b. Valvular damage interferes with this forward flow by stenosis (narrowing) of
the valve or by impaired closure of the valve that allows a backward leakage of blood.
This is called valvular insufficiency or regurgitation.
c. If the heart muscle itself remains strong, the circulatory mechanisms can
adjust and compensate for a bad valve. These modifications are called compensatory
changes.
d. Valve deficiencies cause two basic types of stress on the heart. If the stress
produced is greater than the heart's ability to compensate, eventual deterioration will
occur. The two types of heart stress associated with valve deficiencies are:
(1)
Pressure overload (associated with valvular stenosis).
(2) Volume overload (associated with valvular insufficiency and
regurgitation).
1-30. INFECTIVE ENDOCARDITIS
a. Infective (bacterial) endocarditis is a microbial infection of endocardial tissue.
The endocardium is the layer of tissue that lines the heart's cavities and covers the flaps
of its valves.
b. When an area of endocardium becomes inflamed, a fibrin clot called a
vegetation may form. This clot will later form into a mass of scar tissue. The scarred
endothelium becomes stiff, thick, and deformed. Vegetations on the valves may
eventually cause chronic valvular disease.
c. Endocarditis is categorized as either acute or subacute. This is determined
by the virulence of the causative organism.
(1) In acute infective endocarditis, the infecting organism is highly virulent,
causing rapid and severe complications.
(2) In subacute infective endocarditis, the infecting organism is of low
virulence. Severe complications do not occur until late in the illness, if at all.
d. Because standard medical treatment for infective endocarditis involves
intravenous antimicrobial agents for a period of 4-6 weeks, the patient will require
nursing intervention to prevent depression and alleviate the boredom that will result
from the lengthy hospitalization. As the patient begins to feel better, he will feel
confined and restricted by intravenous (IV).
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