Myocardial and Pericardial Disease Flashcards
Myocarditis
inflammatory reaction within the myocardium
Clinical, functional and pathologic patterns of Myocardial disease
dilated (90%)
hypertrophic
restrictive (least common)
Diagnosis of myocardial disease depends on
endomyocardial biopsy; small pieces of tissue removed from right ventricular septum
Dilated cardiomyopathy
gradual development of cardiac failure with 4-chamber hypertrophy and dilatation of heart of unknown etiology
Suspected etiologies of dilated cardiomyopathy
alcohol or other toxicities; previousmyocarditis; pregnancy assocaited with nutritional deficiency or immunologic
Clinical picture of dilated cardiomyopathy
slowly developing CHF which is progressive and unremitting; may have precipitous decompensation; 50% die within 2 years
treatment for dilated cardiomyopathy
transplant
Gross morphology of dilated cardiomyopathy
large, dilated hearts 2-3X normal size; all chambers involved; wall thickness may be normal; mural thrombi common; functional mitral regurgitation
Histology of dilated cardiomyopathy
most myofibers hypertrophied stretched; interstitial and endocardial fibrosis; replacement fibrosis
Two kinds of hypertrophic cardiomyopathy
idiopathic hypertrophic subaortic stenosis (IHSS)
hypertrophic obstructive cardiomyopathy
Clinical associations of hypertrophic cardiomyopathy
heaving muscular hypercontracting heart
Heart failure with hypertrophic cardiomyopathy is due to
decrease in chamber size, poor compliance with decreased stroke volume (diastolic failure)
What must hypertrophic cardiomyopathy be differentiated from
amyloidosis and hypertensive heart disease
Hypertrophic cardiomyopathy is what percent genetic
100% genertic causes
genetic causes of hypertrophic cardiomyopathy
sarcomere proteins with direct sarcomeric dysfunction; defect in energy transfer from mitochondria
Problems resulting from hypertrophic cardiomyopathy
atrial fibrillation with mural thrombus formation; infective endocarditis on mitral valve; intractable CF; sudden death
Morphology of IHSS
disproportionate thickening of ventricular septum compared to free wall
Morphology of hypertrophic cardiomyopathy
endocardial thickening or mural plaque formation of left ventricular outflow tract; thickening of anterior mitral leaflet secondary to contact of anterior mitral leaflets with septum during ventricular systole
Histology of hypertrophic cardiomyopathy
extensive myocyte hypertrophy; myofiber disarray; interstitial and replacement fibrosis
Restrictive cardiomyopathy
diastolic disorder; diastolic relaxation and left ventricular filling impeded by inability of myocardium to expand; contractile (systolic) function of ventricle usually unaffected
Restrictive cardiomyopathy results from
infiltrative diseases such as amyloidosis, hemochromatosis, leukemia, or storage disease; also radiation fibrosis, constrictive pericarditis
endocardial fibrosis
child, young adults in Africa and tropical countries; fibrosis or ventricular endocardium and subendocardium; extends from apex to inflow tract of rt/lt ventricles; may involve mitral, tricuspid valves; ventricular mural thrombi
Loeffler’s endomyocarditis
similar to endocardial fibrosis but unrestricted to specific geographic area; eosinophils, leukocytosis; involvement of other organs; eosinophils appear to be functionally abnormal
Endocardial fibroelastosis
focal or diffuse; cartilage-like fibroelastic thickening; first 2 years; often associated with congenital abnormalities (aortic valve obstruction)
Toxic, metabolic, and other specific causes of myocardial disease
- alcohol
- adriamycin and other drugs
- catecholamines
- peripartum state
- amyloidosis
- iron overload
- hyperthyroidism and hypothyroidism
Alcohol and myocardial disease
ETOH or its metabolites have direct toxic effect; may be complicated by thiamin deficiency (beriberi heart disease)
Adriamycin and other drugs and myocardial disease
anthracycline chemotherapeutic agents doxorubicin, daunorubicin, lithiu, phenothiazines, cocaine; attributed to lipid peroxidation of myofiber membranes; myofiber swelling and vacuolization; resolves with dissolution of the drug
Catecholamines and myocardial disease
pheochromocytoma - contraction band necrosis; dopamine, cocaine
Peripartum state and myocardial disease
globally dialted heart; due to hypertension, volume overload; nutritional deficiency
Amyloidosis
may be part of systemic amyloidosis or only affect heart, particiarly with senile isolated cardiac amyloidosis; two forms: ventricular (transthyretin) and atrial
Iron overload (hemochromatosis, hemosiderosis) and myocardial disease
more prominent in ventricles than atria; interferes with metal-dependent enzyme systems; accumulation of hemosiderin within cardiac myocytes