Hypertrophic cardiomyopathy pathological findings

Editors-In-Chief: C. Michael Gibson, M.S., M.D. [1], Cafer Zorkun, M.D. [2], Caitlin J. Harrigan [3], Martin S. Maron, M.D., and Barry J. Maron, M.D.

Gross Pathological Findings

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  Cardiomyopathy: Intermediate between hypertrophic and dilated

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  Hypertrophic cardiomyopathy, concentric

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  Hypertrophic Obstructive Cardiomyopathy: Gross natural color opened left ventricular outflow tract with subaortic shelf and marked endocardial thickening matching the contour of the anterior mitral leaflet

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  Cardiomyopathy: Gross apical slice of left and right ventricles concentric hypertrophy with cavitary obliteration sudden unexpected death obstructive cardiomyopathy

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  Cardiomyopathy Asymmetrical Septal Hypertrophy

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  Cardiomyopathy: Gross excellent view of mitral valve atrial surface showing thickening which is fibrous in body of valve and myxoid at area of free margin changes presumed secondary to insufficiency due to anterior motion

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  Cardiomyopathy: Gross close up view of a ventricle slice

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  Cardiomyopathy: Gross ventricular slices hypertrophy and extensive myocardial fibrosis a unique case of global fiber disarray with atrophy and fibrosis

Microscopic Pathological Findings

Histopathologically, small vessels have hypertrophy of the tunica media. Combined with increased wall tension, decreased vasodilator reserve and inadequate capillary density, there is a mismatch between blood supply and demand. Over time, it is thought that there is repeated ischemia followed by fibrosis and eventually, dilation and systolic dysfunction (“burned out hypertrophy”).

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  Micro med mag H&E mid-mural myocardium with hypertrophy and interstitial fibrosis atrophy is present marked increase in interstitial fibroblastic cells

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  Micro high mag H&E myofiber hypertrophy and interstitial fibrosis with marked increase in interstitial fibroblastic cells

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  Micro med mag H&E myofiber hypertrophy some atrophy interstitial fibrosis with many fibroblastic cells

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  Micro high mag H&E hypertrophied fibers with some evidence of atrophy and marked interstitial fibrosis with many fibroblastic type cells

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  Micro low mag H&E shows myofiber hypertrophy and interstitial fibrosis

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  Cardiomyopathy: Micro H&E low mag interventricular septum at junction of normal myofiber orientation with asymmetrical hypertrophy (an excellent example)

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  Cardiomyopathy: Micro H&E low mag marked myofiber disarray asymmetrical hypertrophy

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  Cardiomyopathy: Micro trichrome high mag marked myofiber disarray

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  Cardiomyopathy: Micro H&E med mag excellent example myofiber disarray

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  Cardiomyopathy: Micro H&E high mag excellent example myofiber disarray