pericardium

Question 1

what kinds of diseases can affect the pericardium?

Answer 1

pain- pericarditis
filled with fluid to a point where it impedes cardiac filling- tamponade
it can become an inelastic encasement (constriction)

Question 2

pericarditis etiologies

Answer 2

pasically any microbe; TB; bacterial (rare but very aggressive). most are transient, resolve spontaneously, and are attributed to viral infections
also rhematoid disease, lupus
and uremia
metastatic disease, esp. from lung, breast, and lymphoma
or, inflammation of adjacent structures
basically always inflammed in acute MI and may become inflammed several weeks after MI as part of Dressler’s syndrome

Question 3

symptoms of pericarditis

Answer 3

pain- similar to MI pain but often sharper. often pleuritic and position sensitive- worse supine. radiates like MI but may also go to the trapezius

Question 4

signs of pericarditis

Answer 4

pathognomonic sign: pericardial rub. may be evanescent and position-dependent
widespread ST elevation and/or PR depression during first phase. usually downward convexity (downward convexity ST elevation also common among young African American men, but usually confined to precordial leads and without PR depression)

Question 5

prognosis and treatment of idiopathic pericarditis

Answer 5

idiopathic and viral: good, though recurrences common

these kinds of pericarditis may be treated with NSAIDs and will run a self-limiting course

Question 6

What determines severity of pericardial effusion?

Answer 6

largely determined by rate- slow effusions better tolerated than acute ones.

Question 7

etiology of pericardial effusion

Answer 7

like pericarditis (TB, viral, bacterial, rheumatoid disease, mets), plus vol overload and CHF

Question 8

some symptoms of pericardial effusion

Answer 8

tamponade
dysphagia, dyspnea or hoarseness form compression of adjacent structures, even in the absence of tamponade/hemodynamic probs

Question 9

etiology of tamponade

Answer 9

any disease that can cause effusion can cause tamponade, though uncommon with myxedema (severe hypothyroid)
most effusions resolve without causing tamponade
malignancy is not the most common cause of effusion, but is the most freq cause of tamponade

Question 10

pressure vol curves related to tamponade

Answer 10

pericardial sac has a slightly sub-atmospheric pressure until a critical vol is reached, and then the pressure rises rapidly. cardiac chamber pressures rise more gradually, but compliance curves become governed by pericardial sac pressures above a certain volume

Question 11

pathophysiology of tamponade

Answer 11

as the pressures in the pericardial sac rise, the right ventricle (which has a thinner, more compressable wall) experiences higher right ventricular end-diastolic pressures. eventually, it will equal the left ventricular end-diastolic pressure. This is called tamponade and has a hemodynamic impact. There is an equalization of diastolic ventricular, atrial, and PCWP. Cardinal finding of tamponade.

Question 12

What is the sequence of events once tamponade is present?

Answer 12

stroke volumes begin to fall off
sympathetic activation maintains cardiac output and bp. as tamponade worsens, RV and LV filling pressures rise, so stroke vol doesn’t increase.

Question 13

what are the special physical findings of tamponade? explain JVP thing

Answer 13

attenuated y descent on JVP and pulsus paradoxus
this is a pan-diastolic compression of the heart, so filling the ventricles is impeded throughout diastole and must occur only when blood is leaving the heart. the y descent of the JVP is the fall in pressure that happens after systole is over and blood pours through the open tricuspid valve. this flow is impeded during tamponade, causing the disappearance of the y descent

Question 14

explain pulsus paradoxus

Answer 14

exaggerated inspiratory fall of bp
basically, during normal inspiration, pleural pressures decrease, and air and blood rush into the thorax and right heart. somehow, this causes outward tug on left ventricle and increases afterload against which it must contract. so blood pressure normally falls by <10 mmHg during respiration.
if inspiration fall is greater than 10 mmHg, it is pulsus paradoxus. most commonly seen in people with obstructive lung disease (also raises afterlaod)
in tamponade, blood flows into right heart during inspiration. left heart has no place to got, so it becomes compressed. myofiber stretch decreases and LV contraction force goes down (Starling)

Question 15

when isn’t pulsus paradoxus useful

Answer 15

A fib. extremely thick LV, weird cardiac outflow

Question 16

Signs and symptoms of tamponade

Answer 16

syptoms related to hemodynamic consequences- dyspnea, cough from J receptors in lungs.
bedside: pulsus paradoxus, elvated JVP, attenuation of y descent.
basically ruled out when pulsus paradoxus and JVP are normal

Question 17

lab eval for cardiac tamponade

Answer 17

usually nothing on EKG, though electrical alternans possible
clear lungs with incr. heart size
echo

Question 18

What is pericardial constriction

Answer 18

uncommon condition

imprisonment of the heart by dense and inelastic tissue (fibrosis, tumor, calcification)

Question 19

causes of cardiac constriction

Answer 19

TB, idiopathic, post infection radiation or surgery malignancy

Question 20

pathophysiology of cardiac constriction

Answer 20

hard to distend in diastole; hard to contract in systole
when systole is comple, heart springs back to prefered dimention- filling pressure plummets and y descent is accentuated
also true for x descent
JVP - rapidly rising and falling waves
both ventriles face a common resistance to inflow- equal end-diastolic pressures. flow impeded for latter 2/3 of diastole

Question 21

Is pulsus paradoxus a part of cardiac constriction?

Answer 21

not really- inelastic pericardium shields the heart from respiration-dependent fluctuations
constancy of JVP with inspiration is called Kussmaul’s sign

Question 22

What do you see in a right ventricle pressure catheter with cardiac constriction?

Answer 22

square root sign:
pressure in early diastole plummets as the ventricle springs back to preferred position
then, pressure rises rapidly and plateaus as the pericardial limit is reached
this is a disease of the latter 2/3 of diastole- most inflow occurs in first 1/3, so tachycardia is enough to sustain cardiac output

Question 23

DDx for right&raquo_space; left CHF symptoms

Answer 23

pericardial disease, restrictive cardiomyopathy, diseases of the lung or pulmonary vasculature

Question 24

symptoms of pericardial constriction

Answer 24

equal PCWP and JVP. no edema in lungs (they have lots of lymphatics), but periphery does suffer due to lack of lymphatics. See edema, ascites, cardiac cirrhosis with portal HTN.

Question 25

PE in cardiac constriction

Answer 25

marked JVP
accentuated y descent
clear lungs
cardiac exam has a loud sound in early diastole (pericardial knock) that represents the rapid deceleration of blood flow into the ventricles- like an S3 gallop but higher pitch

Question 26

How do you distinguish between hepatic cirrhosis and pericardial constriction?

Answer 26

both can cause liver cirrhosis and portal HTN

pericardial constriction will also have greatly elevated venous pressures

Question 27

how do you distinguish between pericardial constriction and restrictive cardiomyopathy?

Answer 27

not usually equalization of diastolic pressures in restrictive cardiomyopathy
less ventricular interdependence in restriction