Heart

Heart lab 2 Congenital heart disease And myocarditis

Heart, atrial septal defects - Gross, cut surfaces: unusual occurrence of a primum and a secundum ASD in the same heart. The primum ASD lies just above the valve leaflet and is oval. The secundum ASD is more rounded and is more centrally located in the atrial septum.

Heart, small ventricular septal defect - Gross, endocardial surfaces in the muscular portion of the interventricular septum.

Heart, large ventricular septal defect - Gross, cut surfaces The VSD is located near the membranous portion of the interventricular septum, at the junction of the atria and ventricles.

Heart, patent ductus arteriosus - Gross

Heart, transposition of the great vessels - Gross, longitudinal section, cut surface:

Aorta, coarctation - Gross, cross section

There is hyperplasia of smooth muscle and fibrous tissue in an aortic coarctation. The hyperplasia obstructs blood flow into the descending aorta. If the coarctation is severe, the infant is dependent on blood flowing through the patent ductus arteriosus to support perfusion to the lower extremities.



Aorta, coarctation - Low power

myocarditis

Gross: Dilated, flabby heart. Pale patches with foci of hemorrhage. Mural thrombi can be seen.

Dilated, heart in myocarditis

Interstitial inflammatory infiltrate.Myocyte necrosis.Fibrosis.Types of inflammatory cells: Mononuclear cells – idiopathic or viralNeutrophils – bacterialEosinophils –hypersensitivity or protozoaGranulomatous – TB or sarcoid

Myocarditis – lymphocyte infiltrate and myocyte necrosis. This is usually either viral or of unknown cause.

Diphtheria myocarditis – due to a toxin rather than bacterial invasion. There is some inflammation, myocyte changes (see the big nucleolus). Myocyte necrosis (not shown) also happens.

Bacterial colony in myocarditis

Toxoplasmosis



Chagas disease: trypanosomes distend a myofiber, surrounding inflammatory cells and necrosis.


Myocyte necrosisMultinucleated giant cellsLymphocytes, plasma cells, macrophages, eosinophils, and neutrophilsOften fulminant, rapid progression to deathDifferential diagnosis – cardiac sarcoidosis

Giant Cell Myocarditis

Giant Cell Myocarditis

Rheumatic fever – Aschoff body – A collection of cells, often near a vessel, with a few multinucleate cells and some vesicular nuclei with big nucleoli (Aschoff cells). Anichkov myocytes (not shown) are myocytes with very elongated big nucleoli. This is a marker for rheumatic fever, but the serious damage is to the valves.