Flashcards in Microbiology of Heart Disease Hersh DSA Deck (53)
produced by noninfectious infl diseases (rheumatic fever, SLE, scleroderma), tumors, uremia
fibrinous and serofibrinous pericarditis- composed of? causes?
-most frequent types of pericarditis!
-serous fluid mixed with fibrinous exudate
-postinfarction (Dressler) syndrome (autoimmune response days/wks after MI)
-rheumatic fever, SLE
fibrinous and serofibrinous pericarditis- symptoms
-pain (sharp, pleuritic, position dependent) and fever!!
-loud pericardial friction rub- most striking finding!!!
purulent or suppurative pericarditis- caused by? outcome?
-active infection caused by microbial invasion of pericardial space (via direct extension, blood, lymph, cardiotomy)
-serosal surfaces are reddened, granular, coated with exudate
-outcome- scarring- frequently produces constrictive pericarditis?
hemorrhagic pericarditis- composed of? caused by?
-exudate of blood mixed with fibrinous or suppurative effusion
-caused by malignant neoplasm spread to pericardial space
-also found in bacterial infections, in pts with bleeding diathesis and tb
caseous pericarditis- caused by?
-tb!! and fungal infections
-spread from tb foci within tracheobronchial nodes
-common antecedent of disabling, fibrocalcific, chronic constrictive pericarditis
chronic or healed pericarditis
-plaque-like fibrosis thickenings of serosal membranes
-thin, delicate lesions
-adhesive pericarditis- fibrosis in mesh-like stringy adhesions-obliterates the pericardial sac
adhesive mediastinopericarditis- after? effects?
-after infectious pericarditis, cardiac surgery, or mediastinal irradiation
-obliterated pericardial sac- adherence of external aspect of parietal layer to surround structures- strains cardiac fxn!!
-hearts pulls against parietal pericardium and surround structures
-systolic retraction of rib cage and diaphragm- pulsus paradoxus
-cardiac hypertrophy and dilatoin
constrictive pericarditis- effects? signs?
-heart encases in a dense, fibrous or fibrocalcific scar that limits diastolic expansion and CO
-fibrous scar obliterates the pericardial space and sometimes calcifying- if extreme resembles a plaster mold (concretio cordis)
-dense enclosing scar- cardiac hypertrophy cannot occur
-CO reduced at rest- heart cannot inc its output in response to inc demands
-signs- muffled heart sounds, elevated jugular venous P, peripheral edema
acute pericarditis- diagnosis
-anterior pleuritic chest pain, worse supine
-erythrocyte sedimentation rate usually elevated
-ECG- diffuse ST-segment elevation, PR depression
-colchicine- helps prevent recurrences
-ibuprofen (600-800 mg 3x daily for 1-2 wks) or indomethacin (50 mg 3x daily)
post-MI pericarditis- treatment
-aspirin and colchicine (instead of NSAIDs)
-aspirin (650-1000 mg 3x daily for 1-2 wks)
-colchicine (3 months)
pericarditis treatment- if colchicine therapy fails?
-immunosuppression (cyclophosphamide or methotrexate)
Picornaviridae- 2 subtypes
1- Enteroviridae (infect intestinal epit and lymphoid cells- excreted in feces and spread fecal-oral route):
-coxsackie A and B
2- Rhinoviridae (common cold)
Coxsackie B- causes?
-pleurodynia (resp infection)
-myocarditis/pericarditis (50% of cases!!)- self-limited chest pain or serious arrhythmias, cardiomyopathy, HF
Mycobacterium tb- morphology
-40% of total cell dry weight is lipid
Mycobacterium tb- metabolism
-slow growth rate
Mycobacterium tb- virulence
-mycosides- cord factor, sulfatides, wax D
-facultative intracellular growth
Mycobacterium tb- clinical
-primary- asymptomatic, overt disease involving lungs or other organs
-reactivation/secondary- pulm, pleural or pericardial, LN, kidney, skeletal joints, CNS
Mycobacterium tb- diagnositcs
-PPD skin test
-IGRA (interferon gamma release assay)
-Gene Xpert MT/Rif
mycobacterium endocarditis- treatment
-microbial infection of heart valves- leads formation of vegetations composed of thrombotic debris and organisms, often assoc with destruction of underlying cardiac tissues
acute infective endocarditis- caused by?
-prev normal heart valve by a highly virulent organism (staph aureus)- rapidly produces necrotizing lesions
-difficult to cure with antibiotics; need surgery
-death can occur within days/wks
subacute infective endocarditis- caused by?
-organisms with lower virulences (viridans streptococci)- infections of deformed valves with less destruction
-course days/wks; cured with antibiotics
risks of developing infective endocarditis
-rheumatic heart disease with valvular scarring
-mitral vavle prolapse
-degenerative calcific valvular stenosis
-bicuspid aortic valve
endocarditis of prev damaged/abnormal valves- caused by?
streptococcus viridans (50%)
endocarditis of healthy valves- caused by??
-S aureus (20-30%)- major in IV drug abusers
endocarditis- other bacterial causes
prosthetic valve endocarditis- caused by?
S epidermidis (coagulase-neg)