Diseases of the valves of the heart. Rheumatic disease. Cardiomiopathy

♦ Complications include congestive heart failure, conduc_x0002_tion defects, arrythmias, and sudden death

Macroscopic

♦ Range from normal to biventricular dilation/hypertro_x0002_phy with pale “flappy” myocardium or fibrosis

Microscopic

♦ In most cases, a T-cell lymphocytic infiltrate admixed with histiocytes

♦ Occasionally with eosinophils, necessarily with myo_x0002_cyte damage

♦ Giant cells are seen in giant cell or Fiedler’s myo_x0002_carditis (idiopathic), as well as sarcoidosis

♦ Distinction between these two entities may be difficult

• Variant

Giant Cell Myocarditis

♦ Occur in young and middle aged adults

♦ Present with arrythmias, conduction defects, cardiac failure, and sudden death (50%)

♦ Rapidly progressive and fatal, heart transplantation may be indicated

♦ Association: thymoma, SLE, thyrotoxicosis

♦ Microscopically, lymphohistiocytic infiltration and geographic myocyte necrosis

♦ Lack discrete granulomas or epithelioid histiocytes

♦ Giant cells are of both macrophage and myocyte origin

Differential Diagnosis

Cardiac sarcoidosis

♦ Myocardial necrosis associated with discrete nonnecrotizing epithelioid granuloma

♦ Giant cells are exclusively of macrophage origin

Pericarditis

Clinical

♦ Fever, friction rub, heart failure, pain

Macroscopic

♦ Serous exudate: usually non-infectious

♦ Fibrinous: acute MI, post MI (Dressler’s syndrome), uremia, radiation, trauma, lupus, rheumatic fever

♦ Purulent: usually infections

♦ Hemorrhagic: usually due to malignancy in pericar_x0002_dium, also tuberculosis in other countries

♦ Caseous: TB until proven otherwise, infrequently fungi

Chronic Pericarditis

♦ Healed phase of acute pericarditis

♦ May result in constrictive pericarditis

♦ Fibrosis, sometimes residual collections of lymphocytes

• Endocarditis
• Infectious