Myocardial and Pericardial Disease

Pericarditis – inflammation of the pericardium

Hydropericardium – serous fluid around the heart (etiol: nephrotic syndrome)

Hemopericardium – partially clotted blood around the heart (etiology: trauma, post MI rupture, aortic dissection)

Acute Fibrinous Pericarditis – fibrin exudate on the visceral pericardium, etiology is usually not infectious but rather a reaction to an insult (radiation damage, MI, SLE, caused by trauma, uremia)

Gross – "bread and butter" appearance, a shaggy fibrinous precipitate that extends into the pericardial space.

Histology – large patches of precipitated fibrin well stained by eosin

Organizing pericarditis – the fibrin strands are in granulation tissue, the pericardium thickens

Fibrous pericarditis – an even later stage of organization where the epicardium is covered by a thick layer of hyalinized vascularized connective tissue. Often adhesions between the epicardium and the pericardium.

Constrictive pericarditis – visceral and pericardial layers are fused, the heart has to work harder to pump blood.

Tuberculosis pericarditis – grossly visible exudate, histologically demonstrates caseating granulomas with giant cells.

Metastatic Tumor invasion of the pericardium – often direct seeding from bronchiogenic carcinoma but lymphatic (lymphomas) and hematogenous spread are possible. Often give rise to a hemopericardium, the tapped fluid of which may be diagnostic for the cancer. Many times more likely to be a secondary tumor (met) than a primary tumor.

Other Cardiac Pathology

1⁰ Cardiac myopathy – grossly a globoid (rounded) heart, dilated ventricle, feels "floppy" (etiology: EtOH, nutritional deficiencies, and more)

Fat infiltrate – atrophy of muscle fibers with replacement of fat

Myocarditis – an infection of the heart. Histo: the myocardium is densely infiltrated with lymphocytes and large mononuclear cells. The case in lab was of a Coxsackie B virus infection

Acute suppurative myocarditis – Histo: small cavities filled with purulent exudate. Colonies of bacteria are recognizable in central regions of some of the abscesses. The case is lab was a Staphylococcus pneumonia infection.

Myocardial Sarcoidosis – epicardial and myocardial scars, granulomas, and giant cells.

Cardiac Amyloidosis – proteins deposited systemically and in the heart, thickened endocardium with valve involvement

Histo: myofibers separated by a pink amorphous stuff, amyloid appears reddish-violet on Crystal violet stain and exhibits apple green bifringence with Congo red staining.

Senile amyloidosis – the protein transthyrotin is deposited just in the heart (not systemically) in folks > 60 y/o

Endocardial fibroelastosis – a thickening of the endocardial layer. 2 types (congenital and adolescent onset)

Histo: see deposits of elastin and smooth muscle

Atrial myxoma – most common primary tumor of the heart, most often formed at the limbus fossa ovalis. A benign tumor that causes hemodynamic problems and is a source for emboli.

Histo: myxoid background with stellate cells

Carcinoid syndrome – a tumor that produces 5-HT. Since lung monoamine oxidase breaks 5-HT down, most of the cardiac pathology is on the right side of the heart. Causes grossly visible U-shaped plaques.