A 66-year-old woman dies of severe congestive hea failure. Her past medical history is remarkable for rheumatoid ahritis that first manifested at the age of 35. The autopsy revealed splenomegaly, hepatomegaly, and glomerulopathy. The spleen, liver, and kidneys showed a similar waxy texture. Which of the following mechanisms explains these clinical and pathologic findings?
Correct Answer: Accumulation of amyloid
Description: Chronic inflammatory conditions, such as collagen vascular diseases, rheumatoid ahritis, and bronchiectasis, may lead in time to accumulation of a specific form of amyloid, known as AA (amyloid-associated protein). Systemic amyloidosis affects many organs, especially the hea, kidneys, spleen, GI tract, liver, and tongue. The ventricular walls become thickened and inelastic, and the resulting pathophysiologic picture is that of restrictive cardiomyopathy. Congestive hea failure ensues because of decreased ventricular compliance and secondary reduced stroke volume. Note how the ventricular lumen are narrowed and the walls are extremely thickened. A waxy texture is highly suggestive of amyloid deposition, which can be confirmed histologically by using Congo red staining.Note:Atherosclerosis of coronary aeries may give three different types of clinical manifestations: arrhythmias (with sudden death), angina pectoris, and myocardial infarction. Loss of myocardial tissue due to ischemic necrosis may lead to congestive hea failure. The hea will show evidence of old infarcts in the form of scars, and the ventricular cavities will become dilated. Coxsackievirus myocarditis is the most common etiologic form of viral myocarditis, which may resolve without clinical consequences or lead to dilated cardiomyopathy and hea failure. Mutations of myosin chain genes are the most common causes of hyperophic cardiomyopathy. This manifests with thickening of the interventricular septum (so-called asymmetric cardiac hyperophy), with resultant impediment to both systolic outflow and diastolic filling. Here, the ventricular walls are uniformly thickened, and the remaining postmoem findings (liver, kidney, and spleen changes) cannot be explained based on a diagnosis of hyperophic cardiomyopathy. Ref: Kim H.W., Farzaneh-Far A., Klem I., Rehwald W., Kim R.J. (2011). Chapter 23. Magnetic Resonance Imaging of the Hea. In V. Fuster, R.A. Walsh, R.A. Harrington (Eds), Hurst's The Hea, 13e.
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