pericarditis, myocarditis, and endocarditis

Question 1

What are the common etiologies of pericarditits, myocarditis, and endocarditis?

Answer 1

pericarditis in the community is usually viral. in the hospital, it is usually non-infectious: post MI, uremia, hypothermia, bypass, malignancy

myocarditits: viral&raquo_space; bacterial. (ocasional toxins- very rare)
endocarditis: bacterial&raquo_space; viral

Question 2

mechanism of damage in pericarditis and myocarditis

Answer 2

coxachie, adeno, or rheumatic fever, toxic. may be via direct destruction

Question 3

predisposing factors for endocarditis

Answer 3

infectious agent in the blood stream and endocardial lesion (except occasioally S aureas from IV drug use)

Question 4

Pain in pericarditis

Answer 4

sharp and positional; usually better sitting forward and worse lying down. afferent fibers with the phrenic nerve

Question 5

pain in myocarditis

Answer 5

through the myocardial mechanism- poorly localized

Question 6

pain in endocarditis

Answer 6

often none, unless the infection spreads to the myocardium

Question 7

PE findings in pericarditis

Answer 7

rub that is present when the pt holds his breath and cycles with the pericardial cycle.

Question 8

PE findings in myocarditis

Answer 8

none, or potentially an S4

Question 9

PE findings in endocarditis

Answer 9

classically, a new murmur as a high velocity jet of blood goes through a narrow orifice. vegetations are usually on the low pressure sides of valves and usually cause regurg murmurs

Question 10

EKG findings for pericarditis

Answer 10

diffuse ST elevation, though focal ST elevations are possible. Only exception is that AVR usually shows ST seg depression.
often see PR depression in the atrium

Question 11

EKG findings in myocarditis

Answer 11

EKG changes in a patchy distribution (patchiness also means biopsy is only 30% sensitive)
hard to distinguish from coronary ischemia

Question 12

EKG changes with endocarditis

Answer 12

potentially PR increase. no ST changes unless infection gets to the myocardium. you can see prolongation of PR interval as infection spreads to AV node

Question 13

troponin in pericarditis, myocarditis, and endocarditis

Answer 13

may be elevated in pericarditis and myocarditis
not usually elevated in endocarditis unless the infection invades the myocardium.
this is a lengthy troponin elevation- helps distinguish it from MI, which usually shows rapid rise and fall

Question 14

DDx of pericarditis

Answer 14

pleuritic pain, pneumonia
this is a clinical diagnosis- you must see rub, EKG, chest pain- 2/4 criteria:
1. rub
2. pain
3. EKG changes
4. Echo with effusion

Question 15

myocarditis DDx

Answer 15

coronary ischemia, vasospastic angina
potentially with angiogram you will have a pt without coronary disease. if the pt has co-existing coronary disease or vasospastic angina, it can be very hard.
try cardiac MRI with uptake of gadolinium. IF it is myocarditis, uptake will be very patchy

Question 16

Tx of pericarditis and complications

Answer 16

NSAIDs, colchicine to reduce recurrence (but be wary of bad diarrhea)
watch for tamponade and pericardial constriction
Inflammed pericardium may heal with a rigid scar and can act like an eggshell around the heart to prevent expansion during diastole

Question 17

Tx for myocarditis and complications

Answer 17

steroids, IVIg, antivirals, but nothing is actually effective. basically, do supportive care and exclude ischemia
this is a problem, since myocarditis can be fulminant and lead to severe arrhythmias and death

Question 18

Tx of endocarditis and complications

Answer 18

IV abx. long duration, cidal. usually 4-6 wks of continuous IV therapy. can be accomplished as an outpatient.
complications: valve destruction, CHF, septic emboli, infarcts, myocarditis
if these are occuring, you must make a difficult decision about valve replacement- if you put a new valve in before the infection has been cleared, it will invite infection. On the other hand, waiting too long invites further complications