatous degeneration of the mitral valve, sometimes associated with Marfan syndrome. The etiology of dilated cardiomyopathy is heterogeneous, and most cases are idiopathic. Of the remaining cases, viral infections, toxic insults (especially alcohol), metabolic disorders (hemochromatosis), pregnancy, and genetic influences are the underlying causes. Ref: Levi M., Seligsohn U. (2010). Chapter 130. Disseminated Intravascular Coagulation. In J.T. Prchal, K. Kaushansky, M.A. Lichtman, T.J. Kipps, U. Seligsohn (Eds), Williams Hematology, 8e.
Decreased compliance
Depressed myocardial contractility
Infectious etiology
Risk of systemic thromboembolism