Flashcards in Quiz 2 Deck (40)
Three major categories of cardiomyopathies?
Dilated (90%), Hypertrophic, & Restrictive
Most common cause of non-ischemic dilated cardiomyopathy (DCM) in the US:
chronic alcoholism (Thiamine & carnitine deficiency, as well as alcohol toxicity to tissues)
Dilated cardiomyopathy is characterized by enlargement of which chamber(s)?
All four - becomes rounder, basketball shaped
Hypertrophic cardiomyopathy primarily affects which chamber(s)?
Left ventricle (classically the ventricular septum)
Genetic [NOT d/t HTN]
The most common cause(s) of restrictive cardiomyopathy?
amyloidosis & hemochromatosis
Restrictive cardiomyopathy is caused by:
infiltration of normal tissue, which results in impaired motion and abnormal contraction and relaxation
What area is affected most? Side?
inflammation of the valve leaflets, potentially also lining of atria and ventricles. Leads to vegetations.
Tends to begin at area of greatest pressure = lines of closure.
Atrial side of AV valves / Vent side of semilunar valves
Most common cause of infectious endocarditis?
BACTERIA (staph aureus - 30-50% of community acquired cases, and 60-80% of nosocomial cases [MRSA])
Marantic endocarditis is:
non-bacterial thrombotic endocarditis, deposition of small, pink, embolizing, sterile vegetations on valve leaflets [marantikos = wasting away]; d/t hypercoagulable state known as Trousseau's syndrome.
Portals of entry of endocarditis include:
IV drug use
poor dental health, recent procedure, infection
GU infections or instrumentation (catheter)
skin infections (impetigo)
Acute vs. sub-acute endocarditis:
Acute - rapidly developing, destructive, usually d/t infection, 50% mortality within days, abscess in ring of tissue below leaflets common.
Subacute - slower development, less severe, typically d/t previous valvular damage, infection by less virulent organism, likely recovery, vegetations that embolize common.
Microemboli in the fingernail beds are called:
In the skin:
In the retina:
Risk factors for endocarditis:
IV drug use
artificial valves / vascular grafts
immunocompromised (steroids, RA drugs, etc)
Most common cause of infectious endocarditis in native valves, perhaps damaged, & main cause of subacute endocarditis?
Strep viridans (alpha hemolytic)
Organism associated with endocarditis in pts with prosthetic valves:
Organism associated with IV drug users endocarditis:
Organism associated with alcoholics with endocarditis:
anaerobes & oral cavity bacteria
Organism associated with endocarditis after procedures (cytoscopy, prostatectomy, indwelling catheters):
E coli & other gram negative
Organism associated with endocarditis in pts with carcinoma of the colon:
strep bovis (so if found => colonoscopy needed to r/o CA)
Endocarditis associated with SLE is called:
Libman-Sacks endocarditis (flat spreading vegetations on mitral valve surface & chordae tendineae)
Myocarditis results from:
infection of the heart
Rheumatic heart dz (common worldwide, less in US - abx)
collagen vascular dzs - SLE, RA
Most common infectious agent of myocarditis:
Others include Lyme's, CMV, HIV, typhus, Chaga's, meningococcus, toxoplasmosis, trichinosis, etc
Compare valvular stenosis & insufficiency:
Valvular stenosis is a failure to open completely, impeding forward flow.
Valvular insufficiency is a failure to close completely, allowing reverse flow (regurg)
The most frequent valvular abnormalities that account for 2/3 of all valvular dz:
acquired stenosis of the aortic and mitral valves
Most common valvular disease:
(there is debate that MVP is more common)
Left sided valvular dz more common than right
* pathological weakening of the connective tissue, most often used to describe MVP
* one of the most common forms of valvular heart dz
* the most common cause of pure mitral valve insufficiency.
Possible complications of MVP:
stroke / systemic infarct - from emboli
arrhythmia - atrial or ventricular
Rheumatic fever often follows:
group A beta-hemolytic streptococcus [strep pyogenes] pharyngitis (strep throat)
NOT skin infections of strep, like impetigo
Why are antibiotics used so often in strep throat infections?
to shorten the course, diminish infectivity, & diminished sequelae (RF).
* Abx do not shorten the course of RF.
* Untreated pts may remain infected with strep for weeks after symptoms resolve.