HLTH 2501: inflammation and infection in the heart Flashcards
rheumatic fever
an acute systemic inflammatory condition that results from an abnormal immune reaction occuring a few weeks after an untreated infection
what is the main cause of infection in rheumatoid fever
group A beta-hemolytic Strepococcus
where does inflammation occur in rheumatoid fever?
in the heart, brain, joints, and skin
who does rheumatic fever most commonly affect?
children aged 5 to 15
long-term effects of rheumatic fever
rheumatic heart disease, infective endocarditis, and heart failrue
what does the preceding infection of rheumatic fever commonly persist as?
an upper respiratory infection, tonsillitis, pharyngitis, or strep throat
how does rheumatic fever cause damage to the heart?
antibodies to the infection react with collagen in the heart, but scar tissue will develop which causes rheumatic heart disease
pericaditis
inflammation of the heart outer layer and may include effusion which impairs filling
effusion
excessive fluid accumulation
myocarditis
inflammation develops as localised lesion in the heart muscle (Aschoff bodies), and these interfere with heart conduction
lesions in myocarditis
are called aschoff bodies
endocarditis
inflammation that affects the valves, causing them to become edematous and verruca; this disrupts the flow of blow leads to stenosis and rheumatic heart disease
verrucae
rows of small, wart like vegetations along the outer edge of the valve cusps
what valve is most commonly affected by endocarditis?
the mitral valve
how are the joints affected in rheumatic fever?
large joints, particularly in the legs may have synovitis
how is the skin affected in rheumatic fever?
a nonpruritic rash known as erythema marginatum develops (red with white centre)
how are the wrists, elbows, knees, and ankles affected in rheumatic fever?
non tender subcutaneous nodules may develop
how are the basal nuclei affected in rheumatic fever?
cause involuntary jerky movements of the face, arms, or legs; called sydenham chorea or saint vitus dance
what is diagnosis of rheumatic fever based on?
general signs of inflammatory disease, high levels of antistreptolysin O antibodies, anemia, leukocytosis, a history or a prior streptococcal infection, and an abnormal ECG
signs and symptoms of rheumatoid fever
low-grade fever, leukocytosis, malaise, anorexia, fatigue, tachycardia, heart murmurs, epistaxis, and abdominal pain
epistaxis
nose bleeding
treatment for rheumatoid fever
antibacterial agents such as penicillin V, ASA, corticosteroids all help will preventing additional infection and inflammation; valve replacement may be necessary
infective endocarditis
occurs in two types (subacute and acute) and in general is when a microorganism invades heart valves
subacute type of infective endocarditis
occurs when defective valves are invaded by organisms of low virulence
example of a low virulent organism in subacute infective endocarditis
streptococcus viridans (part of the normal flora in the mouth)
acute type of infective endocarditis
occurs when normal heart valves are attacked by highly virulent organisms; vegetations in valves may interfere with the opening and closing of valves
example of microorganism in the acute type of infective endocarditis
staphylococcus aureus (can cause severe tissue damage)
basic effects of infective endocarditis
the microorganism in the general circulation attaches to the endocardium and invade the heart valves, causing inflammation and the formation of vegetations on the cusps
what are vegetations?
large, fragile masses made up of fibrin strands, platelets, other blood cells, and microbes
causes of infective endocarditis
presence of abnormal heart tissue, presence of microbes in the blood, reduced host defences, and predisposing conditions
predisposing conditions of infective endocarditis
congenital defects, rheumatic fever, mitral prolapse, and valve replacements
diagnostic tests for infective endocarditis
new heart murmurs and transesophageal echocardiogram
signs and symptoms of subacute infective endocarditis
low-grade fever, anorexia, splenomegaly, olser nodes, vascular occlusion, and CHF in severe case
osler nodes
painful red nodes on the fingers; present in subacute infective endocarditis
signs and symptoms of acute infective endocarditis
spiking fever, chills, drowsiness, and severe impairment of heart function
treatment for infective endocarditis
blood test to identify the microbial agent and antimicrobial drugs
pericarditis
usually occurs secondary due to other conditions and is normally classified based on the type of exudate associated with the inflammation
2 types of pericarditis
acute or chronic
acute pericarditis
simple inflammation of the pericardium, in which rough, swollen surface cause chest pain and a friction rub, and in some cases effusion may develop
friction rub
a grating heart sound heard on the chest with a stethoscope
types of exudate in pericarditis
serous, fibrinous, purulent, and blood containing
what are the effects of pericarditis
if lots of fluid accumulates, the heart ability to expand and fill is impaired, thus decreasing CO
cardiac tamponade
CO is decreased due to fluid in the pericardium
what side of the heart is affected in pericarditis?
the right side because it is the low pressure side
chronic pericarditis
formation of adhesions between the pericardial membranes that may become constrictive, causing the pericardium to become a tight, fibrous enclose, thus limiting the movement of the heart
causes of acute pericarditis
can be secondary to open heart surgery, MI, rheumatic fever, renal failure, trauma, or a viral infection
causes of chronic pericarditis
tuberculosis or radiation to the mediastinum or infection or inflammation developing from adjacent structures
signs of pericarditis
chest pain, tachycardia, dyspnea, and cough, as well as changes in ECG or a friction rub
what can effusion in pericarditis lead to?
distended neck veins, faint heart sounds, and pulsus paradoxus (systolic pressure drop during inspiration_
treatment for pericarditis
fluid must be aspirated from the cavity
paracentesis
aspirating fluid from the pericardial cavity
